664
FXUS61 KALY 220757
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
257 AM EST MON DEC 22 2025
WHAT HAS CHANGED
WINTER WEATHER ADVISORIES FOR SOUTHERN HERKIMER COUNTY HAS ENDED
NOW THAT THE LAKE EFFECT BAND HAS WEAKENED AND SHIFTED SOUTH.
THE TIMING FOR THE SNOW EVENT MONDAY NIGHT INTO TUESDAY HAS
SHIFTED SLIGHTLY LATER WITH MORE CONFIDENCE IN SNOW ARRIVING
FROM SOUTHWEST TO NORTHEAST RIGHT AT THE START OF THE A.M
COMMUTE INSTEAD OF OVERNIGHT.
TEMPERATURES FOR FRIDAY HAVE TRENDED COLDER AND THEREFORE
PRECIPITATION TYPE NOW FAVORS MORE SNOW AT THE START OF THE
EVENT. THERE REMAINS UNCERTAINTY IN HOW AND WHERE PRECIPITATION
TYPES CHANGE DURING THE DAY FRIDAY AS WARM AIR ADVECTS FROM
SOUTH TO NORTH.
KEY MESSAGES
1. MODERATE TO HIGH CONFIDENCE IN THE POTENTIAL FOR A LIGHT SNOWFALL
EVENT ON TUESDAY WITH MODERATE AMOUNTS IN THE SOUTHERN ADIRONDACKS
AND SOUTHERN GREENS. THE START OF THE EVENT LIKELY IMPACTS THE
MORNING COMMUTE WITH SNOW CHANGING TO A WINTRY MIX BY THE
AFTERNOON/EVENING BEFORE TRANSITIONING BACK TO SNOW SHOWERS
OVERNIGHT. THERE IS A 50 TO 75% CHANCE FOR AT LEAST 2 INCHES OF
SNOW REGIONWIDE.
2. AFTER A QUIET STRETCH CHRISTMAS EVE/DAY, THERE IS INCREASING
CONFIDENCE FOR ANOTHER DISTURBANCE ON FRIDAY WITH A 50-60%
CHANCE THAT 24-HR PRECIPITATION AMOUNTS EXCEED 0.50" REGIONWIDE.
TEMPERATURES HAVE TRENDED COLDER AND NOW FAVOR MAINLY SNOW AT
LEAST FOR THE START OF THE EVENT BEFORE UNCERTAINTY IN P-TYPE
INCREASES AS WARMER AIR TRIES TO NOSE NORTHWARD.
DISCUSSION
KEY MESSAGE 1...
LARGE SCALE RIDGING BUILDS NORTHEASTWARD FROM THE SOUTHERN
PLAINS HEADING INTO TUESDAY WITH A CONVEYOR BELT OF FAST WEST-
NORTHWEST FLOW ALONG ITS NORTHERN PERIPHERY. AN EMBEDDED SHORTWAVE
IN THE UPPER PLAINS RESULTS IN A SFC LOW WITH AN AREA OF ENHANCED
WARM AIR AND MOISTURE ADVECTION AHEAD OF ITS WARM FRONT LEADING
TO AN ORGANIZED PRECIPITATION SHIELD THAT EXPANDS FROM THE OHIO
VALLEY INTO EASTERN NY AND WESTERN NEW ENGLAND EARLY TUESDAY
MORNING. WITH SHORTWAVE RIDGING DEVELOPING AHEAD OF THE WARM AIR
ADVECTION MONDAY NIGHT, THE ONSET OF THE PRECIPITATION HAS
TRENDED SLIGHTLY LATER AND NOW LOOKS TO ARRIVE FROM SOUTHWEST TO
NORTHEAST 09 - 15 UTC TUESDAY OR BEGINNING DURING THE A.M
COMMUTE (ESPECIALLY SOUTH OF I-90). SNOW LOOKS TO HOLD OFF FOR AREAS
NORTH OF THE CAPITAL DISTRICT UNTIL THE TAIL END OF THE A.M
COMMUTE. INITIAL THERMAL PROFILES FAVOR SNOW ACROSS THE REGION
WITH A PERIOD OF STEADY LIGHT SNOW LASTING FOR A FEW HOURS DUE
TO ENHANCED MID-LEVEL FRONTOGENESIS; HOWEVER, OVERALL FORCING
LOOKS WEAK SO NOT EXPECTING ANY HEAVY SNOWFALL RATES. IN FACT, STRENGTHENING
SOUTHWEST FLOW ALOFT LOOKS TO LEAD TO DOWNSLOPING OFF THE
CATSKILLS WHICH SHOULD ACT TO WEAKEN SNOWFALL INTENSITY IN THE
CAPITAL DISTRICT, PARTS OF THE NORTHERN CATSKILLS AND MID-HUDSON
VALLEY BY EARLY AFTERNOON. THERE IS EVEN POTENTIAL FOR SOME
PATCHY FREEZING RAIN WHERE TEMPERATURES REMAIN NEAR OR SLIGHTLY
BELOW FREEZING AS THE MID- LEVELS DRY OUT AND NO LONGER SUPPORT
ICE NUCLEI IN THE CLOUDS. MEANWHILE, SNOW CONTINUES IN THE
UPPER HUDSON VALLEY, SOUTHERN ADIRONDACKS, AND WESTERN NEW
ENGLAND (POTENTIALLY MIXING WITH SLEET AS WARM AIR SURGES
NORTHWARD) WITH UPSLOPING ENHANCING SNOWFALL ALONG SOUTH FACING
SLOPES IN THE SOUTHERN ADIRONDACKS. CURRENT FORECAST PREDICTS A
GENERAL 1 TO 3 INCHES OF SNOW REGIONWIDE DURING THE DAY TUESDAY.
THE HIGHEST AMOUNTS ARE EXPECTED IN THE SOUTHERN ADIRONDACKS
WHERE THERE IS A 30% CHANCE OF EXCEEDING 4 INCHES AND CONFIDENCE
IS HIGHEST IN NEEDING A WINTER WEATHER ADVISORY.
THE STRONGEST FORCING FOR ASCENT AND AXIS OF MID-LEVEL MOISTURE EXITS
TO OUR NORTH BY 21 - 00 UTC AS A DRY SLOT PUNCHES NORTHWARD
ALLOWING PRECIPITATION REGIONWIDE TO DECREASE IN COVERAGE AND
INTENSITY. WITH SFC TEMPERATURES REMAINING IN THE LOW TO MID 30S
IN VALLEY AREAS, PATCHY PLAIN RAIN SHOWERS LINGERS INTO THE
EVENING HOURS WHILE SFC TEMPERATURES IN HIGHER TERRAIN AREAS OF
THE NORTHERN/EASTERN CATSKILLS, UPPER HUDSON VALLEY, AND IN
WESTERN NEW ENGLAND HOVER IN THE UPPER 20S/LOW 30S SUPPORTING
MORE PATCHY FREEZING RAIN AS FORECAST SOUNDINGS SUGGEST CLOUDS
ARE TOO MILD TO SUPPORT ICE NUCLEI. WHILE THE DRY SLOT LINGERS
THROUGH ABOUT 06 UTC, THE MAIN COMPACT AND RATHER VIGOROUS
SHORTWAVE AND ASSOCIATED ARCTIC COLD FRONT SWEEP ACROSS THE
NORTHEAST FROM 06-12 UTC. THIS SHOULD RESULT IN A SECOND PERIOD
OF SNOW SHOWERS AS WESTERLY WINDS TURN QUITE GUSTY AND USHER IN
A CHILLY CANADIAN AIR MASS WITH A 50 TO 75% CHANCE FOR GUSTS TO
EXCEED 30MPH. AN ADDITIONAL COATING TO 2 INCHES OF SNOW IS
EXPECTED OVERNIGHT WITH THE HIGHEST SNOWFALL AMOUNTS LIKELY
ACROSS THE SOUTHERN ADIRONDACKS AND SOUTHERN GREENS WHERE
WESTERLY WINDS CAN UPSLOPE THE TERRAIN. LUCKILY, MOST OF THE
SNOW SHOWERS DIMINISH WEDNESDAY MORNING AS HIGH PRESSURE BUILDS
ACROSS THE REGION WITH GUSTY WINDS DECREASING BY THE AFTERNOON.
KEY MESSAGE 2...
HIGH PRESSURE AT THE SURFACE AND RIDGING ALOFT BUILD OVER THE REGION
FOR CHRISTMAS EVE INTO CHRISTMAS DAY, RESULTING IN TRANQUIL
WEATHER CONDITIONS WITH SEASONABLE TEMPERATURES.
WE CONTINUE TO KEEP A CLOSE EYE ON OUR NEXT POTENTIAL FOR
WIDESPREAD PRECIPITATION FRIDAY INTO SATURDAY AS THE CONVEYOR
BELT OF FAST NORTHWESTERLY FLOW REMAINS POSITIONED ACROSS THE
GREAT LAKES INTO THE NORTHEAST WITH YET ANOTHER SHORTWAVE
TRACKING WITHIN IT. THIS TIME, A LARGE SCALE CANADIAN HIGH LOOKS
TO BE LOCKED ACROSS EASTERN ONTARIO INTO QUEBEC WHICH MAINTAINS
A SOURCE OF CHILLY AIR TO OUR NORTH. AS THE SHORTWAVE APPROACHES
DURING THE DAY ON FRIDAY, THE INITIAL SURGE OF WARM AIR/MOISTURE
ADVECTION AHEAD OF IT SHOULD PROVIDE ENOUGH FORCING FOR ASCENT
TO RESULT IN ANOTHER ORGANIZED PRECIPITATION SHIELD. GIVEN THE
COLDER AIR MASS TO OUR NORTH, THERMAL PROFILES ONCE AGAIN LIKELY
SUPPORT MAINLY SNOW TO START. THERE REMAINS SOME UNCERTAINTY ON
THE OVERALL TRACK OF THE INCOMING SFC LOW WHICH WILL DETERMINE
HOW AND IF PRECIPITATION TYPE CHANGES AS A FURTHER NORTH TRACK
WOULD ALLOW WARMER AIR TO SURGE NORTHWARD SUPPORTING A
TRANSITION TO A WINTRY MIX WHILE A FURTHER SOUTH TRACK WOULD
SUPPORT MAINLY SNOW. LATEST GUIDANCE HAS TRENDED FURTHER SOUTH
WITH THE SFC LOW TRACK SUGGESTING A COLDER SOLUTION; HOWEVER,
THE SPREAD BETWEEN THE 25TH AND 75TH PERCENTILE IN SFC
TEMPERATURES ON FRIDAY REMAINS QUITE HIGH RANGING 15 TO 20
DEGREES SO WE CONTINUE TO MESSAGE INITIAL SNOW ON FRIDAY
CHANGING TO A RAIN/SNOW MIX IN VALLEY AREAS WHILE HIGHER TERRAIN
AREAS REMAIN ALL SNOW. GIVEN THERE IS A 50 TO 60% CHANCE FOR
REGIONWIDE 24-HR PRECIPITATION AMOUNTS TO EXCEED 0.50" FROM 7AM
FRI TO 7AM SAT AND THAT INITIAL PRECIPITATION FAVORS SNOW
REGIONWIDE, WE ARE BECOMING CONCERNED FOR SLIPPERY TRAVEL DURING
THIS PERIOD, ESPECIALLY IN THE HILL TOWNS AND HIGHER TERRAIN
AREAS WHERE PRECIPITATION TYPE FAVORS MORE SNOW. WHILE THERE IS
AN INCREASING CONSENSUS FOR A WIDESPREAD AND MODERATE
PRECIPITATION EVENT, THE UNCERTAINTY IS TIED TO TEMPERATURES
AND IF AND WHERE PRECIPITATION TYPES CHANGE BASED ON THE STORM
TRACK AND THE INFLUENCE OF THE CANADIAN HIGH TO THE NORTH. THE
00 UTC/22 GEFS AND ENS ENSEMBLES SUGGEST A 30 TO 60% CHANCE FOR
AT LEAST 2 INCHES OF SNOW REGIONWIDE THROUGH 1AM SATURDAY WHILE
THE GEPS SHOW SLIGHTLY LOWER PROBABILITIES AT 20 TO 40%. WE WILL
CONTINUE TO MONITOR TRENDS AS THIS EVENT CAN IMPACT POST-
HOLIDAY TRAVEL.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THROUGH 06Z TUESDAY...VFR CONDITIONS EXPECTED TO PREVAIL
THROUGH THE 24 HOUR TAF PERIOD. SCT-BKN LAKE EFFECT CLOUDS WILL
CONTINUE MOVE ACROSS THE TAF SITES PRIOR TO 12Z, ESPECIALLY
KALB/KPSF IN THE NW FLOW REGIME. CLOUDS SHOULD GENERALLY
DISSIPATE BY 12Z AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM THE
WEST. SCT-BKN MID LEVEL CLOUDS WILL BE AROUND LATER THIS MORNING
THROUGH THE AFTERNOON, WITH OVC SKIES DEVELOPING THIS EVENING
AHEAD OF A CLIPPER SYSTEM STARTING TO APPROACH FROM THE UPPER
GREAT LAKES. WINDS WILL INITIALLY BE NORTHWEST AROUND 8-15 KT
WITH GUSTS OF 20-25 KT LOWERING T 5-10 KT BY LATER THIS MORNING.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHRA...SHSN.
WEDNESDAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
CHRISTMAS DAY: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
FRIDAY: HIGH OPERATIONAL IMPACT. DEFINITE SN.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
DISCUSSION...31
AVIATION...07
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