FXUS61 KBGM 081624
AFDBGM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
1124 AM EST TUE DEC 8 2009
.SYNOPSIS...
LAKE EFFECT SNOW WILL AFFECT THE MOHAWK VALLEY AND TUG HILL PLATEAU
THIS MORNING BEFORE DIMINISHING. A STORM SYSTEM MOVING ACROSS THE
PLAINS STATES WILL BEGIN TO SPREAD SNOW INTO CENTRAL NEW YORK AND
NORTHEAST PENNSYLVANIA BY MIDNIGHT. THE SNOW WILL MIX WITH SLEET
WEDNESDAY MORNING...BEFORE CHANGING TO RAIN BY AFTERNOON. COLD AND
BLUSTERY CONDITIONS CAN BE EXPECTED BEHIND THIS SYSTEM...WITH
SCATTERED LAKE EFFECT SNOW SHOWERS ACROSS UPSTATE NEW YORK LINGERING
THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS ARE GRADUALLY DIMINISHING ACROSS THE AREA LATE THIS
MORNING... AND EXPECT ALL AREAS TO SEE AT LEAST SOME SUNSHINE THIS
AFTERNOON. TEMPERATURES ARE ON TRACK TO REACH THE MID TO UPPER
30S. HIGH CLOUDS ASSOCIATED WITH THE STORM IN THE PLAINS WILL
BEGIN TO OVERSPREAD THE AREA LATE THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
WOUND UP LOW PRESSURE TREKS INTO THE GREAT LKS LATE TONIGHT. AHD OF
THIS...WARM ADVECTION PCPN WILL KICK IN ACRS WRN/SRN SXNS BTWN
03Z-06Z THEN OVERSPREAD RMNDR OF CWA AFT 06Z. PROFILES AT THIS POINT
INDICATE ALL SNOW STARTING OFF. AS USUAL...MODELS HVG A HARD TIME
HANDLING A POSSIBLE WARM LAYER WITH NAM CLDR THAN GFS. NAM KEEPS AVP
AT ALL SNOW THRU 12Z BFR MIXING AND THEN CHGNG TO RAIN BY 15Z.
IN CONTRAST...GFS MIXES AVP OVR BY 09Z WITH ALL RAIN EXPECTED BY
12Z. REALITY WL LKLY BE SOMEWHERE IN BTWN. STRONG FRCG EXPECTED WITH
INITIAL SHOT OF SNOW LEADS ME TO LEAN TWD SNOW LONGER THAN WHAT GFS
IS INDICATING DUE TO DYNAMIC COOLING. HWVR...CANNOT RULE OUT A MIX
IN THE WYOMING/LACKAWANNA VLYS SHORTLY AFTER ONSET OF PCPN. EVEN THE
NAM PROFILES INDICATE A FAIRLY ISOTHERMAL SNDG DOWN SOUTH TWD
DAYBREAK. THUS...WILL PLAN TO SPLIT THE DIFFERENCE BTWN NAM/GFS AND
MIX FAR SOUTH WITH SN/RA/IP BTWN 06Z-09Z. THIS WL CUT DOWN ON AMNTS
SOME ACRS THE AREA BUT WILL NOT LOWER RATIO TOO MUCH DUE TO
UNCERTAINTY.
LATEST SPC ANALYSIS INDICATING SNOW/LIQUID RATIO FM 10:1 INITIALLY
THEN MORE TWD 5 TO 8:1 BY 12Z WED. THESE RATIOS WUD INDICATE A GNRL
3-5 INCH SNOWFALL FM 03Z-12Z WED FM APPROX STEUBEN CNTY DOWN INTO
POCONOS.
WARM AIR WILL GRADUALLY WORK ITS WAY INTO CWA WED MRNG. WHILE GFS
INDICATES A FASTER CHANGEOVER...BOTH MODELS INDICATE A MIX ACRS MOST
OF THE CWA ARND 15Z...BCMG ALL RAIN DRG THE AFTN. TOTAL ACCUMS LOOK
TO BE ON THE ORDER OF 3-6 INCHES FM LATE TONIGHT THRU WED MRNG.
WILL LKLY BE ISSUING WINTER WX ADVISORY FOR ENTIRE CWA WITH THIS
PACKAGE.
DRY AIR MVS IN LATE THIS AFTN WITH ONLY CHC POPS EXPECTED TONIGHT.
FLOW TURNS SWRLY TONIGHT AND H8 TEMPS DROP BLO -5C WITH GOOD
POTENTIAL FOR LK EFFECT SETTING UP LATE TONIGHT. HWVR...FLOW WILL
KEEP STRONGEST PCPN TO NORTH OF CWA THRU 18Z THURSDAY BFR VEERING TO
MORE WRLY DRG THE AFTN.
STRONG WINDS BHND SYSTEM EXPECTED WITH GUSTS OF 40-45 MPH NOT OUT OF
THE QUESTION ACRS THE LK PLAIN LATE WED NIGHT INTO THURSDAY.
LK EFFECT SNOW WILL PLAGUE NRN SXNS THRU THE END OF THE SHORT TERM
PD. FLOW WILL WAFFLE BTWN 250-270 WITH NO CLEAR-CUT LOCATION WHERE
LK BANDS MAY SET UP. HEAVIEST SNOW STILL LOOKS TO BE JUST NORTH OF
CWA BUT ERIE BAND MAY BE ABLE TO PENETRATE INTO PORTIONS OF THE
FINGER LKS. LK INSTABILITY/FRCG WILL MOST CERTAINLY BE PRESENT AND
ACCUMS WILL DEPEND STRICTLY ON FLOW REGIME.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS IN FAIR AGREEMENT WITH ZONAL FLOW FROM THE EASTERN PLAINS
ACROSS TO THE ATLANTIC. WITH THE FLOW ORIGINATING FROM THE ALASKA
REGION...THE AIR WILL BE QUITE CHILLY. 850 RANGE FROM -14C TO -17C
IN THE MODELS. WITH A WESTERLY FLOW...LAKE EFFECT SHOULD BEGIN TO
CRANK UP FOR THE END OF THE WEEK. IT IS TOO EARLY TO PINPOINT
WHERE ANY BANDS WILL SET UP. THE CURRENT GUESS WOULD BE UP IN THE
TUG HILL REGION.
BY SATURDAY NIGHT...A RIDGE WILL BUILD AHEAD OF THE NEXT LOW. THIS
WILL ALLOW TEMPS TO WARM SIGNIFICANTLY. 850 TEMPS WILL RISE TO
AROUND -4C BY 00Z SUNDAY. THIS RIDGE WILL BE VERY SHORT LIVED AS A
STRONG LOW PRESSURE SYSTEM ALOFT RIDE ALONG THE NORTHERN PORTION
OF THE FLOW. THERE IS SOME DISCREPANCY IN THE MODELS AT THIS
POINT. THE GFS HAS TWO SFC LOWS...ONE THAT TRACKS ALONG THE ST
LAWRENCE AND THE OTHER FROM THE OUTER BANKS OF NORTH CAROLINA
NORTHEASTWARDS INTO THE ATLANTIC. THE NORTH LOW WOULD HAVE A
STRONG COLD FRONT ASSOCIATE WITH IT. THIS WOULD QUICKLY PROGRESS
THROUGH THE CWA.
THE ECMWF MAINTAINS THE SINGLE MAIN LOW OFF THE EAST COAST...WITH
SOME WRAP AROUND PRECIP AFFECTING THE CWA. IT DOES HINT AT A
SECONDARY LOW PRESSURE CENTER...BUT FAIRLY WEAK IN THE LATEST
MODEL RUN. THIS HAS WEAK FLOW ACROSS THE CWA AND PERHAPS KEEPS THE
LAKE EFFECT GOING IN THE BEGINNING OF THE WEEK. HAVE LEANED MORE
TOWARDS THIS OPTION ATTM.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
CONDITIONS HAVE BEGUN TO IMPROVE IN VARIOUS LOCATIONS. THIS IS
EXPECTED TO BE TEMPORARY AND CEILINGS WILL MOST LIKELY BOUNCE
BETWEEN IFR AND VFR TODAY AS BANDS OF LAKE EFFECT MOVE INTO SOME
AREAS AND A LOW PRESSURE SYSTEM APPROACHES. LATER TONIGHT...EXPECT
SNOW TO MOVE INTO THE REGION. THIS WILL BRING IFR TO LIFR
CONDITIONS DUE TO CEILINGS AND VIS. WINDS MAY ALSO BECOME GUSTY
WITH THE FRONTAL PASSAGE. THIS LOOK NOT TO BE SO MUCH A COLD
FRONTAL PASSAGE AS AN OCCLUDED FRONT. THIS WILL LIKELY KEEP WINDS
FROM GUSTING TO EXTREME WITH THIS SYSTEM. HOWEVER...THERE MAY
STILL BE GUSTS OF 35 TO 40KTS...ESPECIALLY ALONG THE MOHAWK
VALLEY. FURTHER SOUTH...THE WINDS WILL NOT BE AS STRONG...BUT
GUSTS MAY STILL REACH UP TO AROUND 30KTS. THE FRONTAL PASSAGE LOOKS TO
BE BETWEEN 12 AND 18Z WEDNESDAY ACROSS THE REGION.
OUTLOOK...
TUE NGT...MVFR/IFR LATE IN SNOW. MOVING SW TO NE STARTING AT ELM
AND AVP BY MIDNIGHT TO RME BY 08Z.
WED...MVFR/IFR IN SNOW AND MIXED PRECIP...CHGNG TO ALL RAIN BY
AFTN.
WED NGT THRU SATURDAY...OCCASIONAL MVFR/IFR IN LAKE EFFECT SNOW
SHOWERS PRIMARILY KRME/KSYR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO NOON EST
WEDNESDAY FOR PAZ038>040-043-044-047-048-072.
NY...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO NOON EST
WEDNESDAY FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
&&
$$
SYNOPSIS...PVN
NEAR TERM...MSE
SHORT TERM...PVN
LONG TERM...10
AVIATION...10
