623
FXUS61 KBGM 090238
AFDBGM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
938 PM EST THU DEC 8 2022
SYNOPSIS
SPOTTY LAKE EFFECT SPRINKLES OR FLURRIES WILL OCCUR SOUTHEAST
OF LAKE ONTARIO, BEFORE ENDING OVERNIGHT. DRY, SEASONABLE AND
PARTLY SUNNY WEATHER IS EXPECTED FRIDAY AND SATURDAY. SUNDAY
WILL BRING LIGHT SNOW, MIXED WITH VALLEY RAIN. SOME LIGHT
SNOW ACCUMULATIONS ARE POSSIBLE. A FEW SNOW SHOWERS WILL LINGER
ON MONDAY, THEN DRY WEATHER IS LIKELY TUESDAY AND WEDNESDAY.
NEAR TERM /THROUGH FRIDAY NIGHT/
930 PM UPDATE...
FORECAST ADJUSTED TO KEEP UP WITH FINE DETAILS. SOME HOLES IN
THE CLOUDS OPENED UP IN YATES-STEUBEN COUNTIES WHICH ALLOWED FOR
MORE ABRUPT RADIATIONAL COOLING, THOUGH THIS IS ONLY TEMPORARY.
VEERING FLOW WILL SEND CLOUDS BACK INTO THAT AREA OVERNIGHT. IN
GENERAL, EXPECTATIONS HAVE NOT CHANGED.
PREVIOUS DISCUSSION...
AS OF 615 PM, THE CHANCES OF SPRINKLES/FLURRIES WERE TWEAKED
BASED ON LATEST HIGH-RESOLUTION MODELS AS WELL AS THE CANADIAN-
REGIONAL; LITTLE CHANGE OVERALL. MOISTURE DEPTH WILL CONTINUE
TO GET SHALLOWER WHICH WILL MOSTLY PREVENT ADDITIONAL
PRECIPITATION EXCEPT WHERE UPSLOPE AND LAKE MOISTURE MANAGE TO
EKE OUT A FEW RAINDROPS OR SNOWFLAKES; IN ALMOST ALL CASES NOT
EVEN MEASURABLE. WITH A LAYER OF MOISTURE TRAPPED UNDER A
LOWERING SUBSIDENCE INVERSION, I UTILIZED THE NAM MODEL RELATIVE
HUMIDITY VALUES WITHIN 925-850MB LEVEL TO SOMEWHAT DELAY
BREAKUP OF CLOUDS ESPECIALLY WEST OF I-81 FRIDAY MORNING.
HOWEVER, WITH FLOW ABOVE THE BOUNDARY LAYER VEERING DRY
NORTHEASTERLY, THIS WILL TEND TO MIX OUT/BREAK UP HEADING INTO
FRIDAY AFTERNOON.
GENERALLY QUIET AND SEASONABLE WEATHER IN THE NEAR TERM.
EVENTUALLY DRIER AIR WORKS IN FROM THE NORTHEAST COURTESY OF A
SPRAWLING 1040MB HIGH ALONG THE CENTRAL ONTARIO/QUEBEC BORDER.
WITH THE CLOUD COVER EXPECTED TO REMAIN IN PLACE MOST OF THE
NIGHT (EXCEPT FOR OUR FAR EASTERN ZONES) DECIDED TO GO A FEW
DEGREES ABOVE THE NBM GUIDANCE FOR OVERNIGHT LOWS...KEEPING
TEMPERATURES IN THE UPPER 20S TO LOWER 30S...EXCEPT LOW TO
MID-20S FOR ONEIDA COUNTY AND THE CATSKILLS (WHERE CLEARING
LOOKS TO TAKE PLACE LATE).
HEADING INTO FRIDAY, THERE WILL STILL BE SOME LINGERING STRATUS
CLOUDS OVER THE CENTRAL TO WESTERN HALF OF THE CWA. THESE WILL
SHIFT WEST, SCATTER OUT AND DISSIPATE BY MID TO LATE MORNING AS
HIGH PRESSURE CONTINUES TO BUILD. EXPECT PARTLY TO MOSTLY SUNNY
SKIES MIDDAY, INTO THE AFTERNOON AREAWIDE WITH LIGHT NORTHERLY
WINDS. TEMPERATURES WILL BE SEASONABLE, WITH HIGHS IN THE UPPER
30S TO MID-40S EXPECTED. QUIET AND COLD WEATHER EXPECTED FRIDAY
NIGHT, UNDER CLEAR SKIES AND LIGHT WINDS. THE CANADIAN HIGH
REMAINS IN PLACE JUST TO OUR NORTH IN QUEBEC AND STRENGTHENS TO
AROUND 1050MB BY DAYBREAK. THIS DRY NORTH-NORTHEAST FLOW SHOULD
ALLOW OVERNIGHT LOWS TO DIP DOWN INTO THE 10S TO LOWER 20S.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
340 PM UPDATE...
THE MAIN CONCERN IN THE NEAR TERM IS GOING TO BE A CHANCE OF
ACCUMULATING SNOW ON SUNDAY INTO EARLY MONDAY. SATURDAY STARTS
OFF WITH STRONG HIGH PRESSURE TO THE NORTH HELPING SUPPRESS A
SHORTWAVE APPROACHING FROM THE WEST. WEAK UPPER LEVEL RIDGING
BUILDS IN HELPING KEEP THE SKIES SOMEWHAT CLEAR IN THE MORNING
BUT INCREASING SW FLOW IN THE AFTERNOON BRINGS IN CLOUDS FROM
THE SW AHEAD OF SUNDAYS SHORTWAVE.
SATURDAY NIGHT INTO SUNDAY, THE UPPER LEVEL RIDGE BREAKS DOWN
WITH SOME LOW LEVEL MOISTURE ADVECTING IN AHEAD OF THE
SHORTWAVE. 12Z MODEL RUNS HAVE SHOWN A LESS FAVORABLE
INTERACTION WITH THE NORTHERN VORT MAX AND THE SOUTHERN VORT MAX
SO THERE IS LESS OF A PHASE BETWEEN THE TWO MEANING THE
SHORTWAVE IS LOOKING A LITTLE WEAKER AND FURTHER NORTH AS IT
MOVES IN. TRENDS WILL BE WATCHED TO SEE IF THE SOUTHERN WAVE
WILL CONTINUE TO SLOW AND IF THERE IS BETTER INTERACTION WITH
THE NORTHERN WAVE OVER EASTERN CANADA THAT COULD CONTINUE TO
PULL THE SHORTWAVE NORTH. ISENTROPIC LIFT WILL STILL BE ENOUGH
TO GET PRECIPITATION TO DEVELOP AND OVERSPREAD THE REGION FROM
WEST TO EAST LATE SATURDAY NIGHT INTO SUNDAY. FORECAST SOUNDINGS
FROM THIS AFTERNOON ARE SHOWING THAT THE BEST LIFT IS JUST
OUTSIDE OF THE DGZ BUT THERE WILL STILL BE DENDRITE DEVELOPMENT
AND THERE WILL BE DEEP ENOUGH MOISTURE BELOW THE DGZ FOR THE
DENDRITES TO LIKELY BECOME SOMEWHAT RIMED RESULTING IN HIGHER
RATIOS. RIGHT NOW 8-9:1 RATIOS WERE USED THROUGH THE EVENT TO
CALCULATE SNOW TOTALS. PRECIPITATION RATES WILL ALSO BE LIGHT
BUT PERSISTENT THROUGH THE DAY SUNDAY INTO SUNDAY NIGHT. 6 HOUR
QPF IS LARGELY UNDER A TENTH OF AN INCH WITH HIGHER ELEVATIONS
GETTING TO AS HIGH AS 0.15 IN A 6 HOUR PERIOD. THIS MEANS THAT
THE SNOWFALL RATES WILL BE LIGHT THROUGH THE STORM AND MOST
LIKELY STAY BELOW A HALF INCH PER HOUR. THE LACK OF
FRONTOGENESIS AS WELL GIVES LOWER CONFIDENCE THAT THERE WILL BE
ANY BANDING WITH THIS EVENT THAT COULD RESULT IN LOCALLY HIGHER
AMOUNTS.
LOOKING AT SNOW TOTALS AND PROBABILITIES, THE NBM ONLY GIVES
ABOUT A 30% CHANCE OF EXCEEDING ADVISORY AMOUNTS MAINLY LIMITED
TO HIGHER ELEVATIONS THAT WILL BE COLDER AND SEE A LITTLE HIGHER
SNOW RATIOS. THERE IS ALSO A GREATER WEIGHT TOWARDS LOWER END
AMOUNTS AS WELL WITH QUITE A FEW MEMBERS SHOWING LOWER END SNOW
AMOUNTS OF LESS THAN 2 INCHES ESPECIALLY FOR THE SOUTHERN TIER
AND SOUTH GIVEN THE NORTHERN NUDGE OF THE SHORTWAVE IN RECENT
RUNS. AS OF NOW IT IS LOOKING LIKE VALLEYS WILL SEE 2 INCHES OR
LESS WITH HIGHER ELEVATIONS OF CNY SEEING UP TO 3 INCHES.
LONG TERM /MONDAY THROUGH THURSDAY/
340 PM UPDATE
THE LONG TERM IS LOOKING COOLER WITH THE POSSIBILITY OF A LATE
WEEK SYSTEM. SOME SNOW WILL CONTINUE INTO MONDAY MORNING AS CAA
BEHIND THE DEPARTING SHORTWAVE AND DEVELOPING COASTAL LOW
STEEPENS LOW LEVEL LAPSE RATES WITH SOME LAKE EFFECT SNOW
SHOWERS POSSIBLE IN THE FINGER LAKES. AS THE COASTAL LOW MOVES
INTO THE CANADIAN MARITIMES IT RETROGRADES DUE TO STRONG
GREENLAND BLOCKING WITH A RIDGE OF HIGH PRESSURE DEVELOPING OVER
MUCH OF THE MID ATLANTIC UP INTO THE GREAT LAKES REGION. A
DEVELOPING COLORADO LOW IN THE PLAINS HELPS STRENGTHEN THE UPPER
LEVEL RIDGING BETWEEN THE TWO SYSTEMS KEEPING US DRY THROUGH
MID WEEK. THE CHANCES OF PRECIPITATION WAS PUSHED LATER IN THE
WEEK AS THE SYSTEM IN THE PLAINS STRUGGLES TO PROGRESS EAST WITH
THE RETROGRADING SYSTEM IN THE CANADIAN MARITIMES. WITH
PRECIPITATION MOVING IN LATER IN THE WEEK AND A MORE FAVORABLE
UPPER LEVEL PATTERN FOR COLD AIR ACROSS MUCH OF THE NORTHEAST
ESPECIALLY IN THE LOWER ATMOSPHERE. PRECIPITATION TYPES WERE
TOUGH TO FIGURE OUT AND REALLY THIS FAR OUT NOT MUCH TIME WAS
PUT INTO IT QUITE YET. LOOKING AT THE WPC CLUSTER ANALYSIS TOOL,
THERE IS A STRONG SIGNAL OF RIDGING IN ALASKA BUT STILL A
PACIFIC TROUGH. COLD AIR WILL STILL BE ABLE TO SPILL INTO THE
NORTHERN US BUT WILL LIKELY BE MODIFIED BY THE TIME IT GETS
HERE. THERE IS HIGH CONFIDENCE THAT THE TEMPERATURES WILL BE
BELOW AVERAGE BUT THE ANOMALIES WONT BE SIGNIFICANTLY BELOW
AVERAGE. THE PATTERN IS ALSO FAVORABLE THAT AS THE SYSTEM IN THE
PLAINS OCCLUDES, A NEW SYSTEM WILL LIKELY FORM AT THE TRIPLE
POINT OF THE OCCLUDING FRONT EXTENDING INTO THE CENTRAL AND
EASTERN US. WHERE THIS LOW FORMS WILL DETERMINE THE PTYPES WITH
A MORE SNOWY SOLUTION WITH A COASTAL LOW BUT A MIXED PRECIP
EVENT IS MORE LIKELY IF THE NEW LOW FORMS WEST OF THE
APPALACHIAN MOUNTAINS.
AVIATION /03Z FRIDAY THROUGH TUESDAY/
630 PM UPDATE...
A COLD NORTHWEST TO NORTH UPSLOPE FLOW WILL KEEP STRATUS CLOUDS
LOCKED IN OVER JUST ABOUT THE ENTIRE FORECAST AREA TONIGHT.
WITH THE LOW LEVEL WINDS TURNING MORE TO THE NORTH, VFR CIGS AT
RME WILL SCATTER OUT. SYR SHOULD REMAIN VFR AND SCATTER OUT LATE
TONIGHT OR FRIDAY MORNING. AVP WILL BE SIMILAR TO SYR.
BGM/ITH/ELM WILL BE SIMILAR. MOISTURE FROM LAKE ONTARIO AND THE
FINGER LAKES IS LOCKED IN UNDER THE INVERSION. BGM/ITH HAVE/WILL
BE SOON MVFR CIGS. THIS DROPS TO FUEL ALTERNATE AROUND 10Z. ELM
WILL BECOME MVFR AROUND 04Z, THEN POSSIBLY FUEL ALTERNATE 11 TO
14Z. ALL 3 SITES SCATTER OUT AROUND 16Z.
NORTHWEST TO NORTH WINDS AT 5 KTS TONIGHT, BECOME NORTH AT 5 TO
10 KTS FRIDAY.
OUTLOOK...
FRIDAY NIGHT THROUGH SATURDAY NIGHT...VFR EXPECTED.
SUNDAY THROUGH MONDAY...CHANCE OF SNOW OR MIXED RAIN AND SNOW
WITH ASSOCIATED RESTRICTIONS. SLOW IMPROVEMENTS ON MONDAY.
TUESDAY...VFR EXPECTED UNDER HIGH PRESSURE.
BGM WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NY...NONE.
SYNOPSIS...MJM/MDP
NEAR TERM...MJM/MDP
SHORT TERM...AJG
LONG TERM...AJG
AVIATION...TAC
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