SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
435 AM PDT FRI AUG 22 2008
...UPDATED AVIATION DISCUSSION...
.SHORT TERM (TODAY-SUNDAY)...MARINE LAYER EARLIER SCOURED
SOME ALONG THE OUTER WATERS...BUT EARLY THIS MORNING REFORMATION
APPEARS TO OCCURRING. SURFACE GRADIENTS ARE ALL TRENDING ONSHORE
THIS MORNING...AND THIS SHOULD BRING COOLER TEMPERATURES TO THE
COASTAL...VALLEY...AND LOWER COASTAL SLOPES FOR TODAY.
HOWEVER...WARMER TEMPERATURES ALOFT WILL WARM TEMPERATURES OVER
THE INTERIOR PORTIONS OF THE AREA. NAM-WRF 950 MB TEMPERATURES
COOL OVER THE CENTRAL COAST AND THE LOWER VALLEYS NORTH OF POINT
CONCEPTION...WHILE WARMING OCCURS OVER THE ANTELOPE VALLEY AND
SOUTHERN MOUNTAINS AND HIGH VALLEYS THIS AFTERNOON.
GOOD AGREEMENT EXISTS IN SURFACE GRADIENTS TRENDING OFFSHORE
THROUGH THE WEEKEND...THIS SHOULD BRING LESS COVERAGE AND DEPTH IN
THE MARINE LAYER AND BRING WARMER TEMPERATURES TO THE AREA.
TEMPERATURES HAVE BEEN WARMED...ESPECIALLY OVER THE INLAND
PORTIONS FOR THE WEEKEND. NAM-WRF 975 MB AND BOUNDARY LAYER
RELATIVE HUMIDITY PATTERNS INDICATE THE MARINE LAYER BECOMING
ALMOST NON-EXISTENT BY SUNDAY. TEMPERATURES HAVE BEEN BUMPED UP
FOR THE WEEKEND TO BRING THEM TO NEAR OR ABOVE MOS GUIDANCE
VALUES.
.LONG TERM (MONDAY-THURSDAY)...HOT CONDITIONS WILL LIKELY PERSIST
TO START THE WORK WEEK. AN UPPER LEVEL TROUGH SLIDING BY TO THE
NORTH OF THE AREA WILL BRING A SLIGHT COOLING TREND FOR THE FIRST
PART OF THE WEEK.
BY MIDWEEK...BOTH GFS AND ECMWF SOLUTION SUGGEST A STRONG RIDGE
BUILDING IN BEHIND THE TROUGH AND NOSING INTO THE CENTRAL COAST.
IN ADDITION...OFFSHORE FLOW DEVELOPING IN LEE OF THE TROUGH COULD
BRING WARMING FOR NEXT WEDNESDAY AND BEYOND. WITH GFS ENSEMBLE
SOLUTION GIVING A WIDE VARIANCE OF POSSIBILITIES...TEMPERATURES
HAVE BEEN WARMED FOR THE HIGHER VALLEY AREAS AND OVER THE INTERIOR
PORTIONS FOR MID-TO-LATE NEXT WEEK. HOWEVER...IF OPERATIONAL GFS
AND ECMWF SOLUTIONS VERIFY...IT COULD BE WARMER THAN THE CURRENT
PACKAGE.
&&
.AVIATION...22/1135Z
CURRENT AMDAR SOUNDINGS INDICATE MARINE INVERSION AROUND 2000 FT.
LATEST SATELLITE/SURFACE OBS INDICATE STRATUS/PATCHY FOG IN ALL
COASTAL AND COASTAL VALLEY TAF SITES WITH CIGS BETWEEN 006 AND
012. EXPECT THIS CLOUD COVER TO BURN OFF IN THE VALLEYS AROUND
16Z AND THE COAST AROUND 18Z. WITH NO SIGNIFICANT CHANGES IN
THE PATTERN TONIGHT...WILL EXPECT VERY SIMILAR MARINE LAYER DEPTH
AND AREAL COVERAGE.
KLAX...MODERATE TO HIGH CONFIDENCE IN 12Z TAF. STRATUS BURNOFF
THIS MORNING SHOULD BE WITHIN A HOUR OF THE 18Z TIME FRAME. THE
STRATUS SHOULD RETURN TONIGHT AROUND 05Z WITH CIGS AROUND 010.
KBUR...MODERATE TO HIGH CONFIDENCE IN 12Z TAF. IFR CIGS SHOULD
BURNOFF WITHIN ONE HOUR OF 16Z TIME FRAME...WITH A RETURN AROUND
11Z TONIGHT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...HALL
AVIATION...RAT
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS DENVER CO
248 PM MDT SAT AUG 23 2008
.SHORT TERM...A WEAK WAVE OVER NORTHWEST COLORADO IS SHOWING UP IN
THE RUC QG ANALYSIS OVER THE LAST SEVERAL HOURS WITH WEAK ASCENT NOW
MAXIMIZED OVER THE CWA. THE WAVE SHOULD TRAVERSE THE REST OF THE
CWA DURING THE EVENING WITH SUBSIDENCE TAKING OVER IN ITS WAKE.
CONVECTION HAS FIRED OVER THE MOUNTAINS WITH THE AID OF THIS ASCENT
BUT IS HAVING A DIFFICULT TIME SURVIVING OVER THE PLAINS WHERE
STATIC STABILITY IS STILL RATHER HIGH ACCORDING TO LAPS ANALYSES AND
LOCAL AIRCRAFT SOUNDINGS. BECAUSE OF THIS HAVE PAINTED THE HIGHEST
POPS OVER AND NEAR THE HIGHER TERRAIN WITH LESSER AMOUNTS FURTHER ON
THE PLAINS THIS EVENING. BELIEVE TOMORROW WILL SEE LESS TERRAIN
SIGNAL IN THE CONVECTIVE ACTIVITY AS MODELS PREDICT LESS STABILITY
ON THE PLAINS THAN TODAY AS SURFACE HIGH PRESSURE RETREATS
EASTWARD. NOT MUCH CHANGE IN THE OTHER PARAMETERS FROM TODAY.
.LONG TERM...NOT MUCH TO CHANGE IN THE LONG TERM. THE UPPER LEVEL
RIDGE WILL REMAIN CENTERED OVER THE FOUR CORNERS REGION THROUGH
MONDAY. SUFFICIENT MOISTURE OVER THE CWFA THROUGH MONDAY BUT SOME
MID LVL SUBSIDENCE AS WELL TO CAP THE AMS. MAIN FOCUS FOR TSTMS
WILL BE OVER THE HIGHER TERRAIN...WITH SOME DEVELOPMENT IN THE
PLAINS DURING THE EVNG HOURS. THIS ALREADY REFLECTED IN THE GRIDS
SO NO CHANGES THERE. THE AIRMASS WILL DRY OUT SOME ON TUESDAY WITH
A LEE SIDE TROUGH DVLPG OVER ERN CO. THE RIDGE DOES GET SUPPRESSED
FURTHER SOUTH LATE TUESDAY AS THE NEXT STORM SYSTEM MOVES ACRS THE
NRN ROCKIES. MOST OF THE GFS ENSEMBLE RUNS FM 12Z THIS MORNING KEEP
A ZONAL PROGRESSIVE FLOW ASSOCIATED WITH THIS SYSTEM. AS A RESULT
QG ASCENT ASSOCIATED WITH THIS TROF MAY STAY WELL NORTH OF THE
CWFA...WITH MAINLY DOWNSLOPE COMPONENT OVER ERN CO. THE ECWMF
SUPPORTS THIS TREND AND IS EVEN FASTER WITH THE PASSAGE OF THE UPPER
TROF. TIMING OFF THIS SYSTEM STILL IN QUESTION AND WILL STICK WITH
CURRENT POPS OF 10-20 PERCENT COVERAGE. LITTLE IF ANY QPF GENERATED
BY THE MDLS FOLLOWING THE PASSAGE OF THIS TROF WITH A DRY WEST TO
NORTHWESTERLY FLOW ALOFT OVER CO. WL HOLD ON TO ISOLD POPS FOR
THURSDAY BUT EVEN THAT MAY BE OVERKILL AND KEEP NIL POPS FOR THE
RMNDR OF THE PERIOD.
&&
.AVIATION...A FEW THUNDERSTORMS WILL BE AROUND THE AREA DURING THE
EVENING HOURS...MOST LIKELY AFFECTING AREAS NEAR THE HIGH TERRAIN.
THESE SHOULD END BY AROUND 04Z WITH VFR CONDITIONS EXPECTED
THEREAFTER.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
$$
ET/FMC
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
351 PM EDT SAT AUG 23 2008
.SHORT TERM...
CDFNT LOCATED FROM NWRN LAKE MICHIGAN TO WEST CENTRAL IL AT 18Z. WK
LOW LEVEL CONVERGENCE AND 1000-2500J/KG MLCAPE HAS RESULTED IN A BKN
LINE OF TSTMS ALONG THE CDFNT ACROSS IL/MI. CONTD WITH A CHC OF
TSTMS ACROSS THE AREA TONIGHT AS CDFNT MOVES INTO THE AREA WITH HIGHEST
POPS IN NW IN CLOSER PROXIMITY TO CDFNT/INSTABILITY AXIS. LIGHT
UPR LEVEL WIND FIELDS/SHEAR LIMITING SVR TSTM POTENTIAL LATE THIS
AFTN/EVE DESPITE MODEST INSTABILITY. MOS MINS STILL LOOK A LITTLE
TOO COOL TONIGHT BASED ON LATEST FCST SOUNDINGS AND RECENT MOS COOL
BIAS ON MINS...EXPECTING LOWS RANGING FROM THE U60S SE TO M60S NW.
CDFNT EXPECTED TO MOVE THROUGH SE PORTION OF CWA SUNDAY
MORNING...CLEARING THE AREA BY 18Z. WITH SOME ELEVATED INSTABILITY
REMAINING IN VCNTY OF FRONT...FCST LOW CHC OF TSTMS IN THE A.M. IN
THAT AREA. OTRWS DECREASING CLOUDINESS FM NW-SE EXPECTED ACROSS
THE AREA DURING THE DAY. BASED ON UPSTREAM TEMPS THIS
AFTN...COOLER MET MOS PREFERRED FOR HIGHS SUNDAY...EXPECTING RANGE
FROM M80S SE TO M70S NEAR LAKE MICHIGAN.
HIGH PRES BUILDING SE INTO THE GRTLKS SUNDAY NIGHT WILL PROVIDE
DRIER AND COOLER CONDITIONS. NE GRADIENT WINDS WILL LIMIT
RADIATIONAL COOLING DESPITE MOSTLY CLEAR SKIES AND DRY
AIRMASS...GENERALLY STAYED CLOSE TO MOS CONSENSUS WITH LOWS
EXPECTED IN THE M-U50S ACROSS THE AREA.
&&
.LONG TERM...
MONDAY THROUGH SATURDAY.
NO CHANGES PLANNED AS MODELS ARE NOT A WHOLE LOT BETTER THAN
YESTERDAY OVERALL. ENERGETIC TROUGH STILL FORECAST TO DIG INTO THE
AREA TOWARDS THE END OF THE WEEK. ITS EXACT TIMING IS STILL A BIT
TRICKY BUT MODELS SUGGEST STILL IN THE THURS NGT TO FRI TIME FRAME.
MED RANGE MODELS BEGIN TO MOVE THE UPPER LOW NORTH AND NORTHEAST
INTO THE EASTERN GREAT LAKES. THE BULK OF ITS EFFECTS STILL LOOK TO
PASS TO THE EAST OF THE AREA. AS A RESULT WILL MAINTAIN DRY FORECAST
INTO WEDS NGT. QUESTION REMAINS WHAT IF ANY RESIDUAL MSTR COULD BE
IN THE AREA FROM FAY AS THE TROUGH ARRIVES. THIS TROUGH STILL SHOULD
BRING IN A CHANCE FOR SOME SHOWERS AND STORMS...HOWEVER WITH LACK OF
THE BETTER MSTR AND BEST S/W ENERGY PASSING NORTH OF THE AREA...WILL
PROBABLY NOT AMOUNT TO MUCH MORE THAN SCT AT THIS POINT BUT STILL
ENOUGH TO MAINTAIN THE CHCS. TEMPS THROUGH MUCH OF THE PERIOD WILL
STAY WITHIN A FEW DEGREES EITHER SIDE OF CLIMO.
&&
.AVIATION...
CDFNT CONTG TO MOVE SE TOWARD THE AREA THIS AFTN...EXTENDING FROM
NRN LWR MI TO WEST CENTRAL IL AT 17Z. BAND OF TS ONGOING ALONG
FRONT OVER NRN/CENTRAL MI...WHILE CONVECTION WHICH DEVELOPED
FARTHER SOUTH ALONG FRONT LAST NIGHT HAS DISSIPATED. CU FIELD
DEVELOPING OVER NRN INDIANA ATTM AND AIRMASS AHEAD OF THE FRONT
BECOMING VERY UNSTABLE WITH NO CAP INDICATED BY MORNING SOUNDINGS
OR TAMDAR DATA. MAIN FORCING IN OUR AREA IS WK CONVERGENCE ALONG
CDFNT. BEST CHANCES FOR TS IN OUR AREA AT SBN...CLOSER TO FRONT
DURING PEAK HEATING...SO CONTD WITH PREVIOUS FCST OF VCTS LATE
THIS AFTN/EVE THERE WITH NO MENTION AT FWA. FROPA EXPECTED AROUND
08Z AT SBN AND 13Z AT FWA. MAY BE SOME FOG/STRATUS AROUND TIME OF
FROPA...FOR NOW JUST FCST MVFR VSBYS AT THAT TIME WITH VFR
CONDITIONS RETURNING BY LATE SUNDAY MORNING.
$$
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...FISHER
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1244 PM EDT SAT AUG 23 2008
.SHORT TERM...
TODAY THROUGH SUNDAY NIGHT...THE MAIN CHALLENGE THIS PERIOD IS THE
TIMING AND COVERAGE OF STORMS THROUGH SUNDAY. DEEP MOISTURE HAD
SPREAD OVER THE AREA WITH PRECIPITABLE WATER VALUES CLOSE TO 1.75
INCHES. THE SEVERE WEATHER POTENTIAL FROM STORMS LOOKS SMALL AS
BULK SHEAR AND FORECAST CAPE IS NOT EXPECTED TO BE LARGE ENOUGH TO
SUPPORT SUPERCELLS THIS AFTERNOON OR THIS EVENING. FORECAST WET
BULB ZERO HEIGHTS ALSO LOOK TOO HIGH TO SUPPORT LARGE HAIL. THE
FRONT SHOULD MOVE ACROSS THE AREA SUNDAY MORNING...WITH COOLER AND
DRIER AIR SPREADING OVER THE AREA...ENDING THE CHANCE FOR STORMS.
AS FOR TEMPS...KEPT SE AREAS/AOH MUCH ABOVE NORMAL WITH HIGHS
AROUND 90F GIVEN PERSISTENCE AND ONGOING DRY CONDITIONS.
&&
.LONG TERM...
BRIEF COOLDOWN IN ASSOCN/W SFC RIDGING BLDG SEWD ACRS THE GREAT
LAKES SUN AND MON W/SIG DRYING TO OCCUR W/DEWPOINTS PROBABLY
DROPPING INTO THE 40S MON AFTN. PROGRESSIVE YET RELATIVELY FLAT
WESTERLY FLW WILL THEN STEER INCOMING PAC SYS THROUGH THE NRN US
MID WEEK W/SHRT AMPLITUDE RIDGING DOWNSTREAM. RTN FLW BEHIND
DEPARTING SFC RIDGE QUITE WEAK AND MORE A FUNCTION OF LL FLW
DISRUPTION ASSOCD/W FAY REMNANT CIRC LIFTING UP THROUGH THE
APPALACHIANS. IN LIGHT OF THIS...THE ADDITION OF POPS IN DYS 7/8
YDA REMAINS PRESUMPTIVE AND LIKELY ERRONEOUS IN LIGHT OF 00Z
GFS/GEFS/ECMWF SOLIDARITY ON TIMING OF SW TROUGH UPSTREAM OVR THE
NEPAC THIS MORNING COMING INLAND FASTER AND IN A MUCH WEAKER
FASHION. THIS WOULD EFFECTIVELY SPLIT THE AREA W/LG SCALE
SUBSIDENT SINK INBTWN AND LIKELY LTL IF ANY IMPLIED CHC OF PCPN
LATE WEEK.
&&
.AVIATION...
CDFNT CONTG TO MOVE SE TOWARD THE AREA THIS AFTN...EXTENDING FROM
NRN LWR MI TO WEST CENTRAL IL AT 17Z. BAND OF TS ONGOING ALONG FRONT
OVER NRN/CENTRAL MI...WHILE CONVECTION WHICH DEVELOPED FARTHER SOUTH
ALONG FRONT LAST NIGHT HAS DISSIPATED. CU FIELD DEVELOPING OVER NRN
INDIANA ATTM AND AIRMASS AHEAD OF THE FRONT BECOMING VERY UNSTABLE
WITH NO CAP INDICATED BY MORNING SOUNDINGS OR TAMDAR DATA. MAIN
FORCING IN OUR AREA IS WK CONVERGENCE ALONG CDFNT. BEST CHANCES FOR
TS IN OUR AREA AT SBN...CLOSER TO FRONT DURING PEAK HEATING...SO
CONTD WITH PREVIOUS FCST OF VCTS LATE THIS AFTN/EVE THERE WITH NO
MENTION AT FWA. FROPA EXPECTED AROUND 08Z AT SBN AND 13Z AT FWA. MAY
BE SOME FOG/STRATUS AROUND TIME OF FROPA...FOR NOW JUST FCST MVFR
VSBYS AT THAT TIME WITH VFR CONDITIONS RETURNING BY LATE SUNDAY
MORNING.
$$
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...SKIPPER
LONG TERM...HOLSTEN
AVIATION...JT
AREA FORECAST DISCUSSION...UPDATED
NWS BALTIMORE MD/WASHINGTON DC
415 PM EDT SAT AUG 23 2008
.SYNOPSIS...
HIGH PRESSURE WILL MOVE INTO THE WESTERN ATLANTIC THROUGH THE
WEEKEND. THE NEXT COLD FRONT WILL SLOWLY PASS THROUGH THE REGION
MONDAY. THIS FRONT WILL STALL OUT JUST SOUTH OF THE AREA FOR THE
MIDDLE OF NEXT WEEK. SOME MOISTURE FROM FAY MAY BE DRAWN INTO THIS
BOUNDARY BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HAVE UPDATED PRE FIRST PD FCST TO INCLUDE ISOLD SHRA. HEATING OF
MOIST AMS VCTY CHSPK BAY HAS YIELDED PCPN MAINLY ACRS ERN COASTAL
AND MARINE ZONES. ANY PCPN SHUD SUBSIDE BY TNGT WITH LOSS OF
HEATING.
OTHERWISE...WATER VAPOR LOOP SHOWS THE UPPER PORTION OF FAYS
CIRCULATION TRANSLATING WEST OVER THE FLORIDA PANHANDLE. A RIDGE
DOMINATES THE MID ATLANTIC AND NEW ENGLAND. AN UPPER LOW IS
LIFTING INTO THE HUDSON BAY REGION...WITH THUNDERSTORMS IGNITING
LAST NIGHT AS HEIGHTS LOWER NEAR THE SHEAR ZONE STRETCHED SOUTH TO
NORTH OVER THE CENTRAL CONUS. ACARS 400-250MB WIND OBSERVATIONS
REVEAL A 60-105KT CYCLONICLY CURVED JET FROM THE NORTHERN ROCKIES
TO THE UPPER MIDWEST AND NORTHEAST INTO SOUTH CENTRAL CANADA. 11Z
SURFACE MAP SHOWS RIDGING FROM NEW ENGLAND SOUTH TOWARD ATLANTA. A
BAROCLINIC ZONE REMAINS FROM THE SOUTHERN EXTENT OF THE
DAMMING...NORTHWEST THROUGH THE TENNESSEE VALLEY...THEN NORTHEAST
THROUGH THE GREAT LAKES REGION. A COLD FRONT WAS ENTERING THE
MIDWEST AND PLAINS. THE CENTER OF TROPICAL STORM FAY CONTINUES TO
TRACK WEST ACROSS THE FLORIDA PANHANDLE.
MARINE AIRMASS WHICH ADVECTED IN LAST NIGHT ON SOUTHEASTERLY FLOW IS
GRADUALLY MIXING OUT FROM WEST TO EAST THIS AFTERNOON. WITH LOSS OF
DIURNAL HEATING...MOST OF CUMULUS SHOULD DIMINISH THIS EVENING.
OTHERWISE SCATTERED CIRRUS WILL BE MOVING OVERHEAD FROM THE WEST.
KLWX VWP AND 1745Z KIAD ACARS SOUNDING INDICATE LOW LEVEL FLOW HAS
VEERED SOUTHERLY AS FORECAST BY NAM/GFS. THIS SHOULD DECREASE MUCH
OF THE MARINE SATURATION OVERNIGHT COMPARED TO WHAT OCCURRED LAST
NIGHT.
LOW TEMPERATURES ARE FORECAST TO BE SIMILAR TO LAST NIGHT. LIGHT
RETURN FLOW ANTICIPATED WHERE DECOUPLING DOES NOT OCCUR.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
CUMULUS DEVELOPMENT EXPECTED DURING THE EARLY MORNING ACROSS EASTERN
FORECAST AREA WHERE RESIDUAL MARINE AIRMASS LIKELY REMAINS. UPPER
LEVEL MOISTURE WITH TELECONNECTIONS TO TROPICAL STORM FAY/UPPER
LEVEL SHEAR AXIS...FORECAST TO MOVE IN FROM THE WEST DURING THE
AFTERNOON. WARM ADVECTION SHOULD PROMOTE HIGH TEMPERATURES ABOUT A
CATEGORY HIGHER THAN TODAY...ON INCREASING SOUTHERLY FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIPRES RDG MVS OFFSHORE SUN NGT AS WK CDFNT APPCHS FM NW. SIMLR TO
PRVS RUNS...SYSTM LOOKS STARVED FOR MSTR AND LACKS DYNAMIC FORCING.
SFC CNVGNC LMTD...BUT IT GET CLOSE TO NW CRNR OF CWFA BY ELY MON
MRNG. THAT/S WHERE THE 3RD PD POPS WL BE.
CDFNT PASSES THRU CWFA MON. UPR DIVGNC INCR A LTL DUE TO RRQ OF 60
KT UPR JET...BUT DYNAMICS REMAINS UNIMPRESSIVE. POPS NO HIER THAN 30
PCT...AND WL SHUNT EVERYTHING TO SRN FRINGE OF CWFA BY EVE AS LRG
HIPRES BUILDS FM GRTLKS.
HIPRES WL LARGELY KEEP PCPN S OF CWFA TUE. MSTR WL REBOUND INTO AREA
MIDWEEK AS STALLED BNDRY RTNS N AS A WMFNT. BY THEN...MSTR FM FAY WL
BCM INFUSED W/ WLYS...LEADING TO GREATER TRANSPORT ALNG BAROCLINIC
ZN. THIS WL BE WELCOMED RAFL FOR CWFA...AS PARTS BDRG ON DROUGHT
ONCE AGN. TIMING PRETTY MUCH THE ONLY QSTN. ATTM...HV CNTRD THREAT
ON WED-FRI PD /LEANING ON ENS GDNC INSTEAD OF OP RUNS/...W/ LWR POPS
/SCHC/ FRI NGT-SAT. HV ANTHR NRN STREAM CDFNT TO CONSIDER FOR THE
WKND...BUT CAN DO THAT TMRW. DUE TO AMPLE CLDCVR AND OCNL QPF...MAXT
WL BE LWR THAN CLIMO. MIN-T WL BE CLS TO NORMS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
DAYTIME MIXING WILL CONT TO LEAD TO HIGHER CIGS THAN SEEN THIS
MORNING. AS A RESULT...P6SM AND VFR COND EXPECTED THROUGH EARLY
TONIGHT. BR IN WESTERN LOCALES POSSIBLE LATE TONIGHT...LEADING TO
SOME MVFR CONDITIONS. SIMILAR TO THIS MORNING...MIXING WILL YIELD
LOWER CIGS SHORTLY AFTER SUNRISE. LIGHT SE WINDS THIS AFTERNOON WILL
BEGIN TO VEER TONIGHT...AND SHIFT TO A MORE SW DIRECTION DURING THE
DAY SUNDAY AS HIGH PRESSURE MOVES FURTHER OFF THE COAST.
LCL MVFR PSBL IN TSRA INVOF CDFNT MON. FLGT RESTRICTIONS LKLY AGN
WED-THU AS FNT RTNS NWD...INFUSED W/ REMNANT MSTR FM FAY.
&&
.MARINE...
HIGH PRESSURE WILL ALLOW MESOSCALE CIRCULATIONS TO DOMINATE THIS
AFTERNOON...LEADING TO LIGHT ONSHORE FLOW. GRADIENT SOUTHEASTERLY
FLOW ENSUES TONIGHT INTO SUNDAY. SOUTHERLY CHANNELING STRENGTHENS
TOMORROW EVENING AS HIGH PRESSURE DIMINISHES.
WNDS WL APPCH SCA IN SLY CHANNELING SUN NGT. BETTER CHC AT SCA COMES
MON NGT-TUE MRNG AS COLD AIR DRAINS SWD IN WAKE OF CFP.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...KRAMAR
PREV DISC...SJR/HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
256 PM EDT SAT AUG 23 2008
.SYNOPSIS...
HIGH PRESSURE WILL MOVE INTO THE WESTERN ATLANTIC THROUGH THE
WEEKEND. THE NEXT COLD FRONT WILL SLOWLY PASS THROUGH THE REGION
MONDAY. THIS FRONT WILL STALL OUT JUST SOUTH OF THE AREA FOR THE
MIDDLE OF NEXT WEEK. SOME MOISTURE FROM FAY MAY BE DRAWN INTO THIS
BOUNDARY BRINGING THE CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WATER VAPOR LOOP SHOWS THE UPPER PORTION OF FAYS CIRCULATION
TRANSLATING WEST OVER THE FLORIDA PANHANDLE. A RIDGE DOMINATES THE
MID ATLANTIC AND NEW ENGLAND. AN UPPER LOW IS LIFTING INTO THE
HUDSON BAY REGION...WITH THUNDERSTORMS IGNITING LAST NIGHT AS
HEIGHTS LOWER NEAR THE SHEAR ZONE STRETCHED SOUTH TO NORTH OVER THE
CENTRAL CONUS. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 60-105KT
CYCLONICLY CURVED JET FROM THE NORTHERN ROCKIES TO THE UPPER MIDWEST
AND NORTHEAST INTO SOUTH CENTRAL CANADA. 11Z SURFACE MAP SHOWS
RIDGING FROM NEW ENGLAND SOUTH TOWARD ATLANTA. A BAROCLINIC ZONE
REMAINS FROM THE SOUTHERN EXTENT OF THE DAMMING...NORTHWEST THROUGH
THE TENNESSEE VALLEY...THEN NORTHEAST THROUGH THE GREAT LAKES
REGION. A COLD FRONT WAS ENTERING THE MIDWEST AND PLAINS. THE CENTER
OF TROPICAL STORM FAY CONTINUES TO TRACK WEST ACROSS THE FLORIDA
PANHANDLE.
MARINE AIRMASS WHICH ADVECTED IN LAST NIGHT ON SOUTHEASTERLY FLOW IS
GRADUALLY MIXING OUT FROM WEST TO EAST THIS AFTERNOON. WITH LOSS OF
DIURNAL HEATING...MOST OF CUMULUS SHOULD DIMINISH THIS EVENING.
OTHERWISE SCATTERED CIRRUS WILL BE MOVING OVERHEAD FROM THE WEST.
KLWX VWP AND 1745Z KIAD ACARS SOUNDING INDICATE LOW LEVEL FLOW HAS
VEERED SOUTHERLY AS FORECAST BY NAM/GFS. THIS SHOULD DECREASE MUCH
OF THE MARINE SATURATION OVERNIGHT COMPARED TO WHAT OCCURRED LAST
NIGHT.
LOW TEMPERATURES ARE FORECAST TO BE SIMILAR TO LAST NIGHT. LIGHT
RETURN FLOW ANTICIPATED WHERE DECOUPLING DOES NOT OCCUR.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
CUMULUS DEVELOPMENT EXPECTED DURING THE EARLY MORNING ACROSS EASTERN
FORECAST AREA WHERE RESIDUAL MARINE AIRMASS LIKELY REMAINS. UPPER
LEVEL MOISTURE WITH TELECONNECTIONS TO TROPICAL STORM FAY/UPPER
LEVEL SHEAR AXIS...FORECAST TO MOVE IN FROM THE WEST DURING THE
AFTERNOON. WARM ADVECTION SHOULD PROMOTE HIGH TEMPERATURES ABOUT A
CATEGORY HIGHER THAN TODAY...ON INCREASING SOUTHERLY FLOW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIPRES RDG MVS OFFSHORE SUN NGT AS WK CDFNT APPCHS FM NW. SIMLR TO
PRVS RUNS...SYSTM LOOKS STARVED FOR MSTR AND LACKS DYNAMIC FORCING.
SFC CNVGNC LMTD...BUT IT GET CLOSE TO NW CRNR OF CWFA BY ELY MON
MRNG. THAT/S WHERE THE 3RD PD POPS WL BE.
CDFNT PASSES THRU CWFA MON. UPR DIVGNC INCR A LTL DUE TO RRQ OF 60
KT UPR JET...BUT DYNAMICS REMAINS UNIMPRESSIVE. POPS NO HIER THAN 30
PCT...AND WL SHUNT EVERYTHING TO SRN FRINGE OF CWFA BY EVE AS LRG
HIPRES BUILDS FM GRTLKS.
HIPRES WL LARGELY KEEP PCPN S OF CWFA TUE. MSTR WL REBOUND INTO AREA
MIDWEEK AS STALLED BNDRY RTNS N AS A WMFNT. BY THEN...MSTR FM FAY WL
BCM INFUSED W/ WLYS...LEADING TO GREATER TRANSPORT ALNG BAROCLINIC
ZN. THIS WL BE WELCOMED RAFL FOR CWFA...AS PARTS BDRG ON DROUGHT
ONCE AGN. TIMING PRETTY MUCH THE ONLY QSTN. ATTM...HV CNTRD THREAT
ON WED-FRI PD /LEANING ON ENS GDNC INSTEAD OF OP RUNS/...W/ LWR POPS
/SCHC/ FRI NGT-SAT. HV ANTHR NRN STREAM CDFNT TO CONSIDER FOR THE
WKND...BUT CAN DO THAT TMRW. DUE TO AMPLE CLDCVR AND OCNL QPF...MAXT
WL BE LWR THAN CLIMO. MIN-T WL BE CLS TO NORMS.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
DAYTIME MIXING WILL CONT TO LEAD TO HIGHER CIGS THAN SEEN THIS
MORNING. AS A RESULT...P6SM AND VFR COND EXPECTED THROUGH EARLY
TONIGHT. BR IN WESTERN LOCALES POSSIBLE LATE TONIGHT...LEADING TO
SOME MVFR CONDITIONS. SIMILAR TO THIS MORNING...MIXING WILL YIELD
LOWER CIGS SHORTLY AFTER SUNRISE. LIGHT SE WINDS THIS AFTERNOON WILL
BEGIN TO VEER TONIGHT...AND SHIFT TO A MORE SW DIRECTION DURING THE
DAY SUNDAY AS HIGH PRESSURE MOVES FURTHER OFF THE COAST.
LCL MVFR PSBL IN TSRA INVOF CDFNT MON. FLGT RESTRICTIONS LKLY AGN
WED-THU AS FNT RTNS NWD...INFUSED W/ REMNANT MSTR FM FAY.
&&
.MARINE...
HIGH PRESSURE WILL ALLOW MESOSCALE CIRCULATIONS TO DOMINATE THIS
AFTERNOON...LEADING TO LIGHT ONSHORE FLOW. GRADIENT SOUTHEASTERLY
FLOW ENSUES TONIGHT INTO SUNDAY. SOUTHERLY CHANNELING STRENGTHENS
TOMORROW EVENING AS HIGH PRESSURE DIMINISHES.
WNDS WL APPCH SCA IN SLY CHANNELING SUN NGT. BETTER CHC AT SCA COMES
MON NGT-TUE MRNG AS COLD AIR DRAINS SWD IN WAKE OF CFP.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HTS
NEAR TERM...ROGOWSKI
SHORT TERM...ROGOWSKI
LONG TERM...HTS
AVIATION...KLEIN/ROGOWSKI/HTS
MARINE...ROGOWSKI/HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1052 AM EDT FRI AUG 22 2008
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN CENTERED OFF THE NORTHEAST COAST THROUGH
THIS WEEKEND. THE NEXT COLD FRONT WILL MOVE INTO THE REGION EARLY
NEXT WEEK AND IS EXPECTED TO STALL OUT OVER OR JUST SOUTH OF THE
AREA FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WATER VAPOR LOOP SHOWS THE UPPER PORTION OF FAYS CIRCULATION
TRANSLATING WEST ACROSS NORTHERN FLORIDA. A RIDGE DOMINATES THE MID
ATLANTIC AND NEW ENGLAND. MEANWHILE...A SHEAR ZONE HAS SUPPORTED A
LINE OF WEAK SHORT WAVES FROM THE LOWER MISSISSIPPI RIVER VALLEY
NORTH INTO THE GREAT LAKES. A COMPACT UPPER LOW IS CROSSING THE
NORTHERN ROCKIES. ACARS 400-250MB WIND OBSERVATIONS REVEAL UPPER
LEVEL RIDGING CENTERED TO THE WEST...WITH A TROUGH AXIS OVER THE
CENTRAL CONUS. A 80-140KT CYCLONICLY CURVED JET HAS EMERGED FROM
THE NORTHERN ROCKIES. 11Z 1029MB ANTICYCLONE WAS LOCATED OVER NEW
ENGLAND...RIDGING DOWN TOWARD ATLANTA. A BAROCLINIC ZONE REMAINS
FROM THE SOUTHERN EXTENT OF THE DAMMING...NORTHWEST THROUGH THE
TENNESSEE VALLEY AND GREAT LAKES REGION. AN INVERTED TROUGH WAS
NOTED FROM NEAR THE CENTER OF FAY IN NORTHERN FLORIDA...NORTHEAST
ALONG THE CAROLINA COAST.
STEEP NOCTURNAL INVERSION SUPPORTED PATCHY VALLEY FOG EARLIER THIS
MORNING...WHICH HAS ERODED AS TEMPERATURES WARMED.
CIRRUS ADVANCING FROM THE WEST INTO THE RIDGE AXIS AND CUMULUS
DEVELOP ACROSS PIEDMONT AND ON RIDGES WILL CONTRIBUTE TO SKY COVER
TODAY. WORDED MOSTLY SUNNY MOST LOCATIONS...PARTLY SUNNY ACROSS THE
PIEDMONT WITH A LITTLE MORE MOISTURE AND UPSLOPE FLOW IN PLACE.
OTHERWISE 12Z KIAD RAOB WAS QUITE DRY WITH 1.03 PRECIPITABLE WATER
VALUE...MEDIAN VALUE 1960-2005 IS 1.25 INCHES THIS TIME OF YEAR.
HIGH PRESSURE MOVING OFF NEW ENGLAND WILL CONTINUE TO SUPPORT LIGHT
EASTERLY FLOW. TEMPERATURES SHOULD TOP OUT NEAR YESTERDAYS VALUES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
ALL GUIDANCE SUGGEST LOW CLOUDS WILL BECOME WIDESPREAD TOWARD SAT
MORNING UNDER AN ESE ONSHORE FLOW. MINT A LITTLE WARMER AS A RESULT.
NO PRECIP EXPECTED.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL HAVE MOVED OFF THE EASTERN SEABOARD BY 12Z
SATURDAY. CLOCKWISE FLOW AROUND SURFACE HIGH PRESSURE WILL BRING
EASTERLY SURFACE WINDS ACROSS OUR CWA TO START SATURDAY. SOME LOW
CLOUDS WILL HAVE ALREADY DEVELOPED/ADVECTED INTO OUR CWA BY THEN.
WE/RE NOT SURE EXACTLY HOW WIDESPREAD THE STRATUS WILL BE RIGHT
NOW...BUT WHATEVER COVERAGE IS PRESENT WILL LINGER INTO THE MID TO
LATE MORNING. THEREFORE...HAVE INCREASED SKY COVER TO NEAR 60
PERCENT TO BEGIN SATURDAY...DECREASING TO AROUND 40 PERCENT IN THE
AFTERNOON. THIS WILL LEAD TO TEXT PRODUCTS READING SOMETHING LIKE
PARTLY SUNNY IN THE MORNING BECOMING MOSTLY SUNNY IN THE AFTERNOON.
GIVEN FORECAST SOUNDINGS FROM THE 00Z NAM AND GFS...A MORE
PESSIMISTIC APPROACH MAY BE NECESSARY WHERE SKY GRIDS MAY NEED TO BE
INCREASED ABOVE 70 PERCENT FOR A MOSTLY CLOUDY SKY CONDITION TO
START SATURDAY.
SATURDAY NIGHT INTO EARLY SUNDAY...THERE MAY ONCE AGAIN BE SOME LOW
CLOUDS ACROSS THE CWA IF THE FORECAST SOUNDINGS FROM THE 00Z NAM AND
GFS ARE TO BE BELIEVED. SURFACE FLOW WILL BE MORE TOWARD THE
SOUTHEAST BY 12Z SUNDAY...THEN SOUTH BY 00Z MONDAY. UPPER HEIGHTS
WILL ALSO BEGIN TO DROP ON SUNDAY AS THE UPPER RIDGE OVER OUR CWA
BECOMES SQUEEZED SOUTH IN ADVANCE OF A SHORTWAVE TROUGH. SOME MID TO
HIGH CLOUDS AHEAD OF THE TROUGH CAN BE EXPECTED SUNDAY AFTERNOON
ALTHOUGH GOOD AGREEMENT EXISTS AMONG THE NAM/GFS/ECMWF AND SREFS IN
MEASURABLE RAIN REMAINING OUTSIDE OF OUR CWA THROUGH 00Z MONDAY.
FRONT APPROACHES THE CWA SUNDAY NIGHT AND MOVES INTO THE CWA ON
MONDAY. FRONT WILL ORIENT ITSELF AS A BACKDOOR BOUNDARY...LIKELY
STALLING OUT OVER CENTRAL VIRGINIA THROUGH TUESDAY. CONTINUE TO NOT
BE EXCITED ABOUT PROSPECTS FOR RAIN WITH THE FRONT...WHICH IS
UNFORTUNATE BECAUSE OUR CWA IS ABNORMALLY DRY AND NEEDS SOME RAIN.
THERE IS A BAND OF HIGHER PRECIPITABLE WATERS ALONG THE FRONT /MAYBE
BRIEFLY EXCEEDING 1.5 INCHES ACCORDING TO THE GFS/...SO WILL
CONTINUE LOW POPS NEAR THE FRONT MONDAY AND MONDAY NIGHT.
TUESDAY THROUGH THURSDAY...THE FRONT WILL CONTINUE TO LINGER OVER OR
CLOSE TO OUR CWA. INITIALLY...SOUTHERN PORTIONS WILL BE THE TARGET
FOR ANY CONVECTION ON TUESDAY. HOWEVER...BOTH GFS AND ECMWF MODELS
BEGIN TO BRING AN INFLUX OF MOISTURE FURTHER NORTH INTO THE CWA
WEDNESDAY INTO THURSDAY. THIS MOISTURE INFLUX WOULD BE COURTESY OF
THE REMNANTS OF TROPICAL CYCLONE FAY
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR THOUGH SUNSET WITH LIGHT EASTERLY FLOW.
STRATUS LYR XPCT TO ADVECT IN UNDER ONSHORE FLOW. WILL LIKELY ADD
SOME MVFR CIGS TOWARD AFTER 06Z SAT.
EASTERLY FLOW WILL BRING ABOUT SOME LOW CLOUDS SATURDAY MORNING AND
AGAIN LATE SATURDAY NIGHT AND SUNDAY MORNING AT AREAL
TERMINALS...WITH MVFR /LCL IFR/ CIG RESTRICTIONS POSSIBLE. HIGH
PRESSURE WILL REMAIN OFF THE EASTERN SEABOARD OVER THE
WEEKEND...THEN A FRONT WILL SINK SOUTH THROUGH MOST TERMINALS MONDAY
/EXCEPT PERHAPS KCHO WHERE IT MAY STALL NEAR/. THE FRONT MAY LIFT
BACK NORTH TOWARD THE MIDDLE OF THE WEEK.
&&
.MARINE...
EASTERLY FLOW PRESIDES TODAY WITH STRONGEST GRADIENT NEAR THE MID
BAY. FURTHER NORTH...GRADIENT MAY ALLOW WINDS TO BECOME ONSHORE AS
MESOSCALE FORCING BECOMES MORE DOMINATE.
SOUTHERLY FLOW SUNDAY EVENING COULD PRODUCE SMALL CRAFT ADVISORY
CONDITIONS...ESPECIALLY UP THE MAIN CHANNEL OF THE MID BAY. A FRONT
WILL MOVE SOUTH OF THE WATERS MONDAY...LIKELY STALLING JUST SOUTH OF
THE WATERS MONDAY NIGHT INTO TUESDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BPP
NEAR TERM...ROGOWSKI
SHORT TERM...LFR
LONG TERM...BPP
AVIATION...ROGOWSKI/LFR/BPP
MARINE...ROGOWSKI/BPP
AREA FORECAST DISCUSSION
NWS GAYLORD MI
145 AM EDT FRI AUG 22 2008
.AVIATION...A WARM SOUTHERLY WIND WILL CONTINUE TO BRING IN MID
AND HIGH LEVEL CLOUDS WHICH WILL CONTINUE TO THICKEN INTO THE
AFTERNOON. THIS MOISTURE WILL COMBINE WITH DAYTIME HEATING TO
SPARK OFF SCATTERED SHOWERS WITH EMBEDDED RUMBLES OF THUNDER. MOST
OF THIS ACTIVITY IS EXPECTED TO DEVELOP OVER THE HIGHER
TERRAIN...AND MOSTLY BETWEEN THE TAF SITES. WILL HAVE VCSH WITH A
BKN060CB FOR THE AFTERNOON. MUCH OF THE ACTIVITY WILL FADE WITH
NIGHTFALL. VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HRS. SMD
&&
.PREV DISCUSSION... /ISSUED 1014 PM EDT THU AUG 21 2008/
UPDATE...SHORTWAVE TROF TRACKING THROUGH WISCONSIN WITH SCATTERED
LIGHT PCPN ASSOCIATED WITH 310K AREA OF ISENTROPIC ASCENT. FURTHER
SOUTH...ANOTHER AREA OF SHWRS/TSTMS ON TRAILING EDGE OF SHORTWAVE
AND WITHIN DEEPER H8-H7 THETA-E AIRMASS. SFC DWPTS ARE STEADILY
RISING THROUGH THE 50S INTO THE 60S IN SOME AREAS OF NRN MICHIGAN AS
MOISTURE SURGES NORTHWARD. TAMDAR SOUNDINGS/00Z UPR AIR KAPX
SOUNDING SHOW PLENTY OF AMBIENT DRY AIR AND THIS WILL LIKELY KEEP
MOST OF THE PCPN AT BAY FOR NORTHERN MICHIGAN OVERNIGHT. WITH H8
THETA-E AIR SURGING INTO THE AREA OVERNIGHT AND AT LEAST SOME 310K
ADIABATIC OMEGA BRUSHING WESTERN PARTS OF THE CWA...THINK WE
STILL MAY SEE A FEW SHOWERS/SPRINKLES ACROSS THE AREA. I WILL PULL
BACK ON POPS OVERNIGHT...BASICALLY HAVING SCATTERED SHWERS/SPRINKLES
WEST OF INTERSTATE-75 THROUGH MORNING. MID LEVEL LAPSE RATES QUITE
UNIMPRESSIVE OVERNIGHT /4-5 DEGC/KM / BUT AM RELUCTANT TO REMOVE
THEM COMPLETELY GIVEN LIGHTNING STRIKES TO THE SOUTH WITH SURGE OF
DEEER H8 THETA-E AIR. WILL HAVE ISOLATED THUNDER IN THE FORECAST
AFTER 09Z.
JK
PREV DISCUSSION... /ISSUED 357 PM EDT THU AUG 21 2008/
SYNOPSIS...THE REMNANTS OF UPPER LEVEL RIDGING ACROSS NORTHERN
MICHIGAN WILL GIVE WAY OVERNIGHT AS A PRONOUNCED UPPER LOW
LOW/SHORTWAVE ADVANCES THROUGH IOWA/ILLINOIS THIS AFTERNOON AND
EVENTUALLY SLIPS WEST OF THE AREA OVERNIGHT. A STRONG COLD FRONT
WILL THEN MAKE A RUN AT THE AREA LATE SATURDAY BEFORE HIGH PRESSURE
ONCE AGAIN TAKES OVER THROUGH MUCH OF NEXT WEEK.
SHORT TERM (TONIGHT AND FRIDAY)... /ISSUED 357 PM/
PRIMARY FCST CONCERNS FOCUSED ON PRECIP POTENTIAL THRU THE
PERIOD. LATE AFTN SATELLITE/RADAR PICS TELL THE STORY FOR
TONIGHT...AS UPR LOW OVR IA/IL THIS AFTN ON TRACK TO SLIP JUST
WEST OF THE AREA TONIGHT. LATE AFTN REGIONAL RADAR SHOWS FAIRLY
HEALTHY AREA OF PRECIP ADVANCING INTO WI ALONG AXIS OF MODEST
305-310K ISENTROPIC ASCENT/700-500MB QG UPWARD FORCING... WHILE
SECOND AREA TRAILS BACK INTO SOUTHERN INDIANA IN CHANNEL OF STRONG
850-700MB THETA-E ADVECTION. AFOREMENTIONED FEATURES WILL CONTINUE
TO SLIP ALMOST DUE NORTH TONIGHT ON THE BACKSIDE OF STRONG DEEP
LAYER RIDGE OVR THE EAST COAST...WITH PRONOUNCED ISENTROPIC
UPGLIDE/DOWNGLIDE COUPLET OVR LAKE MI ARGUING TO A SHARP CUTOFF TO
PRECIP CHANCES OVR THE APX CWA. AT THIS JUNCTURE...APPEARS
SUFFICIENT LIFT WILL BE IN PLACE TO PROVIDE SCATTERED SHOWERS FOR
THE FAR WESTERN CWA AFTER 03Z...THOUGH OVERALL MOISTURE PROFILES
SUB-700MB RATHER UNIMPRESSIVE (I.E. DRY DOWNSTAIRS). FARTHER
EAST...DIFFICULT TO FORESEE ANY SIGNIFICANT PRECIP CHANCES THRU
THE NIGHT...THOUGH NOT COMPLETELY ZERO GIVEN HEALTHY SHOT OF
THETA-E ADVECTION ARRIVING AFTER 06Z. THUNDER CHANCES NOT TERRIBLY
IMPRESSIVE WITH SCANT MID LEVEL LAPSE RATES (THANKS TO SATURATION)
THOUGH INFLUX OF MOISTURE DOWN LOW (TIPPING OF LOW LEVEL LAPSE
RATES UPWARD) COULD PROVIDE A FEW RUMBLES AS EVIDENCED BY UPSTREAM
NLDN PLOTS THIS AFTN. TEMPS MUCH WARMER WITH ONGOING WARM
ADVECTION... MAINLY LOW/MID 60S.
FOR FRIDAY...TRICKY PRECIP FCST. AIRMASS SHOULD BE BASICALLY THE
COMPLETE OPPOSITE OF THAT IN PLACE THE PAST FEW DAYS...WITH UPSTREAM
DEW POINTS WELL INTO THE 60S (IF NOT NEAR 70) GLIDING NORTH TONIGHT.
BASIC PROBLEM FOR ADDITIONAL CONVECTIVE INITIATION WILL BE LACK OF
DEFINED TRIGGER MECHANISM AS OVERNIGHT WAVE/QG SUPPORT SHEARS OUT
INTO ONTARIO AND LOW LEVEL FLOW WAY TOO STRONG FOR ANY LAKE
COMPONENT TO WIND. HOWEVER...STRONGLY BELIEVE ADDITIONAL CONVECTIVE
WILL FIRE GIVEN SIMPLE AIRMASS ARGUMENTS...NAMELY PROGGED UPTICK IN
850-700MB MOISTURE TRANSPORT ON THE BACKSIDE OF SPRAWLING EAST COAST
HIGH AND LOCALIZED FORCING ON THE HIGHER TERRAIN. UPSTREAM RADARS
ALREADY BEAR THIS OUT WITH LONG AXIS OF CONVECTING STRUNG OUT FROM
LOUISIANA INTO SOUTHERN MISSOURI AND DIFFICULT TO IGNORE NAM/SREF
PROGS OF RATHER HIGH POPS. SEVERE POTENTIAL RATHER MINIMAL WITH ONLY
MODEST LAPSE RATES (TOO WARM ALOFT) AND SCANT WIND FIELDS. EVEN WITH
EXPECTED BETTER CLOUD COVER...SHOULD HAVE LITTLE TROUBLE REACHING
THE 80S MOST SPOTS WITH BETTER SHOT OF WARM ADVECTION AHEAD OF
APPROACHING COLD FRONT.
LAWRENCE
LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)... /ISSUED 357 PM/
A LOT OF THIS FORECAST RESTS ON WHAT FAY DOES OR DOESN`T
DO, AS A TROPICAL SYSTEM CAN PUT A HALT ON THE MOVEMENT OF THE
SYSTEMS COMING ACROSS THE CONTINENT.
FRIDAY NIGHT...INITIAL CONVECTION WITH 500 MB SHORTWAVE TROUGH LOOKS
TO BE SHEARING OUT, WITH THE COLD FRONT BEARING DOWN ON THE GREAT
LAKES. THE COLD FRONT BEGINS TO REALLY BRING IN THE CHANCE FOR RAIN
SHOWERS AND THUNDERSTORMS.
SATURDAY...THE FRONT PASSES THROUGH THE STATE DURING THE DAY. THE
FRONT LOOKS FAIRLY STRONG WITH THE THERMAL PACKING, REINFORCED BY
THE 500 MB WAVE. SO TRIED TO SPLIT THE DAY TO SHOW THE FRONT PASSING
THROUGH INSTEAD OF HAVING ONE FULL DAY OF RAIN.
SATURDAY NIGHT...THE FRONT LEAVES THE REGION. THE SUBSIDENCE BEHIND
THE FRONT LOOKS PRETTY STRONG AS THE SFC HIGH BUILDS INTO THE
WESTERN GREAT LAKES PRETTY QUICKLY. SO WILL GO WITH RAPIDLY LOWERING
CHANCES FOR PRECIPITATION.
SUNDAY...SUNDAY MORNING THE A SECOND 500 MB SHORTWAVE PUSHES INTO
THE REGION. THE GFS, ECMWF, AND NAM ALL HAVE THE 850-700 MB MOISTURE
RH NEAR 70% WITH THE +3C OR SO 850 MB TEMPERATURE. WITH THE NW FLOW
AND THE QG FORCING, WOULD EXPECT AT THE LEAST, SPRINKLES AND
SELF-DESTRUCT SUNSHINE. HAVE SOME VERY SMALL CHANCE FOR SPRINKLES IN
THE EVENING, THE THINGS DRY OUT AGAIN.
EXTENDED (MONDAY THRU THURSDAY)...WITH THE SLOW MOVEMENT OF FAY,
WILL HAVE TO PUT IN THE CAVEAT THAT THIS FORECAST MAY NOT PAN OUT
DUE TO THE MODELS INABILITY TO HANDLE THE TROPICAL SYSTEMS. WITH
THAT SAID, IF FAY STAYS SUPPRESSED TO THE SOUTH THEN...MONDAY STRONG
HIGH PRESSURE MOVES INTO THE GREAT LAKES, AND DRIES THINGS OUT. THIS
LOOKS LIKE IT WOULD ALLOW TEMPERATURES TO REBOUND. TUESDAY, THE SFC
HIGH WOULD CONTINUE TO CONTROL THE WEATHER. WEDNESDAY, TEMPERATURES
GET BACK TO 80 DEGREES AS THE HIGH MOVES TO THE EAST AND THE RETURN
FLOW BEGINS TO WARM THINGS. THURSDAY, WE GET INTO A SIMILAR SCENARIO
LIKE WE HAVE TODAY, FRONT IN THE ROCKIES AND CENTRAL PLAINS WITH
TROPICAL MOISTURE MOVING INTO THE REGION AND THE REMNANTS OF FAY
MOVING INTO THE TENNESSEE VALLEY. WILL ALLOW FOR THE CHANCE OF
THUNDERSTORMS, BUT IT WILL MORE THAN LIKE BE DRY OVER MOST OF
NORTHERN MICHIGAN.
LUTZ
MARINE... /ISSUED 357 PM/
NO CONCERNS THROUGH FRIDAY...THOUGH WINDS WILL BE ON THE INCREASE
OVER THE WATER IN ADVANCE OF AN APPROACHING COLD FRONT. DECENT
SHOT AT SMALL CRAFT CONDITIONS FRIDAY NIGHT INTO SATURDAY AS FLOW
CRANKS UP JUST AHEAD OF THE FRONT.
LAWRENCE
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
133 AM EDT FRI AUG 22 2008
.UPDATE...
WATER VAPOR LOOP SHOWS SHORTWAVE LIFTING NORTH THROUGH ERN IA AND
SRN WI. RADAR LOOP REVEALS SCATTERED RETURNS ACROSS MUCH OF NRN WI
INTO FAR WRN AND SCNTRL UPR MI AHEAD OF THIS SHORTWAVE ALTHOUGH SFC
OBS INDICATE RAIN REACHING THE GROUND IS SOMEWHAT SPOTTY.
THE DRY EASTERLY FLOW OVER THE REGION AS NOTED IN THE VERY DRY LOW
LEVELS OFF THE RAOB AND TAMDAR SOUNDINGS THIS EVENING CAN BE BLAMED
FOR THE DIMINISHED APPEARANCE OF SHOWERS ON RADAR AND THUS SPOTTY
PCPN OBSERVED AT THE SFC. MODELS INDICATE THAT FORCING ASSOC WITH
SHORTWAVE WILL WEAKEN OVERNIGHT SO IF ANYTHING WOULD EXPECT SHOWERS
TO MAYBE DIMINISH SOME LATE TONIGHT. THUS...HAVE DECIDED TO TRIM
BACK SHOWER COVERAGE FROM NUMEROUS TO SCATTERED OVERNIGHT INTO FRI
MORNING OVER WEST AND CENTRAL COUNTIES WITH JUST ISOLD COVERAGE IN
THE EAST.
&&
.SYNOPSIS...
UPPER LEVEL RIDGE EXTENDS FROM THE MID ATLANTIC COAST INTO JAMES
BAY. UPPER LOW OVER THE SOUTHERN STATES HAS QUICKLY MOVED NORTH WITH
EDGE OF RAIN NOW REACHING WINONA MN TO LA CROSSE WI. AREA OF
STEADIER RAIN REACHES AS FAR SOUTH AS SOUTHEAST IA INTO NORTHERN
IL. FARTHER SOUTH INTO MO/IL/AR ARE ISOLD/SCT TSRA BUBBLING UP IN A
HUMID AIRMASS WITH TD IN THE LWR 70S. IN ADDITION TO THE WELL
DEFINED SHORTWAVE WITH A SUBTLE BAROCLINIC LEAF SIGNATURE OVR UPR
MISSISSIPPI VALLEY...OTHER SHORTWAVES ARE SHOWING UP OVR SOUTHERN MO
AND SOUTHERN AR. THESE FEATURES AFFECT UPR LAKES THROUGH TOMORROW...
THEN THE BROAD TROUGH OVR PACIFIC NW INTO WESTERN CANADA PLOWS INTO
THE REGION TO START THE WEEKEND. SOME RAIN POSSIBLE ON FRI NIGHT...
BUT MAIN IMPACT WITH BE GUSTY WINDS AND COOLER TEMPS FOR LATER
SATURDAY INTO SUNDAY.
&&
.SHORT TERM (TONIGHT AND FRIDAY)...
SEEMS LIKE WE ARE ON TRACK FOR SOME MUCH NEEDED RAINFALL. MAIN
CHANCE OF RAIN IS MIDNIGHT TONIGHT THROUGH MID MORNING FRIDAY.
SHORTWAVE AND AREA OF H85-H5 DEEP MOISTURE/BROAD LIFT SHOULD BEGIN
AFFECTING SOUTHWEST CWA WITH SHOWERS AROUND 00Z AND NORTHERN CWA BY
06Z. ADDED LIFT COMES VIA RRQ LIFTING IN JET STREAK OVR ONTARIO.
EARLIER SOUNDINGS SHOWED FAIRLY LOW DEWPOINT DEPRESSIONS FM SFC-H8
AT SAW/RHI. ONLY DRY AIR WAS IN THE MID LEVELS...BUT GIVEN LARGE
SCALE LIFTING...THIS SHOULD BE ERODED QUICKLY AS HAS BEEN CASE
UPSTREAM ALL DAY. UPSTREAM OBS INDICATE A 10-12 HR DURATION OF
RAIN...FAIRLY LIGHT TO START...BUT INTENSIFYING FOR A TIME AFTER
MIDNIGHT. COULD SEE UP TO A QUARTER INCH OF RAIN...BUT LACK OF
CONVECTION SHOULD PROHIBIT MUCH MORE THAN THAT. STEADY RAIN ENDS
TOMORROW MORNING...BUT LOW CLOUDS REMAIN TRAPPED BLO INVERSION.
COULD NOT EVEN COUNT OUT SOME FOG IN NCNTRL WITH UPSLOPE SOUTH
WINDS. EVENTUALLY...SKIES SHOULD PARTIALLY CLEAR IN AFTN. STRONG
WINDS JUST ABOVE INVERSION WILL EVENTUALLY RESULT IN A GUSTY
SOUTHERLY SFC WIND IN THE AFTN. ALSO OF NOTE WILL BE THE HIGHER
TD...IN THE MID-UPR 60S...MAKING IT FEEL QUITE HUMID. TEMPS SHOULD
RISE TOWARD LWR 80S BUT IT MAY BE A SITUATION WITH LATE DAY HIGHS
GIVEN THE CLOUDS IN THE MORNING.
WITH SIMILAR T/TD REGIME COMPARED TO THAT SEEN IN LWR MISSISSIPPI
VALLEY TODAY...THERE IS SOME POTENTIAL FOR CONVECTION TO RE-DEVELOP
OVR CWA IN THE AFTN. MAIN NEGATIVE FACTOR IS H85-H65 CAPPING SEEN ON
NAM/GFS SOUNDINGS WHICH IS BENEATH THE DRY SLOT SEEN ON WV LOOP THIS
AFTN FM CNTRL ONTARIO INTO WRN MN AND SOUTH INTO NEB/KS. KEPT LOW
CHANCE POPS IN THE GRIDS IN CASE SOME CONVECTION DEVELOPS...BUT BEST
CHANCES APPEAR IN THE FAR SOUTH AND EAST CLOSER TO LINGERING HIGHER
H85-H7 RH AND NEAR THE MOST LIKELY TRACK OF ANY SHORTWAVES MOVING UP
IN SW FLOW ALOFT.
.LONGER TERM (FRIDAY NIGHT ONWARD)...
TROUGH ACROSS THE NORTHERN PLAINS AFFECTS THE AREA FRI NIGHT AND
SAT. NAM TAKES THE UPPER LEVEL TROUGH AND A CLOSED 500 MB LOW TO THE
NORTH OF AREA WITH THE CLSOED LOW GOING FROM LAKE WINNIPEG 00Z SAT
TO NORTHERN ONTARIO 00Z SUN TO EAST OF HUDSON BAY IN WESTERN QUEBEC
00Z MON. NAM SHOWING 850-500 MB Q-VECTOR CONVERGENCE FRI NIGHT ALONG
WITH A NARROW RIBBON OF MOISTURE WHICH IS ALONG A COLD FRONT. BOTH
PARAMETERS MOVE ACROSS THE CWA FRI NIGHT AND ACROSS THE ERN CWA SAT
MORNING BEFORE THE MOISTURE MOVES OUT BY 00Z SUN. GFS SIMILAR TO THE
NAM AS WELL WITH DYNAMICS AND MOISTURE MOVING THROUGH FRI NIGHT AND
SAT MORNING. NOT REAL IMPRESSED WITH POP CHANCES WITH BAND OF
MOISTURE NARROW ALONG THE FRONT. WILL CONTINUE TO GO CHANCE POPS
UNTIL IT BECOMES CLOSER TO THE EVENT TO SEE HOW MUCH CONVECTION
BREAKS OUT WITH THE COLD FRONT. PUT SPRINKLES IN THE NORTH AND EAST
FOR SUN BASED ON COLD 850 MB TEMPERATURES...UPPER TROUGH AND A BIT
OF WRAPAROUND MOISTURE IN THE AREA AND LAKE ENHANCEMENT COULD HAPPEN
AS WELL. NAM AND GFS 850 MB TEMPERATURES DROP TO 1C TO 3C AT 18Z SUN
AND THEN TEMPERATURES MODIFY. LAKE TEMPERATURES ARE AROUND 13C-16C
OVER THE LAKE...SO ENOUGH DELTA-T TO PUT SPRINKLES AND DEFINITELY
SOME LAKE EFFECT CLOUDS INTO THE FORECAST FOR SUN AS WELL. DID NOT
MAKE TOO MANY CHANGES OTHER THAN ABOVE TO GOING FORECAST. SUN LOOKS
COOL WITH HIGHS STRUGGLING TO GET OUT OF THE 60S IN MOST PLACES.
IN THE EXTENDED...GFS...ECMWF AND CANADIAN SHOW A 500 MB TROUGH AXIS
EAST OF THE UPPER GREAT LAKES 00Z MON WITH SFC HIGH PRESSURE IN THE
AREA THEN. 500 MB RIDGING MOVING IN BY 00Z TUE ONWARD. LOOKS DRY FOR
THE EXTENDED WITH SYSTEMS STAYING WEST AND SOUTH OF THE AREA.
FOLLOWED THE 00Z ECMWF FOR THIS FORECAST AND KEPT REMAINS OF FAY OUT
OF THE AREA THU WITH A 500 MB TROUGH REMAINING STILL TO THE WEST
THEN. TEMPERATURES LOOK TO STAY NEAR NORMAL TO SLIGHTLY ABOVE
NORMAL. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
&&
.AVIATION (FOR THE 06Z TAF ISSUANCE)...
RADAR LOOP INDICATES SHOWERS HAVING A HARD TIME FIGHTING THROUGH DRY
LOW LEVEL AIR IN PLACE OVER UPR MI. THUS...HAVE DECIDED TO FOLLOW
MORE CLOSELY WITH NEW MODEL GUIDANCE AND DELAY ARRIVAL OF SHOWERS
AND IN TURN NOT GO AS PESSIMISTIC ON VSBY/CLOUD COVER. PLAN ON MVFR
CIGS WITH LIGHT RAIN SHOWERS REACHING BOTH TAF SITES AFTER 12Z.
EXPECT MVFR CLOUDS DECK TO PERSIST THROUGH EARLY AFTERNOON AND THEN
BREAK OUT OR LIFT TO VFR WITH INCREASED DIURNAL MIXING. EXPECT SOUTH
WIND GUSTS TO REACH OR EXCEED 25 KNOTS BY LATE MORNING...ESPECIALLY
AT KSAW IN FAVORED DOWNSLOPE DIRECTION. INCLUDED A PROB30 FOR SHOWER
AT KCMX BY 04Z AS FRONTAL SYSTEM APPROACHES FROM THE WEST.
INCLUDED LLWS AT BOTH TAF SITES UNTIL AFTER SUNRISE THIS MORNING AS
LOW LEVEL JET MAX MOVES THROUGH THE REGION.
&&
.MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)...
LOW PRES ORGANIZING OVER SOUTHERN MANITOBA BY FRI MORNING AND HIGH
PRES JUST OFF THE E COAST WILL RESULT IN SRLY WINDS PREVAILING OVER
MUCH OF LAKE SUPERIOR. WINDS STRENGTHEN TONIGHT THRU FRI NIGHT AS
THE LOW LIFTS NE AND A COLD FRONT APPROACHES. WIND GUSTS SHOULD
INCREASE TO AROUND 25KT...WITH GUSTS TO AROUND 30KT POSSIBLE FRI
NIGHT JUST AHEAD OF THE APPROACHING COLD FRONT. AS IS TYPICAL FOR
SRLY FLOW...THE STRONGEST WINDS ARE EXPECTED TO OCCUR OVER THE E
HALF OF LAKE SUPERIOR. COLD FRONT CROSSES LAKE SUPERIOR ON SATURDAY.
IN THE WAKE OF THE FRONT...EXPECT W TO NW WINDS OF 15-25KT WITH
GUSTS TO 30 KT. WINDS WILL THEN DIMINISH FROM W TO E BY SUN AS HIGH
PRES BUILDS INTO THE UPPER LAKES. WITH HIGH PRES OVER THE AREA...
LIGHT WINDS ARE EXPECTED MON AND TUE.
&&
$$
SYNOPSIS...JLA
SHORT TERM...JLA
AVIATION...VOSS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
342 AM CDT FRI AUG 22 2008
.DISCUSSION...
FRONTAL BOUNDARY PUSHING INTO THE AREA TODAY IS STILL THE PRIMARY
FORECAST CONCERN. HOW WARM WILL IT GET AND HOW TO HANDLE CHANCE OF
PCPN ARE THE TWO BIGGEST PROBLEMS.
UPPER AIR CHARTS FROM 00Z SHOWED DECENT MOISTURE AT 850 MB FROM THE
CNTRL GULF COAST ACROSS AR AND INTO KS. POCKET OF WARM AIR NOTED
FROM UT...WY AND WRN CO INTO WRN SD...WITH TEMPERATURES AT 850 MB
30 C OR HIGHER. WARM AIR WAS ALSO IN PLACE AT 700 MB. KOAX SOUNDING
LAST EVENING HAD FAIRLY COOL MID LEVEL TEMPS...BUT THIS SHOULD BE
CHANGING FRIDAY. BEST HEIGHT FALLS AT 500 MB WERE OVER MT OR ALONG
THE CANADIAN BORDER. MODELS SHOW THIS AREA OF HEIGHT FALLS MOVING
ACROSS ND AND SRN MANITOBA BY THIS EVENING THEN INTO WRN ONTARIO
TONIGHT. NO HEIGHT FALLS ARE FORECAST BY THE 00Z GFS OR NAM ACROSS
NE OR IA. AT 300 MB...THERE WAS A NICE JET SEGMENT OF 120 KTS (VIA
AN AIRCRAFT REPORT) NEAR THE WA/OR/ID BORDER. THIS WILL TRANSLATE
ACROSS THE NRN PLAINS TODAY AND INTO CANADA ON SATURDAY. SURFACE
ANALYSIS AT 08Z SHOWED A COLD FRONT STRETCHING FROM CNTRL ND INTO
NWRN NE. A LOW PRESSURE CENTER OF AROUND 993 MB WAS NOTED OVER SD
SW OF KMBG. STRONG NW WINDS WERE OCCURRING BEHIND THE FNT...WITH
KRAP GUSTING TO 51 KTS.
TODAY...DID NOT MAKE MANY CHANGES TO THE PREVIOUS FORECAST. THERE
WERE SOME VERY LIGHT RAIN AMOUNTS YESTERDAY OVER PARTS OF SERN NE
AND SWRN IA...BUT IN GENERAL THE LOCAL AREA HAS BEEN PRETTY DRY
THE LAST 7-10 DAYS. 00Z NAM SHOWED TEMPS REACHING THE LOWER 90S
OR HIGHER AHEAD OF THE FRONT THIS AFTERNOON. BOOSTED HIGHS JUST A
LITTLE AHEAD OF THE FRONT FOR TODAY. MODEL SHOW THE CAP HOLDING
INTO MID AFTERNOON BEFORE WEAKENING. LEFT SOME 20-30 PERCENT POPS
IN FOR THE 20Z TO 00Z PERIOD...BUT CHANCES LOOK BETTER AFTER 00Z.
AGREE WITH SPC THAT SOME ISOLD SEVERE STORMS ARE POSSIBLE. SHEAR
IS NOT IMPRESSIVE. 00Z BUFKIT SOUNDINGS SHOWED CAPE INCREASING TO
AROUND 2500 J/KG AND LIFTED INDICES AROUND -5. FREEZING LEVEL IS
EXPECTED TO BE FAIRLY HIGH FOR HAIL AND STORMS SHOULD BE OF THE
MULTICELL VARIETY. MAIN THREAT SHOULD BE GUSTY WINDS...BUT SOME
HAIL (MOSTLY SMALL) IS NOT OUT OF THE QUESTION.
AS MENTIONED EARLIER...CHANCE OF PCPN LOOKS BETTER FOR TONIGHT AS
COLD FRONT MOVES SOUTH AND MID LEVEL TEMPS COOL. NAM IS SLIGHTLY
SLOWER WITH SWD PUSH OF THE FRONT COMPARED TO THE GFS AND FOR NOW
PREFER THE NAM SOLUTION. HIGH PRESSURE WILL BUILD OVER THE NRN
PLAINS AND PARTS OF THE CNTRL PLAINS ON SATURDAY. HELD ONTO THE
LOW POPS ACROSS OUR SRN ZONES FROM PREVIOUS FORECAST FOR THE NEXT
FEW DAYS. CHANCES MAY IMPROVE SUNDAY NIGHT INTO MONDAY NIGHT AS
HIGH PRESSURE MOVES EWD AND S/SE RETURN FLOW DEVELOPS IN THE LOW
LEVELS WITH NW FLOW ALOFT.
FARTHER OUT...THE 00Z GFS AND ECMWF SHOW A FAIRLY STRONG TROUGH
MOVING THROUGH THE NRN AND CNTRL PLAINS DURING THE MID PART OF THE
WEEK. GFS IS SLIGHTLY FASTER THAN ECMWF. NORMALLY MY CONFIDENCE
LEVEL WOULD BE AT OR A LITTLE ABOVE NORMAL WITH A MID WEEK PCPN
EVENT...BUT HPC SAYS THERE IS A LARGE SPREAD IN BOTH THE GFS AND
ECMWF ENSEMBLE MEMBERS.
&&
.AVIATION...
FOR TAF SITES KOMA/KLNK/KOFK THROUGH 23/06Z.
CDFNT PUSHING INTO NW NEBRASKA AT 08Z WITH MODELS MOVING IT INTO
THE KOFK AREA AROUND 18Z AND KLNK AND KOMA AROUND 00Z. GENERALLY
VFR CONDITIONS EXPECTED THROUGH THE PERIOD BUT A SMALL CHANCE OF
TSTMS AT KOMA AND KLNK 22Z-02Z IN ASSOCIATION WITH THE FRONT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DISCUSSION...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
942 AM EDT FRI AUG 22 2008
.DISCUSSION...
SURFACE ANALYSIS SHOWS A RIDGE OF HIGH PRESSURE EXTENDING FROM NEW
ENGLAND TO THE SOUTHERN APPALACHIANS...RESULTING IN A DIFFLUENT
FLOW OVER THE TENNESSEE VALLEY. ACARS SOUNDINGS AND MODEL FORECAST
SOUNDINGS CONTINUE TO SHOW A STABLE AIR MASS THAT WILL INHIBIT
CONVECTION THIS AFTERNOON. THE MODELS PROJECT SOME RAIN FROM AN
OUTER RAIN BAND OF T.S. FAY APPROACHING OUR EXTREME SW NC COUNTIES
THIS EVENING...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH YET TO ADD ANY
MENTION OF PRECIP. SOME THIN CIRRUS SHOULD NOT PREVENT TEMPS FROM
REACHING FORECAST HIGHS IN THE UPPER 80S TO LOWER 90S IN MOST
SPOTS.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
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