359
FXUS61 KALY 061756
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
156 PM EDT TUE MAY 6 2025
SYNOPSIS
A CLOSED LOW PRESSURE SYSTEM CONTINUES TO IMPACT THE
REGION THROUGH TOMORROW, BRINGING ADDITIONAL ROUNDS OF SHOWERS AND
SOME THUNDERSTORMS. WEST OF THE HUDSON VALLEY, AN ISOLATED INSTANCE
OF A SEVERE THUNDERSTORM OR TWO IS POSSIBLE THROUGH THIS EVENING
WITH STRONG TO SEVERE WIND GUSTS AND SMALL HAIL POSSIBLE. MORE RAIN
IS EXPECTED AT THE END OF THE WEEK AND INTO THE FIRST HALF OF THE
WEEKEND BEFORE A MUCH NEEDED RESPITE COMES IN TIME FOR MOTHER'S DAY.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- FLOOD WATCH IN EFFECT FOR THE EASTERN CATSKILLS, MID HUDSON
VALLEY, CENTRAL AND SOUTHERN TACONICS, BERKSHIRES AND
LITCHFIELD HILLS THROUGH 8 PM TUESDAY.
- SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TODAY. ANY STORMS
COULD PRODUCE LOCALLY HEAVY RAIN, AND A FEW STORMS COULD BE
SEVERE FOR AREAS FROM THE HUDSON VALLEY WESTWARDS.
DISCUSSION:
UPDATE...AS OF 155 PM EDT
SHOWERS HAVE BEGUN FILTERING BACK
INTO THE REGION THIS AFTERNOON AS A SHORTWAVE TROUGH PULSES
ABOUT THE SOUTHEAST PERIPHERY OF OUR VERTICALLY STACKED, CUTOFF
LOW CURRENTLY NESTLED IN THE SOUTHEAST GREAT LAKES/NORTHEAST
OHIO VALLEY. WHILE THUNDER HASN'T QUITE BEGUN IN EASTERN NEW
YORK AND WESTERN NEW ENGLAND JUST YET, INSTABILITY IS INCREASING
ESPECIALLY WEST OF THE HUDSON RIVER VALLEY WHERE THE RAP-DERIVED
SPC MESOSCALE ANALYSIS HAS AN AREA OF 500 J/KG OUTLINED. HEIGHT
FALLS AHEAD OF THE PROGRESSION OF THE SHORTWAVE WILL PROVIDE
ADDITIONAL FORCING ACROSS THE AREA, ESPECIALLY WEST OF THE
HUDSON RIVER VALLEY WHERE THUNDERSTORMS ARE STILL EXPECTED THIS
AFTERNOON. HEAVY DOWNPOURS WITH GUSTY WINDS AND SMALL HAIL
REMAIN THE PRIMARY THREATS WITH AN ISOLATED INSTANCE OF A STORM
OR TWO BECOMING SEVERE POSSIBLE. ADDITIONAL DETAILS CAN BE FOUND
IN THE PREVIOUS DISCUSSION BELOW.
PREVIOUS
CURRENT GOES 16 WV IMAGERY SHOWS OUR UPPER LOW NOW
LOCATED OVER OHIO, AND IT IS NEARLY VERTICALLY STACKED WITH A
COLLOCATED SURFACE LOW. WITH SURFACE HIGH PRESSURE CENTERED NEAR
NOVA SCOTIA, THIS IS SETTING UP A LONG FETCH OF SOUTHERLY FLOW
INTO THE NORTHEAST. THIS SOUTHERLY FLOW IS ADVECTING A DEEP
PLUME OF MOISTURE-RICH AIR INTO THE REGION AS SEEN ON CIRA ALPW
SATELLITE IMAGERY. UNSURPRISINGLY, THIS HAS RESULTED IN PERIODS
OF WIDESPREAD RAIN AND SHOWERS OVERNIGHT, WHICH ARE CONTINUING
TO TAPER OFF ACROSS THE REGION AT THIS TIME.
TODAY, THE CUTOFF UPPER LOW SLIDES EASTWARDS OVER PA, EVENTUALLY
TRACKING OVER THE SOUTHERN TIER OF NY TONIGHT. THIS SETUP WILL
KEEP THE S/SE LLJ FOCUSED OVER EASTER NY AND WESTERN NEW
ENGLAND. WHILE THE CORE OF THE LLJ AND THE HIGHEST PWATS SLIDE
OFF INTO EASTERN NEW ENGLAND TODAY AS THE UPPER LOW PROGRESSES
EASTWARDS, OUR PWATS STILL REMAIN WELL ABOVE NORMAL AT 1 - 1.25"
FOR MOST OF TODAY. WE WILL LIKELY SEE A LULL IN SHOWER ACTIVITY
FOR A FEW HOURS THIS MORNING AS THIS CURRENT BATCH OF SHOWERS
MOVES OFF TO THE NORTH/EAST, BUT ADDITIONAL SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP BY THIS AFTERNOON. FORCING
FOR ASCENT LOOKS IMPRESSIVE TODAY, WITH A SHORTWAVE LOBE
ROTATING AROUND THE PERIPHERY OF THE UPPER LOW, THE APPROACHING
RIGHT ENTRANCE OF THE UPPER JET, AND THE OCCLUDED FRONT
ASSOCIATED WITH THE SURFACE LOW ALL PASSING OVER OUR REGION
THIS AFTERNOON. ADDITIONALLY, THERE WILL BE MORE INSTABILITY
COMPARED TO YESTERDAY, SO RAINFALL RATES TODAY WILL LIKELY BE
HIGHER THAN YESTERDAY, UP TO AROUND OR POSSIBLY EVEN IN EXCESS
OF 1" PER HOUR WITH CONVECTION.
THEREFORE, THE PRIMARY THREAT TODAY WILL BE FOR LOCALLY HEAVY
RAIN LEADING TO SOME PONDING OF WATER IN URBAN/POOR DRAINAGE
AREAS, AND ISOLATED FLASH FLOODING. SOILS ARE ALREADY SATURATED
FROM ALL THE RAIN WE HAVE RECEIVED OVER THE PREVIOUS DAYS.
UNIDIRECTIONAL FLOW PROFILES INDICATE THAT THERE COULD BE SOME
TRAINING OF CONVECTION TODAY, ALTHOUGH STORM MOTIONS SHOULD BE
ON THE FASTER SIDE OUTSIDE OF ANY BACKBUILDING STORMS. THE
LOCATION OF THE UPPER LOW AND MOISTURE PLUME FIT THE CONCEPTUAL
MODEL FOR HEAVY RAIN DEVELOPED AS PART OF LOCAL CSTAR RESEARCH,
AND WPC HAS MAINTAINED THEIR MARGINAL RISK ERO FOR TODAY ACROSS
THE REGION. THE TIMING FOR ANY HEAVY RAIN LOOKS TO BE PRIMARILY
THIS AFTERNOON INTO EARLY TONIGHT. MINOR FLOODING ON A FEW MAIN
STEM RIVERS IS ALSO POSSIBLE DUE TO PERSISTENT RAINS OVER THE
LAST FEW DAYS. PLEASE SEE THE HYDRO SECTION FOR MORE DETAILS.
A SECONDARY THREAT THIS AFTERNOON/EVENING IS THAT FOR A FEW
SEVERE STORMS. SPC HAS EXPANDED THE MARGINAL RISK OUTLOOK
FURTHER EAST INTO THE HUDSON VALLEY, LIKELY DUE IN PART TO
SLIGHTLY QUICKER EXPECTED FORWARD PROGRESS OF THE UPPER LOW
COMPARED TO YESTERDAY. FALLING HEIGHTS ALOFT LEADING TO
STEEPENING MID-LEVEL LAPSE RATES WILL BE ASSOCIATED WITH UP TO
AROUND 1000 J/KG OF SBCAPE IN THE WESTERN MOHAWK VALLEY, AND
AROUND 250-750 J/KG FOR MOST OF THE REST OF THE REGION WEST OF
THE HUDSON VALLEY. THIS WILL OVERLAP WITH DEEP-LAYER BULK SHEAR
OF 30-40 KT. HODOGRAPHS ARE FAIRLY STRAIGHT, SO WE WOULD NOT BE
SURPRISED TO SEE SOME LOOSELY ORGANIZED CLUSTERS OF STORMS OR
BROKEN LINE SEGMENTS THIS AFTERNOON/EVENING, ESPECIALLY FOR THE
WESTERN HALF OF THE REGION. PRIMARY HAZARD WITH ANY STRONGER
STORMS WILL BE DAMAGING WINDS, ALTHOUGH SOME MARGINALLY SEVERE
HAIL CAN'T BE RULED OUT DUE TO LOW WBZ HEIGHTS BELOW 10 KFT.
CONVECTION SHOULD WEAKEN EARLY TONIGHT WITH THE LOSS OF DAYTIME
HEATING, SO BOTH THE SEVERE AND HEAVY RAINFALL THREATS WILL ALSO
DECREASE AS WE HEAD INTO TONIGHT. THERE WILL LIKELY STILL BE
SOME SHOWER ACTIVITY CONTINUING INTO TONIGHT, HOWEVER. TONIGHT
ONCE AGAIN REMAINS ON THE MILD SIDE WITH LOWS IN THE 40S TO 50S
LIKE WE HAVE HAD THE LAST FEW NIGHTS.
SHORT TERM /WEDNESDAY THROUGH FRIDAY/
WEDNESDAY...THE CUTOFF UPPER LOW MOVES OVERHEAD, WHILE THE
AFOREMENTIONED SURFACE LOW TRACKS OFF TO OUR NORTH/NORTHEAST.
THE UPPER LOW NOW LOOKS TO TRACK EASTWARDS SLIGHTLY QUICKER
THAN PREVIOUSLY EXPECTED, SO THE CORE OF THE COLD POOL ALOFT MAY
BE STARTING TO DEPART TO OUR EAST BY THE TIME WE GET INTO PEAK
AFTERNOON HEATING. WHILE WE WILL STILL LIKELY SEE SOME POP-UP
SHOWERS AND A FEW THUNDERSTORMS, ESPECIALLY NORTH AND EAST OF
THE CAPITAL DISTRICT, INSTABILITY OVERALL LOOKS LESS IMPRESSIVE
COMPARED TO YESTERDAY'S FORECAST. WHILE A FEW INSTANCES OF SMALL
HAIL WILL BE POSSIBLE DUE TO THE PROXIMITY TO THE COLD POOL
ALOFT, SEVERE WEATHER IS NOT EXPECTED (SHEAR WILL BE WEAK UNDER
THE UPPER LOW). ADDITIONALLY, HEAVY RAIN SHOULD NOT POSE A
THREAT EITHER, AS THE BEST MOISTURE WILL BE WELL TO OUR EAST.
SHOWER ACTIVITY SHOULD DIMINISH HEADING INTO THE EVENING WITH
RIDING HEIGHTS AND SUBSIDENCE ALOFT BEHIND THE DEPARTING UPPER
LOW. HIGHS WEDNESDAY WILL BE A FEW DEGREES WARMER, MAINLY IN THE
MID TO UPPER 60S OUTSIDE OF THE MOUNTAINS.
WEDNESDAY NIGHT AND THURSDAY...THE UPPER LOW MOVES OFF INTO
NORTHEASTERN NEW ENGLAND, AS ANOTHER UPPER TROUGH DIGS INTO THE
GREAT LAKES REGION. THIS WILL HELP TO PUSH A COLD FRONT THROUGH
OUR REGION WEDNESDAY NIGHT, AND THE COLD FRONT SETTLES NEAR THE
I-84 CORRIDOR THURSDAY AFTERNOON. WHILE A FEW LIGHT SHOWERS WILL
BE POSSIBLE WITH THE COLD FRONTAL PASSAGE, MOST OF WEDNESDAY
NIGHT LOOKS DRY. THERE COULD BE A FEW MORE SHOWERS FOR SOUTHERN
AREAS THURSDAY, ESPECIALLY IN THE AFTERNOON, IF THE UPPER TROUGH
PHASES WITH AN UPPER SHORTWAVE TRACKING INTO THE OHIO VALLEY
(SEE LONG TERM SECTION BELOW FOR MORE DETAILS). WEDNESDAY NIGHT
LOWS WILL BE A FEW DEGREES COOLER THAN PREVIOUS NIGHTS. HIGHS
THURSDAY WILL RANGE FROM THE UPPER 50S IN THE ADKS TO LOW 70S
AHEAD OF THE FRONT FOR AREAS NEAR THE I-84 CORRIDOR.
LONG TERM /FRIDAY NIGHT THROUGH MONDAY/
KEY MESSAGE:
- INCREASING CONFIDENCE IN WIDESPREAD RAINFALL FRIDAY THROUGH
SATURDAY WITH LOW TO MEDIUM PROBABILITIES (30-70%) FOR ACCUMULATIONS
OF AT LEAST 0.25" ACROSS EASTERN NEW YORK AND WESTERN NEW ENGLAND.
DISCUSSION:
LIKE IN THE PREVIOUS TWO PERIODS, RAIN WILL BE NO STRANGER TO THE
EXTENDED FORECAST PERIOD AS MUCH OF EASTERN NEW YORK AND WESTERN NEW
ENGLAND WILL END THE WORK WEEK AND START THE WEEKEND RATHER WET.
WITH A POTENT, NEUTRALLY-TILTING SHORTWAVE TROUGH DIGGING SOUTH FROM
SOUTHWEST QUEBEC THROUGH WESTERN NEW YORK, THE EASTERN OHIO VALLEY,
AND THE WESTERN MID-ATLANTIC THROUGHOUT THE DAY FRIDAY, AN INVERTED
SURFACE TROUGH WILL NOSE NORTHWARD ALONG THE MID-ATLANTIC COAST.
SOUTHERLY TO SOUTHWESTERLY FLOW WILL ADVECT ATLANTIC AIR INTO THE
REGION, SUPPLYING PLENTY OF MOISTURE TO INITIATE AND MAINTAIN RAIN.
WHILE MOST AREAS WILL SEE LIGHT RAINFALL RATES TO START, THE
DEEPENING OF THE SHORTWAVE INTO A CLOSED LOW WILL TRIGGER A SURFACE
RESPONSE WITH THE DEVELOPMENT OF A COASTAL LOW WHICH COULD CAUSE
STEADIER TO MORE MODERATE RAINFALL RATES ESPECIALLY SOUTH AND EAST
OF ALBANY FRIDAY EVENING THROUGH FRIDAY NIGHT. HIGH TEMPERATURES
FRIDAY WILL BE IN THE UPPER 40S TO UPPER 50S WITH LOWS FRIDAY NIGHT
COOLING OFF TO THE UPPER 30S TO MID/UPPER 40S.
RAIN CONTINUES INTO SATURDAY, THOUGH AS THE CLOSED LOW AND ITS
SURFACE COUNTERPART TRACK NORTH AND EAST THROUGH THE NORTHEAST, IT
WILL GRADUALLY TAPER OFF THROUGH SATURDAY AFTERNOON WITH HIGH
PRESSURE BUILDING IN QUICKLY IN THE WAKE OF THE SYSTEM. BY SATURDAY
EVENING, QPF LOOKS TO RANGE FROM ABOUT 0.15" TO 0.9" WITH THE
GREATEST AMOUNTS LYING GENERALLY EAST OF THE HUDSON RIVER VALLEY AND
THE LEAST TO THE NORTH AND WEST OF I-90. NOW, IT IS IMPORTANT TO
NOTE THAT THIS FORECAST IS NOT CERTAIN AT THIS TIME. WHILE GENERAL
CONSENSUS AGREES WITH THIS SOLUTION, THERE ARE STILL SOME MEMBERS OF
GUIDANCE POINTING TO THE RESPONSIBLE SYSTEM KICKING OUT TO OUR SOUTH
AND EAST SUCH THAT ONLY LIGHT RAIN AMOUNTS ARE ACCUMULATED. WITH ALL
OF THE RAIN LEADING UP TO THIS POTENTIAL EVENT, WE WILL CONTINUE TO
MONITOR THIS SITUATION CLOSELY FOR ANY POTENTIAL HYDROLOGIC ISSUES.
HIGH TEMPERATURES SATURDAY WILL BE IN THE UPPER 50S TO UPPER 60S
WITH LOWS IN THE UPPER 30S TO UPPER 40S.
BETTER NEWS COMES FOR MOTHER'S DAY AND THE BEGINNING OF THE NEW WORK
WEEK AS SURFACE HIGH PRESSURE AND WEAK UPPER-LEVEL RIDGING BUILD IN
ACROSS THE NORTHEAST. RESULTANT LARGE SCALE SUBSIDENCE WILL
REINFORCE DRY CONDITIONS ACROSS EASTERN NEW YORK AND WESTERN NEW
ENGLAND, PROVIDING A MUCH NEEDED RESPITE TO WET WEATHER. AND, WITH
TEMPERATURES GRADUALLY MODERATING INTO THE UPPER 60S TO UPPER 70S BY
MONDAY, CONDITIONS WILL FINALLY BE MORE PLEASANT.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
THROUGH 18Z WEDNESDAY...PERIODS OF SHOWERS WILL CONTINUE TO ROTATE
AROUND AN UPPER LEVEL LOW PRESSURE SYSTEM CENTERED TO THE WEST OF
THE REGION. WITH INSTABILITY BUILDING THIS AFTERNOON, SCATTERED
THUNDERSTORMS ARE ALSO EXPECTED TO DEVELOP, MOSTLY BETWEEN 18Z-24Z.
SO HAVE MENTION OF PROB30 FOR TSRA WITH BRIEF REDUCTION TO MVFR/IFR.
OTHERWISE, CONDITIONS SHOULD MAINLY BE MVFR THROUGH EARLY EVENING
EXCEPT IFR CIGS AT KPOU. SHOWERS SHOULD DECREASE IN COVERAGE THIS
EVENING, WITH MOST OF THE ACTIVITY SHIFTING BACK TO CENTRAL NY AS
THE UPPER LOW PIVOTS. MAINLY MVFR CIGS ARE EXPECTED AT THE TAF SITES
TONIGHT, AND LASTING THROUGH 18Z WED ALTHOUGH SOME BRIEF BREAKS IN
THE CLOUDS MAY DEVELOP. WINDS WILL BE SOUTHEAST AROUND 5-10 KT,
SHIFTING TO THE SOUTH-SOUTHWEST TONIGHT INTO WED MORNING.
OUTLOOK...
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SATURDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHRA.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
HYDROLOGY
FLOOD WATCH IN EFFECT FOR THE EASTERN CATSKILLS, MID HUDSON
VALLEY, CENTRAL AND SOUTHERN TACONICS, BERKSHIRES AND LITCHFIELD
HILLS THROUGH 8 PM THIS EVENING.
PERIODS OF RAIN CONTINUE THROUGH TODAY, WITH LOCALLY HEAVY RAIN
EXPECTED, ESPECIALLY THIS AFTERNOON AND EARLY EVENING. WHERE
HEAVY RAIN CAN REPEATEDLY MOVE OVER THE SAME AREAS, SOME
FLOODING OF URBAN, LOW-LYING AND POOR DRAINAGE AREAS IS
EXPECTED. EVEN ISOLATED FLASH FLOODING MAY OCCUR WHERE THE
HEAVIEST RAIN FALLS, ESPECIALLY IF IT OCCURS OVER THE MORE
SUSCEPTIBLE URBAN AREAS. WPC CONTINUES TO HAVE A MARGINAL RISK
FOR EXCESSIVE RAINFALL ACROSS THE REGION TODAY.
ADDITIONAL RAINFALL AMOUNTS TONIGHT THROUGH TONIGHT RANGING
BETWEEN 1 AND 3 INCHES (WITH THE HIGHEST AMOUNTS IN THE EASTERN
CATSKILLS DUE TO UPSLOPE ENHANCEMENT), COMBINED WITH ALREADY
SATURATED GROUND HAS INCREASED THE RISK OF FLASH FLOODING IN THE
WATCH AREA.
THE HOUSATONIC AT STEVENSON DAM AND THE STILL RIVER AT
BROOKFIELD HAVE HIT MINOR FLOOD STAGE DUE TO THE RAIN OVERNIGHT.
LATEST ENSEMBLE RIVER FORECASTS INDICATE LOW TO MEDIUM
PROBABILITIES (~10-30%) FOR SOME ADDITIONAL POINTS TO REACH
MINOR FLOOD STAGE, MOST NOTABLY ALONG THE HOUSATONIC RIVER,
ESOPUS CREEK, WEST CANADA CREEK, HOOSIC RIVER, SCHOHARIE CREEK,
AND ON THE WALLOOMSAC.
ALY WATCHES/WARNINGS/ADVISORIES
CT...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NYZ047-051-058>061-
063>066.
MA...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT...NONE.
SYNOPSIS...GANT
NEAR TERM...GANT/MAIN
SHORT TERM...MAIN
LONG TERM...GANT
AVIATION...JPV
HYDROLOGY...MAIN/JPV
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