671
FXUS61 KALY 191731
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1231 PM EST FRI DEC 19 2025
WHAT HAS CHANGED
ASIDE FROM MINOR ADJUSTMENTS TO REFLECT LATEST OBSERVATIONS AND
MODEL TRENDS, NO CHANGES WERE MADE THAT WOULD SIGNIFICANTLY
ALTER THE INTEGRITY OF THE PREVIOUS FORECAST. WIDESPREAD
RAINFALL, BECOMING MODERATE TO LOCALLY HEAVY AT TIMES, AND
STRONG WIND GUSTS REMAIN THE PRIMARY CONCERN OVER THE NEXT
TWENTY-FOUR HOURS.
KEY MESSAGES
1. WIDESPREAD RAINFALL WILL LAST THROUGH THIS EVENING, BECOMING
MODERATE TO LOCALLY HEAVY AT TIMES AND POSING THE POTENTIAL FOR
NUISANCE URBAN AND POOR DRAINAGE PONDING OF WATER.
2. THE POTENTIAL FOR ISOLATED RUMBLES OF THUNDER EXISTS AROUND
MID-MORNING THROUGH EARLY AFTERNOON TODAY WITHIN A HEAVY BAND OF
RAIN THAT WILL TRAVERSE EASTERN NEW YORK AND WESTERN NEW ENGLAND
FROM WEST TO EAST.
3. STRONG SOUTH TO SOUTHEASTERLY WINDS THROUGH THIS MORNING WILL
POSE THE THREAT OF POWER OUTAGES AND POTENTIAL PROPERTY DAMAGE
SHOULD TREES, TREE LIMBS, AND/OR WIRES BE DOWNED. WINDS WILL
REMAIN STRONG THROUGH LATE THIS EVENING, MAINTAINING THIS
THREAT, BUT WILL INSTEAD BE BLOWING OUT OF THE WEST BEGINNING
THIS AFTERNOON.
4. COLD WEATHER SWIFTLY RETURNS TONIGHT, RESULTING IN PATCHY
FREEZING AND SUBSEQUENT SLIPPERY SURFACES.
5. THE UPCOMING WEEK FEATURES THE CONTINUATION OF AN ACTIVE
WEATHER PATTERN THAT COULD IMPACT HOLIDAY TRAVEL.
DISCUSSION
KEY MESSAGE 1...
A POTENT SURFACE LOW PRESSURE SYSTEM, CURRENTLY RESIDING IN
SOUTHWEST ONTARIO AT A PRESSURE OF 982MB, WILL TRAVERSE
SOUTHEAST CANADA TODAY BENEATH A NEGATIVELY- TILTED, UPPER-LEVEL
TROUGH. AHEAD OF THE PRIMARY, COLD FRONTAL BOUNDARY ASSOCIATED
WITH THE LOW, A SOUTHERLY FLOW REGIME HAS INFLICTED UNSEASONABLE
AND NON-DIURNAL WARMTH ACROSS THE REGION. IN FACT, HIGH
TEMPERATURES WILL OCCUR LATER THIS MORNING AHEAD OF THE FROPA
AND COULD CHALLENGE THE DAILY RECORD TEMPERATURES AT TWO OF OUR
CLIMATE SITES. SEE THE CLIMATE SECTION BELOW FOR ADDITIONAL
DETAILS.
AN INITIAL SURGE OF WARM-ADVECTION RAIN IS ANTICIPATED TO
SPREAD INTO THE REGION FROM SOUTH TO NORTH THIS MORNING AS
PERSISTENT SOUTHERLY FLOW PROVIDES AN INFLUX OF MOISTURE INTO
THE DIVERGENT, RIGHT ENTRANCE REGION OF THE UPPER JET.
INITIALLY, RAINFALL RATES WILL BE ON THE LIGHTER SIDE AS THE
STRONGEST FORCING REMAINS TIGHTLY BOUND TO THE COLD FRONT.
ADDITIONALLY, THIS PRELIMINARY BATCH OF RAIN WILL HAVE TO
COMPETE WITH DRY AIR ENTRAINING INTO THE LEADING EDGE OF THE
UPPER TROUGH, WHICH CAN CLEARLY BE SEEN ON LATEST WATER VAPOR
IMAGERY AND WITHIN A DRY SLOT ON THE NORTHEAST MOSAIC RADAR.
BY ABOUT MID-MORNING, THE AFOREMENTIONED COLD FRONT WILL BE
ENCROACHING UPON THE WESTERN BOUNDARY OF OUR CWA, BRINGING WITH
IT A RATHER INTENSE COOL-FRONTAL RAIN BAND. A VERY STRONG AXIS
OF FRONTOGENETICAL FORCING, A STEEP THETA-E GRADIENT, OMEGA
INTERSECTING A DEEP MOIST LAYER, AND LLJ DYNAMICS ALIGN WITH
THIS BAND, LEADING LATEST CAMS TO INDICATE POTENTIAL RAINFALL
RATES OF 0.25" TO 0.5" PER HOUR. IN FACT, FORECAST SOUNDINGS
INDICATE K INDICES OF AROUND 24-27 WHICH HINT AT THE INCREASED
POTENTIAL FOR HEAVY RAIN.
ALL THAT SAID, THIS WILL BE A VERY PROGRESSIVE BAND, AS ITS
PARENT FRONT IS ALSO QUITE PROGRESSIVE. THEREFORE, IT IS NOT
EXPECTED THAT HEAVY RAINFALL RATES WILL LINGER OVER A GIVEN AREA
FOR EXTENDED PERIODS OF TIME. FLASH FLOODING IS SUBSEQUENTLY NOT
ANTICIPATED. HOWEVER, GIVEN THE MODERATE TO LOCALLY HEAVY
RAINFALL RATES AT TIMES, ESPECIALLY WITHIN THE BAND ITSELF AND
WHEN THE BAND CONGEALS WITH THE BATCH OF RAIN AHEAD OF IT,
THERE IS A POTENTIAL FOR LOCALIZED PONDING OF WATER IN URBAN AND
POOR-DRAINAGE AREAS. THIS PONDING WILL BE ENHANCED BY SNOWMELT
FROM THE PRE-EXISTING SNOWPACK. ADDITIONALLY, MODEST RISES,
ESPECIALLY SMALL CREEKS AND STREAMS, CAN ALSO BE EXPECTED FROM
THE SAME FACTORS. BUT THE PROGRESSIVE NATURE OF THE STORM WILL
NOT ALLOW TIME ENOUGH FOR ANY MAIN-STEM RIVERS TO EVEN FLIRT
WITH ACTION STAGE.
KEY MESSAGE 2...
THE AFOREMENTIONED COOL-FRONTAL RAIN BAND POSES A RARE, THOUGH
LIMITED, THREAT OF THUNDER FOR LATE DECEMBER. THOUGH THERE IS AN
OVERALL LACK OF EVEN ELEVATED INSTABILITY, THE POTENCY OF THE
FORCING COULD BE SUFFICIENT TO OVERCOME IT.
FORECAST SOUNDINGS INDICATE VERY STRONG AND DEEP OMEGA
INTERSECTING DEEP MOISTURE THROUGHOUT THE COLUMN. SUCH RAPID
VERTICAL MOTION WILL LEAD TO RAPID COOLING. TO AID THIS FURTHER,
FORECAST SOUNDINGS ALSO INDICATE, FOR THE MOST PART, THE
STRONGEST OMEGA INTERSECTING THE STEEPEST LAPSE RATES WITHIN THE
850-500MB LAYER. THIS WILL ONLY HELP TO FURTHER ENHANCE THE RATE
AT WHICH AIR COOLS, LEADING TO THE EXPECTATION THAT DYNAMICAL
FORCING ALONE COULD BE THE DRIVING FACTOR IN SOME ISOLATED
RUMBLES OF THUNDER WITHIN THE BAND. HAVE THEREFORE INCLUDED SOME
ISOLATED RUMBLES ALONG THE PROGRESSION OF THE BAND WITHIN THE
FORECAST. WE ALSO MENTIONED GUSTY WINDS AS DOWNWARD MOMENTUM
TRANSFER FROM RAPID COOLING, PRECIPITATION LOADING, AND HEAVY
RAINFALL RATES COULD CAUSE ISOLATED WIND GUSTS WHOSE MAGNITUDES
SURPASS THAT WHICH IS COVERED BY THE CURRENT WIND ADVISORY.
KEY MESSAGE 3...
SOUTH TO SOUTHEASTERLY WINDS WILL REMAIN IN PLACE THROUGH THIS
MORNING BEFORE SHARPLY VEERING TO THE WEST IN THE WAKE OF THE
COLD FRONT THIS AFTERNOON. ACCORDING TO THE LATEST HIRES MODELS,
THE 850 MB LLJ WILL SURGE TO 65-80KT THIS MORNING AHEAD OF THE
COLD FRONT, GIVING SURFACE WINDS THE POTENTIAL TO REACH
SUSTAINED SPEEDS OF 15 TO 30 MPH WITH GUSTS UP TO 50-60 MPH.
NOW, WHAT MAY HINDER THIS IS THE LOW-LEVEL INVERSION THAT LOOKS
FAIRLY PROMINENT ON LATEST FORECAST SOUNDINGS COMPARED TO
PREVIOUS. HOWEVER, WITH PRECIPITATION LOADING, RAPID COOLING
WITHIN THE COLUMN, AND STEEP PRESSURE FALLS, IT IS CERTAINLY
POSSIBLE FOR THIS TO BE OVERCOME.
ONCE WINDS VEER TO THE WEST THIS AFTERNOON BEHIND THE FRONT,
RAPID COOLING AND STEEP PRESSURE RISES INTO LATE THIS EVENING
WILL CONTINUE TO SUPPORT STRONG WINDS. THE NEW REGIME WILL ALSO
SUPPORT DOWNSLOPING OFF THE HIGHER TERRAIN AND CHANNELING DOWN
THE MOHAWK AND HUDSON VALLEYS, SO CONFIDENCE IS HIGHER IN WINDS
REACHING THE AFOREMENTIONED MAGNITUDES DURING THIS TIME PERIOD.
KEY MESSAGE 4...
PERSISTENT COLD AIR ADVECTION IN THE WAKE OF THE COLD FRONT,
AND EVENTUALLY THE UPPER-LEVEL TROUGH BY LATE TONIGHT, WILL BE
SUPPORTED THROUGH THE NEWLY-INTRODUCED WESTERLY FLOW REGIME
TONIGHT INTO SATURDAY. HOWEVER, RAPIDLY COOLING TEMPERATURES
WILL NOT BE MET WITH RAPID REDUCTIONS IN WIND SPEEDS. WITH STEEP
PRESSURE RISES ANTICIPATED THROUGH TONIGHT AS HIGH PRESSURE
SLIDES EASTWARD, WINDS WILL REMAIN GUSTY IN MOST AREAS.
THEREFORE, DESPITE AN OVERALL GRADUAL DECLINE IN WIND SPEEDS,
THE PROBABILITY OF A WIDESPREAD FLASH FREEZE IS VERY LOW AS
PREVIOUSLY WET SURFACES COULD DRY OUT BEFORE BECOMING ICY. THAT
SAID, PATCHES OF SLIPPERY, ICY SURFACES WILL BE POSSIBLE,
ESPECIALLY IN PORTIONS OF THE MID-HUDSON VALLEY, UPPER-HUDSON
VALLEY, AND WESTERN ADIRONDACKS WHERE THE LOWEST WIND SPEEDS ARE
ANTICIPATED AND WHERE ROADWAYS GO UNTREATED.
KEY MESSAGE 5...
LATEST MEDIUM TO LONG RANGE GUIDANCE IS HINTING AT A CLIPPER
SYSTEM THAT COULD IMPACT HOLIDAY TRAVEL LATER THIS WEEK. WHILE
THE SYSTEM ITSELF APPEARS MORE ROBUST THAN IN PREVIOUS RUNS,
THERE STILL REMAINS MANY TIMING DISCREPANCIES BETWEEN MODEL
SOLUTIONS. THAT SAID, THE HIGHEST PROBABILITIES FOR ADVISORY-
LEVEL (>4") OF SNOWFALL ARE ATTRIBUTED TO TUESDAY EVENING,
ACCORDING TO THE LATEST NBM, MAINLY ACROSS THE HIGHER TERRAIN.
HOWEVER, THESE PROBABILITIES ONLY SPAN 10-25% SO CONFIDENCE
REMAINS LOW IN SIGNIFICANTLY IMPACTFUL WEATHER AT THIS TIME. WE
WILL CONTINUE TO KEEP AN EYE ON IT THROUGHOUT THE WEEKEND AND
PROVIDE MORE DETAILS AS THEY BECOME AVAILABLE.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
SURFACE COLD FRONT IS OVER THE REGION AND HAS NOW PASSED THROUGH
THE HUDSON VALLEY TAF SITES. TEMPERATURES ARE STARTING TO FALL
AND WINDS HAVE SWITCHED TO THE WEST-SOUTHWEST. KPSF IS ALSO NOW
HAVING THE FRONT JUST ABOUT TO CROSS AND WINDS ARE STARTING TO
SWITCH AROUND THERE TOO.
BEHIND THE FRONT, WINDS WILL INITIALLY BE NOT QUITE AS STRONG,
AS THERE WILL BE A LULL BEFORE THE DEEPER MIXING IS IN PLACE AND
THE PRESSURE GRADIENT INCREASES AGAIN. WESTERLY WINDS WILL BE
INITIALLY BE 10 TO 15 KTS WITH GUSTS IN THE 20-30 KT RANGE.
HOWEVER, ONCE THE GRADIENT INCREASE BY LATER THIS AFTERNOON/THIS
EVENING, WINDS WILL BE STRONG AND GUSTY INTO TONIGHT, WITH
WESTERLY WINDS AROUND 20 KTS AND SOME GUSTS IN THE 30-40 KT
RANGE, ESPECIALLY FOR KALB AND KPSF. THESE WINDS MAY START TO
DECREASE AFTER 08Z OR SO, AND START GRADUALLY COMING DOWN
TOWARDS DAYBREAK SATURDAY.
SOME STEADY RAINFALL WILL LINGER FOR A FEW MORE HOURS ON THE
BACKSIDE OF THE FRONT BEFORE TAPERING OFF. VISIBILITY WILL
GENERALLY BE IN THE MVFR RANGE WITHIN THIS LINGERING LIGHT
RAINFALL. IT SHOULD BE DONE FOR MOST AREAS BY 20Z OR SO. SOME
INTERMITTENT UPSLOPE RAIN AND SNOW MAY LINGER AT KPSF INTO THE
EVENING, WHICH MAY BRIEFLY KEEPER LOWER VISIBILITY THERE INTO
THE EVENING, MAINLY IN THE MVFR RANGE. INTO THE OVERNIGHT, ANY
PRECIP WILL JUST BE SOME SPOTTY LIGHT SNOW SHOWERS OR FLURRIES,
BUT THIS WILL BE BRIEF WITH LITTLE IMPACT ON VISIBILITY. FLYING
CONDITIONS WILL RETURN TO VFR FOR MOST SITES, WITH SCT-BKN CIGS
AROUND 3500-5000 FT, ALTHOUGH SOME MVFR UPSLOPE CLOUDS COULD
LINGER AT KPSF INTO PARTS OF THE OVERNIGHT HOURS.
ON SATURDAY, FLYING CONDITIONS WILL BE VFR FOR ALL SITES WITH
NO PRECIP WITH JUST SCATTERED MID LEVEL CLOUDS. WINDS WILL BE
MUCH LIGHTER, WITH SUSTAINED WINDS ONLY AROUND 10 KTS FROM THE
SOUTH TO SOUTHWEST FOR ALL SITES.
OUTLOOK...
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: MODERATE OPERATIONAL IMPACT. WINDY WITH GUSTS TO 32 KTS. NO SIG WX.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
TUESDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF RA.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
ALY WATCHES/WARNINGS/ADVISORIES
CT...WIND ADVISORY UNTIL 1 AM EST SATURDAY FOR CTZ001-013.
NY...WIND ADVISORY UNTIL 1 AM EST SATURDAY FOR NYZ032-033-038>043-
047>053-058>060-063>066-082>084.
HIGH WIND WARNING UNTIL 1 AM EST SATURDAY FOR NYZ054-061.
MA...HIGH WIND WARNING UNTIL 1 AM EST SATURDAY FOR MAZ001-025.
VT...WIND ADVISORY UNTIL 1 AM EST SATURDAY FOR VTZ014-015.
HIGH WIND WARNING UNTIL 1 AM EST SATURDAY FOR VTZ013.
DISCUSSION...37
AVIATION...27
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