428
FXUS61 KALY 210505
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
105 AM EDT TUE APR 21 2026
WHAT HAS CHANGED
LEANED ON THE COLDER END OF GUIDANCE FOR OVERNIGHT LOW
TEMPERATURES TONIGHT AS THERE IS MEDIUM TO HIGH CONFIDENCE THAT
TUESDAY A.M TEMPERATURES WILL DROP BELOW 30 DEGREES ACROSS MUCH
OF EASTERN NY AND WESTERN NEW ENGLAND. ALSO, LOWERED RH VALUES
AND INCREASED WIND GUSTS THURSDAY AFTERNOON IN COLLABORATION
WITH NEIGHBORING WFOS GIVEN INCREASING CONFIDENCE FOR DEEP
BOUNDARY LAYER MIXING AND A DRIER INCOMING AIR MASS THAT MAY
RESULT IN WEATHER CONDITIONS THAT FAVOR ENHANCED FIRE SPREAD.
KEY MESSAGES
1) BELOW NORMAL TEMPERATURES THROUGH TOMORROW THEN THERE IS A
LOW TO MEDIUM CHANCE FOR WEATHER CONDITIONS ON THURSDAY THAT
CAN FAVOR ENHANCED FIRE SPREAD.
DISCUSSION
KEY MESSAGE 1...ISOLATED TO WIDELY SCATTERED CONVECTIVELY
DRIVEN SHOWERS CONTINUE THIS AFTERNOON TRACKING FROM NORTHWEST
TO SOUTHEAST AS OUR UPPER TROUGH AND ASSOCIATED COLD POOL
TRACKS OVERHEAD. WITH 850-700HPA LAPSE RATES STEEPENING TO
7.5C/KM OR GREATER, ANY TALLER SHOWERS CAN PRODUCE BRIEF PERIODS
OF GRAUPEL. GIVEN TEMPERATURES IN THE 30S IN THE HILL TOWNS AND
HIGHER TERRAIN AREAS TODAY, ANY STEADIER SHOWERS CAN LEAD TO
WET-BULB COOLING AND MIX OR BRIEFLY CHANGE TO WET SNOW.
HOWEVER, THE BRIEF NATURE OF ANY SNOW SHOWERS PLUS THE APRIL SUN
ANGLE WILL LIKELY PREVENT ANY APPRECIABLE ACCUMULATIONS.
SNOW SHOWERS DIMINISH TOWARDS SUNSET WITH THE LOSS OF DAYTIME
HEATING AND STRONG SUBSIDENCE BUILDING INTO THE NORTHEAST FROM
THE OHIO VALLEY. RIDGING AND HIGH PRESSURE TONIGHT WILL SUPPORT
CLEARING SKIES AND NEAR IDEAL RADIATIONAL COOLING RESULTING IN
CHILLY TEMPERATURES. AS DISCUSSED IN THE PREVIOUS DISCUSSION, WE
LEANED ON THE COOLER END OF GUIDANCE FOR OVERNIGHT LOWS TONIGHT
GIVEN PROBABILISTIC GUIDANCE SHOWING GREATER THAN 75% CHANCE
FOR OVERNIGHT LOWS THROUGHOUT MUCH OF EASTERN NY AND WESTERN
NEW ENGLAND FALLING BELOW 30 DEGREES. DESPITE LAST WEEK'S WARM
UP, THE GROWING SEASON DOES NOT OFFICIALLY BEGIN UNTIL MAY 1 IN
THE HUDSON VALLEY SO FROST/FREEZE PRODUCTS WILL NOT BE ISSUED.
GFL AND POU MAY TIE OR BREAK THEIR RESPECTIVE RECORD LOWS FOR
APRIL 21 BUT ALBANY WILL LIKELY BE OUT OF REACH. SEE OUR CLIMATE
SECTION FOR DETAILS.
TUESDAY STARTS OFF QUITE CHILLY WITH MORNING SUN MIXING WITH
INCREASING AFTERNOON CLOUDS AS MOISTURE SPILLS OVERTOP THE
RIDGE AXIS. WHILE DEW POINTS WILL TURN QUITE LOW SUPPORTING RH
VALUES DROPPING TO 25 TO 30%, WINDS WILL BE RATHER LOW WITH
GUSTS UNDER 20KTS SO NOT EXPECTING AN INCREASED RISK OF FIRE
SPREAD. SOUTHWESTERLY RETURN FLOW WILL ALLOW TEMPERATURES TO
WARM INTO THE 40S TO LOW 50S BUT THIS IS STILL 5 TO 10 DEGREES
BELOW NORMAL FOR LATE APRIL. A WARM FRONT THEN APPROACHES FROM
THE SOUTHWEST HEADING INTO TOMORROW NIGHT. THIS FRONT LOOKS TO
GET HUNG UP AROUND THE I-84 CORRIDOR IF NOT SLIGHTLY SOUTH AS
HIGH PRESSURE REMAINS PARKED OFF THE NEW ENGLAND COAST AND A
WEAK LOW MOVES ALONG THE BOUNDARY. WEAK WARM AIR ADVECTION IN
THE LOW AND MID-LEVELS SHOULD SUPPORT A PERIOD OF SHOWERS
OVERNIGHT FOCUSED SOUTH OF I-90 CLOSER TO STRONGER FORCING AND
MOISTURE. LATEST NBM PROBABILISTIC GUIDANCE FOR GREATER THAN
0.01" OF PRECIPITATION TUES NIGHT REMAINS RATHER LOW AT ONLY 20
TO 25% AND CONFINED TO AREAS MAINLY SOUTH OF I-90 SUGGESTING
THAT INCOMING PRECIPITATION WILL BE QUITE LIGHT. WITH DEW POINTS
STILL NEAR OR BELOW FREEZING TUES NIGHT, THE INCOMING LIGHT
SHOWERS COULD ALLOW THE COLUMN TO COOL IN RESPONSE TO WET-
BULBING SUPPORTING A RAIN/SNOW OR EVEN WET SNOW IN THE EASTERN
CATSKILLS, TACONICS, NW CT AND BERKSHIRES WHERE SOUTHWEST FLOW
CAN UPSLOPE THE TERRAIN. EVEN STILL, THE LIGHT AMOUNTS WILL
LIKELY MITIGATE ANY IMPACTS.
DRIER WEATHER RETURNS THURSDAY AND FRIDAY AS AN OMEGA BLOCK
DEVELOPS UPSTREAM OVER THE GREAT LAKES AND DRY, NORTHWEST FLOW
PERSISTS. WHILE TEMPERATURES FINALLY TREND WARMER BECOMING MORE
SEASONABLY FOR SPRING, DEEP BOUNDARY LAYER MIXING AND A WEAK
SURFACE PRESSURE GRADIENT ON THURSDAY SHOULD ALSO SUPPORT GUSTY
WINDS AND WITH RH VALUES DROPPING UNDER 40%. WE WILL CLOSELY
MONITOR WINDS AND RH AS WEATHER CONDITIONS MAY FAVOR ENHANCED
FIRE SPREAD.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
THROUGH 06Z WEDNESDAY...VFR CONDITIONS EXPECTED TO PREVAIL
THROUGH THE 24 HOUR TAF PERIOD. SKC WILL OCCUR THROUGH THE REST
OF THE NIGHT, WITH GRADUALLY INCREASING HIGH/MID LEVEL CLOUDS
DURING THE DAY. AN APPROACHING FRONT WILL BRING SCATTERED -SHRA
TOWARDS THE END OF THE TAF PERIOD LATER THIS EVENING, SO WILL
MENTION PROB30 STARTING BETWEEN 03Z-05Z. WINDS WILL INITIALLY BE
VARIABLE LESS THAN 5 KT, BECOMING SOUTH-SOUTHWEST AROUND 5-10
KT BY LATER THIS MORNING.
OUTLOOK...
WEDNESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
CLIMATE
RECORD LOW TEMPERATURES FOR APRIL 21:
GLENS FALL, NY: 20 DEGREES SET IN 1925
ALBANY, NY: 20 DEGREES SET IN 1875
POUGHKEEPSIE, NY: 26 DEGREES SET IN 2018
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
DISCUSSION...31
AVIATION...07
CLIMATE...31
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