FXUS61 KBGM 021749
AFDBGM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
1249 PM EST WED DEC 2 2009
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE OHIO VALLEY TO WESTERN NEW YORK
TONIGHT AND BRING RAIN TO THE REGION. HIGH PRESSURE WILL BUILD IN
BEHIND THE LOW ON THURSDAY AND BRING COOLER AND DRIER AIR.
&&
.NEAR TERM /THROUGH TONIGHT/...
.1015 AM UPDATE...
FORECAST GENERALLY IN DECENT SHAPE WITH ONLY MINOR ADJUSTMENTS TO
ACCOUNT FOR INCREASING CLOUDS AND EARLIER ARRIVAL OF PRECIP ACROSS THE
SOUTHERN ZONES LATE THIS AFTERNOON. NATIONAL MOSAIC RADAR IMAGERY
SHOWING THE LEADING EDGE OF PRECIP NOW LOCATED ACROSS
WV/MD/EXTREME SOUTHERN PA. PRECIP SHIELD WILL CONTINUE EXPANDING
NORTH THIS AFTERNOON WITH EVENTUAL ARRIVAL ACROSS SOUTHERN ZONES
BY LATE AFTERNOON/EARLY EVENING. IN FACT...KBGM 88D IS ALREADY PICKING
UP ON ELEVATED VIRGA ACROSS CENTRAL PA LIKELY IN ASSOCIATION WITH
THE ELEVATED H85 WARM FRONT. SYSTEM CURRENTLY LOCATED ACROSS THE
NORTHERN AL/MS WILL CONTINUE MOVING NORTHEAST TODAY ACROSS THE
MID-ATLANTIC. FEATURE WILL HAVE ACCESS TO HIGH AMOUNTS OF GULF
MOISTURE THANKS IN PART TO A STRONG SOUTHERLY H85 LLJ OF 60+ KTS.
STRONG ISENTROPIC UPGLIDE ALONG THE 300 AND 305K THETA SUFACES
WILL RESULT IN FAVORABLE CONDITIONS FOR A DECENT SOAKING RAIN
THROUGH THE OVERNIGHT HOURS. ONLY MINOR HYDROLOGIC IMPACTS
EXPECTED AS THE FEATURE ZIPS PAST THE AREA RELATIVELY QUICKLY.
NEW ZONES ALREADY POSTED.
.PREVIOUS NEAR TERM DISCUSSION...
MAINLY CLR SKIES OVER THE FCST AREA ATTM WITH CI STREAMING OUT AHD
OF THE NEXT LOW ALREADY INTO MUCH OF PA. XPCT A SLOW INCRS IN CLDS
TODAY AS THE SYSTEM APRCHS...BUT SLOWER TIMING ON THE 00Z AND 06Z
NAM RUN HAS CAUSED ME TO BACK OFF ON THE TIMING OF THE ONSET OF
THE PCPN. ONLY THE XTRM SWRN ZONES SHD SEE MEASURABLE RAIN BEFORE
00Z.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PROGRESSIVE OPEN WV RACES THRU THE AREA IN THE LRGR SCALE SW FLOW.
SFC LOW DEEPENS SLOWLY AS IT RACES FROM THE OH VLY TO WRN NY BY
12Z THU. THE FAST MVMT DOES NOT ALLOW THE SYSTEM TO DVLP A GOOD
SELY INFLOW OR LINGER MUCH IN THE FCST AREA SO I/M NOT XPCTG
EXCESSIVE RAINFALL AMTS. THIS ALSO KEEPS THE GRADIENT FROM
TIGHTENING TO THE POINT WHERE WNDS WLD RCH THE ADV CAT. SO...WHILE
SOME GUSTY WINDS ARE LIKELY LTR TNGT...FLAGS WILL NOT BE NEEDED.
DRY SLOT PUSHES IN FROM THE SOUTH THU AND BRINGS A QUICK END TO
THE RAIN. THIS LEAVES THE AREA IN A RELATIVELY DRY AND SHEARED
FLOW BHD THE LOW. TEMPS ARE VERY MRGNL FOR LES...AND WITH THE
SHEAR...JUST SOME CHANCE POPS SEEM JUSTIFIED FOR THE NRN AND WRN
ZONES FOR SOME LGT LES.
WITH THE UPR TROF AXIS REMAINING WELL TO THE WEST...COLD AIR IS
SLOW TO FILTER IN AND THRU THE SHRT TERM...REALLY NOT ALL THAT
FVRBL FOR ANY LES IN THE FCST AREA.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
NO BIG CHANGES TO THE EXTENDED. 0Z AND 06Z GFS CREATED SOME
EXCITEMENT WITH A COASTAL STORM BRINGING SYNOPTIC SNOWS TO THE CWA.
THE 12Z GFS IS A BIT FARTHER EAST BUT STILL BRUSHES THE EASTERN CWA
WITH PRECIP. GOING WITH HPC THINKING THAT THE LOW WILL BE FAR ENOUGH
TO THE EAST AND NOT AS STRONG AS THE GFS IS INDICATING...THUS
PRECIP WILL REMAIN EAST OF THE AREA. THE NEW EURO JUST CAME IN AND
WHILE IT IS CLOSER TO THE GFS IN TERMS OF DEVELOPING THIS LOW...VS.
THE PREVIOUS RUN...IT IS STILL WEAKER THAN THE GFS AND WOULD KEEP
ANY PRECIP TO OUR EAST.
PUTTING THAT TO THE SIDE OUR FOCUS WITH THE LONG TERM WILL CONTINUE
TO BE THE FIRST SIGNIFICANT LAKE SNOWS TO IMPACT OUR CWA FOR THE
SEASON. A SOUTHWEST FLOW FRIDAY NIGHT VEERS MORE TOWARD 280/290 FROM
MID SATURDAY MORNING THROUGH MID SUNDAY MORNING. DELTA T'S APPROACH
20 DURING THIS STRETCH WITH MODERATE TO EXTREME INSTABILITY. THIS
FLOW FAVORS LAKE SNOWS ACROSS OUR SNOWBELTS OF NORTHERN/WESTERN
ONEIDA COUNTY ALONG WITH NORTHERN ONONDAGA COUNTY. STILL A WAYS OUT
BUT THE MODELS HAVE BEEN CONSISTENT ENOUGH TO MENTION LIKELY POPS
FOR SNOW SQUALLS IN THESE AREAS.
WE REMAIN CHILLY ENOUGH FOR LAKE SNOWS TO CONTINUE FROM SUNDAY
AFTERNOON INTO MONDAY BUT NOT CONFIDENT ENOUGH TO DETERMINE WHERE SO
I KEPT POPS AT CHANCE FOR NOW. BEST BET WOULD STILL BE ON A
WEST-NORTHWEST FLOW. NEXT SYSTEM APPEARS TO BE A RAIN MAKER LATE
TUESDAY AND WEDNESDAY WITH A TRACK TO OUR WEST.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A DEVELOPING STORM OVER THE LOWER MISSISSIPPI VALLEY WILL RAPIDLY
MOVE NORTHEAST ACROSS PENNSYLVANIA AND NEW YORK TONIGHT. RAIN
ASSOCIATED WITH THIS STORM WILL OVERSPREAD THE REGION FROM SOUTH
TO NORTH BETWEEN 23Z-02Z. FLIGHT CONDITIONS WILL DETERIORATE FROM
VFR TO MVFR EARLY THIS EVENING...WITH OCCASIONAL IFR IN MDT/HVY RAIN
OVERNIGHT. A STRONG LOW LEVEL CORRIDOR OF 50-70 KT SELY WINDS IS
EXPECTED TO PASS THROUGH NORTHEAST PENNSYLVANIA BETWEEN THE WARM
AND COLD FRONTAL BOUNDARIES BETWEEN 03Z-09Z. THE POSSIBILITY OF
LLWS BELOW 2K FT WILL INCREASE DURING THIS TIME ESPLY AT KAVP
WHERE E-SE APROACH WINDS MAY BE RATHER LIGHT. POST FRONTAL WINDS
FROM THE W-SW WILL ALSO BECOME STRONG AND GUSTY ON THURSDAY
MORNING WITH GUSTS APCHG 30 KTS POSSIBLE FROM 14Z-18Z.
OUTLOOK...
THUR....BECOMING VFR AREAS MVFR. GUSTY SW-W WINDS. AM RAIN
TAPERING TO SHOWERS.
THUR NGT...VFR. AREAS MVFR/IFR IN LAKE SNOW BANDS VCNTY KRME.
FRI...VFR. AREAS OF MVFR/IFR IN LAKE SNOW BANDS VCNTY KRME EARLY.
SAT/SUN...VFR. AREAS OF MVFR/IFR IN LAKE SNOW BANDS VCNTY KRME/KSYR.
MON...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...
AVIATION...JAB
