790
FXUS61 KALY 081027
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
627 AM EDT THU MAY 8 2025
SYNOPSIS
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY WITH SOME
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS MAINLY FROM THE CAPITAL
REGION SOUTH AND EAST IN THE AFTERNOON. A LOW PRESSURE SYSTEM
APPROACHES THE REGION FROM THE MID ATLANTIC REGION TONIGHT AND MOVES
ALONG THE BOUNDARY WITH A WIDESPREAD PROLONGED RAINFALL FROM LATE
TONIGHT THROUGH FRIDAY. THE RAIN TAPERS FRIDAY NIGHT INTO SATURDAY
MORNING WITH HIGH PRESSURE BUILDING IN FOR MOTHERS DAY, AS
TEMPERATURES MODERATE CLOSER TO NORMAL.
NEAR TERM /UNTIL 6 PM THIS EVENING/
AS OF 627 AM EDT...A MID AND UPPER LEVEL TROUGH CONTINUES TO BE
SITUATED OVER QUEBEC WITH CYCLONIC FLOW PERSISTING ACROSS NY
AND NEW ENGLAND THIS MORNING. A COLD FRONT IS MOVING ACROSS
EASTERN NY THIS HOUR WITH A FEW ISOLATED SHOWERS OVER THE
SOUTHERN ADIRONDACKS. SOME PATCHY FOG WEST OF THE HUDSON VALLEY
WILL BURN OFF EARLY. THE CYCLONIC VORTICITY ADVECTION ASSOCIATED
WITH THE STRETCHED AND ELONGATED POSITIVELY TILTED TROUGH AND
THE COLD FRONT WILL ALLOW FOR SOME ISOLATED TO SCATTERED SHOWERS
TO DEVELOP ACROSS THE REGION IN THE LATE MORNING INTO THE
AFTERNOON. THE LOW-LEVEL MOISTURE IS MEAGER WITH BOUNDARY. THE
COLD FRONT WILL STALL OVER SOUTHERN NY INTO WEST/SOUTHWEST NEW
ENGLAND.
SOME VERY WEAK ELEVATED INSTABILITY IS PRESENT CLOSER TO THE I-84
CORRIDOR ON SOME OF THE CAMS. MUCAPES ARE GENERALLY LESS THAN
500 J/KG. WE PLACED SOME ISOLATED THUNDERSTORMS FOR LOCATIONS IN
THE SOUTHEAST CATSKILLS, MID HUDSON VALLEY, BERKSHIRES AND NW
CT. SOME LOCALIZED HEAVY RAINFALL MAY OCCUR. MOSTLY CLOUDY
CONDITIONS WILL CONTINUE AND IT WILL BE COOL. HIGHS NORTH AND
WEST OF THE CAPITAL REGION WILL BE IN THE 50S WITH SOME UPPER
40S OVER THE SOUTHERN DACKS. FROM THE TRI CITIES SOUTH AND EAST
MAX TEMPS WILL BE IN THE 60S TO LOWER 70S.
SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/
KEY MESSAGES:
- FLOOD WATCH ISSUED FOR WESTERN NEW ENGLAND AND ALL OF EASTERN
NY EXCLUDING HERKIMER, HAMILTON, NORTHERN WARREN AND NORTHERN
WASHINGTON COUNTIES 5 AM FRIDAY TO 8 AM SATURDAY.
- MODERATE TO HIGH CONFIDENCE FOR A WIDESPREAD MODERATE TO
HEAVY RAIN EVENT LATE TONIGHT INTO SATURDAY MORNING WITH WET
ANTECEDENT CONDITIONS IN PLACE INCREASED POTENTIAL THREAT FOR
MINOR FLOODING OF MAIN STEM RIVERS, CREEKS, STREAMS AND
BROOKS AND ISOLATED FLASH FLOODING IS POSSIBLE.
- THERE IS A 30 TO 60% CHANCE OF AT LEAST 1.5 INCHES OF
RAINFALL OCCURRING ACROSS EASTERN NY AND WESTERN NEW ENGLAND
FOR THE 48-HR TIME FRAME ENDING 8 AM SATURDAY.
DISCUSSION:
FAIRLY HIGH CONFIDENCE A SPRING RAIN STORM WILL IMPACT THE
ENTIRE ALY FORECAST AREA LATE TONIGHT INTO SATURDAY. A
POSITIVELY-TILTED H500 TROUGH WILL BE OVER SOUTHEAST CANADA,
THE EASTERN GREAT LAKES REGION AND OHIO VALLEY EXTENDING INTO
THE NORTHEAST. SHORT-WAVE ENERGY WILL BE ROUNDING THE BASE OF
THE TROUGH OVER THE TN AND LOWER OHIO VALLEY. THE OLD COLD FRONT
WITH EXTEND NORTH/NORTHEAST OF THE DEVELOPING SFC CYCLONE OVER
THE MID ATLANTIC STATES. THE INVERTED SFC TROUGH OR OLD FRONTAL
BOUNDARY WILL FOCUS THE RAINFALL TONIGHT. SOME EMBEDDED
ELEVATED CONVECTION MAY LINGER EARLY ON SOUTH AND EAST OF THE
CAPITAL REGION.
THE ISENTROPIC LIFT INCREASES IN THE EARLY MORNING HOURS WITH
PWATS RISING ABOVE NORMAL. THE CLOSED H500 CIRCULATION DIPS
SOUTHWARD OVER EASTERN OH AND PA TOWARDS 12Z/FRI. AN ANOMALOUS
LOW-LEVEL JET TAPS SOME GULF AND ATLANTIC MOISTURE FOR PERIODS
OF RAIN...MODERATE TO LOCALLY HEAVY INCREASE SHORTLY BEFORE AND
JUST AFTER DAYBREAK ON FRIDAY. THE SFC WAVE WILL BE APPROACHING
FROM THE DELMARVA REGION WITH UPPER LEVEL DIFFLUENCE AHEAD OF
IT, FAVORABLE JET DYNAMICS, AND STRENGTHENING LOW TO MID LEVEL
FGEN. THE NBM...AS WELL AS THE GFS, NAM, EC, AND CMC ARE ALL ON
BOARD FOR A 24-30 HR MODERATE TO HEAVY RAIN EVENT WITH 1-3" OVER
MOST OF THE REGION. THE CMC IS THE WETTEST. THE 3-KM HRRR
CONTINUES TO BE A BIT OF AN OUTLIER WITH THE WAVE DEVELOPING AND
TRACKING A LITTLE BIT FURTHER EAST AND IMPACTING WESTERN NEW
ENGLAND MORE AND EASTERN NY LESS. THE FLOOD WATCH IS JUSTIFIED
BY THE WET ANTECEDENT CONDITIONS AND QPF AND WE DID NOT PLACE
IT ACROSS THE NORTH AND WESTERN PERIPHERY OF THE AREA DUE TO
DROP OFF IN QPF. SOME MORE ZONES OR COUNTIES MAY BE ADDED IN
LATER. SEE THE HYDRO DISCUSSION SEGMENT FOR MORE DETAILS.
IT SEEMS LIKE SOUTHERN VT, THE CAPITAL REGION AND THE EASTERN
CATSKILLS SOUTH AND EAST WILL BE IN THE BEST QG LIFT, FGEN AND
MOISTURE CONVERGENCE FOR 1.5-3" OF RAIN WITH PERHAPS SOME
ENHANCEMENT WITH THE EAST TO SOUTHEAST FLOW OFF THE EASTERN
CATSKILLS AND WESTER NEW ENGLAND HIGHER TERRAIN AS THE LOW
APPROACHES NYC AND LONG ISLAND BY EARLY FRIDAY EVENING.
PAST CSTAR WARM SEASON CLOSED LOW RESEARCH HAS SHOWN PATTERNS
OF VERY HEAVY RAINFALL AND FLOODING WITH POSITIVELY TILTED TO
NEUTRAL CUT-OFF LOWS. SOME ISOLATED THUNDERSTORMS MAY POP UP
ACROSS EXTREME EASTERN NY AND WESTERN NEW ENGLAND BY FRIDAY
EVENING. PERIODS OF RAIN CONTINUE MOST OF THE NIGHT. MAX TEMPS
WILL BE SURPRESSED BY THE RAIN COOLED AIR WITH HIGHS ONLY IN THE
MID 40S TO MID 50S. IT WILL BE CHILLY ACROSS THE HIGHER
TERRAIN. LOWS WILL BE IN THE UPPER 30S TO LOWER 40S OVER THE
MTNS FRI NIGHT WITH 40S IN THE VALLEY, THE DRY SLOT TO THE
SYSTEM MAY APPROACH THE CAPITAL REGION/EASTERN CATSKILLS/MID
HUDSON VALLEY AND SOUTHWEST NEW ENGLAND BY DAYBREAK SATURDAY.
THE MID AND UPPER DEFORMATION ZONE TO THE SYSTEM AND THE H500
CLOSED CIRCULATION WILL KEEP SCATTERED SHOWERS IN MOST OF THE
FORECAST AREA SATURDAY MORNING, AND THEN THEY WILL TAPER OFF
LAST NORTH AND EAST OF THE CAPITAL REGION DURING THE AFTERNOON,
AS THE SYSTEM BEGINS TO ACCELERATE INTO NORTHERN NEW ENGLAND
AND NEW BRUNSWICK. HIGHS WILL CREEP CLOSER TO MID 50S TO AROUND
60F OVER THE HIGHER TERRAIN ON SATURDAY AND LOWER TO MID 60S IN
THE VALLEYS.
A DRYING TREND OCCURS SATURDAY NIGHT WITH A 1030 HPA OR SO SFC
ANTICYCLONE BUILDING IN FROM SOUTH OF JAMES BAY. THE SKIES WILL
BECOME PARTLY CLOUDY TO MOSTLY CLEAR, AS THE MID AND UPPER
LEVEL TROUGH AXIS MOVES THROUGH WITH LOWS IN THE UPPER 30S TO
MID 40S.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
KEY MESSAGES:
- TEMPS TREND BACK ABOVE NORMAL MOTHERS DAY AND CONTINUE INTO EARLY
NEXT WEEK WITH DRY WEATHER.
- CHANCES FOR RAIN RETURN BY MID WEEK.
DISCUSSION:
HIGH PRESSURE AND RIDGING ALOFT WILL BE POSITIONED JUST WEST OF THE
REGION TO START THE LONG TERM PERIOD, AND IS PROGGED TO SLOWLY BUILD
EAST THROUGH EARLY NEXT WEEK. THE INCREASING SUBSIDENCE WILL PROVIDE
A PLEASANT AND DRY MOTHER'S DAY WITH NEAR NORMAL TEMPERATURES IN THE
60S TO LOW 70S. SURFACE TEMPS WILL WARM FURTHER BEGINNING MONDAY
WITH RETURN FLOW INCREASING 925-850 HPA TEMPS TO AROUND +10C TO
+15C, TRANSLATING TO WIDESPREAD HIGHS IN THE UPPER 60S TO NEAR 80
(AROUND 5-10 DEGREES ABOVE NORMAL FOR MID MAY) THROUGH MID WEEK.
LOWS SUNDAY NIGHT WILL RANGE FROM THE LOW TO MID 40S, BUT SHOULD
INCREASE INTO THE MID TO UPPER 50S BY TUESDAY NIGHT.
OUR WELCOMED RELIEF FROM THE RAIN LOOKS TO END TUESDAY NIGHT INTO
WEDNESDAY AS OUR NEXT SYSTEM APPROACHES FROM THE SOUTHEAST. MODEL
GUIDANCE REMAINS MIXED ON THE SYSTEM STRENGTH, EVOLUTION AND PRECIP
PLACEMENT SO HAVE ELECTED TO MAINTAIN SLIGHT TO CHANCE POPS UNTIL
GUIDANCE COMES INTO BETTER AGREEMENT.
AVIATION /12Z THURSDAY THROUGH MONDAY/
THROUGH 06Z FRIDAY...BROKEN TO OVERCAST SKIES ARE EXPECTED FOR THE
MAJORITY OF THE TERMINALS TONIGHT WITH AN APPROACHING DISTURBANCE
FROM THE NORTHWEST. CEILINGS WILL RANGE FROM VFR TO MVFR, WITH THE
LATER FAVORED AT KGFL/KALB/KPSF. KPSF WILL SEE AN IMPROVEMENT BACK
TO VFR BY MID MORNING, WITH MVFR CEILINGS LINGERING AT KALB/KGFL
THROUGH THE DAY. LATE IN THE AFTERNOON, RAIN CHANCES WILL BEGIN TO
INCREASE AT KPOU/KPSF WITH A DEVELOPING SYSTEM ACROSS THE MID
ATLANTIC. CANNOT RULE OUT A THUNDERSTORM IN THE VICINITY OF KPOU,
THOUGH LOW CONFIDENCE PRECLUDES MENTION IN THE CURRENT TAF. THIS
RAIN IS EXPECTED TO BUILD FROM SOUTH TO NORTH THROUGH THE REMAINDER
OF THE PERIOD WITH MVFR CONDITIONS FAVORED AT THIS TIME. LIGHT WINDS
OUT OF THE WEST INITIALLY WILL INCREASE OUT OF THE NORTH TO AROUND 5-
10 KTS BY MID MORNING.
OUTLOOK...
FRIDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE RA...TSRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF SHRA...RA.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
HYDROLOGY
A FLOOD WATCH HAS BEEN ISSUED FOR ALL OF WESTERN NEW ENGLAND,
AND THE EASTERN CATSKILLS, HELDERBERGS, SCHOHARIE VALLEY, MID
HUDSON VALLEY, TACONICS, GREATER CAPITAL REGION, CENTRAL AND
EASTERN MOHAWK VALLEY AND THE SOUTHERN REACHES OF THE LAKE
GEORGE AND NORTHERN SARATOGA REGION FROM 5 AM FRIDAY UNTIL 8 AM
SATURDAY.
A LOW PRESSURE SYSTEM AND A FRONTAL BOUNDARY WILL BRING MODERATE
TO HEAVY RAINFALL FOR POSSIBLE FLOODING LATE TONIGHT INTO
SATURDAY. 1.5 TO 3 INCHES OF RAINFALL IS LATE TONIGHT INTO
SATURDAY MORNING. WPC HAS PLACED MOST OF OUR REGION INTO A
MARGINAL RISK FOR EXCESSIVE RAINFALL DURING THIS PERIOD. WHILE
ISOLATED FLASH FLOODING WOULD BE POSSIBLE WITH ANY TRAINING AND
HEAVIER RAINFALL RATES, THE GREATER THREAT APPEARS TO BE THE
POTENTIAL FOR ADDITIONAL RIVER FLOODING. MMEFS ENSEMBLE GUIDANCE
CONTINUES TO SHOW 30-50% CHANCES FOR MINOR FLOODING ON MANY
MAIN STEM RIVERS, ESPECIALLY THE ESOPUS, HOOSIC, HOUSATONIC,
SCHOHARIE, WALLOOMSAC, AND THE HUDSON RIVER AT TROY AND
WATERFORD.
ALY WATCHES/WARNINGS/ADVISORIES
CT...FLOOD WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
CTZ001-013.
NY...FLOOD WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
NYZ039>041-047>054-058>061-063>066-082>084.
MA...FLOOD WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
MAZ001-025.
VT...FLOOD WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
VTZ013>015.
SYNOPSIS...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...SPECK
AVIATION...SPECK
HYDROLOGY...GANT/WASULA
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