640
FXUS61 KALY 252336
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
736 PM EDT SAT APR 25 2026
WHAT HAS CHANGED
SIMILAR TO THE PREVIOUS FORECASTER, LOWERED TEMPERATURES ACROSS
THE MID-HUDSON VALLEY, NW CT AND THE EASTERN CATSKILLS DUE TO
EXPECTED EVAPORATIVE COOLING DUE TO ONGOING STEADY PRECIPITATION
AND CLOUDS. THE DECREASED TEMPERATURES IN THE EASTERN CATSKILLS
CONTINUES TO FAVOR A RAIN/SNOW MIX THIS AFTERNOON TURNING TO
MAINLY WET SNOW FOR A PERIOD TONIGHT ABOVE 2000FT TONIGHT. THERE
IS NOW A LOW TO MEDIUM CHANCE FOR LIGHT SNOW ACCUMULATIONS
(MAINLY UNDER 1 INCH) FOR ELEVATIONS AT AND ABOVE 2000 FEET.
WE AGAIN LEANED TOWARDS THE LOWER END OF THE BLENDED GUIDANCE
FOR DEW POINTS DURING PEAK HEATING HOURS BOTH MONDAY AND TUESDAY
AFTERNOON. WITH AN INCREASING PRESSURE GRADIENT, WE ALSO
INCREASED WINDS AND GUSTS FOR TUESDAY AFTERNOON. THERE IS NOW A
LOW CHANCE THAT RELATIVE HUMIDITY VALUES AND WINDS WILL NEAR
CRITICAL FIRE WEATHER CONDITIONS ON TUESDAY.
KEY MESSAGES
1) WHILE WIDESPREAD RAIN WILL IMPACT THE WESTERN MOHAWK VALLEY,
NORTHERN/EASTERN CATSKILLS, MID-HUDSON VALLEY, CENTRAL AND
SOUTHERN TACONICS AND LITCHFIELD COUNTY TODAY INTO TONIGHT, NO
FLOODING IMPACTS ARE ANTICIPATED.
2) DRIER WEATHER RETURNS TO START THE UPCOMING WEEK WITH A MEDIUM
CHANCE THAT RELATIVE HUMIDITY AND WINDS REACH NEAR CRITICAL
FIRE WEATHER LEVELS ON TUESDAY.
DISCUSSION
KEY MESSAGE 1...
A WEAK SFC LOW IN WESTERN PA WILL TRACK SOUTHEASTWARD TODAY
ALONG A STATIONARY BOUNDARY POSITIONED IN THE MID-ATLANTIC. HIGH
PRESSURE PARKED IN EASTERN NEW ENGLAND TODAY AND STRONG CONFLUENT
NORTHWESTERLY FLOW OVER THE NORTHEAST ADVECTING DRY AIR ALOFT
WILL SUPPLY PLENTY OF DRY AIR TO AREAS NORTH OF I-90 RESULTING
IN A SHARP MOISTURE GRADIENT FROM SOUTH TO NORTH. LATEST WATER
VAPOR IMAGERY INCLUDING THE ADVECTED LAYER PRECIPITABLE WATER
(ALPW) SHOW DISTINCT MOISTURE FETCHES FROM THE WESTERN ATLANTIC
AND FROM THE GULF GETTING STRETCHED ALONG THE AXIS OF DILATATION
JUST NORTH OF THE BOUNDARY. THIS HAS LED TO A REGION OF ENHANCED
MID-LEVEL FGEN AND A SWATH OF WIDESPREAD STEADY RAIN POSITIONED
ACROSS SOUTHERN NY AND EASTERN PA EXTENDING INTO EASTERN CT AND
NYC/LONG ISLAND. DRIER AIR CLOSER TO I-90 AS NOTED ON THE 12
UTC ALY SOUNDING CONTINUES TO ERODE THE PRECIPITATION SHIELD AS
IT TRIES TO BUILD NORTHWARD. THIS WILL LEAD TO A SHARP SOUTH TO
NORTH RAINFALL GRADIENT BETWEEN I-90 AND THE MID- HUDSON
VALLEY/EASTERN CATSKILLS AND NW CT THROUGH TONIGHT.
THE HIGHEST FORECAST UNCERTAINTY IN OUR RAINFALL FORECAST
TODAY/TONIGHT LIES CLOSER TO I-90 WHERE THE NORTHERN EDGE OF THE
RAIN HAS HIT THE BRAKES. WHILE THE I-90 CORRIDOR AND ESPECIALLY
AREAS TO THE NORTH WILL REMAIN DRY THROUGH MUCH OF THE
AFTERNOON, POPS TREND UPWARDS TO LOW END CHANCE (30 - 50%) BY 21
UTC NEAR I-90 AND REMAIN IN THE CHANCE CATEGORY THROUGH ALMOST
MIDNIGHT AS THE PARENT SHORTWAVE MOVES OVERHEAD. AREAS IN THE
SOUTHWEST ADIRONDACKS, GLENS FALLS/LAKE GEORGE REGION AND MOST
OF SOUTHERN VT HAVE THE LIGHTEST CHANCE TO REMAIN MAINLY DRY
THROUGH TONIGHT. ON THE OTHER HAND, THERE IS MEDIUM TO HIGH
CONFIDENCE THAT AT LEAST 0.75" OF PRECIPITATION WILL FALL IN THE
MID-HUDSON VALLEY, EASTERN CATSKILLS, AND NW CT IN THE 24HOUR
PERIOD ENDING 12 UTC SUNDAY; HOWEVER, NO FLOODING IS EXPECTED.
EVAPORATIVE COOLING WILL KEEP TEMPERATURES MUCH COOLER SOUTH OF
I-90 WHERE TEMPERATURES WILL STAY STUCK IN THE 40S THE REST OF
THE DAY WITH EVEN LOW TO MID 30S FOR ELEVATIONS 2000FT AND
HIGHER IN THE EASTERN CATSKILLS SUPPORTING A RAIN/SNOW MIX THIS
AFTERNOON AND A PERIOD OF WET SNOW TONIGHT. HOWEVER, MARGINAL
TEMPERATURES WILL LIMIT WET SNOW ACCUMULATIONS WITH THE LATEST
NBM PROBABILISTIC GUIDANCE SHOWING JUST A 30 TO 50% CHANCE FOR
AMOUNTS TO EXCEED 1" AT ELEVATIONS 2000FT+ AND MAINLY UNDER A
25% CHANCE TO EXCEED 2". FURTHER NORTH, A THINNER CLOUD CANOPY
WILL ALLOW TEMPERATURES TO WARM INTO THE LOW TO MID 50S. THE
STEADIEST RAIN DEPARTS FROM WEST TO EAST AFTER MIDNIGHT WITH A
DRY AND SPRING-LIKE CONDITIONS RETURNING FOR SUNDAY.
KEY MESSAGE 2...
SUBSIDENCE BUILDS OVER THE NORTHEAST SUNDAY THROUGH TUESDAY IN
RESPONSE TO AN AMPLIFYING RIDGE SHIFTING EASTWARD OUT OF THE
OHIO VALLEY. THIS WILL KEEP US VERY DRY EACH DAY WITH DEEP
BOUNDARY LAYER MIXING TRENDING RELATIVE HUMIDITY VALUES
DOWNWARDS EACH AFTERNOON. FORECAST SOUNDINGS SHOW A POTENTIAL
"DEW POINT" BOMB ON MONDAY AS THE RIDGE AXIS REMAINS TO OUR WEST
AND LIMITS MUCH OF A SUBSIDENCE INVERSION. GIVEN THIS PLUS
SUNNY SKIES, WE USED NBM10TH PERCENTILE GUIDANCE FOR MONDAY P.M
DEW POINTS TO HIGHLIGHT LOW RH VALUES, SIMILAR TO THE PREVIOUS
FORECAST. WHILE THE SUBSIDENCE INVERSION RETURNS ON TUESDAY,
FORECAST GUIDANCE CONTINUES TO SUPPORT DRY AIR ADVECTION, DEEP
MIXING LEADING TO WARMER TEMPERATURES, AND BREEZIER WINDS WITH
GUSTS UP TO 25MPH DUE TO A TIGHTENING PRESSURE GRADIENT. THEREFORE,
WE AGAIN USED NBM10TH GUIDANCE FOR DEW POINTS TO RELAY LOW RH
VALUES. WHILE THERE IS MEDIUM TO HIGH CONFIDENCE THAT BOTH MONDAY
AND TUESDAY WILL FEATURE RH VALUES IN THE 25 TO 35% RANGE ACROSS
EASTERN NY AND WESTERN NEW ENGLAND, BREEZIER WINDS ON TUESDAY
HAS INCREASED CONFIDENCE IN REACHING NEAR CRITICAL FIRE WEATHER
CONDITIONS, ESPECIALLY NEAR/NORTH OF I-90 WHICH WILL MISS OUT
ON THE WIDESPREAD RAIN TODAY/TONIGHT. WE WILL CONSULT OUR FIRE
WEATHER PARTNERS EARLY THIS WEEK TO LEARN IF FUELS ARE AVAILABLE
FOR FIRE SPREAD AND DECIDE IF WE NEED TO MESSAGE WEATHER
CONDITIONS THAT CAN ENHANCE FIRE SPREAD.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
THROUGH 00Z/MONDAY, AREA OF LIGHT TO MODERATE RAIN WILL CONTINUE
EXPANDING NORTH AND EAST, BRIEFLY REACHING KALB AND KPSF THIS
EVENING BEFORE SHIFTING BACK SOUTH. VFR CONDITIONS MAY
OCCASIONAL DROP TO MVFR AT TIMES AT THESE LOCATIONS THROUGH
AROUND 04Z/SUN, MAINLY FOR CIGS, WITH MVFR CIGS THEN PREVAILING
AT THESE SITES LATER TONIGHT WITH POCKETS OF IFR CIGS POSSIBLE.
AT KGFL, MAINLY VFR CONDITIONS THROUGH THIS EVENING WITH RAIN
REMAINING TO THE SOUTH, THEN A PERIOD OF MVFR/IFR CIGS AND
VSBYS POSSIBLE TOWARD DAYBREAK AS SOME PATCHY FOG MAY DEVELOP.
AT KPOU, PERIODS OF LIGHT TO MODERATE RAIN WILL CONTINUE WITH
MVFR/IFR CONDITIONS (BOTH CIGS AND VSBYS), WITH IFR CIGS THEN
PERSISTING THROUGH DAYBREAK. ON SUNDAY, LINGERING LOW
CLOUDS/PATCHY FOG AND POSSIBLE IFR CONDITIONS SHOULD BECOME VFR
BY MID MORNING WITH VFR CONDITIONS THEN PREVAILING SUNDAY
AFTERNOON.
LIGHT SOUTH TO SOUTHEAST WINDS LESS THEN 8 KT OVERNIGHT WILL
BECOME LIGHT/VARIABLE AROUND DAYBREAK, THEN SHIFT INTO THE NORTH
TO NORTHEAST AT 4-8 KT BY SUNDAY AFTERNOON.
OUTLOOK...
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHRA.
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
DISCUSSION...31
AVIATION...24
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