Forecast Discussions mentioning "ACARS", "MDCRS", "AIRCRAFT", "TAMDAR", or "AMDAR" received at FSL on 08/04/07

FORECAST DISCUSSION

.SYNOPSIS... MOIST AND UNSTABLE AIR WILL CONTINUE ACROSS THE SOUTHWEST UNITED STATES INTO EARLY NEXT WEEK. THIS...COMBINED WITH A SERIES OF WEAK UPPER LEVEL WEATHER DISTURBANCES...WILL RESULT IN A DAILY CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...MAINLY OVER ARIZONA. THE THREAT FOR HEAVY THUNDERSTORM RAINS WILL CONTINUE. && .SHORT TERM... TODAY THROUGH SATURDAY... COMPARISON OF VIS SATELLITE IMAGES TODAY AND YESTERDAY SHOW MUCH LESS CONVECTIVE DEBRIS CLOUDINESS ENVELOPING THE CWA TODAY. EXCEPTION TO THIS IS OVER ZONE 24 WHERE LEFTOVERS FROM LAST NIGHTS LARGE MCS WERE STILL BLANKETING THE AREA. SO...ONE WOULD THINK THAT WITH LOTS OF INSOLATION/LOW LEVEL HEATING TODAY...IT WOULD BE A RELATIVE UP DAY CONVECTIVE-WISE. HOWEVER...A CHECK OF BOTH THE KPSR AND K1Y7 MORNING SOUNDINGS INDICATES SOME SIGNIFICANT MID LEVEL WARMING HAS DEVELOPED OVER THE DESERTS...WITH ONLY VERY SMALL CAPES. AND...BOTH NAM/GFS INDICATE LITTLE IF ANY COOLING IS ON TAP AT THESE SAME LEVELS DURING THE DAY TODAY. WITH VERY WEAK STEERING FLOWS AND LITTLE IN THE WAY OF SYNOPTIC/MESO-SCALE LIFT FORESEEN...BELIEVE TODAY COULD BE A RELATIVE DOWN DAY...IN SPITE OF THE FAVORABLE INSOLATION...WITH ONLY ISOLD HEAVY RAINERS MAINLY ZONES 21/26 EWD. MOUNTAINOUS ZONE 24 COULD SEE MORE ACTION...WHAT WITH A WEAK MCV TREKKING ACROSS THAT AREA. WILL LEAVE ZONES ALONE FOR NOW...BUT WITH THE ABOVE IN MIND...MAY NEED TO TRIM BACK POPS SOME FOR THIS EVENING IN THE AFTERNOON PACKAGE IF NOT MUCH DEVELOPS THIS AFTN. BY FRIDAY...BETTER STEERING FLOWS...FROM THE NE ARND 15KTS...ARE EXPECTED OVER SCNTRL DESERT ZONES. ALSO...SOME MID-LEVEL COOLING THAT IS PROGGED BY MODELS WILL ALLOW FOR MORE CAPE AND INCREASING INSTBY. SO...WILL LEAVE CHANCE POP TYPE OF FORECAST GOING TOMORROW. STILL APPEARS LIKE WE WILL BE SEEING AN INCREASE IN TSTM CHANCES OVER THE WEEKEND AS STRONG INVERTED TROUGH LIFTS INTO THE STATE FROM THE S...AND DYNAMICS INCREASE FROM W COAST TROUGH. MORE ON THAT IN AFTERNOON DISCUSSION. NO UPDATES. && .LONG TERM... SATURDAY NIGHT THROUGH WEDNESDAY... A LARGE PACIFIC TROF IS FORECAST TO MOVE INTO THE WESTERN STATES SUNDAY AND MONDAY. INCREASING SOUTHWESTERLY JET STREAM WINDS... AHEAD OF THE TROF ...WILL DEVELOP ENTRANCE REGION DYNAMICS OVER THE COLORADO RIVER VALLEY AND SOUTHWEST AZ FOR INCREASED CONVECTION SUNDAY. AT THE SAME TIME ON SUNDAY...A LARGE INVERTED TROF APPROACHES SOUTHEAST AZ FROM MEXICO. THE MEXICAN INVERTED TROF MOVES INTO PARTS OF SOUTHEAST AZ MONDAY... AS ENTRANCE REGION JET DYNAMICS SPREADS INTO NORTHERN AZ. THEREFORE...THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER AZ AT LEAST THROUGH TUESDAY...WITH A POSSIBLE BREAK IN THE MONSOON OVER SOUTHEAST CA AND FAR SOUTHWEST AZ WEDNESDAY...AS DRIER WESTERLY FLOW MOVES INTO THE AREA. && .AVIATION... AUG 2 1145 UTC (AUG 2 0445 MST) LIGHT WINDS AND MOSTLY CLEAR SKY THIS MORNING. EXPECT THESE CONDITIONS TO PREVAIL THROUGH 18Z /11 AM LST/. BIG QUESTION TODAY... WHICH IS EVERY DAY...IS WILL THERE BE AFTN/EVE TSTMS AND IF SO... WILL THEY IMPACT THE AIRFIELDS. LATEST MODELS INDICATE THAT THERE WILL BE SOME WARMING IN THE MID LEVELS OF THE ATMOSPHERE...WHICH WILL REDUCE THE AMOUNT OF INSTABILITY /FUEL FOR TSTMS/ AND INCREASE THE CAP /INHIBITS TSTMS/. LATEST ACARS SOUNDINGS CONFIRM THE MID LEVEL WARMING. EAST OF PHX WILL LIKELY BE THE MORE ACTIVE AREA TODAY...WITH LESS ACTIVITY TO THE WEST. WILL HAVE TO WATCH FOR OUTFLOW BOUNDARIES FROM THE FOOTHILLS NE OF PHX TODAY WHICH COULD IMPACT KPHX/KIWA. A STRONG ENOUGH OUTFLOW COULD OVERCOME THE INHIBITION AND TAKE ADVANTAGE OF THE LIMITED AMOUNTS OF ATMOSPHERIC FUEL AVAILABLE. ASSUMING THAT DOES OCCUR...COVERAGE WOULD NOT BE EXPECTED TO BE WIDESPREAD. LACK OF LIFTING MECHANISMS ACROSS SE CA/SW AZ MEANS WIDESPREAD TSTMS ARE NOT LIKELY. OVERALL...LOW PROBABILITY /LESS THAN 20 PERCENT/ FOR TSTMS AT ALL TAF SITES TDA...WHICH IS REFLECTED IN TAFS. SEE TAFS PHXTAFPHX...PHXTAFIWA...PHXTAFYUM...LAXTAFBLH AND LAXTAFIPL FOR MORE DETAILED INFORMATION. AVIATION DISCUSSION IS NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... AUG 2 1207 UTC (AUG 2 0507 MST) ELEVATED PRECIPITATION CHANCES WILL CONTINUE THROUGH THE WEEKEND...WITH THE GREATEST PROBABILITIES ELEVATED SITES IN ARIZONA...AND THE LOWEST PROBABILITIES ACROSS THE DESERTS OF SOUTHEAST CALIFORNIA. A BROAD UPPER LEVEL TROUGH WILL APPROACH THE REGION FROM THE NORTHWEST BY EARLY NEXT WEEK. THIS WILL START A DRYING TREND...WHICH WILL RESULT IN THE REDUCTION OF PRECIPITATION CHANCES AS WELL AS A LOWERING OF RH VALUES. WINDS WILL LIKELY INCREASE AHEAD OF THE SYSTEM...RESULTING IN GUSTY AFTERNOON AND EVENING WINDS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT WEATHER.GOV/PHOENIX SHORT TERM...ESTLE LONG TERM...VASQUEZ AVIATION...INIGUEZ FIRE WX...INIGUEZ
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
230 PM PDT THU AUG 2 2007 .SYNOPSIS... AN UPPER LEVEL TROUGH OFF THE WEST COAST SHOULD DRIFT SLOWLY EAST OVER THE COASTLINE DURING THE NEXT SEVERAL DAYS. THIS WILL BRING IN SOME DRIER SOUTHWEST FLOW...REDUCING THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS AND DESERTS. THE COASTAL MARINE LAYER LOW CLOUDS WILL BECOME SLIGHTLY MORE EXTENSIVE AND PERSISTENT OVER THE NEXT SEVERAL DAYS AS THE MARINE LAYER DEEPENS. MOSTLY CLEAR AFTERNOONS ARE EXPECTED MOST AREAS. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (TODAY THROUGH SATURDAY)... CONVECTION HAS BEGUN OVER THE MOUNTAINS UNDER EXCELLENT HEATING AND GOOD MOISTURE PROFILES IN THE LOWER-MID LEVELS. THE CONVECTION SHOULD LEAK OUT INTO THE DESERTS AS THE AFTERNOON WEARS ON. STEERING WINDS ARE WEAK...SO WILL HAVE TO KEEP AN EYE ON SOME OF THE STRONGER THUNDERSTORMS FOR AT LEAST URBAN AND SMALL STREAM FLOODING POSSIBILITIES. ACTUALLY THE WESTERN EDGE OF THE MONSOONAL MOISTURE IN THE WATER VAPOR IMAGERY DID NOT PUSH EAST MUCH. MAKES ONE WONDER WHETHER OR NOT THE THUNDERSTORMS ARE OVER FOR THE WEEK. LATER SHIFTS WILL NEED TO MONITOR ITS PROGRESS. AS FOR THE MARINE LAYER...IT SHOULD NOT CHANGE MUCH...BUT WILL LIKELY RESPOND TO THE TROUGH WITH SOME DEEPENING...HENCE COOLING WEST OF THE MOUNTAINS...BUT NOT MUCH. TEMPERATURES SHOULD NOT BE MUCH DIFFERENT THAN NORMAL. THE LOW CLOUDS WILL PROBABLY HANG AROUND A LITTLE LONGER AT THE COASTLINE...EXCEPT FOR A PERIOD OF MID AFTERNOON CLEARING... MOST DAYS. && .LONG TERM (SUNDAY THROUGH WEDNESDAY)... SOME MINOR FLUCTUATIONS IN THE TEMPERATURE AND MARINE LAYER LOOKS LIKE A GOOD SOLUTION AS THE UPPER TROUGH SETTLES IN. TEMPERATURES SHOULD BE A BIT BELOW NORMAL...ESPECIALLY WEST OF THE MOUNTAINS. && .AVIATION... 021900Z...LATE MORNING MDCRS SOUNDINGS SHOW THE MARINE LAYER DEPTH AROUND 1800 FEET MSL. AREAS OF STRATUS OVER THE COASTAL WATERS SHOULD EXPAND AND MOVE ONTO THE COAST EARLY THIS EVENING THEN PUSH INLAND DURING THE EVENING. COASTAL AIRPORTS SUCH AS KSAN...KCRQ AND KSNA SHOULD RECEIVE CEILINGS BETWEEN 04Z AND 07Z. STRATUS COULD REACH KONT BY SUNRISE FRIDAY MORNING. EXPECT CLEARING ON FRIDAY BETWEEN 15Z AND 18Z. ISOLATED THUNDERSTORMS ARE EXPECTED OVER THE MOUNTAINS AND ADJACENT DESERT AREAS FROM THE MEXICAN BORDER NORTH TO VICINITY OF BIG BEAR LAKE THROUGH THE AFTERNOON. BASES SHOULD BE AROUND FL080 WITH TOPS TO FL400 AT TIMES. THUNDERSTORM ACTIVITY SHOULD END BY SUNSET. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...SMALL AVIATION/MARINE...HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
930 AM PDT THU AUG 2 2007 .SYNOPSIS... A TROUGH OF LOW PRESSURE OFF THE WEST COAST WILL DRIFT SLOWLY WEST OVER THE COASTLINE. THIS WILL BRING IN A DRIER SOUTHWEST FLOW AND REDUCE THE POSSIBILITY OF THUNDERSTORMS IN THE MOUNTAINS AND DESERTS. THE COASTAL MARINE LAYER LOW CLOUDS WILL DEEPEN SLOWLY WITH A TEMPORARY COOLING TREND. THE NIGHT AND MORNING LOW CLOUDS AND FOG WILL LIKELY PUSH INLAND A BIT MORE EACH DAY THROUGH SATURDAY. MOSTLY CLEAR AFTERNOONS ARE EXPECTED. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .SHORT TERM (TODAY THROUGH SATURDAY)... THE MONSOONAL MOISTURE...AT LEAST AT THE UPPER LEVELS...CAN BE SEEN TO BE RETREATING TO THE EAST PER WATER VAPOR IMAGERY. THERE SHOULD STILL BE A MOIST LOWER MID-LEVEL AIRMASS IN PLACE FOR THE POSSIBILITY OF THUNDERSTORMS. LITTLE HIGH CLOUDINESS THIS MORNING... SO HEATING ON THE MOUNTAINS SLOPES AND DESERTS SHOULD BE EXCELLENT. RIGHT NOW WE WILL BE GOING WITH ENOUGH DRYING TO END THE THUNDERSTORMS AFTER TODAY...BUT WE SHOULD STILL KEEP THE THOUGHT IN MIND AT LEAST ON FRIDAY. THE MARINE LAYER MAY RESPOND TO THE TROUGH WITH SOME DEEPENING...HENCE COOLING WEST OF THE MOUNTAINS...BUT NOT MUCH. TEMPERATURES SHOULD NOT BE MUCH DIFFERENT THAN NORMAL. THE LOW CLOUDS WILL PROBABLY HANG AROUND AT THE COASTLINE...EXCEPT FOR A PERIOD OF MID AFTERNOON CLEARING MOST DAYS. && .LONG TERM (SUNDAY THROUGH WEDNESDAY)... DRY SOUTHWEST FLOW AROUND THE TROUGH SHOULD BRING A SLIGHTLY DEEPER THAN NORMAL MARINE LAYER AND SLIGHTLY BELOW NORMAL AFTERNOON TEMPERATURES TO THE REGION. && .AVIATION... 021430Z...MDCRS SOUNDINGS AND MORNING TOP REPORTS PUT THE MARINE LAYER DEPTH AROUND 2000 FEET MSL...SIMILAR TO WEDNESDAY MORNING. STRATUS WITH BASES AROUND 1500 FEET MSL...EXTENDS INTO THE WESTERN VALLEYS AND NEAR KONT THIS MORNING BUT SHOULD BURN OFF TO THE COAST BETWEEN 15Z AND 18Z. EXPECT STRATUS TO PUSH BACK ONSHORE AND INLAND DURING THE EVENING WITH KSAN...KCRQ AND KSNA RECEIVING CEILINGS BETWEEN 04Z AND 07Z. STRATUS COULD REACH KONT BY SUNRISE FRIDAY MORNING. ISOLATED THUNDERSTORMS ARE EXPECTED OVER THE MOUNTAINS AND ADJACENT DESERT AREAS FROM THE MEXICAN BORDER NORTH TO VICINITY OF BIG BEAR LAKE LATE THIS MORNING THROUGH THE AFTERNOON. BASES SHOULD BE AROUND FL080 WITH TOPS TO FL400 AT TIMES. THUNDERSTORM ACTIVITY SHOULD END BY SUNSET. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...SMALL AVIATION/MARINE...HORTON NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS DENVER CO
300 PM MDT THU AUG 02 2007 .SHORT TERM...PLENTY OF LOW LEVEL MOISTURE ON THE PLAINS BEHIND YESTERDAY`S FRONT WITH DEWPOINTS ONLY DROPPING INTO THE MID TO UPPER 50S THIS AFTERNOON TO LOWER 60S FARTHER EAST. COOLER TEMPERATURES THOUGH ARE ALSO IN PLACE AND THIS HAS KEPT MOST OF THE PLAINS CAPPED SO FAR EXCEPT FOR AN AREA OF CONVERGENCE ALONG THE PALMER DIVIDE. IT MAY REMAIN TOO COOL FOR CONVECTION TO DEVELOP OVER THE MORE EASTERN PLAINS...BUT STORMS FROM ELSEWHERE COULD MOVE IN EVEN AFTER DARK. FLOW IS BECOMING MORE SELY AND INCREASING AND THE NAM SHOWS PRETTY BRISK SE FLOW OVERNIGHT WHICH COULD SUPPORT SOME STORMS WELL INTO THE NIGHT ON THE PLAINS THAT MOVE IN FROM THE WEST. THE UPPER LEVEL FLOW IS MORE FAVORABLE TODAY FOR STORMS TO MOVE TO THE EAST AS THE UPPER LEVEL RIDGE HAS SHIFTED SLIGHTLY EAST AND SOUTH. SO WITH STORMS DEVELOPING NOW IN THE MOUNTAINS IN THE MONSOON MOISTURE THESE ARE EXPECTED TO EVENTUALLY PUSH OFF/REDEVELOP EASTWARD INTO THE URBAN CORRIDOR OVER THE NEXT FEW HOURS. SO FAR STORMS ARE MOVING FROM THE SOUTHWEST BUT HAVE WEEKEND AS THEY COME OFF THE FOOTHILLS WITH THE LOWER LEVEL AIR STILL TOO STABLE. TEMPERATURES HAVE WARMED INTO THE LOW 80S WHICH SHOULD BE GETTING CLOSER TO SUPPORTING STORMS OFF THE FOOTHILLS. LATEST ACARS SOUNDINGS HEADING EAST INDICATE A SLIGHT COOLING WHERE THE CAP NEAR 700 MB WAS BUT AN INCREASE IN THE HIGHER LEVEL TEMPS AND THIS MAY BE WHAT IS ALSO KEEPING THINGS DOWN. BUT WITH MOISTURE HOLDING (GPS PRECIPITABLE WATER INSTRUMENT IN BOULDER HAS SHOWN PRECIPITABLE WATER INCREASING ALL DAY WITH OVER 1.3 INCHES NOW) WOULD HAVE TO THINK STORMS HAVE A DECENT CHANCE OF GETTING ONTO THE PLAINS. PROBABLY THE 40 PERCENT POPS CURRENTLY IN THE FORECAST FOR THIS EVENING WILL SUFFICE. GIVEN SOME UNCERTAINTIES WILL HOLD OFF ON HOISTING ANY FLASH FLOOD WATCH AT THIS TIME BUT CERTAINLY AT LEAST BRIEF HEAVY RAINS COULD BE PRODUCED BY SOME STORMS. TOMORROW THE FLOW BECOMES EVEN MORE WESTERLY ALOFT AND THE MAIN MOISTURE PLUME CENTERS OVER THE MOUNTAINS SO STORMS SHOULD BE ABLE TO EASILY MOVE OFF THE HIGHER TERRAIN. TEMPERATURES ARE ALSO EXPECTED TO REBOUND BUT THE AMOUNT OF LOW LEVEL MOISTURE AND THE CAP STRENGTH WILL BE THE UNCERTAINTIES. PRETTY MUCH KEPT THE CURRENT FORECAST WHICH INDICATES BEST CHANCE ON THE PLAINS AS YOU MOVE CLOSER TO THE FOOTHILLS WITH A CAP HOLDING THINGS DOWN FARTHER EAST. .LONG TERM...HOPE REMAINS ALIVE FOR THOSE OF US STILL WISHING FOR SOME BENEFICIAL RAINFALL. HOT MID-UPPER LEVEL TEMPERATURES AT THE CORE OF THE MEAN HIGH PRES RIDGE ALOFT NOW WOBBLING OVER THE STATE STILL PROGGED BY THE VARIOUS MODELS AT OUR DISPOSAL TO SHIFT E-SEWRD OVER THE NEXT FEW DAYS. THIS E-SEWRD DISPLACEMENT WILL ALLOW A SIMILAR SHIFT IN THE SUBTROPICAL MOISTURE PLUME CURRENTLY TO OUR WEST...BUT IT NOW APPEARS NOT UNTIL LATE IN THE WEEKEND. EVEN SO A SLIGHT SHIFT IN TH RIDGE RESULTS IN SLIGHT COOLING ALOFT ON SATURDAY. AT LOWER LEVELS...WIND/TEMPERATURE/PRESSURE FIELDS SHOW A WEAK FRONTAL BNDRY SLIDING SWRD ACROSS THE NERN PLAINS SATURDAY MORNING. DO NOT SEE MUCH COOLING WITH ITS PASSAGE...BUT DEWPT AND THETA-E FIELDS INDICATE A STEADY REDUCTION IN LOW-LEVEL MOISTURE BEHIND THE FRONT THROUGH THE DAY. HOWEVER FORECAST SOUNDINGS AND SPATIAL CROSS SECTIONS STILL INDICATE ADEQUATE MOISTURE...AND STEEP ENOUGH LAPSE RATES TO GENERATE SCATTERED T-STORMS IN THE HIGH COUNTRY AND FOOTHILLS AND ISOLATED TO WDLY SCATTERED STORMS ON THE PALMER DVD AND NEARBY PLAINS DURING THE AFTERNOON AND EVENING. POST-FRONTAL ENVIRONMENT FARTHER OUT ACROSS THE NERN PLAINS APPEARS TOO STABLE FOR ANY T-STORMS DVLPMNT. EXPECT TEMPERATURES ON SATURDAY TO BE ABOUT THE SAME AS THE DAY BEFORE EVEN WITH THE WEAK FRONTAL PASSAGE. BY SUNDAY...WITH THE MONSOONAL MOISTURE PLUME INCHING CLOSER TO THE FRONT RANGE...CHANCES FOR MEASURABLE PRECIPITATION SHOULD GO UP. MODELS SHOW THE PREVIOUS DAYS FRONTAL BNDRY STALLING OUT SOMEWHERE ACRS SERN COLORADO. MODELS SHOW SELY LOW-LEVEL FLOW DVLPG ON THE PLAINS DURING THE MORNING WHICH ADVECTS HIGHER THETA-E AIR UP FM SERN COLORADO/SWRN KANSAS DURING THE DAY. AS A RESULT SFC BASED CAPES BY AFTERNOON IN THE 1500-2500 J/KG JUST EAST OF THE I-25 URBAN CORRIDOR. FURTHERMORE MODELS HINT AT A WEAK DISTURBANCE NEAR 500MB WHICH THEY SHOW PASSING OVER THE AREA AROUND 00Z/MONDAY. FOR THESE REASONS...HAVE RAISED PRECIP CHANCES ALL AREAS...ESPLY DURING THE EVENING HOURS. AS FOR TEMPERATURES...SLIGHT MODERATION IN THE POST FRONTAL ENVIRONMENT SHOULD EQUATE TO A 1-3F WARMUP IN DAYTIME SFC TEMPERATURES. BY MONDAY...MODELS SHOW THE BACK EDGE OF THE SUBTROPICAL MOISTURE PLUME PASSING OVER THE AREA. EMBEDDED WITHIN THIS FLOW MODELS SHOW A WELL PRONOUNCED MID-LEVEL SHORTWAVE TROUGH AND VORT MAXIMA. TIMING THEIR ARRIVAL ALWAYS A BIG CHALLENGE. BUT SHOULD THIS FEATURE ARRIVE AS PROGGED BY THE GFS...SOMETIME LATE AFTERNOON OR EVENING...COULD SEE THE BEST CHANCE FOR SIGNIFICANT RAINFALL ACROSS THE CWFA...MAYBE A BIT TOO MUCH RAIN IN SOME AREAS. OF COURSE TIMING THESE FEATURES THIS FAR OUT IS ALWAYS A REAL CHALLENGE. FOR THAT REASON WILL REFRAIN FROM MAKING TOO MANY CHANGES TO THE PREVIOUS FCST PACKAGE. JUST SOMETHING TO KEEP IN MIND. FOR THE REMAINDER OF THE EXTENDED PERIOD...WITH THE MEAN UPPER RIDGE MAKING SLOW WWRD PROGRESS BACK OVER THE CNTRL/SRN ROCKY MTN REGION BY MIDWEEK...SHOULD SEE A GRADUAL REDUCTION IN STORM COVERAGE AS WELL AS A SLIGHT INCREASE IN TEMPERATURES EACH DAY. && .AVIATION...LIKELY TRW HIGHER TERRAIN AND SCT TRW LOWER TERRAIN THROUGH 06Z. SOME STORMS COULD LINGER LATER.S MVFR CONDITONS CIGS/VSBYS POSSIBLE WITH PASSING TSRA THUR PRD. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SZOKE/BAKER
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
830 PM EDT FRI AUG 3 2007 .UPDATE... REMOVED "REST OF THE AFTN" PERIOD FROM THE ZFP AND EOL AND LOWERED POPS FOR THE EVENING. MAY BE ABLE TO REMOVE THEM COMPLETELY BY 10 OR 11 PM. CONVECTION SHOULD BE DIURNAL...AND DIE OFF DUE TO LACK OF SFC HTG. && .SYNOPSIS... SCATTERED THUNDERSTORMS AREAWIDE THIS AFTERNOON AND EVENING AS A MID LEVEL DISTURBANCE PASSES OVERHEAD. CONTINUED WARM TEMPS SATURDAY AS A WEAK FRONT PUSHES SOUTH OF THE AREA. SHOWERS AND THUNDERSTORMS RIDING THE FRONT FROM THE GREAT LAKES MAY AFFECT THE REGION SUNDAY. THIS FRONT WILL LIFT NORTHEAST AS A WARM FRONT BY MONDAY WITH HEAT AND HUMIDITY RETURNING FOR NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... WATER VAPOR LOOP SHOWS AN UPPER TROUGH MOVING THROUGH THE OHIO VALLEY. ACARS 400-250MB OBSERVATIONS ALSO SHOW THE UPPER LEVEL TROUGH...WITH A 50-70KT SOUTHWESTERLY JET FROM THE EASTERN GULF STATES THROUGH THE CAROLINAS. 11Z SURFACE ANALYSIS PLACED THE NEXT COLD FRONT SOUTHWEST ACROSS THE GREAT LAKES AND CHICAGOLAND...TO A 1016MB CYCLONE NEAR ST LOUIS. A PRE-FRONTAL TROUGH WAS EVIDENT...COINCIDING WITH THE UPPER TROUGH OVER THE OHIO VALLEY. EARLY MORNING CONVECTION IN THE APPALACHIANS INDICATES AMOUNT OF MID LEVEL INSTABILITY AVAILABLE TODAY. ADJUSTED 12Z KIAD RAOB INDICATES ABOUT 1200 J/KG MIXED LAYER CAPE. WHEN COMBINED WITH WEAK BOUNDARY LAYER FLOW...THIS IS MORE THAN ENOUGH ENERGY FOR SOLENOIDAL CIRCULATION TERRAIN STORM DEVELOPMENT. IN ADDITION...WILL HAVE TO MONITOR THE PASSAGE OF THE MID LEVEL TROUGH LATE THIS AFTERNOON AS THIS MAY TRIGGER ADDITIONAL DEVELOPMENT AND AID IN STORM ORGANIZATION. WITH WARM TEMPERATURES ALOFT...THE DRY SOUNDING SUGGESTS GREATEST STORM RISK IS LOCALLY DAMAGING WINDS. GIVEN SLOW STORM MOVEMENT...A FEW LOCATIONS COULD SEE LOCALLY HEAVY RAINFALL. OTHER CONSIDERATION IS THE AFTERNOON HEAT. HIGHS ARE BASED ON YESTERDAY (GIVEN NEARLY ZERO ADVECTION). DEWPOINTS SHOULD LEVEL OFF OR SLOWLY DECLINE THIS AFTERNOON. THIS COMBINES TO PRODUCE HEAT INDEX VALUES NEARING 100F. WILL AGAIN HIGHLIGHT IN HWO AS IS LOOKS JUST SHY OF ADVISORY CRITERIA IN THE CITIES. BEST CONVECTIVE COVERAGE EXPECTED THIS EVENING COINCIDENT WITH PASSAGE OF MID LEVEL TROUGH. DID ADJUST POPS TO INDICATE BEST COVERAGE EAST OF THE BLUE RIDGE BASED ON THE TIMING OF THIS FEATURE. WILL HAVE TO MONITOR FOR A FEW STRONG TO SEVERE STORMS. EXPECT TO CLEAR OUT BEHIND THE TROUGH. WITH DEWPOINTS EXPECTED TO SLOWLY CLIMB THERE COULD BE SOME AREAS OF LIGHT FOG...MORE CONCENTRATED IN SHELTERED VALLEYS WHICH RECEIVE RAINFALL. LOWS ARE BASED ON MET GUIDANCE WHICH HAS BEEN PREFORMING WELL RECENTLY...ADJUSTED FOR LOCAL BIAS. WIND FORECAST IS BASED ON THE 12Z 4KM WRF-ARW. && .SHORT TERM /SATURDAY/... MID LEVEL TROUGH PASSES TO THE EAST TOMORROW...WITH SUBSIDENCE SUPPORTING EARLY SUNSHINE. A FEW STORMS WILL BE POSSIBLE...ESPECIALLY IN THE PIEDMONT AS THE COLD FRONT MOVES SOUTH INTO MARYLAND LATE DURING THE AFTERNOON. WITH SLIGHTLY LESS MOISTURE AND ADDED SUBSIDENCE...FORECAST MAX TEMPERATURES ARE SEVERAL DEGREES WARMER THAN TODAY. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... EC/GFS MODELS/ENSEMBLES CONTINUE TO BE IN GOOD AGREEMENT WITH OVERALL PATTERN. MAIN WEATHER FEATURES AFFECTING THE U.S. OVER THE NEXT WEEK WILL BE A BROAD TROF ACROSS THE WEST COAST WHILE A FLAT UPPER RIDGE WILL PREVAIL ACROSS THE EASTERN THIRD OF THE COUNTRY. WESTERLIES WILL MIGRATE NORTH ACROSS THE CANADIAN BORDER BUT PERIODICALLY DIP INTO THE GREAT LAKES AREA FOR THE UPCOMING WEEK. AS A RESULT...THIS WILL ALLOW WEAK FRONTS TO MIGRATE INTO OR JUST NORTH OF THE AREA THROUGH FRIDAY. STATIONARY FRONTAL BOUNDARY ACROSS AREA WILL BE THE FOCUS MECHANISM FOR A WEAKENING MCS SLIDING EASTWARD INTO AREA FOR SUNDAY AFTERNOON/NIGHT. GFS HAS BEEN ADVERTISING THIS FOR SEVERAL DAYS SO HIGH CHANCE POPS SHOULD SUFFICE. A SECOND...BACKDOOR FRONT...FORECAST TO SLIDE SOUTH ACROSS CWA LATE MONDAY AND STALL ACROSS SOUTHEAST ZONES. ANOTHER WAVE SLIDING BY TO OUR NORTH SHOULD GIVE THE STALLED FRONT A KICK SOUTH OF THE REGION BY FRIDAY. GIVEN THE ABOVE...WILL NEED TO HAVE A MENTION OF DIURNAL CHANCE/SLIGHT POPS IN EXTENDED FORECAST EACH DAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... ISOLATED LATE AFTERNOON CONVECTION SHOULD STRENGTHEN AND INCREASE IN COVERAGE EARLY THIS EVENING WITH ARRIVAL OF MID LEVEL TROUGH. PATCHY LIGHT FOG EXPECTED ACROSS RURAL SITES...WHICH MAY BECOME LOCALLY DENSE IF RAINFALL OCCURS. MORE ISOLATED CONVECTION SATURDAY. SCATTERED STORMS EXPECTED SUNDAY AFTERNOON/EVENING...MORE ISOLATED AFTERNOON AND EVENING STORMS FORECAST FOR THE REST OF THE WEEK. WINDS WILL BE HIGHER NEAR STORMS. LOCALLY REDUCED VISIBILITIES AND CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE. && .MARINE... SOUTHERLY WINDS EXPECTED TO CHANNEL TO NEAR SMALL CRAFT CRITERIA THIS EVENING ACROSS THE BAY AND LOWER POTOMAC (BASED ON 12Z GFS/ETA MOS AND 12Z WRF-LWX). SCATTERED STORMS THIS EVENING...MORE ISOLATED SATURDAY. SCATTERED STORMS EXPECTED SUNDAY AFTERNOON/EVENING...ISOLATED AFTERNOON/EVENING STORMS FORECAST FOR THE REST OF THE WEEK. WINDS AND WAVES WILL BE HIGHER NEAR STORMS. LOCALLY REDUCED VISIBILITIES AND CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...ROGOWSKI NEAR TERM...RDH/ROGOWSKI SHORT TERM...ROGOWSKI LONG TERM...RW AVIATION...ROGOWSKI/RW MARINE...ROGOWSKI/RW
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
130 AM EDT THU AUG 2 2007 UPDATED AVIATION SECTION FOR 06Z TAF ISSUANCE .DISCUSSION... THE MAIN FCST CONCERN WILL FOCUS ON FRONTAL TIMING AND PCPN CHCS/COVERAGE TONIGHT INTO EARLY THU. BROKEN LINE OF CONVECTION HAS FORMED AHEAD OF PLAINS SHORTWAVE AND ALONG/BEHIND ASSOC COLD FRONT AS NOTED ON SATELLITE AND RADAR IMAGERY. STORMS OVER CENTRAL MN HAVE FORMED IN ENVIRONMENT OF 500-1500 J/KG MLCAPE AND 25-30 KT DEEP LAYER SHEAR. SO FAR...NO SVR STORMS INDICATED ON UPSTREAM RADARS BUT THERE IS A SLIGHT RISK OVER CENTRAL MN. OUR CWFA IS ONLY UNDER A GENERAL RISK OF CONVECTION TONIGHT. FCST FRONTAL TIMING FAIRLY SIMILAR BETWEEN NAM AND GFS...BUT PREFER SLOWER POST-FRONTAL ARRIVAL OF PCPN OF GFS GIVEN THAT MID-UPR DYNAMICS OF SYSTEM APPEAR TO BE LAGGING BEHIND COLD FRONT. GFS HAS PCPN REACHING INTO WRN COUNTIES JUST AFTER 00Z THEN INTO NORTH CENTRAL COUNTIES AROUND 06Z AND INTO ERN AND SOUTH CENTRAL COUNTIES AROUND 12Z. BIG CONCERN/QUESTION IS WHETHER WARM/DRY MID-LVLS AS NOTED ON 12Z RAOB SNDGS AND LOCAL TAMDAR SNDGS WILL LIMIT COVERAGE OF PCPN ALONG AND BEHIND THE FRONT AS IT MOVES THROUGH UPR MI TONIGHT. LOCAL MESOSCALE MODELS SEEM TO SUGGEST MORE OF A BROKEN LINE OF CONVECTION SPREADING ACROSS FCST AREA WITH FRONTAL PASSAGE...AND THIS SEEMS REASONABLE GIVEN UPSTREAM RADAR TRENDS SO FAR AND FACT THAT FRONTAL PASSAGE WILL OCCUR PAST THE PEAK HEATING OF DAY. KEPT LOW CHC POPS (30 PCT) IN FOR WRN COUNTIES BUT TRIMMED BACK POPS TO 20 PCT FOR CENTRAL AND ERN COUNTIES WHEN FRONTAL PASSAGE WILL BE EVEN LATER...GENERALLY AFT 03Z. ANY LINGERING ISOLD CONVECTION OVER SCNTRL AND SE COUNTIES SHOULD END BY THU MORNING AS Q-VECT DIV/SUBSIDENCE SPREADS IN FROM THE NORTHWEST AND DRIES OUT MID-LVLS. HIGH TEMPS SHOULD STILL REACH INTO THE MID TO UPR 80S OVER SCNTRL COUNTIES WHERE 850 MB TEMPS ARE PROGGED TO BE 15-17C. FARTHER NORTH EXPECT INLAND HIGHS IN THE LOW-MID 80S. COOLER TEMPS (MID-UPR 70S) CAN BE EXPECTED OVER THE KEWEENAW AND ERN SHORELINES IN A WNW FLOW. CONFLUENT FLOW AHEAD OF MID-LVL RDG OVER THE PLAINS AND ASSOC SUBSIDENCE WILL KEEP CONDITIONS DRY FRI AND SAT AS WELL. MODEL FCST 850 MB TEMPS 12-14C MIXING TO SFC WILL ALLOW INLAND HIGH TEMPS TO REACH THE LOW TO MID 80S...WARMEST OVER THE INTERIOR WEST ALONG THE WI BDR. DEVELOPING LAKE BREEZES WILL ACT TO KEEP TEMPS COOLER (MID 70S) ALONG THE GREAT LAKES SHORES. 12Z ECMWF PRETTY CONSISTENT WITH PREV RUNS AND 12Z GFS INDICATING SIMILAR TREND OF DELAYING NORTHWARD MOVEMENT OF WARM FRONT STATIONED OVER CNTRL PLAINS/LOWER MIDWEST. THUS...HAVE TRIMMED POPS BACK TO SLIGHT CHC SAT NIGHT INTO SUN OVER WRN AND CENTRAL COUNTIES WHILE LEAVING ERN COUNTIES DRY. LOOKS LIKE BETTER CHC OF WAA PCPN WILL BE SUN NIGHT INTO MON AS WARM FRONT BEGINS TO APPROACH THE UPPER GREAT LAKES SO INCLUDED A LOW CHC POP FOR NOW OVER THE ENTIRE CWA. WITH MODELS AND GFS ENSEMBLES HINTING AT SERIES OF WEAK SHORTWAVES MOVING THROUGH AREA INTO MIDWEEK KEPT IN SCHC POPS FOR MON NIGHT THROUGH WED. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... NARROW LINE OF SHOWERS AND THUNDERSTORMS AROUND A COLD FRONT EXTENDING ACROSS CENTRAL LAKE SUPERIOR INTO SOUTHERN MN WILL CONTINUE MOVING E OVERNIGHT. THE STORMS HAVE BEEN IN THE PROCESS OF FALLING APART...BUT SOME MAY MAKE IT THROUGH SAW BTWN 06-08Z. TS MENTION MAY ALSO BE NEEDED IF LIGHTNING CAN SUSTAIN ITSELF...BUT RIGHT NOW GIVEN THE PCPN TREND...HAVE DECLINED TO INCLUDE ANY. BEHIND THE FRONT...VFR CONDITIONS WILL BE THE RULE FOR BOTH TAF SITES INTO THU NIGHT. DID PUT IN SOME HIGHER GUSTS AT CMX BEGINNING LATE THU MORNING DUE TO DAYTIME HEATING AND FUNNELING EFFECTS OF WEST WINDS BEHIND THE COLD FRONT. WINDS SHOULD RELAX THU EVENING WITH LOSS OF HEATING. && .MARINE (FOR 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... A COLD FRONT WILL MOVE OUT OF WESTERN ONTARIO AND ACROSS LAKE SUPERIOR TONIGHT CAUSING THE WINDS TO SHIFT TO THE WEST AND WEST-NORTHWEST. WINDS MAY SNEAK TOWARD 20-25 KT FOR A PERIOD ON THU IN WAKE OF THE FRONT...BUT LACK OF STRONG PRESSURE RISES OR COLD AIR ADVECTION NEAR SFC...SHOULD PRECLUDE STRONGER WINDS. HIGH PRESSURE/LIGHT WINDS RETURN ON FRI AND SAT...THEN ANOTHER FRONTAL SYSTEM ARRIVES IN THE UPPER GREAT LAKES SUN INTO MON. WINDS SHOULD REMAIN BLO 20 KT INTO EARLY NEXT WEEK. $$ .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...VOSS AVIATION...AJ MARINE...DLG
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
300 AM MDT THU AUG 2 2007 .DISCUSSION... 12Z SFC ANALYSIS EARLY THIS MORNING SHOWS 1017MB HIGH PRES OVER SE CO NOSING SW INTO NE NM. 400-250MB AIRCRAFT DATA SHOWS A 30-40 KNOT NW TO SE ORIENTED JET FROM KFMN SE ACROSS KROW INTO KMAF. RADAR TRENDS SHOW INCREASING ACTIVITY ACROSS MUCH OF THE E PLAINS AND OVER PORTIONS OF THE CENTRAL VALLEY. LATEST RUC GUIDANCE INDICATES THE UPPER JET WILL TRANSLATE SE TOWARD W TX AND DISSIPATE THROUGH THE EARLY MORNING HOURS AS THE 500-300MB UPPER HIGH MOVES WESTWARD INTO SW NM. RAISED POPS TO HIGH CHANCE/LOW LIKELY IN AREAS E OF THE CENTRAL MTN CHAIN FOR THIS MORNING SINCE CONVECTION SHOULD HOLD TOGETHER AS UPPER DIVERGENCE ASSCD WITH EXITING UPPER JET MOVES ACROSS THE AREA. LOCALLY HEAVY RAINS ARE POSSIBLE WITH ANY STORMS TODAY...ESPECIALLY ACROSS THE E PLAINS AND SW MTNS AS GOES PWATS SHOW VALUES 150 PERCENT OF NORMAL IN THESE AREAS. THETA E RIDGE CURRENTLY POSITIONED FROM SE TO NW ACROSS THE SW HALF IS ADVERTISED TO BECOME MORE NORTH TO SOUTH ORIENTED INTO FRIDAY WITH THE BEST LIFT AND MOISTURE CONVERGENCE TO FOLLOW. LEFT HIGHEST POPS OVER THE W HALF OF THE STATE THROUGH WEEKEND AS ADVERTISED BY THE 00Z NOGAPS/GFS/UKMET. AN UPPER TROUGH IS PROGGED TO BUILD ALONG THE WEST COAST PUSHING THE UPPER HIGH EAST INTO THE CENTRAL PLAINS STATES. THIS TREND INDICATES THE MOISTURE PLUME WILL SLOWLY SHIFT FROM WEST TO EAST ACROSS THE STATE EARLY NEXT WEEK WITH DAILY ROUNDS SHOWERS AND STORMS. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 92 64 91 65 / 30 30 40 40 GALLUP.......................... 85 56 83 56 / 30 30 40 40 GRANTS.......................... 87 57 85 56 / 20 30 40 40 GLENWOOD........................ 85 61 85 61 / 40 30 50 50 CHAMA........................... 80 48 79 50 / 30 50 50 40 LOS ALAMOS...................... 84 56 82 56 / 40 50 40 40 RED RIVER....................... 73 44 76 44 / 60 50 50 40 TAOS............................ 85 53 85 53 / 40 30 30 30 SANTA FE........................ 83 57 84 58 / 40 40 40 30 SANTA FE AIRPORT................ 86 60 86 60 / 40 40 30 30 ESPANOLA........................ 90 61 89 59 / 20 30 20 30 ALBUQUERQUE HEIGHTS............. 89 66 89 65 / 30 40 30 30 ALBUQUERQUE VALLEY.............. 90 64 91 63 / 30 40 30 30 ALBUQUERQUE FOOTHILLS........... 86 62 87 62 / 30 40 30 30 ALBUQUERQUE WEST MESA........... 91 64 90 65 / 30 40 30 30 SOCORRO......................... 90 64 90 63 / 20 30 30 20 SANDIA PARK/CEDAR CREST......... 80 56 81 56 / 50 50 40 40 MORIARTY/ESTANCIA............... 84 53 84 52 / 50 60 30 20 CARRIZOZO....................... 83 61 84 61 / 40 60 30 20 RUIDOSO......................... 75 55 75 55 / 60 60 50 20 RATON........................... 85 55 86 57 / 50 50 20 20 LAS VEGAS....................... 80 52 82 54 / 60 40 30 20 ROY............................. 81 59 84 60 / 50 50 20 20 CLAYTON......................... 85 61 87 62 / 40 30 20 10 SANTA ROSA...................... 87 62 87 63 / 60 50 20 20 TUCUMCARI....................... 87 67 90 68 / 50 40 20 20 FORT SUMNER..................... 87 65 89 66 / 60 50 20 20 CLOVIS.......................... 85 63 85 64 / 60 30 20 10 PORTALES........................ 88 64 87 65 / 60 30 20 10 ROSWELL......................... 88 68 88 68 / 50 50 40 20 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
930 PM PDT FRI AUG 3 2007 .SYNOPSIS... HIGH PRESSURE OVER THE SOUTHWEST WILL BRING ANOTHER HOT DAY SATURDAY. SUNDAY WILL BE A LITTLE COOLER AS THE HIGH SLOWLY RETREATS EAST. NEXT WEEK A LOW PRESSURE TROUGH OVER THE EASTERN PACIFIC WILL DEEPEN THE MARINE LAYER AND KEEP THE DEEP MONSOON MOISTURE EAST OF OUR AREA. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES. CU FORMED OVER THE MOUNTAINS TODAY BUT THERE WAS NOT ENOUGH INSTABILITY AND MOISTURE TO GENERATE CONVECTION. IT TURNED OUT TO BE QUITE HOT WITH HIGH TEMPS HITTING THE CENTURY MARK AT RIALTO AND BEAUMONT...105 AT HESPERIA...109 AT BORREGO AND 111 AT PALM SPRINGS. 850 MB TEMPS REMAIN NEARLY UNCHANGED TOMORROW FOR ANOTHER HOT DAY...THEN DROP SEVERAL DEGREES SUNDAY AS THE RIDGE AXIS SHIFTS A LITTLE FARTHER SOUTHEAST. SO TEMPS SUNDAY WILL BE A LITTLE LOWER. WE ARE WATCHING THE WESTWARD PROGRESS OF AN EASTERLY WAVE SOUTH OF ARIZONA THIS EVENING. THE INFRARED SATELLITE LOOP SHOWS MIDLEVEL MOISTURE STREAMING TOWARD NORTHERN BAJA ON SOUTHEAST WINDS. ONCE AGAIN WE SHOULD SEE CU FORM OVER THE MOUNTAINS TOMORROW BUT THE CHANCES FOR CONVECTION ARE SMALL. ON SUNDAY...DEEPER MOISTURE SURGES INTO IMPERIAL COUNTY IN WHAT LOOKS TO BE THE LAST WE WILL SEE OF THE MONSOON FOR A WHILE. A SHARP MOISTURE GRADIENT SETS UP ACROSS THE LOWER DESERTS SUNDAY WITH DEEPEST MOISTURE OVER IMPERIAL COUNTY BUT LOWER VALUES OVER SAN DIEGO COUNTY. TOSS IN THE EFFECTS OF THE DYNAMIC FORCING ASSOCIATED WITH THE EASTERLY WAVE AND THERE COULD BE SUFFICIENT INSTABILITY FOR CONVECTION. WILL CONTINUE TO MONITOR. NEXT WEEK THE DRY SOUTHWEST FLOW ALOFT WILL PREVAIL. DEWPOINTS LOWER IN THE MOUNTAINS AND DESERTS...ESPECIALLY AFTER MONDAY WHEN THE SOUTHWEST FLOW TAKES HOLD...AND HUMIDITIES WILL BE MUCH LOWER THERE. WEST OF THE MOUNTAINS...A DEEPER MARINE LAYER WILL PUSH THE STRATUS INTO THE INLAND VALLEYS. && .AVIATION...040400Z ACARS SOUNDINGS SHOW THE INVERSION HEIGHT AT 1400 FEET. STRATUS WILL CONTINUE TO SPREAD FROM THE COAST INTO THE COASTAL VALLEYS OVERNIGHT WITH BASES IN THE 1200-1400 FOOT MSL RANGE AND TOPS TO 2000 FEET. THE INVERSION HEIGHT SHOULD LIFT SLIGHTLY SATURDAY AS AN EDDY WILL DEVELOP. CLEARING WILL BE SLIGHTLY LATER...GENERALLY AROUND 17Z. ABOVE THE MARINE LAYER...VFR CONDITIONS WITH A MOSTLY CLEAR SKY AND UNRESTRICTED VISIBILITIES WILL CONTINUE THROUGH SATURDAY NIGHT. ONLY A FEW AFTERNOON CUMULUS ARE EXPECTED OVER THE MTNS. && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MOEDE AVIATION/MARINE...MAXWELL
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
256 AM MDT SAT AUG 4 2007 .DISCUSSION... 400-250MB AIRCRAFT WIND PLOT SHOWS THE UPPER LEVEL HIGH CENTERED OVER THE NORTHERN MTNS...A 50-70 KNOT SW JET OVER THE GREAT BASIN...AND A 20-30 KNOT NE JET OVER W TX. WATER VAPOR LOOP SHOWS THE MOISTURE PLUME OVER E AZ/W NM ROTATING AROUND THE UPPER HIGH INTO SE CO. 08Z SURFACE ANALYSIS SHOWS A 1005MB LOW PRES CENTER OVER SE CO WITH A WEAK SURFACE TROUGH EXTENDING SW ACROSS W NM BENEATH THE MOISTURE PLUME. 03Z SREF/06Z MREF GUIDANCE SHOWS A 576DM H5 TROUGH SHARPENING OVER THE NW CONUS WITH RIDGING BUILDING OVER THE LOWER MS VALLEY THROUGH EARLY NEXT WEEK. THIS WILL HOLD THE CURRENT MOISTURE PLUME IN PLACE OVER NM WITH A GRADUAL SHIFT TO THE EAST TOWARD THE EARLY PART OF NEXT WEEK. IN THE SHORT TERM...NO BIG CHANGES FOR TODAY AS THE HIGHEST POPS WILL BE FROM THE CONTINENTAL DIVIDE WEST TO THE AZ BORDER. E PLAINS WILL SEE THE LEAST AMOUNT OF ACTIVITY THIS AFT AS THE UPPER RIDGE SHIFTS EAST ACROSS THE STATE WITH PLENTY OF SUBSIDENCE IN THE MID AND UPPER LEVELS AS INDICATED BY THE 00Z KAMA SOUNDING. RAISED POPS IN THE NE PLAINS SUNDAY AS A BOUNDARY INDICATED BY THE 00Z NAM/GFS SAGS SOUTH INTO THE AREA WHILE A 20-40 KNOT UPPER JET ROTATES NW AROUND THE UPPER HIGH. SAME SCENARIO WILL ENSUE FOR MONDAY WITH THE HIGHEST POPS FROM THE NE PLAINS SW THROUGH THE CENTRAL VALLEYS INTO THE GILA REGION. CPC 6-10 AND 8-14 DAY OUTLOOKS SHOW ABOVE NORMAL PRECIP PROBABILITIES THRU NEXT WEEK AS THE MOISTURE PLUME REMAINS IN PLACE OVER NM. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 87 65 91 65 / 50 40 30 30 GALLUP.......................... 81 59 85 59 / 60 50 40 30 GRANTS.......................... 83 57 84 59 / 50 50 30 40 GLENWOOD........................ 83 63 87 63 / 60 50 40 30 CHAMA........................... 80 50 79 51 / 60 50 40 40 LOS ALAMOS...................... 83 58 85 58 / 30 50 30 30 RED RIVER....................... 72 49 71 52 / 30 50 50 40 TAOS............................ 84 56 86 56 / 30 30 30 40 SANTA FE........................ 82 59 85 58 / 30 40 40 40 SANTA FE AIRPORT................ 84 60 87 60 / 20 40 30 30 ESPANOLA........................ 88 61 90 61 / 20 30 20 30 ALBUQUERQUE HEIGHTS............. 89 67 90 68 / 20 40 20 30 ALBUQUERQUE VALLEY.............. 90 65 92 66 / 20 40 20 30 ALBUQUERQUE FOOTHILLS........... 86 65 88 65 / 30 50 30 30 ALBUQUERQUE WEST MESA........... 89 67 92 67 / 30 50 20 30 SOCORRO......................... 90 66 93 67 / 30 30 20 30 SANDIA PARK/CEDAR CREST......... 83 60 86 61 / 30 50 30 40 MORIARTY/ESTANCIA............... 86 62 89 59 / 20 40 20 30 CARRIZOZO....................... 85 64 89 65 / 20 30 10 20 RUIDOSO......................... 75 57 79 61 / 30 40 30 20 RATON........................... 83 58 88 57 / 30 30 30 30 LAS VEGAS....................... 79 56 86 58 / 20 40 20 30 ROY............................. 85 63 88 64 / 10 20 30 20 CLAYTON......................... 89 64 93 66 / 10 20 30 20 SANTA ROSA...................... 91 66 94 68 / 10 10 20 10 TUCUMCARI....................... 93 69 97 70 / 5 10 20 10 FORT SUMNER..................... 91 68 96 69 / 10 10 5 10 CLOVIS.......................... 90 66 95 68 / 5 5 5 5 PORTALES........................ 90 67 95 67 / 5 5 5 5 ROSWELL......................... 91 69 96 70 / 20 10 5 10 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ GUYER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 AM CDT SAT AUG 4 2007 .SHORT TERM...TODAY THROUGH MONDAY WHERE THE THUNDERSTORM COMPLEX TO OUR WEST WILL TRACK TODAY AND TONIGHT ARE THE MAIN FORECAST CONCERNS FOR THIS TIME PERIOD. AT 3 AM...A MESOSCALE CONVECTIVE COMPLEX WAS LOCATED FROM EASTERN SOUTH DAKOTA SOUTHEAST INTO CENTRAL IOWA. THE THUNDERSTORMS ASSOCIATED WITH THIS SYSTEM ARE MAINLY CONFINED TO EASTERN SOUTH DAKOTA AND NORTHWEST IOWA. THIS IS MAINLY DUE TO THE MOISTURE CONVERGENCE ASSOCIATED WITH AN 850 MB JET AND THE LIFT ASSOCIATED RIGHT ENTRANCE REGION OF A 60 KNOT 300 MB JET. THE MODELS ARE IN VERY GOOD AGREEMENT THAT THIS THUNDERSTORM COMPLEX WILL BE MOVING EAST INTO A RATHER DRY AIR MASS. THE SURFACE DEW POINTS ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA HAVE BEEN A LITTLE MISLEADING OVERNIGHT BECAUSE THEY HAVE SLOWLY CLIMBED INTO THE UPPER 50S AND MID 60S. MUCH OF THIS MOISTURE IS A RESULT OF EVAPOTRANSPIRATION OF MOISTURE INTO THE BOUNDARY LAYER. THE 00Z SOUNDINGS FROM CHANHASSEN EAST INTO MICHIGAN WERE VERY DRY FROM 925 MB AND UP. A TAMDAR SOUNDING FROM CEDAR RAPIDS IOWA AROUND 0430Z CONTINUES TO SHOW A VERY DRY AIR MASS FROM JUST ABOVE THE BOUNDARY LAYER TO 700 MB. EVEN THOUGH THIS IS THE CASE...THEY DIFFER ON THE TRACK AND LOCATION OF THIS SYSTEM. OVERALL...THE GFS IS HANDLING THIS SYSTEM THE BEST SO FAR. HOWEVER IT STILL APPEARS TO BE A BIT TOO FAR NORTH YET. AS A RESULT...I TRENDED MY FORECAST TOWARD IT THIS MORNING. IT SHOWS THAT THE DEEPEST FRONTOGENETIC FORCING WILL MOVE THROUGH THE AREA THIS MORNING. HOWEVER THIS IS WHEN THE SYSTEM WILL BE ENCOUNTERING THE DRIEST AIR. AS WE GET INTO THE AFTERNOON...THE 900 TO 700 MB FRONTOGENETIC FORCING WILL BE LOCATED FROM THE AUSTIN MINNESOTA AND MASON CITY IOWA AREAS SOUTHEAST TOWARD GRANT COUNTY WISCONSIN. AS A RESULT...I PLACED MY HIGHEST PRECIPITATION PROBABILITIES IN THESE AREAS FOR TODAY. THE 0-6 KM SHEAR IS IN THE EXCESS OF 40 KNOTS THIS AFTERNOON. HOWEVER THE MOST UNSTABLE CAPES ARE ONLY IN THE 300 TO 600 J/KG. AS A RESULT...I CANNOT COMPLETELY RULE OUT AN ELEVATED SEVERE THUNDERSTORM...BUT THE CHANCES LOOK VERY LOW RIGHT NOW. THE FRONTOGENETIC FORCING CONTINUES TO WANE TONIGHT. WITH THE BEST OCCURRING IN THE 900 TO 800 MB LAYER FROM AUSTIN MINNESOTA TO SOUTH BEND INDIANA BETWEEN 00Z AND 06Z. AS A RESULT...I KEPT HIGH PRECIPITATION PROBABILITIES IN THESE AREAS...AND QUICKLY DECREASED THEM TO THE NORTH AND EAST. .LONG TERM...MONDAY NIGHT THROUGH FRIDAY THE MEDIUM RANGE MODELS CONTINUE TO SHOW THAT FROM MONDAY NIGHT THROUGH WEDNESDAY NIGHT THAT THE UPPER MISSISSIPPI RIVER VALLEY WILL BE LOCATED ON THE NORTHWEST PERIPHERY OF THE 500 MB HIGH. AS SYSTEMS ROTATE AROUND THIS HIGH...WE WILL SEE SEVERAL WEAK VORTICITY MAXIMUMS MOVE THROUGH THE REGION. EACH OF THESE SYSTEMS WILL HAVE THE POTENTIAL OF PRODUCING SHOWERS AND THUNDERSTORMS. SINCE THESE SYSTEMS ARE TYPICALLY MESOSCALE...THE GLOBAL AND REGIONAL MODELS USUALLY HAVE A VERY HARD TIME WITH THE TIMING AND PLACEMENT OF THESE SYSTEMS. AS A RESULT...THE CHANCE OF PRECIPITATION THROUGH THIS PERIOD LOOKS GOOD EVEN THOUGH MUCH OF THIS TIME PERIOD WILL LIKELY BE DRY. FROM THURSDAY THROUGH FRIDAY...THE MEDIUM RANGE MODELS CONTINUE TO SHOW THAT THE UPPER LEVEL HIGH WILL GRADUALLY RETROGRADE FROM THE SOUTHEAST UNITED STATES INTO THE SOUTHERN PLAINS. AS THIS OCCURS... THE 500 MB HEIGHTS WILL CLIMB BY ABOUT 30 DECAMETERS. EVEN THOUGH THIS OCCURS...THE 850 MB TEMPERATURES CLIMB VERY LITTLE. AS A RESULT...WE WILL LIKELY SEE TEMPERATURES REMAIN AROUND 90. && .AVIATION...TODAY AND TONIGHT ATTENTION STILL FOCUSED ON RAIN SHIELD TO THE WEST MOVING TOWARD THE LOCAL AREA. TAMDAR AND MODEL SOUNDINGS INDICATE A RATHER SUBSTANTIAL AMOUNT OF DRY AIR IN THE LOWER LAYERS...WHICH IS ERODING THE RAIN SHIELD AS IT MOVES EAST. IT IS DELAYING THE ONSET...BUT FEEL THE MID LEVELS WILL CONTINUE TO RAIN DOWN THE MOISTURE...EVENTUALLY SATURATING THE LAYER. HAVE ADDRESSED THIS SCENARIO IN THE TAF PRODUCTS WITH VCSH FOR A TIME BEFORE CARRYING RAIN. THE BETTER SATURATION...AND BETTER DYNAMIC AND THERMODYNAMIC LIFT WILL COME LATER THIS AFTERNOON AND INTO TONIGHT. AFTER THE RAIN ARRIVES... EXPECT LOWER CEILINGS AND PERHAPS SOME LIGHT FOG LATE TONIGHT. WILL ADDRESS THIS IN THE 12Z TAF ISSUANCES. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT AND LONG TERM...BOYNE AVIATION...MW
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1011 AM EDT SAT AUG 4 2007 .SYNOPSIS... A WEAK FRONTAL BOUNDARY WILL MOVE SOUTH ACROSS THE MID ATLANTIC THIS AFTERNOON AND STALL OVER CENTRAL VIRGINIA THIS EVENING. A DECAYING THUNDERSTORM COMPLEX IS EXPECTED TO AFFECT THE AREA ON SUNDAY. HIGH PRESSURE...ALONG WITH HOT AND HUMID CONDITIONS WILL DOMINATE THE WEATHER TUESDAY THROUGH FRIDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WATER VAPOR LOOP SHOWS SUBSIDENCE OVER THE MID ATLANTIC BEHIND A TROUGH. A MCV IS MOVING EAST ACROSS THE MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL THE POSITION OF THE UPPER LEVEL TROUGH IS ALONG THE EAST COAST. A 80-100KT SOUTHWESTERLY JET EXTENDS FROM THE WEST COAST THROUGH THE GREAT LAKES. 11Z SURFACE ANALYSIS PLACE A WEST TO EAST WARM FRONT LIFTING NORTH ACROSS THE GULF STATES. A COLD FRONT ENTERING NEW ENGLAND IS STALLING ACROSS THE MIDWEST...WITH THE PRE-FRONTAL TROUGH POSITIONED FROM CENTRAL VIRGINIA NORTHEAST ALONG INTERSTATE 95. A 1021MB ANTICYCLONE DOMINATED THE GREAT LAKES. SATELLITE AND GPS PRECIPITABLE WATER SENSORS INDICATE DEEP LAYER MOISTURE IS FALLING ACROSS THE REGION...EVEN AHEAD OF THE COLD FRONT. BEST MOISTURE IS BEING RETAINED ALONG AND EAST OF INTERSTATE 95...COINCIDENT WITH THE POSITION OF THE PRE-FRONTAL TROUGH. THIS IS WHERE THE BEST CHANCE OF CONVECTION WILL BE...AS ALSO SHOWN BY SIMULATED REFLECTIVITY FROM THE NCEP WRF-NMM AND NSSL WRF-ARW. ADJUSTED 12Z KIAD RAOB DOES INDICATE MODERATE INSTABILITY WILL BE PRESENT...AND WITH SUCH A DRY SOUNDING A LOCAL DAMAGING WIND GUST CANNOT BE RULED OUT. ADDED SUBSIDENCE AND DRIER AIRMASS SHOULD COUNTERACT ANY COOL ADVECTION TO PROVIDE ANOTHER DAY IN THE MID TO UPPER 90S (BASED ON 00Z MET GUIDANCE AND ADJUSTED FOR BIAS). WITH DEW POINTS DROPPING DUE TO DEEP LAYER MIXING AND LATE AFTERNOON DRY ADVECTION...HEAT INDEX SHOULD REMAIN BELOW ADVISORY CRITERIA. SENSITIVE GROUPS MAY FEEL THE IMPACT OF THE HEAT HOWEVER...AND THUS MENTION WILL REMAIN IN THE HAZARDOUS WEATHER OUTLOOK. WINDS ARE BASED ON THE LWX 4KM WRF-ARW AND INDICATE A LIGHT NORTH-NORTHWEST COMPONENT. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... CONVECTION SHOULD WIND DOWN QUICKLY ACROSS THE SOUTHEAST ZONES WITH THE LOSS OF HEATING. WHILE CONVECTIVE CLOUDINESS WILL WANE...EXPECT MID AND UPPER LEVEL MOISTURE TO APPROACH FROM THE NORTHWEST LATE DURING THE NIGHT...AHEAD OF A CONVECTIVE COMPLEX. BASED ON RECENT PERFORMANCE...USED THE 00Z MET GUIDANCE FOR LOW TEMPERATURES WHICH WAS ADJUSTED FOR BIAS. WINDS WERE ONCE AGAIN BASED ON THE LWX 4KM WRF-ARW. && .LONG TERM /SUNDAY THROUGH FRIDAY/... OVERALL...NOT MANY CHANGES TO THE LONG TERM FORECAST. NW FLOW ALOFT AT THE BEGINNING OF THE PERIOD...WITH SHORTWAVE ENERGY DROPPING SOUTHWARD. A LARGE HIGH IS CENTERED NEAR THE ARKLATEX. THE HIGH CENTER WILL SHIFT TO THE EAST OVER THE GULF STATES THROUGH MID WEEK. BY THE END OF THE WEEK...A TROUGH WILL BEGIN TO DIG OVER THE EAST COAST WHILE THE HIGH CENTER RETREATS BACK WESTWARD. AT THE SURFACE...A FRONTAL BOUNDARY IS SITUATED JUST TO THE SOUTH OF THE CWFA...AND WILL REMAIN IN THE VICINITY OF THE CWFA THROUGH MONDAY. THE MODELS ARE STILL INDICATING A MCS TO BE DROPPING SE ON SUNDAY. THE GFS SEEMS TO BE OVERDOING POPS A BIT...AND STUCK CLOSER TO THE SREF NUMBERS. AFTER TUESDAY...THE FORECAST WILL BE DOMINATED BY HIGH PRESSURE. A FRONTAL BOUNDARY DOES SET UP NORTH OF THE FORECAST AREA BY MIDWEEK. ANY PRECIPITATION...PAST MONDAY...SHOULD BE DIURNALLY DRIVEN AND MOSTLY ISOLATED IN NATURE. THERE IS MUCH DISAGREEMENT BETWEEN THE MET AND MAV MOS FOR HIGH TEMPERATURES...ESPECIALLY SUNDAY AND MONDAY. HAVE DECIDED TO TAKE A BLEND FOR THIS TIME PERIOD. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... PROBABILITY FOR ISOLATED STORM TO AFFECT TERMINALS TOO REMOTE TO MENTION IN TAFS AT THIS TIME. DRIER AIR WORKS IN FROM THE NORTH WITH AN EVENING FRONTAL PASSAGE. THE NEXT SYSTEM AFFECTS THE REGION SUNDAY INTO SUNDAY NIGHT. LOCALLY REDUCED VISIBILITIES/CEILINGS...GUSTY WINDS AND CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE. && .MARINE... WINDS 10KT OR LESS TODAY AS DICTATED BY VALID MOS GUIDANCE AND LWX WRF-ARW. SCATTERED THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING...AHEAD OF THE NEXT SYSTEM WHICH AFFECTS THE REGION SUNDAY. WINDS AND WAVES WILL BE HIGHER NEAR STORMS. LOCALLY REDUCED VISIBILITIES AND CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...ROGOWSKI NEAR TERM...ROGOWSKI SHORT TERM...ROGOWSKI LONG TERM...NWL AVIATION...ROGOWSKI MARINE...ROGOWSKI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
945 AM EDT SAT AUG 4 2007 .SYNOPSIS... A COLD FRONT WILL CLEAR THE NORTH COUNTRY THIS MORNING...ALLOWING HIGH PRESSURE TO MOVE OVER THE AREA THROUGH THE REST OF THE WEEKEND. ANOTHER SYSTEM RETURNS LATE MONDAY INTO WEDNESDAY FOR YET ANOTHER ROUND OF RAINFALL...BEFORE HIGH PRESSURE RETURNS FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED 945 AM SATURDAY MINOR UPDATE THIS MORNING TO THIS MORNINGS PACKAGE...MAINLY TO REMOVE MENTION OF PCPN ACROSS NERN PORTIONS OF VT...AND TO NUDGE TEMPS UPWARD JUST SLIGHTLY IN A FEW AREAS...NAMELY THE CHVLY. OTW INHERITED FSCT IN GOOD SHAPE. LATEST LAPS SOUNDING ANALYSIS AND MORNING ACARS DATA OUT OF CYUL SUPPORT IDEA OF 850 HPA TEMPS SLOWLY EASING OFF THIS AFTERNOON IN MEAN NW FLOW BEHIND FROPA OVERNIGHT. NONETHELESS ...READINGS AROUND 11-12C UNDER AMPLE PBL MIXING SHOULD ALLOW TEMPS TO CLIMB INTO THE LOWER 80S ACROSS MANY LOWER ELEVATIONS TODAY...ESP WITH LOWS OVERNIGHT REMAINING FAIRLY MILD AREA WIDE. THUS WILL EASE TEMPS UPWARD A DEGREE OR TWO...AGAIN MAINLY ACROSS LWR ELEVATIONS. ONLY OTHER CHANGE WAS TO REMOVE MENTION OF PCPN ACROSS NERN VT. DESPITE TAIL END OF UPPER TROUGH PASSG TO THE NORTH TODAY...AVBL DYNAMICAL AIDS SHOW COLUMNAR MOISTURE PROFILES FAIRLY MEAGER WITH AT LEAST SOME MID LVL CAPPING EVIDENT OFF MORNING SOUNDING PROFILES. CANNOT TOTALLY RULE OUT AN ISOLD -SHRA ACROSS THE NE KINGDOM LATER THIS AFTERNOON/EARLY EVENING...BUT THIS CAN BE HANDLED BY SHORT TERM FCSTS SHOULD DEVELOPMENT OCCUR...IF AT ALL. MOST NOTICEABLE CHANGE OTHER THAN THE COOLER TEMPS WILL BE THE NOTICEABLE DROP IN HUMIDITY LVLS...A WELCOMED RELIEF AFTER A FEW UNCOMFORTABLE DAYS/NIGHTS ACROSS THE NORTH COUNTRY. ENJOY THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... HIGH PRESSURE RIDGE CONTINUES TO MV OVER THE NORTH COUNTRY TNGT AND WILL SET UP OFF THE EAST COAST BY MON MORNING. WILL ADJUST HIGH TEMPS FOR SUNDAY A FEW DEGREES HIGHER THAN ON SATURDAY TO ACCOUNT FOR SW FLOW SETTING UP. WILL ALSO ADJUST POPS TO SHOW BETTER TIMING FOR APPROACHING RAINS ON MONDAY. && .LONG TERM /MONDAY THROUGH FRIDAY/... WILL OPT FOR NO CHANGES TO THE EXTENDED ATTM. MON NGT...FRNT CONTINUES TO PUSH THRU THE CWA...COMBINED W/ WEAK SYSTEM WHICH MVD UP FROM THE MID-ATLANTIC DURING THE DAY MONDAY. STILL EXPECTING LGT RW IN TO TUES MORNING. LATEST MDL RUNS SHOW WEAK RIDGE WILL BUILD INTO AREA...BFR NEXT LOW COMING OUT OF THE GREAT LKS FOR TUES NGT INTO LATE WED NGT FOR ANOTHER ROUND OF RAIN. THIS IS FOLLOWED BY ANOTHER RIDGE TO BUILD OVER AREA THURS INTO FRIDAY. CURRENTLY FORECAST GOING FOR SL CHANCE FOR RW BUT WILL LEAVE TO WAIT FOR MDL CONSISTENCY TO SEE IF RIDGE HOLDS. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... A MID LVL S/W MVG ACRS QUEBEC THIS MRNG WL FINALLY PUSH DELIVER DRIER AIR BEHIND A SLOW MVG CD FNT. THIS WL MEAN VFR CONDS WITH SOME PSBL SCT035 WITH DAYTIME HEATING AND NW WINDS 10-12 KTS. MAINLY SKC WITH WINDS DECOUPLING TNGT WITH TMPS COOLING BLO SFC TMPS...THUS PTCHY MTN/RVR VLY FOG PSBL WITH LCLZD IFR-LIFR CONDS FM 07Z THRU 10-12Z AT KMPV AND KSLK AND PSBLY BRIEFLY AT KBTV...KPBG AND KRUT WHERE LGT DRAINAGE WNDS MAY ADVECT FOG FM ACRS RVRS INTO AIRPORT VCNTY. SUNDAY THROUGH WEDNESDAY...QUIET WEATHER THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS OVER THE AREA. THEN ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS...MVFR TO OCCASIONAL IFR CONDITIONS...POSSIBLE MONDAY AFTERNOON THROUGH MONDAY NIGHT AS A COLD FRONT MOVES THROUGH THE REGION. ANOTHER HIGH PRESSURE AND VFR TUESDAY...THEN SURFACE LOW MOVES FROM UPPER MIDWEST ACROSS NEW ENGLAND...LEADING TO SHOWERY WEATHER AND MVFR/LOCAL IFR CONDITIONS WEDNESDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...JMG SHORT TERM...JN LONG TERM...JN AVIATION...SLW
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
230 PM PDT SAT AUG 4 2007 .SYNOPSIS... UPPER LEVEL LOW PRESSURE WILL BRING COOLER DAYS THROUGH THE MIDDLE OF NEXT WEEK. THE MARINE LAYER AND ONSHORE FLOW WILL CAUSE COASTAL LOW CLOUDS AND FOG IN THE NIGHTS AND MORNINGS...EXTENDING LOCALLY INLAND. VARIABLE MID TO HIGH CLOUDS THROUGH SUNDAY...OTHERWISE DRY SOUTHWEST FLOW ALOFT WILL KEEP THE WEATHER FAIR. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES. .SHORT TERM (TODAY-TUE)... LOW CLOUDS AND LOCAL FOG WERE INTO THE COASTAL AREAS AND WRN SAN DIEGO INLAND VALLEYS THIS MORNING BUT CLEARED TO JUST OFFSHORE BY ABOUT NOON. STRATUS REMAINS EXTENSIVE OFFSHORE. THERE WERE ALSO A FEW MID AND HIGH CLOUDS. EARLY AFTERNOON ACARS SOUNDING INDICATED AN INVERSION BASED NEAR 1800 FT. STRONGER ONSHORE GRADIENTS WITH ABOUT 6 MB SAN-IPL. A FEW CU DEVELOPED OVER THE HIGHER MOUNTAINS THIS AFTERNOON. AN UPPER LEVEL TROUGH OVER THE W COAST WILL DIG INTO SRN CA THROUGH SUN BRINGING GRADUALLY LOWER HEIGHTS. THE MEAN TROUGH REMAINS POSITIONED OVER THE W WITH A SERIES OF SHORT WAVES MOVING THROUGH THE TROUGH TO THE N. THIS WILL MAINTAIN SMALL CHANGES IN LOCAL HEIGHTS MON AND TUE WITH GENERALLY DRY SW FLOW ALOFT. HOWEVER...THE REMNANT CIRCULATION FROM A MCS OVER WRN MEX WILL MOVE UP TOWARD SRN CA AND THEN OFF TO THE NE SUN. THIS SHOULD BRING AN INCREASE IN MID TO HIGH CLOUDS SUN. CANNOT COMPLETELY RULE OUT THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS SUN BUT CHANCES REMAIN RATHER LOW AND WILL LEAVE OUT OF THE FORECAST FOR NOW. THE WEAK TROUGHING ALOFT AND AN INTERMITTENT EDDY WILL DEEPEN THE MARINE LAYER FOR MORE EXTENSIVE NIGHT AND MORNING LOW CLOUDS. COOLER DAYS IN MOST AREAS...ESPECIALLY INLAND. STRONGER ONSHORE GRADIENTS WILL CAUSE LOCAL BREEZY CONDITIONS IN THE MOUNTAINS AND DESERTS DURING THE AFTERNOONS AND EVENINGS. && .LONG TERM (WED-SAT)... A LARGE UPPER HIGH GRADUALLY SHIFTS W AND BECOMES CENTERED OVER THE CENTRAL US BUT A WEAK UPPER TROUGH REMAINS OVER THE W COAST. THIS WILL RESULT IN GRADUAL WARMING...MAINLY INLAND. THE MARINE LAYER WILL ALSO SLOWLY DECREASE IN DEPTH AND INLAND EXTENT. && .AVIATION... 041930Z...MARINE LAYER DEPTH APPROX 2000-2200 FT WITH A WEAK COASTAL EDDY. MARINE LAYER EXPECTED TO DEEPEN FURTHER BY SUNDAY MORN. STRATUS CLEARED OUT WELL THIS MORN BUT SOME PATCHES OF LOW CLOUDS COULD DEVELOP NEAR THE BEACHES WITH THE SEABREEZE THIS AFTN. A SOLID BANK OF STRATUS STRETCHED FAR OFFSHORE. EXPECT THE STRATUS DECK TO DEVELOP EARLIER TONIGHT...BASES AROUND 1500 FT MSL SHOULD PUSH BACK ONTO THE IMMEDIATE COAST BEFORE SUNSET AND SPREAD FURTHER INLAND THRU EARLY SUNDAY MORN. CEILINGS SHOULD REACH SAN/CRQ ABOUT 01Z-03Z AND NEAR FOOTHILLS AFTER MIDNIGHT. LOW CLOUDS WILL REACH NEAR KONT APPROX 11-15Z SUN. ABOVE THE MARINE LAYER...VFR CONDITIONS WITH A FEW MID/HI CLOUDS. SOME CUMULUS THIS AFTN OVER THE MOUNTAINS. && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...DVA AVIATION...LAVIS
AREA FORECAST DISCUSSION
NWS DENVER CO
300 PM MDT SAT AUG 04 2007 SHORT TERM...DEEP PLUME OF SUBTROPICAL MOISTURE CONTINUES TO STRING OUT ALONG THE OUTER EDGE OF THE UPR LVL HIGH PRES RIDGE NOW CENTERED OVER NWRN TEXAS. THE CLOUD BAND EXTENDING OVER THE CWFA THIS AFTERNOON PRETTY MUCH AT THE CENTER OF THIS PLUME. EVEN WITH ALL THE MOISTURE AROUND CONVECTION HAS BEEN SLOW TO DEVELOP THIS AFTERNOON ESPLY IN MTN AREAS NORTH OF INTERSTATE 70 AND OUT ACROSS THE PLAINS. LATEST ACARS SOUNDINGS AT POINTS NORTH AND EAST OF DENVER INDICATE A STRONG STABLE LAYER UP AROUND 550 MBS. SAME SOUNDINGS ALSO INDICATE 5-15KT N/NWLY WINDS UP THROUGH 600 MBS AND 15-30KT SWLY FLOW ABOVE THAT. THOUGH THE STEERING FLOW ALOFT IS SOMEWHAT STRONGER TODAY STORM MOTIONS HAVE REMAIN LIGHT...GENERALLY FM A W-SWLY COMPONENT AT 10-15KT. HIGHEST RUC CAPE VALUES ON THE PLAINS UP AROUND 2200 J/KG UP AROUND FORT COLLINS AND ACROSS WELD COUNTY WHERE LGT S-SELY ANTICYCLONIC FLOW HAS ACCUMULATED AIR WITH NEAR 60F DEW POINTS. BUT STORMS HAVE YET TO FIRE IN THIS AREA. ELSEWHERE DEWPOINTS ON THE PLAINS HAVE SLOWLY FALLEN THROUGH THE DAY WITH THE LIGHT N-NWLY LOW-LEVEL FLOW THAT DEVELOPED EARLIER THIS MORNING FOLLOWING PASSAGE OF A WEAK FRONTAL SURGE. FOR THE REST OF THE AFTERNOON WOULD EXPECT TO SEE WDLY SCT/SCT T-STORMS FORMING OVER MTNS...ALONG THE FRONT RANGE FOOTHILLS AND PALMER DIVIDE...AND POSSIBLY UP ALONG THE CHEYENNE RIDGE AROUND FORT COLLINS. CUMULUS CLOUDS FORMING ACROSS LINCOLN COUNTY POSSIBLY ANOTHER AREA FOR LATE AFTERNOON AND EARLY EVENING STORM FORMATION...BUT SBCAPES AND MID-LEVEL STABILITY LESS FAVORABLE FOR DEEP CONVECTION IN THIS AREA. BELIEVE HEAVY RAIN LESS OF A THREAT THIS EVENING...ALTHOUGH ONE OR TWO STORMS AROUND PARK COUNTY...THE SOUTHERN FOOTHILLS AND WESTERN PORTION OF THE PALMER DIVIDE MAY STILL PRODUCE A BRIEF INTENSE SHOWER. OVERNIGHT...COULD SEE ISOLATED CONVECTION LINGERING IN THE HIGH COUNTRY AND POSSIBLY ON THE NEARBY PLAINS. MODELS SHOW A SHORTWAVE AND VORT MAX IN THE FOUR CORNERS REGION AND ANOTHER WEAKER MID-LEVEL IMPULSE PASSING OVER SRN IDAHO/NRN UTAH AT THIS HOUR. MODELS SHOW THESE FEATURES MERGING OVER NERN COLORADO SOMETIME AFTER MIDNIGHT. MEANWHILE WIND FIELDS SHOW LOW-LEVELS WINDS BACKING AROUND TO A SELY COMPONENT WHICH SLOWLY ADVECTS HIGHER DEW POINTS BACK UP IN THE CWFA. THEREFORE WILL KEEP AT LEAST A SLIGHT CHANCE OF SHWRS/T-STORMS IN THE HIGH COUNTRY AND NEARBY PLAINS OVERNIGHT. ON SUNDAY....MID-LEVEL SHORTWAVE MOVES EAST OF THE CWFA IN THE MORNING WITH QG VERTICAL VELOCITY FIELDS INDICATING SINKING MID/UPR-LEVEL AIR OVER THE AREA. HOWEVER BY THE AFTERNOON...MODELS SHOW S-SELY LOW-LEVEL FLOW STRENGTHENING ACROSS THE PLAINS WHICH INCREASES SFC DEWPOINTS AND THETA-E VALUES. ANOTHER WEAK MID-LEVEL IMPULSE EMBEDDED WITHIN THE MONSOON MOISTURE PLUME IS PROGGED TO SWING OUT OF ERN UTAH AND OVER NERN COLORADO BY 21Z/SUNDAY OR SO. ALTHOUGH SEE LITTLE IMPROVEMENT IN LAYER PRECIPITABLE WATER VALUES IN MTN AREAS. NEVERTHELESS SHOULD SEE STORMS BEGIN TO FIRE IN THE MTNS NOT LONG AFTER MIDDAY AND A FEW HOURS LATER ON THE NEARBY PLAINS. OUTFLOW BOUNDARIES GENERATED BY HIGH COUNTRY STORMS MAY BE NECESSARY TO INITIATE STORM DVLPMNT ON THE PLAINS. BY LATE AFTERNOON WITH PW VALUES INCREASING ON THE PLAINS COULD SEE A FEW HEAVY RAIN PRODUCING STORMS...ESPECIALLY ALONG THE PALMER DIVIDE AND ACROSS FAR ERN PORTIONS OF THE CWFA. TEMPERATURES ON SUNDAY ABOUT THE SAME AS TODAY. .LONG TERM...A WEAK MID LVL SHORTWAVE NOW OVR SRN AZ WL MOV THRU THE REGION MONDAY AFTERNOON WHICH SHOULD ENHANCE TSTM CHANCES TWD EVENING. THIS FEATURE HAS ITS ORIGINS WITHIN THE DEEP MONSOONAL FLOW OVR THE SOUTHWEST AND HIR PRECIP WATER WILL BE INVOF THE SHORTWAVE AS IT MOVES THRU THE CWA. THUS...TSTM COVERAGE LOOKS A BIT HIR MONDAY AFTN/EVENING. HWVR...STRONGER SOUTHWESTERLY FLOW AND FASTER STORM MOVEMENT SHOULD LIMIT QPF AND FLOODING SHOULD NOT BE OF CONCERN. TUESDAY...A WEAK UPR TROUGH WL MOV THRU MONTANA WITH AN ASSOCIATED TROUGH PASSING THRU THE DISTRICT TUESDAY EVENING. DUE TO THE WEAK ASCENT WITH THIS TROUGH TUESDAY EVENING...ELECTED TO KEEP POPS GOING OVERNIGHT AS WE COULD SEE SOME CONVECTION LAST OVERNIGHT. LOOKING AHD...STG HIGH PRESSURE WL RMN STATIONARY OVER THE SOUTHEAST CONUS. HWVR...A SERIES OF TROUGHS FM THE PACIFIC NW WL GRADUALLY CAUSE THE FLOW ALF TO TURN MORE TO THE SOUTHWEST ACRS OUR REGION. MAIN PLUME OF MONSOONAL MSTR WL MOVE TO OUR EAST...BUT CANNOT RULE OUT AFTN/EVENING STORMS IN THE HIGH COUNTRY AS THERE CONTINUE TO BE A THIN LYR OF MSTR IN THE MID LVLS. PLAINS SHOULD DRY OUT AS THE STORMS AFT WED OR THURS SHOULD BE HIGH BASED. TEMPS WL BE VERY WARM THIS WEEK WITH 90 OR BETTER EACH DAY ON THE PLAINS. WARMED UP TEMPS ABOUT 5 DEGREES ACRS THE BOARD ON LONG TERM FCST...BUT OTWS FEW CHGS NEEDED AT THIS TIME. && .AVIATION...ISOLD/WDLY SCT TSRA IN THE DENVER VCNTY THRU 03Z. BRIEF HVY RAIN AND TSRA WND GUSTS TO 30KTS A POSSIBLITY. ISOLATED -TSRA POSSIBLE OVERNIGHT ASA WEAK UPR LVL WX DISTURBANCE EXPECTED TO PASS OVERTHE AREA BTWN 06Z-09Z. VSBYS BRIEFLY MVFR WITH HVY RAINFALL WITH PASSING TSRA. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ BAKER/046
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
340 PM EDT SAT AUG 4 2007 .SYNOPSIS... A WEAK FRONTAL BOUNDARY ACROSS THE REGION THIS EVENING WILL STALL OVER CENTRAL VIRGINIA OVERNIGHT. ON SUNDAY THE REMAINS OF A THUNDERSTORM COMPLEX OVER THE UPPER MID WEST WILL AFFECT THE REGION. WEAK HIGH PRESSURE FEATURING HOT AND HUMID CONDITIONS WILL AFFECT THE REGION FOR THE COMING WORK WEEK. LITTLE ORGANIZED PRECIPITATION IS EXPECTED FOR THE UPCOMING WEEK...OTHER THAN ISOLATED TO SCATTERED THUNDERSTORMS. HEAT INDEX VALUES COULD TOP 100 ON TUE AND WED. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... WATER VAPOR LOOP SHOWS SUBSIDENCE OVER THE MID ATLANTIC BEHIND A TROUGH. A MCV IS MOVING EAST ACROSS THE MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL THE POSITION OF THE UPPER LEVEL TROUGH IS ALONG THE EAST COAST. A 80-100KT SOUTHWESTERLY JET EXTENDS FROM THE WEST COAST THROUGH THE GREAT LAKES. 11Z SURFACE ANALYSIS PLACE A WEST TO EAST WARM FRONT LIFTING NORTH ACROSS THE GULF STATES. A COLD FRONT ENTERING NEW ENGLAND IS STALLING ACROSS THE MIDWEST...WITH THE PRE-FRONTAL TROUGH POSITIONED FROM CENTRAL VIRGINIA NORTHEAST ALONG INTERSTATE 95. A 1021MB ANTICYCLONE DOMINATED THE GREAT LAKES. SATELLITE AND GPS PRECIPITABLE WATER SENSORS INDICATE DEEP LAYER MOISTURE IS FALLING ACROSS THE REGION...EVEN AHEAD OF THE COLD FRONT. BEST MOISTURE IS BEING RETAINED ALONG AND EAST OF INTERSTATE 95...COINCIDENT WITH THE POSITION OF THE PRE-FRONTAL TROUGH. THIS IS WHERE THE BEST CHANCE OF CONVECTION WILL BE...AS ALSO SHOWN BY SIMULATED REFLECTIVITY FROM THE NCEP WRF-NMM AND NSSL WRF-ARW. ADJUSTED 12Z KIAD RAOB DOES INDICATE MODERATE INSTABILITY WILL BE PRESENT...AND WITH SUCH A DRY SOUNDING A LOCAL DAMAGING WIND GUST CANNOT BE RULED OUT. SENSITIVE GROUPS MAY FEEL THE IMPACT OF THE HEAT LATE THIS AFTERNOON...MENTION WILL REMAIN IN THE HAZARDOUS WEATHER OUTLOOK. CONVECTION SHOULD WIND DOWN QUICKLY ACROSS THE SOUTHEAST ZONES WITH THE LOSS OF HEATING. WHILE CONVECTIVE CLOUDINESS WILL WANE...EXPECT MID AND UPPER LEVEL MOISTURE TO APPROACH FROM THE NORTHWEST LATE DURING THE NIGHT...AHEAD OF A CONVECTIVE COMPLEX. BASED ON RECENT PERFORMANCE...USED THE 12Z MET GUIDANCE FOR LOW TEMPERATURES WHICH WAS ADJUSTED LOCALLY FOR BIAS. WINDS WERE BASED ON THE LWX 4KM WRF-ARW. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... MCV FROM THE GREAT LAKES EXPECTED TO IMPACT FORECAST AREA SUNDAY...ESPECIALLY BY THE MID AFTERNOON ACROSS THE EASTERN ZONES. BASED ON TIMING...HIGHEST POPS ARE ACROSS WESTERN ZONES. BEST CHANCE TO SEE PARTIAL SUNSHINE WILL BE ACROSS THE SOUTHERN ZONES. IF SYSTEM BREAKS DOWN FASTER THAN ANTICIPATED...GREATER BREAKS IN CLOUDS WOULD ALLOW FOR GREATER AFTERNOON DESTABILIZATION. GIVEN NORTHWEST FLOW...A FEW STORMS WOULD THEN BE STRONG OR SEVERE. HIGHS ARE TRICKY...DUE TO CLOUD FORECAST AND NORTHEAST FLOW OFF THE OCEAN. WENT WITH GFS MOS HIGHS DUE TO RECENT PERFORMANCE AND LOWER GUIDANCE NUMBERS. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... THE LONG TERM WILL FEATURE ABOVE NORMAL TEMPERATURES AS A BROAD FLAT SUB-TROPICAL RIDGE SETS UP ACROSS THE SOUTHEAST AND EXTENDING WEST INTO THE SOUTHERN PLAINS. ABOVE TO MUCH ABOVE NORMAL PRECIP WATER VALUES ARE EXPECTED MAKING THE PERIOD FAIRLY HUMID. THE WARMEST DAYS WILL LIKELY BE TUE AND WED...WITH SOME READINGS ON WED APPROACHING THE UPPER 90S TO NEAR 100. RAINFALL CHANCES WILL BE DEPENDENT MAINLY ON ANY WEAK FEATURES THAT MANAGE TO MOVE BETWEEN THE NORTHERN PERIPERHY OF THE RIDGE AND THE UPPER LEVEL LOW PRES VORTEX OVER THE HUDSON BAY REGION. WOULD EXPECT TO SEE SOME DAILY LATE AFTERNOON/OVERNIGHT MCS ACTIVITY ACROSS THE NORTHERN PLAINS...GREAT LAKES INTO NEW ENGLAND THROUGH MUCH OF THE WEEK. HENCE RAIN CHANCES WILL BE DUE TO LESS ORGANIZED SYSTEMS THAT FIRE DUE TO LOCAL/MESOSCALE WIND CIRCULATIONS...E.G. BAY BREEZE AND MOUNTAIN-VALLEY. SOME SLIGHT LOWERING OF UPPER LEVEL HEIGHTS LATE IN THE WEEK SUGGESTS A SLIGHT COOLING OF THE AIRMASS...PERHAPS DUE TO A WEAK FRONTAL SYSTEM THE ENSEMBLES ADVERTIZE FOR LATE IN THE WEEK. BUT SURFACE HIGH PRESSURE NOT VERY STRONG ACROSS THE GREAT LAKES...NEED AT LEAST 1020 HPA HIGH CENTERS OVER THIS REGION TO PUSH A FRONT DOWN INTO OUR REGION DURING MID-SUMMER AND DO NOT SEE THAT HAPPENING. HENCE RAINFALL WILL BE SCATTERED AT BEST...MAYBE A FEW LUCKY SPOTS RECEIVE CONVECTIVE RAINS...BUT MOST PLACES WILL REMAIN BONE DRY. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... PROBABILITY FOR ISOLATED STORM TO AFFECT TERMINALS TOO REMOTE TO MENTION IN TAFS AT THIS TIME. DRIER AIR WORKS IN FROM THE NORTH WITH AN EVENING FRONTAL PASSAGE. THINK VISIBILITIES WILL IMPROVE TO P6SM WITH COLD FRONTAL PASSAGE...EXCEPT NEAR CHO WHERE FRONT STALLS LATE TONIGHT. INCREASING MID AND UPPER CLOUDS TONIGHT WITH THE NEXT SYSTEM AFFECTS THE REGION SUNDAY INTO SUNDAY NIGHT. LOCALLY REDUCED VISIBILITIES/CEILINGS...GUSTY WINDS AND CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE NEAR THUNDERSTORMS. MON THROUGH THU EXPECT MOSTLY VFR WITH SOME MVFR IN HAZE AND POSSIBLE IFR AT IAD/CHO/MRB DURING EARLY MORNING HRS DUE TO PRE- DAWN FOG. ISOLATED TSTM ACTIVITY DURING THE MID TO LATE AFTERNOON HOURS AS WELL. && .MARINE... WINDS AROUND 10KT THROUGH TOMORROW AS DICTATED BY VALID MOS GUIDANCE AND LWX WRF-ARW. SCATTERED THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING...AHEAD OF THE NEXT SYSTEM WHICH AFFECTS THE REGION SUNDAY. WINDS AND WAVES WILL BE HIGHER NEAR STORMS. LOCALLY REDUCED VISIBILITIES AND CLOUD TO GROUND LIGHTNING WILL BE POSSIBLE. FOR THE EXTENDED PERIOD...EXPECT TYIPICAL SUMMERTIME PATTERN TO THE WINDS AS THE BERMUDA HIGH REMAINS OFF THE SE U.S. COAST. ON THE BAY EXPECT SOME LATE AFTERNOON/EARLY EVENING CHANNELLING OF SOUTHERLY WINDS ACROSS THE MIDDLE AND LOWER BAY COULD GIVE GUSTS TO SCA LEVELS AT TIMES. OTHER THAN ISOLATED AFTERNOON/EVENING TSTMS...EXPECT MAINLY DRY WEATHER FOR THE COMING WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...SJR NEAR TERM...SJR SHORT TERM...SJR LONG TERM...SMZ AVIATION...SJR MARINE...SJR/SMZ
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
153 PM EDT SAT AUG 4 2007 .SYNOPSIS... A COLD FRONT WILL CLEAR THE NORTH COUNTRY THIS MORNING...ALLOWING HIGH PRESSURE TO MOVE OVER THE AREA THROUGH THE REST OF THE WEEKEND. ANOTHER SYSTEM RETURNS LATE MONDAY INTO WEDNESDAY FOR YET ANOTHER ROUND OF RAINFALL...BEFORE HIGH PRESSURE RETURNS FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED 945 AM SATURDAY MINOR UPDATE THIS MORNING TO THIS MORNINGS PACKAGE...MAINLY TO REMOVE MENTION OF PCPN ACROSS NERN PORTIONS OF VT...AND TO NUDGE TEMPS UPWARD JUST SLIGHTLY IN A FEW AREAS...NAMELY THE CHVLY. OTW INHERITED FSCT IN GOOD SHAPE. LATEST LAPS SOUNDING ANALYSIS AND MORNING ACARS DATA OUT OF CYUL SUPPORT IDEA OF 850 HPA TEMPS SLOWLY EASING OFF THIS AFTERNOON IN MEAN NW FLOW BEHIND FROPA OVERNIGHT. NONETHELESS ...READINGS AROUND 11-12C UNDER AMPLE PBL MIXING SHOULD ALLOW TEMPS TO CLIMB INTO THE LOWER 80S ACROSS MANY LOWER ELEVATIONS TODAY...ESP WITH LOWS OVERNIGHT REMAINING FAIRLY MILD AREA WIDE. THUS WILL EASE TEMPS UPWARD A DEGREE OR TWO...AGAIN MAINLY ACROSS LWR ELEVATIONS. ONLY OTHER CHANGE WAS TO REMOVE MENTION OF PCPN ACROSS NERN VT. DESPITE TAIL END OF UPPER TROUGH PASSG TO THE NORTH TODAY...AVBL DYNAMICAL AIDS SHOW COLUMNAR MOISTURE PROFILES FAIRLY MEAGER WITH AT LEAST SOME MID LVL CAPPING EVIDENT OFF MORNING SOUNDING PROFILES. CANNOT TOTALLY RULE OUT AN ISOLD -SHRA ACROSS THE NE KINGDOM LATER THIS AFTERNOON/EARLY EVENING...BUT THIS CAN BE HANDLED BY SHORT TERM FCSTS SHOULD DEVELOPMENT OCCUR...IF AT ALL. MOST NOTICEABLE CHANGE OTHER THAN THE COOLER TEMPS WILL BE THE NOTICEABLE DROP IN HUMIDITY LVLS...A WELCOMED RELIEF AFTER A FEW UNCOMFORTABLE DAYS/NIGHTS ACROSS THE NORTH COUNTRY. ENJOY THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... HIGH PRESSURE RIDGE CONTINUES TO MV OVER THE NORTH COUNTRY TNGT AND WILL SET UP OFF THE EAST COAST BY MON MORNING. WILL ADJUST HIGH TEMPS FOR SUNDAY A FEW DEGREES HIGHER THAN ON SATURDAY TO ACCOUNT FOR SW FLOW SETTING UP. WILL ALSO ADJUST POPS TO SHOW BETTER TIMING FOR APPROACHING RAINS ON MONDAY. && .LONG TERM /MONDAY THROUGH FRIDAY/... WILL OPT FOR NO CHANGES TO THE EXTENDED ATTM. MON NGT...FRNT CONTINUES TO PUSH THRU THE CWA...COMBINED W/ WEAK SYSTEM WHICH MVD UP FROM THE MID-ATLANTIC DURING THE DAY MONDAY. STILL EXPECTING LGT RW IN TO TUES MORNING. LATEST MDL RUNS SHOW WEAK RIDGE WILL BUILD INTO AREA...BFR NEXT LOW COMING OUT OF THE GREAT LKS FOR TUES NGT INTO LATE WED NGT FOR ANOTHER ROUND OF RAIN. THIS IS FOLLOWED BY ANOTHER RIDGE TO BUILD OVER AREA THURS INTO FRIDAY. CURRENTLY FORECAST GOING FOR SL CHANCE FOR RW BUT WILL LEAVE TO WAIT FOR MDL CONSISTENCY TO SEE IF RIDGE HOLDS. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... UPDATED 150 PM SATURDAY FOR THE NEXT 24 HRS....A SHORT WAVE RIDGE HAS BUILT INTO THE FA TODAY WITH VFR CONDITIONS EXPECTED UNTIL 08Z. DAYTIME HEATING IS CREATING SCT040 FAIR WEATHER CU AND NW WINDS ARE GUSTING UP TO 15KTS. WINDS AND CLOUD COVER WILL DISSIPATE BY EARLY EVENING. STRONG SUBSIDENCE ALOFT, SKC AND STRONG RADIATIONAL COOLING TONIGHT WILL CAUSE PATCHY MTN/RVR VLY FOG PSBL WITH LOCALIZED IFR- LIFR CONDS FM 08Z THRU 10-12Z AT KMPV AND KSLK. POSSIBLE BRIEF MVFR AT KBTV AND KPBG DUE TO LIGHT SURFACE FOG 09-11Z. SUNDAY THROUGH WEDNESDAY...QUIET WEATHER THROUGH THE WEEKEND AS HIGH PRESSURE BUILDS OVER THE AREA. THEN ANOTHER CHANCE OF SHOWERS AND THUNDERSTORMS...MVFR TO OCCASIONAL IFR CONDITIONS...POSSIBLE MONDAY AFTERNOON THROUGH MONDAY NIGHT AS A COLD FRONT MOVES THROUGH THE REGION. ANOTHER HIGH PRESSURE AND VFR TUESDAY...THEN SURFACE LOW MOVES FROM UPPER MIDWEST ACROSS NEW ENGLAND...LEADING TO SHOWERY WEATHER AND MVFR/LOCAL IFR CONDITIONS WEDNESDAY. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...JMG SHORT TERM...JN LONG TERM...JN AVIATION...DUMONT