AREA FORECAST DISCUSSION
NWS MIAMI FL
1015 AM EDT SAT SEP 22 2007
.UPDATE...THE MIAMI SOUNDING THIS MORNING SHOWS EAST WINDS IN THE
LOW LEVELS BECOMING SE TO S IN THE MID LEVELS. MEANWHILE...THE
TAMPA SOUNDING CONTINUES TO SHOW A S-SW WIND FLOW IN THE LOW TO
MID LEVELS. AS MENTIONED BELOW...THIS WILL LEAD TO MASS
CONVERGENCE THIS AFTERNOON...BUT MAINLY OVER INTERIOR/GULF COASTAL
SECTIONS AS THE EAST FLOW IS ALREADY SETTING IN PRETTY GOOD ACROSS
THE ATLANTIC COAST. THE LOW LEVEL WINDS ON THE MIA SOUNDING AND
ACARS DATA SHOW ESE WINDS AT AROUND 15 KT A FEW THOUSAND FEET UP.
THE NAM-WRF SHOWS IT STAYING COMPLETELY DRY ACROSS THE EAST COAST
METRO AREAS TODAY...BRINGING THE ATLANTIC SEA BREEZE QUICKLY INLAND
AND KEEPING THE CONVECTION THIS AFTERNOON ACROSS INTERIOR/GULF
COASTAL AREAS. THIS MAY BE A BIT OVERDONE...BUT I DO LIKE ITS IDEA
AS THE ATLANTIC RIDGE IS BUILDING IN SLOWLY FROM THE EAST.
THUS...TRIMMED POPS TO SCATTERED CATEGORY EAST COAST AND KEPT
NUMEROUS INTERIOR/GULF COAST. NO OTHER SIGNIFICANT CHANGES WILL BE
MADE THIS MORNING. /DG
&&
.PREV DISCUSSION... /ISSUED 454 AM EDT SAT SEP 22 2007/
DISCUSSION...
THE LATEST OBSERVATIONS AND GUIDANCE INDICATE THAT A MORE EASTERLY
LOW LEVEL FLOW IS WORKING ITS WAY INTO AT LEAST THE ATLANTIC
WATERS AND INTO THE EASTERN PORTION OF SOUTH FLORIDA. OBSERVATIONS
AT FOWEY ROCKS AND SOME EAST COAST SITES INDICATE THIS. THIS IS
CONSISTENT WITH A WEAK SURFACE RIDGE FORECAST TO BUILD INTO THE
REGION TODAY. IN ADDITION SOME DRIER LOW TO MID LEVEL AIR IS
BEGINNING EXTEND INTO THE BAHAMAS. HOWEVER...SOUTHWESTERLY LOW
LEVEL FLOW SHOULD CONTINUE TO DOMINATE ACROSS THE LOCAL GULF
WATERS AND GUIDANCE INDICATES THAT LOW LEVEL MASS CONVERGENCE
SHOULD PREVAIL IN THIS REGION TODAY AND RECENT SATELLITE IMAGERY
SEEMS TO INDICATE THIS. GIVEN ALL THIS...THE FORECAST SOUNDINGS
INDICATE THAT THE AFOREMENTIONED DRIER AIR MAY NOT MAKE IT FAR
ENOUGH EAST AND THE PWATS TODAY ACROSS THE PENINSULA SHOULD STILL
BE OVER TWO INCHES. PLUS THERE WILL STILL BE SYNOPTIC SCALE ASCENT
IN THE MID LEVELS AND DIVERGENCE ALOFT. AS THE SKIES ARE STARTING
TO CLEAR OVER SOUTH FLORIDA NOW...GIVEN THE FACTORS ABOVE AND DAY
TIME HEATING NUMEROUS SHOWERS AND THUNDERSTORMS ARE FORECAST FOR
THIS AFTERNOON MAINLY ACROSS THE PENINSULA...WITH THE EASTERLIES
BUILDING BACK IN THIS SHOULD ALSO FAVOR ACTIVITY OVER THE WESTERN
HALF OF SOUTH FLORIDA LATER THIS AFTERNOON AND EVENING. PERIODS OF
LOCALLY HEAVY RAINFALL ARE CERTAINLY POSSIBLE.
GUIDANCE INDICATES SOME OF THAT DRIER LOW TO MID LEVEL AIR MAKING
IT INTO THE REGION TONIGHT INTO SUNDAY AND WITH THE EASTERLIES
STARTING TO PREVAIL SHOULD START TO SEE A RETURN TO MORE DIURNAL
THUNDERSTORM ACTIVITY ON SUNDAY AND IMPROVING AS THE WEEK PROGRESSES.
AVIATION...
VFR CONDITIONS WITH GRADUALLY CLEARING SKIES THROUGH THE EARLY
MORNING HOURS. WILL INTRODUCE VCTS ALL TERMINALS BY 14Z AND EAST
TERMINALS WILL PRIMARILY SEE ONLY VCSH WITH EAST COAST SEABREEZE
PUSHING MOST ACTIVITY INLAND BY MID AFTERNOON. APF MAY SEE THE
MOST ACTIVITY AND GOING INTO THE EARLY EVENING HOURS.
MARINE...
FAIRLY TRANQUIL MARINE CONDITIONS EXPECTED...WITH OFF SHORE
ATLANTIC AND GULF WATERS POSSIBLY HAVING SEAS IN THE RANGE OF 2 TO
4 FEET WITH WINDS IN THE 10 TO 15 KNOT RANGE.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
LONG TERM...60/BD
SHORT TERM/AVIATION...18/GR
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
335 AM CDT SAT SEP 22 2007
.DISCUSSION...
315 PM CDT
VIGOROUS MID LVL TROF CONTINUES TO PUSH ACROSS THE UPPER MIDWEST
THIS AFTN...WITH SFC LOW LIFTING INTO WESTERN ONTARIO AND COLD FRONT
TRAILING FROM KMSP TO KOMA. GUSTY SOUTH/SOUTHWEST WINDS ACROSS FCST
AREA IN TIGHTENING GRADIENT AHEAD OF SFC FRONT/TROF...WITH STEEP
LLVL LAPSE RATES HELPING TO MIX 20-30 MPH WINDS DOWN TO SFC TO
MAINTAIN WINDY CONDITIONS FOR REMAINDER OF AFTN HRS.
NARROW AXIS OF MID-UPR 60S SFC DWPTS IMMEDIATELY AHEAD OF FRONT
EXPECTED TO LIMIT CONVECTIVE THREAT TO VCNTY OF FRONTAL ZONE...WITH
RECENT ACARS ASCENT SOUNDINGS FROM KPIA/KORD INDICATING LLVL PARCELS
STRONGLY CAPPED EAST OF MISSISSIPPI RIVER THIS AFTN. SHORT RANGE
MODELS REMAIN FAIRLY CONSISTENT IN DEPICTING NARROW BAND OF
CONVECTION DEVELOPING ALONG/AHEAD OF COLD FRONT ACROSS IA BY LATE
AFTN...MOVING TOWARD FCST AREA THIS EVENING BEFORE DIMINISHING
OVERNIGHT. WITH NARROW LLVL INSTABILITY AXIS...AND INCREASINGLY
UNFAVORABLE DIURNAL TIMING FOR CONVECTION AS FRONT PUSHES EAST AFTER
SUNSET THIS EVENING...IDEA OF POPS HIGHEST FAR WEST AND DECREASING
TO THE EAST MAINTAINED. WRF/RUC/GFS KEEP SOUTHEAST HALF OF CWA
DRY...AND HARD TO ARGUE WITH QPF TRENDS. THUS HAVE CARRIED CHC POPS
FOR LATE EVENING/AROUND MIDNIGHT MAINLY NORTHWEST OF ROUGHLY
STREATOR TO CHICAGO LINE. WRF TIMING INDICATES COLD FROPA AT KRFD
AROUND 10/11 PM...KORD MIDNIGHT/1 AM...THEN EXITING SOUTHEASTERN
FCST AREA BEFORE SUNRISE WITH WINDSHIFT TO NW. SPC STILL HAS
NORTHWEST CWA IN DAY 1 SLGT RISK. 40-45 KTS 0-6KM SPD SHEAR EXISTS
AND STRONG MID LVL WIND FIELD COULD POTENTIALLY SUPPORT SOME
DAMAGING WIND GUSTS IF ORGANIZED UPDRAFTS ARE ABLE TO DVLP/MAINTAIN
INTO WESTERN CWA DURG EVE HOURS.
S/WV CONTINUES OFF TO THE EAST ON SATURDAY...WITH MID LVL RIDGE
BUILDING OVERHEAD AND SFC HIGH PRESSURE DVLPG EAST ACROSS FCST AREA.
COOLER AND LESS HUMID AFTER NEAR RECORD TEMPS TODAY...THOUGH STILL
AROUND/JUST ABOVE AVERAGE TEMPS IN MID/UPR 70S MOST AREAS WITH FULL
SUNSHINE EXPECTED. LGT WINDS BECOMING EAST DURG AFTN AS SFC HIGH
SLIDES EAST AND LAKE BREEZE PROVIDES SOME MINOR COOLING. PROGRESSIVE
UPPER PATTERN CONTINUES HOWEVER...WITH SFC HIGH PUSHING OFF TO THE
EAST ON SUNDAY AND RETURN FLOW DVLPG BY SUNDAY NIGHT AS UPPER TROUGH
AMPLIFIES OVER WESTERN CONUS. TEMPS CLIMB BACK INTO 80S SUN/MON AS
SFC TROF DVLPS ACROSS NRN PLAINS AHEAD OF UPPER SYSTEM.
NEXT PRECIP POTENTIAL APPEARS TO ARRIVE MONDAY AS UPPER TROUGH
APPROACHES. SOME MODEL DIFFERENCES IN HANDLING OF SMALLER SCALE
DETAILS INCLUDING MINOR LEAD S/WV WHICH LIFTS NORTHEAST MON AFTN.
HOWEVER...INCREASINGLY MOIST LLVLS AND APPROACH OF COLD FRONT MONDAY
NIGHT SUPPORT CHC POPS. TUESDAY AND BEYOND...ECMWF BRINGS ADDITIONAL
S/WV INTO TROF AND THUS IS NOTABLY SLOWER WITH PROGRESSION OF LARGER
SCALE UPPER TROUGH AND THEREFORE SFC FRONT. MORE SUPPORT FOR A
FASTER PROGRESSION FROM NCEP ENSEMBLES...GFS AND CANADIAN. HAVE
BASED EXTENDED FCST ON THIS SOMEWHAT FASTER PROGRESSION...WITH FRONT
MOVG THROUGH DURG DAY TUESDAY. HAVE KEPT CHC POPS TUES ACROSS CWA
WITH FROPA...AND LINGERING INTO TUES NGT FAR SOUTHEAST AS FRONT
SLIDES INTO CENTRAL IL/IND. RETURN TO SEASONABLY MILD TEMPS...70S
WED-FRI AS NO BIG SLUG OF COLD AIR APPEARS READY TO INVADE WITH
UPPER FLOW SOMEWHAT ZONAL THROUGH END OF NXT WEEK.
RATZER
&&
.AVIATION...
1205 AM CDT
RE 06Z TAFORS...COLD FRONT AT 05Z EXTENDS FROM SOUTHERN LAKE MI
SOUTHWESTWARD THROUGH NORTHEASTERN AND WEST CENTRAL IL. SHOWERS
AHEAD OF THE FRONT FIZZLED OUT AS THE MOVED INTO NORTHEASTERN IL
DURING THE MID AND LATE EVENING. A FEW POST FRONTAL SHOWERS CONTINUE
ACROSS THE FAR SOUTHEASTERN CORNER OF WI INTO NORTHEASTERN IL
ALIGNED WITH THE MID LEVEL TROUGH AXIS. EXTRAPOLATION FROM RADAR AND
SATELLITE LOOPS SHOW THE SCATTERED SHOWERS TO BE EXITING THE CHI
VICINITY AROUND 07Z WITH CLEARING OF THE PREDOMINANTLY 7-10K FT
CEILINGS AS STRONG SUBSIDENCE AND DRYING RAPIDLY OVERSPREAD THE AREA
AS THE MID AND UPPER TROUGHS PASS BY. QUICK PRESSURE RISE WITH COLD
FRONT PASSAGE CREATING SOME GUSTINESS BUT OBSERVATIONS FROM UPSTREAM
SHOW A RAPID DROP OFF IN WIND SPEEDS AS SURFACE DECOUPLES UNDER HIGH
PRESSURE RIDGE BUILDING ACROSS IA INTO SOUTHWEST WI AND NORTHWEST IL
DESPITE PROFILER AND 88D WINDS SHOWING NORTH TO NORTHWEST WINDS OF
35 TO 50KTS AT 925 AND 850MB. RIDGING SURFACE AND ALOFT DURING THE
DAY WILL KEEP SKY CLEAR AND WINDS IN THE 5 TO 8KT RANGE.
TRS
&&
.MARINE...
335 AM CDT
EARLY THIS MORNING DEEP LOW PRESSURE IS NEAR JAMES BAY WITH A
TRAILING COLD FRONT SOUTH SOUTHWESTWARD ACROSS LAKE HURON AND
EASTERN LOWER MI. GREATEST PRESSURE RISES FOLLOWING THE FRONT ARE
CURRENTLY FROM EASTERN LAKE SUPERIOR SOUTHWARD DOWN LAKE MICHIGAN.
WITH THE LOW CONTINUING TO MOVE OFF TO THE NORTHEAST...THE PRESSURE
RISES MOVING INTO THE CENTRAL LAKES AND HIGH PRESSURE MOVING EAST
ACROSS THE MID MS VALLEY TO AROUND SOUTHERN LAKE MI BY THIS EVENING
WINDS WILL BE DYING OFF RATER QUICKLY AS THE DAY PROGRESSES WHILE
WAVES TAKE A LITTLE LONGER TO SETTLE DOWN.
THE HIGH SHIFTS EAST TO THE LOWER LAKES SUNDAY WHILE ANOTHER LOW
PRESSURE SYSTEM DEVELOPS ACROSS SOUTH CENTRAL CANADA AND THE
NORTHERN PLAINS. WITH A STRONG ANTICYCLONE OVER THE NORTHEASTERN
U.S. AND A DEEPENING LOW MOVING INTO ONTARIO SUNDAY NIGHT AND MONDAY
A TIGHT PRESSURE GRADIENT WILL BE IN PLACE ACROSS THE UPPER MIDWEST
AND THE UPPER LAKES. HOWEVER WITH THE LOW NOT EXPECTED TO DEEPEN AS
MUCH AS THE CURRENT ONE SOUTH AND SOUTHWEST WINDS NOT EXPECTED TO BE
AS BE A STRONG EITHER. A COLD FRONT EXTENDING FROM THE LOW WILL MOVE
THROUGH THE UPPER LAKES LATE MONDAY NIGHT AND TUESDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1205 AM CDT SAT SEP 22 2007
.DISCUSSION...
315 PM CDT
VIGOROUS MID LVL TROF CONTINUES TO PUSH ACROSS THE UPPER MIDWEST
THIS AFTN...WITH SFC LOW LIFTING INTO WESTERN ONTARIO AND COLD FRONT
TRAILING FROM KMSP TO KOMA. GUSTY SOUTH/SOUTHWEST WINDS ACROSS FCST
AREA IN TIGHTENING GRADIENT AHEAD OF SFC FRONT/TROF...WITH STEEP
LLVL LAPSE RATES HELPING TO MIX 20-30 MPH WINDS DOWN TO SFC TO
MAINTAIN WINDY CONDITIONS FOR REMAINDER OF AFTN HRS.
NARROW AXIS OF MID-UPR 60S SFC DWPTS IMMEDIATELY AHEAD OF FRONT
EXPECTED TO LIMIT CONVECTIVE THREAT TO VCNTY OF FRONTAL ZONE...WITH
RECENT ACARS ASCENT SOUNDINGS FROM KPIA/KORD INDICATING LLVL PARCELS
STRONGLY CAPPED EAST OF MISSISSIPPI RIVER THIS AFTN. SHORT RANGE
MODELS REMAIN FAIRLY CONSISTENT IN DEPICTING NARROW BAND OF
CONVECTION DEVELOPING ALONG/AHEAD OF COLD FRONT ACROSS IA BY LATE
AFTN...MOVING TOWARD FCST AREA THIS EVENING BEFORE DIMINISHING
OVERNIGHT. WITH NARROW LLVL INSTABILITY AXIS...AND INCREASINGLY
UNFAVORABLE DIURNAL TIMING FOR CONVECTION AS FRONT PUSHES EAST AFTER
SUNSET THIS EVENING...IDEA OF POPS HIGHEST FAR WEST AND DECREASING
TO THE EAST MAINTAINED. WRF/RUC/GFS KEEP SOUTHEAST HALF OF CWA
DRY...AND HARD TO ARGUE WITH QPF TRENDS. THUS HAVE CARRIED CHC POPS
FOR LATE EVENING/AROUND MIDNIGHT MAINLY NORTHWEST OF ROUGHLY
STREATOR TO CHICAGO LINE. WRF TIMING INDICATES COLD FROPA AT KRFD
AROUND 10/11 PM...KORD MIDNIGHT/1 AM...THEN EXITING SOUTHEASTERN
FCST AREA BEFORE SUNRISE WITH WINDSHIFT TO NW. SPC STILL HAS
NORTHWEST CWA IN DAY 1 SLGT RISK. 40-45 KTS 0-6KM SPD SHEAR EXISTS
AND STRONG MID LVL WIND FIELD COULD POTENTIALLY SUPPORT SOME
DAMAGING WIND GUSTS IF ORGANIZED UPDRAFTS ARE ABLE TO DVLP/MAINTAIN
INTO WESTERN CWA DURG EVE HOURS.
S/WV CONTINUES OFF TO THE EAST ON SATURDAY...WITH MID LVL RIDGE
BUILDING OVERHEAD AND SFC HIGH PRESSURE DVLPG EAST ACROSS FCST AREA.
COOLER AND LESS HUMID AFTER NEAR RECORD TEMPS TODAY...THOUGH STILL
AROUND/JUST ABOVE AVERAGE TEMPS IN MID/UPR 70S MOST AREAS WITH FULL
SUNSHINE EXPECTED. LGT WINDS BECOMING EAST DURG AFTN AS SFC HIGH
SLIDES EAST AND LAKE BREEZE PROVIDES SOME MINOR COOLING. PROGRESSIVE
UPPER PATTERN CONTINUES HOWEVER...WITH SFC HIGH PUSHING OFF TO THE
EAST ON SUNDAY AND RETURN FLOW DVLPG BY SUNDAY NIGHT AS UPPER TROUGH
AMPLIFIES OVER WESTERN CONUS. TEMPS CLIMB BACK INTO 80S SUN/MON AS
SFC TROF DVLPS ACROSS NRN PLAINS AHEAD OF UPPER SYSTEM.
NEXT PRECIP POTENTIAL APPEARS TO ARRIVE MONDAY AS UPPER TROUGH
APPROACHES. SOME MODEL DIFFERENCES IN HANDLING OF SMALLER SCALE
DETAILS INCLUDING MINOR LEAD S/WV WHICH LIFTS NORTHEAST MON AFTN.
HOWEVER...INCREASINGLY MOIST LLVLS AND APPROACH OF COLD FRONT MONDAY
NIGHT SUPPORT CHC POPS. TUESDAY AND BEYOND...ECMWF BRINGS ADDITIONAL
S/WV INTO TROF AND THUS IS NOTABLY SLOWER WITH PROGRESSION OF LARGER
SCALE UPPER TROUGH AND THEREFORE SFC FRONT. MORE SUPPORT FOR A
FASTER PROGRESSION FROM NCEP ENSEMBLES...GFS AND CANADIAN. HAVE
BASED EXTENDED FCST ON THIS SOMEWHAT FASTER PROGRESSION...WITH FRONT
MOVG THROUGH DURG DAY TUESDAY. HAVE KEPT CHC POPS TUES ACROSS CWA
WITH FROPA...AND LINGERING INTO TUES NGT FAR SOUTHEAST AS FRONT
SLIDES INTO CENTRAL IL/IND. RETURN TO SEASONABLY MILD TEMPS...70S
WED-FRI AS NO BIG SLUG OF COLD AIR APPEARS READY TO INVADE WITH
UPPER FLOW SOMEWHAT ZONAL THROUGH END OF NXT WEEK.
RATZER
&&
.AVIATION...
1205 AM CDT
RE 06Z TAFORS...COLD FRONT AT 05Z EXTENDS FROM SOUTHERN LAKE MI
SOUTHWESTWARD THROUGH NORTHEASTERN AND WEST CENTRAL IL. SHOWERS
AHEAD OF THE FRONT FIZZLED OUT AS THE MOVED INTO NORTHEASTERN IL
DURING THE MID AND LATE EVENING. A FEW POST FRONTAL SHOWERS CONTINUE
ACROSS THE FAR SOUTHEASTERN CORNER OF WI INTO NORTHEASTERN IL
ALIGNED WITH THE MID LEVEL TROUGH AXIS. EXTRAPOLATION FROM RADAR AND
SATELLITE LOOPS SHOW THE SCATTERED SHOWERS TO BE EXITING THE CHI
VICINITY AROUND 07Z WITH CLEARING OF THE PREDEMINANTLY 7-10K FT
CEILINGS AS STRONG SUBSIDENCE AND DRYING RAPIDLY OVERSPREAD THE AREA
AS THE MID AND UPPER TROUGHS PASS BY. QUICK PRESSURE RISE WITH COLD
FRONT PASSAGE CREATING SOME GUSTINESS BUT OBSERVATIONS FROM UPSTREAM
SHOW A RAPID DROP OFF IN WIND SPEEDS AS SURFACE DECOUPLES UNDER HIGH
PRESSURE RIDGE BUILDING ACROSS IA INTO SOUTHWEST WI AND NORTHWEST IL
DESPITE PROFILER AND 88D WINDS SHOWING NORTH TO NORTHWEST WINDS OF
35 TO 50KTS AT 925 AND 850MB. RIDGING SURFACE AND ALOFT DURING THE
DAY WILL KEEP SKY CLEAR AND WINDS IN THE 5 TO 8KT RANGE.
TRS
&&
.MARINE...
204 PM...LOW PRESSURE JUST WEST OF LAKE SUPERIOR CONTINUES TO DEEPEN
THIS AFTERNOON AS IT LIFTS NORTHEAST INTO ONTARIO. THE LOW WILL
CONTINUE TO DEEPEN TONIGHT AS IT REACHES JAMES BAY SATURDAY MORNING.
A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKES REGION TONIGHT.
STRONG SOUTHERLY WINDS TONIGHT WILL TURN WESTERLY AND DIMINISH
SATURDAY MORNING AS HIGH PRESSURE MOVES ACROSS THE PLAINS SATURDAY
AND ACROSS THE SOUTHERN LAKES REGION SATURDAY NIGHT. THIS HIGH
STRENGTHENS SUNDAY AS IT MOVES ACROSS THE EASTERN LAKES AND NEW
ENGLAND. ANOTHER AREA OF LOW PRESSURE WILL DEVELOP OVER THE WESTERN
PLAINS SUNDAY...THEN MOVE NORTHEAST INTO ONTARIO MONDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING NORTH TWO THIRDS UNTIL 09Z SATURDAY.
SMALL CRAFT ADVISORY NEARSHORE UNTIL 07Z SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
215 PM EDT SAT SEP 22 2007
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION THIS EVENING, BRINGING
WITH IT A PASSING SHOWER OR THUNDERSTORM TO THE MOHAWK VALLEY AND
CATSKILL REGIONS. BEHIND THIS FRONT...DRIER AND SOMEWHAT COOLER AIR
WILL SETTLE INTO CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA FOR
TONIGHT AND THE DAY ON SUNDAY. AS WE HEAD INTO EARLY NEXT
WEEK...TEMPERATURES WILL WARM TO WELL ABOVE SEASONAL NORMS...WITH
DRY CONDITIONS LASTING THROUGH TUESDAY.
&&
.NEAR TERM /TONIGHT/...
HERE COMES THE FRONT...BUT CURRENTLY IT IS LOOKING RATHER ANEMIC
FROM BOTH OBS AS WELL AS CURRENT VIS/RADAR IMAGERY. RECENT ACARS
SOUNDING FROM KERI SUGGESTS THE CAP IS STILL IN PLACE JUST AHEAD OF
THE BOUNDARY. HOWEVER...AS THE FRONT MOVES FURTHER EAST...IT WILL
ENCOUNTER WARMER AND SOMEWHAT MORE HUMID LLEVEL AIR. COULD
SEE A SHRA/TSRA POP OFF OVER THE NEXT FEW HOURS...ESPECIALLY OVER
OUR FAR EASTERN ZONES...BUT FEEL ANY CONVECTIVE THREAT IS QUITE
MINIMAL.
BIGGEST CHANGE BEHIND THE FRONT WILL BE THE DECREASE IN
MOISTURE...WITH DEWPOINTS TUMBLING FROM THEIR CURRENT VALUES IN THE
LOW 60S TO THE UPPER 40S BY TOMORROW MORNING. THIS...COMBINED WITH
SOME MODEST COLD AIR ADVECTION...AND A DECENT BREEZE...SHOULD GIVE
US GOOD SLEEPING WEATHER TONIGHT AS LOWS DROP TO NEAR 50.
THE AFOREMENTIONED BREEZE AND DRY ADVECTION WILL CURB ALMOST ALL FOG
POTENTIAL TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
VERY VERY QUIET PERIOD WITH A SURFACE HIGH BUILDING INTO THE REGION
DURING SUNDAY...CRESTING OVERHEAD SUNDAY NIGHT...AND THEN BEGINNING
TO PULL SOUTHEAST OF THE AREA FOR MONDAY. CLEAR SKIES WILL BE THE
RULE THROUGH THE PERIOD.
HIGHS SUNDAY WILL STILL BE ABOUT 7F ABOVE NORMAL...AS T925 IN THE
13-15 RANGE SUGGEST MID 70S UNDER GOOD MIXING AND FULL SUNSHINE.
SUNDAY NIGHT WILL BE A LITTLE CHILLY WITH THE SFC HIGH OVERHEAD AND
A DRY AIRMASS IN PLACE. COULD SEE A FEW UPPER 30S IN LOCATIONS SUCH
AS KELM /ALTHOUGH FEEL THE MAV IS A LITTLE TOO COLD HERE/...BUT MOST
LOCATIONS WILL SEE LOWS FALL INTO THE LOWER TO MIDDLE 40S. RIVER
VALLEY FOG LOOKS TO BE A GOOD BET AFTER MIDNIGHT.
TEMPS ON MONDAY WILL BEGIN TO RISE ONCE AGAIN ON THE BACK SIDE OF
THE HIGH AND WITH T925 NOW IN THE 17-20 RANGE...WILL ONCE AGAIN MAKE
A RUN AT THE 80F MARK...NOW 10-15 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HPC XTNDD FCST GUIDANCE FOLLOWED CLOSELY. HIGH PRES WILL BE MOVG
OFF THE ERN SEABOARD TUES, AS THE NXT CDFNT APRCHS LATER TUES
NGT. THERE ARE SOME TIMING DIFFS W/REGARD TO THE FNT`S SEWD MVMNT,
WITH THE GFS AND DGEX SHOWING SFC WAVE DVLPMNT ALONG THE FNT,
WHICH MOVS INTO THE ERN GTLAKES ON THU...SLOWING DOWN THE FNT.
THE EURO IS MORE PROGRESSIVE WITH THE FNT AS IT DOWNPLAYS THIS
WAVE. AT ANY RATE, THE CRNT FCST WILL CALL FOR THE CHC OF PCPN
STARTING LATER TUES NGT ACRS UPSTATE, WITH CHCS SPREADING ACRS THE
ENTIRE AREA WED, THEN PERSISTING INTO THU EVNG. MDLS ARE IN
AGREEMENT THAT THIS SYSTEM WILL BE EAST OF THE FCST AREA BY
FRIDAY, WITH FAIR WX XPCTD NXT FRI/SAT. TEMPS WILL CONTINUE TO AVG
ABV NORMAL, AND THIS GNRL PTRN XPCTD TO PERSIST THROUGH THE END OF
THE MONTH GIVEN LATEST 6-10 AND 8-14 DAY MEANS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS TO PREVAIL. CDFNT AND WEAK PRE-FNTL TROF ARE
MAKING IT`S WAY ACRS THE FSCT AREA. WE MAY SEE SOME ISOLD
-SHRA/-TSRA LATER THIS AFTN, BUT CHCS NOT GREAT ENUF TO INCLUDE IN
THE TAFS. WINDS WILL SHIFT FROM SWLY TO WNW BEHIND THE CDFNT AND
BE GUSTY (G20-25) FOR THE REMAINDER OF THE AFTN, BUT WINDS XPCTD
TO DIMINISH TO <10 KTS ARND SS. ONLY XPCT A BKN MID DECK WITH
FROPA. WINDS ALONG WITH A DRYING AIRMASS SHUD PRECLUDE ANY VSBY
RESTRICTIONS TNGT, WITH PSBL XCPTN OF ELM ARND DAYBREAK, WHERE
BRIEF MVFR VSBY`S PSBL. SKC TMRW, WITH NNW WINDS ARND 10 KTS.
OUTLOOK (SUN AFTN INTO WED)...
VFR CONDITIONS THRU TUES...ONLY XCPTN WILL BE MRNG VLY FOG OVER
THE TWIN TIERS (ELM). LOWER CLDS AND MVFR CONDITIONS WILL BE PSBL OVER
UPSTATE NY AS NXT FNT APRCHS LATER TUES NGT INTO WED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMA
NEAR TERM...JMA
SHORT TERM...JMA
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
200 PM EDT SAT SEP 22 2007
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION TODAY...AND MAY SPARK A
PASSING SHOWER OR THUNDERSTORM OVER THE MOHAWK VALLEY AND
CATSKILLS. DRIER AND SOMEWHAT COOLER WEATHER WILL BUILD INTO THE
REGION BEHIND THIS FRONT FOR SUNDAY. THE DRY WEATHER...ALONG WITH
A WARMING TREND...WILL SET UP AS WE HEAD INTO THE NEW WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE UPDATED ZONES MOSTLY TO ACCOUNT FOR CURRENT CLOUD TRENDS AND
TO REMOVE ANY REMAINING MORNING WORDING. SFC COLD FRONT IS RACING
INTO THE EASTERN GREAT LAKES ATTM...WITH WV IMAGERY SHOWING THAT
THE UPPER LEVEL FORCING IS ACTUALLY OUTRUNNING THE SURFACE
BOUNDARY SOMEWHAT. IN THE SOUTHERLY FLOW AHEAD OF THE SURFACE COLD
FRONT...A BKN CLOUD LAYER HAS DEVELOPED OVER OUR SOUTHEASTERN
ZONES.
AS FOR CONVECTIVE POTENTIAL THIS AFTERNOON...FEEL THE PREVIOUS
PACKAGE IS ON TARGET. KBUF/KALB SOUNDINGS AS WELL AS MORNING ACARS
DATA SUGGESTS GOOD CAPPING NEAR 600MB. IN ADDITION...THE MOST
AGGRESSIVE MODEL IN TERMS OF CONVECTION THIS AFTERNOON /THE 6 AND
NOW THE NEW 12Z NAM/ SUGGEST LATE MORNING DEWPOINT VALUES THAT ARE
SOME 2-3F HIGHER THAN 10AM OBSERVATIONS. BECAUSE OF THIS...AM
FEELING THAT THE CHANCES OF BREAKING THE CAP ARE PRETTY
MINIMAL. WITH DECENT LLEVEL CONVERGENCE ASSOCIATED WITH THE
BOUNDARY AND SOME MODESTLY SUPPORTIVE DYNAMICS /BEST DYNAMICS
REMAIN WELL TO THE NORTH/...EXPECT A FEW LOW TOPPED SHOWERS TO
DEVELOP OVER OUR EASTERN ZONES THIS AFTERNOON. CAN`T RULE OUT
THUNDER...AS THERE IS CAPE AVAILABLE ABOVE THE CAP...BUT FEEL IT
WILL BE ISOLATED AT BEST. OF COURSE...WILL WATCH ANY CONVECTIVE
ACTIVITY THAT DOES DEVELOP AS THERE IS A DECENT WIND FIELD...AND
SOME DRY AIR ALOFT TO WORK WITH.
NEW ZONES/GRIDS ARE ON THE STREET.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
MUCH DRIER AIR SPILLS BACK IN AS THE AFC HI AND BIG UA RDG TAKE
OVER ONCE AGAIN. THIS WILL KEEP SKIES MAINLY CLR THUR THE SHRT
TERM PD...XCPT FOR THE TYPICAL MRNG FOG IN THE VLYS. TEMPS WILL
RETURN TO NEAR NRML OR SLGTLY ABV FOR THE DAYS...A BIT BELOW FOR
THE NGTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HPC XTNDD FCST GUIDANCE FOLLOWED CLOSELY. HIGH PRES WILL BE MOVG
OFF THE ERN SEABOARD TUES, AS THE NXT CDFNT APRCHS LATER TUES
NGT. THERE ARE SOME TIMING DIFFS W/REGARD TO THE FNT`S SEWD MVMNT,
WITH THE GFS AND DGEX SHOWING SFC WAVE DVLPMNT ALONG THE FNT,
WHICH MOVS INTO THE ERN GTLAKES ON THU...SLOWING DOWN THE FNT.
THE EURO IS MORE PROGRESSIVE WITH THE FNT AS IT DOWNPLAYS THIS
WAVE. AT ANY RATE, THE CRNT FCST WILL CALL FOR THE CHC OF PCPN
STARTING LATER TUES NGT ACRS UPSTATE, WITH CHCS SPREADING ACRS THE
ENTIRE AREA WED, THEN PERSISTING INTO THU EVNG. MDLS ARE IN
AGREEMENT THAT THIS SYSTEM WILL BE EAST OF THE FCST AREA BY
FRIDAY, WITH FAIR WX XPCTD NXT FRI/SAT. TEMPS WILL CONTINUE TO AVG
ABV NORMAL, AND THIS GNRL PTRN XPCTD TO PERSIST THROUGH THE END OF
THE MONTH GIVEN LATEST 6-10 AND 8-14 DAY MEANS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS TO PREVAIL. CDFNT AND WEAK PRE-FNTL TROF ARE
MAKING IT`S WAY ACRS THE FSCT AREA. WE MAY SEE SOME ISOLD
-SHRA/-TSRA LATER THIS AFTN, BUT CHCS NOT GREAT ENUF TO INCLUDE IN
THE TAFS. WINDS WILL SHIFT FROM SWLY TO WNW BEHIND THE CDFNT AND
BE GUSTY (G20-25) FOR THE REMAINDER OF THE AFTN, BUT WINDS XPCTD
TO DIMINISH TO <10 KTS ARND SS. ONLY XPCT A BKN MID DECK WITH
FROPA. WINDS ALONG WITH A DRYING AIRMASS SHUD PRECLUDE ANY VSBY
RESTRICTIONS TNGT, WITH PSBL XCPTN OF ELM ARND DAYBREAK, WHERE
BRIEF MVFR VSBY`S PSBL. SKC TMRW, WITH NNW WINDS ARND 10 KTS.
OUTLOOK (SUN AFTN INTO WED)...
VFR CONDITIONS THRU TUES...ONLY XCPTN WILL BE MRNG VLY FOG OVER
THE TWIN TIERS (ELM). LOWER CLDS AND MVFR CONDITIONS WILL BE PSBL OVER
UPSTATE NY AS NXT FNT APRCHS LATER TUES NGT INTO WED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMA
NEAR TERM...JMA
SHORT TERM...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1044 AM EDT SAT SEP 22 2007
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION TODAY...AND MAY SPARK A
PASSING SHOWER OR THUNDERSTORM OVER THE MOHAWK VALLEY AND
CATSKILLS. DRIER AND SOMEWHAT COOLER WEATHER WILL BUILD INTO THE
REGION BEHIND THIS FRONT FOR SUNDAY. THE DRY WEATHER...ALONG WITH
A WARMING TREND...WILL SET UP AS WE HEAD INTO THE NEW WORK WEEK.
&&
.NEAR TERM /REST OF TODAY/...
HAVE UPDATED ZONES MOSTLY TO ACCOUNT FOR CURRENT CLOUD TRENDS AND
TO REMOVE ANY REMAINING MORNING WORDING. SFC COLD FRONT IS RACING
INTO THE EASTERN GREAT LAKES ATTM...WITH WV IMAGERY SHOWING THAT
THE UPPER LEVEL FORCING IS ACTUALLY OUTRUNNING THE SURFACE
BOUNDARY SOMEWHAT. IN THE SOUTHERLY FLOW AHEAD OF THE SURFACE COLD
FRONT...A BKN CLOUD LAYER HAS DEVELOPED OVER OUR SOUTHEASTERN
ZONES.
AS FOR CONVECTIVE POTENTIAL THIS AFTERNOON...FEEL THE PREVIOUS
PACKAGE IS ON TARGET. KBUF/KALB SOUNDINGS AS WELL AS MORNING ACARS
DATA SUGGESTS GOOD CAPPING NEAR 600MB. IN ADDITION...THE MOST
AGGRESSIVE MODEL IN TERMS OF CONVECTION THIS AFTERNOON /THE 6 AND
NOW THE NEW 12Z NAM/ SUGGEST LATE MORNING DEWPOINT VALUES THAT ARE
SOME 2-3F HIGHER THAN 10AM OBSERVATIONS. BECAUSE OF THIS...AM
FEELING THAT THE CHANCES OF BREAKING THE CAP ARE PRETTY
MINIMAL. WITH DECENT LLEVEL CONVERGENCE ASSOCIATED WITH THE
BOUNDARY AND SOME MODESTLY SUPPORTIVE DYNAMICS /BEST DYNAMICS
REMAIN WELL TO THE NORTH/...EXPECT A FEW LOW TOPPED SHOWERS TO
DEVELOP OVER OUR EASTERN ZONES THIS AFTERNOON. CAN`T RULE OUT
THUNDER...AS THERE IS CAPE AVAILABLE ABOVE THE CAP...BUT FEEL IT
WILL BE ISOLATED AT BEST. OF COURSE...WILL WATCH ANY CONVECTIVE
ACTIVITY THAT DOES DEVELOP AS THERE IS A DECENT WIND FIELD...AND
SOME DRY AIR ALOFT TO WORK WITH.
NEW ZONES/GRIDS ARE ON THE STREET.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
MUCH DRIER AIR SPILLS BACK IN AS THE AFC HI AND BIG UA RDG TAKE
OVER ONCE AGAIN. THIS WILL KEEP SKIES MAINLY CLR THUR THE SHRT
TERM PD...XCPT FOR THE TYPICAL MRNG FOG IN THE VLYS. TEMPS WILL
RETURN TO NEAR NRML OR SLGTLY ABV FOR THE DAYS...A BIT BELOW FOR
THE NGTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HPC XTNDD GUIDANCE LOOKED FINE AND WAS FOLLOWED CLOSELY. AFTER SAT
FROPA, A LARGE AREA OF HIGH PRES WILL BRING SKC AND MILD TEMPS
THROUGH MON. NXT CDFNT WILL APPRCH LATE TUES OR TUES EVNG. SOME
DIFFS AS TO HOW FAST THIS FNT WILL PROGRESS THRU THE FCST AREA.
ATTM XPCT FNT TO CLEAR FAR SE ZONES BY THU MRNG, WITH HIGH PRES
BUILDING BEHIND THE FNT FOR LATE THU AND FRI. TEMPS WILL CONTINUE
TO AVG WELL ABV NORMAL.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
GNRLY VFR CONDITIONS THRU THE PD...STARTING OFF WITH BKN HIGH CLDS
AHEAD OF APPCHG CDFNT. AT KELM EXPECT MVFR VSBYS TO IMPRV BY 14Z
AS MIXING OCCURS. SCT-BKN CUMULUS EXPECTED TO DEVELOP AFTER 14Z
WITH BASES ARND 5KFT AT ALL TERMINALS. A BRIEF PD OF BKN 5-6KFT
CIGS EXPECTED FROM LATE AFTERNOON THRU APPROX 02Z...BUT STILL RMNG
AT VFR LEVELS. AFTER FRONTAL PASSAGE...SKIES CLEAR BEHIND.
WINDS INCRS OUT OF THE SW AT 10-15KTS GUSTING TO 25KTS DRG
AFTERNOON. WITH DRY CONDS AND WARM TEMPS ALOFT HAVE NOT INCLUDED
ANY SHRA/TSRA MENTION THRU TAF VALID TIME BUT CANNOT RULE OUT AN
ISOLD OCCURRENCE...ESPECIALLY AT KRME/KBGM/KAVP. AFTER FRONTAL
PASSAGE FROM 21Z- 00Z...WINDS SHIFT TO W-NW AND LIGHTEN UP AFTER SUNSET.
FOLLOWING CDFNT TONIGHT...VFR WITH GNRLY SKC INTO TUES (ONLY XCPTN
BEING EARLY MRNG VLY FOG AT ELM). NXT FNT APRCHS LATE TUES INTO
WED WITH LOWER CIGS/VSBYS PSBL.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DGM
NEAR TERM...JMA
SHORT TERM...DGM
AVIATION...PVB
|