FXUS61 KBGM 080312
AFDBGM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
1012 PM EST MON DEC 7 2009
.SYNOPSIS...
SNOW SHOWERS WILL PERSIST DOWNWIND OF LAKES ONTARIO AND ERIE
TONIGHT AND TUESDAY MORNING...OTHERWISE DRY WEATHER IS EXPECTED
ACROSS THE REMAINDER OF THE REGION. SNOW WILL OVERSPREAD THE AREA
ON TUESDAY NIGHT...POSSIBLY MIXING BRIEFLY WITH SLEET BEFORE
CHANGING TO RAIN WEDNESDAY MORNING . COLD AND BLUSTERY CONDITIONS
WILL FOLLOW THIS STORM FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
...UPDATED AT 10 PM...
CURRENT FORECAST IN GOOD SHAPE...ONLY MINOR TWEAKS MADE TO SKY
COVER AND TEMPERATURE GRIDS.
NOW THAT AN UPPER-LEVEL WAVE IS LIFTING NORTH OF THE REGION
...SYNOPTIC-SCALE SNOW SHOWERS ARE ON THE WANE. HOWEVER...LAKE-
EFFECT SNOW PLUMES ARE TAKING SHAPE OFF BOTH LAKES ERIE AND
ONTARIO. ALTHOUGH SOME LIGHT SNOW SHOWERS/FLURRIES WILL PROBABLY
BRUSH PORTIONS OF THE CENTRAL SOUTHERN TIER...THE ERIE PLUME
SHOULD OTHERWISE HAVE LITTLE AFFECT ON OUR FORECAST AREA
OVERNIGHT.
DISORGANIZED BAND ACROSS LAKE ONTARIO IS PUSHING INTO OSWEGO
COUNTY AS OF THIS WRITING...AND SHOULD EVENTUALLY REACH AT LEAST
THE NORTHWESTERN CORNER OF ONEIDA. ALTHOUGH THE INVERSION BASE ON
THIS EVENING'S BUFFALO SOUNDING IS ELEVATED (NEAR 2.5 KM)...WITH A
SATURATED MIXED LAYER...THERE ARE SEVERAL THINGS POINTING TOWARDS
ONLY A MINOR LES EVENT IN OUR CWA LATER TONIGHT AND EARLY TUESDAY.
FIRST...THE LAKE BAND IS NOT LIKELY TO PENETRATE VERY FAR INLAND
FROM THE SHORELINE...GIVEN THE LACK OF AN UPSTREAM CONNECTION...AND
FAIRLY LIGHT 0-1 KM WIND FLOW. ALSO...DENDRITE MECHANICS LOOK
RATHER POOR...WITH FORCED ASCENT LOCATED WELL UNDERNEATH THE
DENDRITE GROWTH ZONE. THIRD...THE CAPPING INVERSION SHOULD BEGIN
TO LOWER TOWARDS MORNING...WITH LOW-LEVEL WINDS ALSO VEERING
SOMEWHAT.
BOTTOM LINE...OUR CURRENT 1-3" FORECAST FOR PORTIONS OF NORTHERN
ONEIDA LOOKS GOOD...WITH RELATIVELY LITTLE ACCUMULATION EXPECTED
ACROSS ONONDAGA AND CENTRAL/SOUTHERN ONEIDA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...SFC HIGH PRES WILL BUILD OVER THE REGION DIMINISHING ANY
REMAINING LAKE EFFECT SNOW SHOWERS ACROSS NRN CWA BY MID MORNING.
SKIES WILL GENERALLY START OUT PARTLY SUNNY FOLLOWED BY INCREASING
MID CLOUDS AS THE NEXT SYSTEM STARTS INFLUENCING OUR WEATHER. MAX
TEMPS WILL GENERALLY RANGE IN THE MID TO UPPER 30S.
TUESDAY NIGHT...DEVELOPING SFC LOW IN THE MID WEST WILL DEEPEN AND
TRACK NORTHWEST INTO THE THE UPPER GREAT LAKES BY WED MORNING.
WHILE THIS OCCURS A SECONDARY BUT MUCH WEAKER SFC LOW DEVELOPS IN
THE VCNTY OF DELMARVA. LATEST MODEL RUNS ARE SLIGHTLY COLDER THAN
PREVIOUS RUN WITH PRECIP TYPE REMAINING SNOW EVERYWHERE UNTIL
DAYBREAK. ONLY EXCEPTION TO THIS WOULD BR ACROSS THE WYOMING
VALLEY WHERE RAIN/SNOW MIX WILL BE LIKELY. WITH STRONG SHOT OF
ISENTROPIC LIFT ENTIRE FA WILL SEE SNOW RAPIDLY SPREADING ACROSS
FA AFTER MIDNIGHT. SNOW ACCUM IN GENERAL WILL BE 2 TO 4 INCHES.
WEDNESDAY...AS PRIMARILY LOW CONTINUES TO TRACK NORTHEAST INTO THE
UPPER GREAT LAKES AND SOUTHERN ONTARIO LOW LEVEL WAA WILL CHANGE
PRECIP QUICKLY TO RAIN DURING THE MORNING. PRECIP MAY BRIEFLY
CHANGE TO SLEET AND FREEZING RAIN BUT ONLY FOR AN HOUR OR TWO.
WITH WEAK LOW OFF NEW JERSEY COAST COLD AIR MAY BE A BIT MORE
DIFFICULT TO REMOVE ACROSS THE WESTERN CATSKILLS/WESTERN MOHAWK
VALLEY. THIS AREA WILL HAVE A SLOWER TRANSITION BUT BY MIDDAY RAIN
SHOWERS SHOULD BE THE ONLY PRECIP TYPE. TOTAL SNOW ACCUM WILL BE 2
TO 5 INCHES.
BY AFTERNOON AREA MAY BE DRY SLOTTED WITH ONLY SCATTERED RAIN SHOWERS.
WEDNESDAY NIGHT/THURSDAY...BEHIND SYSTEM COLD AIR WILL GRADUALLY
DEEPEN OVER THE REGION WITH EVENING SNOW SHOWERS POSSIBLE. ATTM
FLOW REMAINS SOUTHWEST THROUGH THURSDAY WITH BULK OF LES REMAINING
NORTH OF FA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ALL GUIDANCE SUGGESTS A COLD WESTERLY FLOW PATTERN WILL START THIS
PERIOD (THURSDAY NIGHT AND FRIDAY). LAKE-EFFECT SNOWS WILL BE
ONGOING...WITH THE PROGGED SURFACE-850 MB FLOW TRAJECTORIES
SEEMINGLY PINPOINTING NORTHERN ONEIDA...OR PERHAPS NORTH OF OUR
FORECAST AREA (OSWEGO/LEWIS/JEFFERSON)...FOR THE MOST PERSISTENT
SNOW SHOWERS/SQUALLS. ONLY A FEW FLURRIES ANTICIPATED ELSEWHERE.
STILL A FAIR AMOUNT OF UNCERTAINTY THIS WEEKEND...WITH MOST MODEL
GUIDANCE SHOWING A SURFACE WAVE DEVELOPING OVER THE GULF OF MEXICO
BY SATURDAY...THEN MOVING NORTHEAST TOWARDS THE MID-ATLANTIC
COAST BY SUNDAY. PRESENT THINKING IS THAT MOST OF THE PRECIPITATION...
SPECIFICALLY FROM THIS SYSTEM...WILL STAY SOUTH AND EAST OF OUR
FORECAST AREA. SINCE THIS IS STILL SEVERAL DAYS AWAY...THOUGH...IT
WILL BEAR WATCHING.
AT ANY RATE...ONCE THIS SYSTEM PROGRESSES OFF TO OUR NORTHEAST
LATER SUNDAY AND MONDAY...LAKE-EFFECT ACTIVITY IN ITS WAKE LOOKS
LIMITED FROM THIS EARLY VANTAGE POINT...WITH HIGH PRESSURE QUICKLY
BUILDING IN.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
IFR CONDITIONS AT SYR AND RME WILL CONTINUE FOR 2 TO 4 HOURS THIS
EVENING. A 260 LL FLOW HAS BROUGHT ADDITIONAL MOISTURE OFF OF LAKE
ERIE TO THESE SITES. THIS IS ENHANCING THE SATURATED LOW LAYERS
FROM THE WEAK SYNOPTIC SYSTEM. THE FLOW WILL SHIFT TO NW LATE THIS
EVENING BRINGING SNOW SHOWERS OFF OF LAKE ONTARIO LATE TONIGHT TO
RME AND SYR. VSBYS COULD FALL TO IFR LATE TONIGHT. AROUND MIDNIGHT
THERE WILL BE A BREAK IN MVFR AND IFR.
OTHER SIRES WIL BE MOSTLY VFR. THE OTHER NY SITES COULD FALL TO
MVFR AS THE FLOW SHIFTS SOUTH PUSHING THE LAKE ERIE BAND THROUGH.
LATE TONIGHT ITH AND BGM COULD HAVE SOME MVFR CONDITIONS WITH
FINGER LAKE SNOW.
THE FLOW WILL WEAKEN AND SHIFT TO SE STARTING MIDDAY ENDING THE
LAKE EFFECT.
S TO SW WINDS AT 5 KTS OR LESS SHIFTING TO W LATE TONIGHT THEN NW
TUE MORNING. LATE TUE EASTERLY WINDS AT 5 KTS OR LESS.
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...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MLJ
SHORT TERM...RRM
LONG TERM...MLJ
AVIATION...TAC
