449
FXUS61 KALY 012311
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
711 PM EDT TUE SEP 1 2026
WHAT HAS CHANGED
THE SEVERE WEATHER THREAT HAS ENDED FOR THE ENTIRE REGION THIS
EVENING, AS A COLD FRONT HAS PUSHED SOUTH RESULTING IN
STABILIZING CONDITIONS THIS EVENING.
07
KEY MESSAGES
1) A FEW STRONG TO SEVERE THUNDERSTORMS POSSIBLE SOUTH AND WEST OF
THE CAPITAL REGION THIS AFTERNOON INTO THIS EVENING WITH AN ISOLATED
FLASH FLOOD THREAT THERE AS WELL.
2) ADDITIONAL ROUNDS OF SHOWERS AND THUNDERSTORMS LATE WEDNESDAY
AFTERNOON/EVENING INTO THURSDAY WITH SOME STRONG/SEVERE
THUNDERSTORMS (WED-WED NIGHT) AND ISOLATED TO SCATTERED
INSTANCES OF HEAVY RAINFALL/FLASH FLOODING POSSIBLE.
3) GENERALLY TRANQUIL WEATHER WITH NEAR TO SLIGHTLY BELOW NORMAL
TEMPERATURES EXPECTED FRIDAY INTO EARLY NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...AS OF 2:40 PM EDT...BROAD UPPER RIDGE IS LOCATED
OVER THE CENTER OF THE COUNTRY, WITH SEVERAL IMPULSES TRACKING
ALONG ITS NORTHERN PERIPHERY OVER THE NEXT FEW DAYS. ONE OF
THOSE MOVED THROUGH THIS MORNING, WITH ANOTHER WEAK IMPULSE BACK
OVER THE EASTERN GREAT LAKES TRACKING TO THE SOUTHEAST OVER THE
NEXT FEW HOURS. AT THE SURFACE, A STATIONARY/WARM FRONT IS
LOCATED NEAR OUR SOUTHWESTERN BORDER WITH BGM ACROSS ULSTER AND
DUTCHESS COUNTIES. NEAR THE FRONT, THERE HAS BEEN SOME BREAKS OF
CLEARING THAT HAVE ALLOWED 1500-2000 J/KG OF SBCAPE TO DEVELOP
WITH STEEPENING MID-LEVEL LAPSE RATES. THIS UNSTABLE AIRMASS IS
OVERLAPPING WITH 40-45 KT OF EFFECTIVE DEEP-LAYER SHEAR PER THE
LATEST SPC MESONANALYSIS. THE APPROACHING SHORTWAVE IMPULSE,
LOW-LEVEL FRONT, DIFFERENTIAL HEATING ALONG THE FRONT, AND
OUTFLOW FROM SHOWERS LOCATED NEAR/JUST SOUTHWEST OF I-90 COULD
ACT AS LIFTING MECHANISMS LEADING TO CI OVER THE NEXT COUPLE OF
HOURS.
IF/WHEN CONVECTION DEVELOPS, DISCRETE SUPERCELLS WILL BE POSSIBLE,
WITH THE MAIN THREATS BEING DAMAGING WINDS AND LARGE HAIL. AN
ISOLATED TORNADO CAN'T BE RULED OUT, WITH THE GREATEST CONCERN WHERE
FLOW IS MORE BACKED IN N/S ORIENTED RIVER VALLEYS. SPC HAS
MAINTAINED A SLIGHT RISK FOR SOUTHWESTERN ULSTER AND DUTCHESS
COUNTIES. GREATEST THREAT WILL EXIST THROUGH EARLY EVENING, AT
WHICH POINTS CONVECTION SHOULD MOVE OFF TO THE SOUTH OF OUR
AREA. LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE WITH ANY OF
THESE CELLS. WPC HAS MAINTAINED THE MARGINAL RISK ERO TODAY FOR
MUCH OF OUR AREA, ALTHOUGH THE THREAT IS REALLY LIMITED TO JUST
THE SOUTHWESTERN CORNER OF OUR CWA, ROUGHLY THE SAME AS WHERE
THE SPC SLIGHT RISK IS. HIGHS THIS AFTERNOON WILL RANGE FROM
AROUND 80 NEAR I-84 TO THE 60S ACROSS NORTHERN AREAS.
CONVECTION SHOULD END THIS EVENING AS SFC HIGH PRESSURE BUILDS IN
FROM THE NORTHEAST. SOME PATCHY FOG/MIST/DRIZZLE WILL BE POSSIBLE
OVERNIGHT WITH SOME LOW-LEVEL MOISTURE TRAPPED BENEATH A DEVELOPING
INVERSION, WITH LOWS IN THE 50S TO LOW 60S.
KEY MESSAGE 2...TOMORROW IS NOW LOOKING RELATIVELY DRY FOR OUR
REGION THROUGH AT LEAST MID TO LATE AFTERNOON. THE SFC FRONTAL
BOUNDARY WILL RETREAT WELL SOUTH AND WEST OF OUR REGION TONIGHT WITH
NO REAL LARGE-SCALE FORCING THROUGH TOMORROW AS HEIGHTS ALOFT
ACTUALLY RISE THROUGH THE MORNING. THE SFC HIGH TO THE E/NE WILL
RESULT IN LOW-LEVEL COOL EASTERLY FLOW INTO THE REGION AND ABUNDANT
CLOUD COVER, WHICH SHOULD HELP KEEP TEMPERATURES IN THE 60S
(TERRAIN) TO 70S (VALLEYS). WE WENT A COUPLE DEGREES BELOW THE NBM
FOR DAYTIME HIGHS TOMORROW. THERE ARE SOME SIGNALS THAT A WEAKENING
MCS MAY TRACK SOUTH OF THE REGION IN ASSOCIATION WITH A WEAK UPPER
IMPULSE DURING THE DAY, BUT NOT EXPECTING ANY IMPACT LOCALLY FROM
THIS FEATURE.
TOMORROW EVENING AND NIGHT INTO THURSDAY, A STRONGER UPER IMPULSE
WILL BE TRACKING OVER THE TOP OF THE UPPER RIDGE, ALONG WITH AN
ASSOCIATED MCS THAT IS EXPECTED TO DEVELOP OVER SOUTHERN CANADA.
ELEVATED INSTABILITY LOOKS TO INCREASES TO 500-1000 J/KG AHEAD
OF THIS MCS TOMORROW EVENING INTO TOMORROW NIGHT AS THERE ARE
SOME HINTS OF A REMNANT EML LAYER TRACKING OVERHEAD. GIVEN THIS
AND IMPRESSIVE UNIDIRECTIONAL DEEP-LAYER SHEAR, WE ARE EXPECTING
CONVECTION TO BE ABLE TO SUSTAIN ITSELF AS IT TRACKS ACROSS OUR
REGION TOMORROW NIGHT. THERE DOESN'T LOOK TO BE MUCH SURFACE-
BASED INSTABILITY, SO WIND THREAT ACTUALLY LOOKS LOWER THAN WE
MIGHT TYPICALLY EXPECT. HOWEVER, LARGE HAIL WILL BE POSSIBLE
WITH ANY STRONGER STORMS GIVEN THE ELEVATED INSTABILITY,
RELATIVELY COOL LOW- LEVELS, AND STRONG DEEP-LAYER
SHEAR/STRAIGHT HODOGRAPHS. SPC HAS MAINTAINED THE MARGINAL RISK
FOR SEVERE FOR WESTERN AREAS TOMORROW, BUT AN EXPANSION FURTHER
EAST IS POSSIBLE OVER THE NEXT 12-24 HRS OR SO.
THERE IS ALSO A THREAT FOR LOCALLY HEAVY RAIN LEADING TO FLASH
FLOODING TOMORROW EVENING INTO THURSDAY. PWATS REMAIN ELEVATED AT
AROUND 1.8-2.0 INCHES. THE CORE OF THE MCS SHOULD TRACK THROUGH THE
REGION RELATIVELY QUICKLY WITH FAST FLOW ALOFT, BUT ALONG THE EDGES
OF THE MCS THERE IS MORE POTENTIAL FOR BACKBUILDING AND TRAINING,
AND CORFIDI UPSHEAR VECTORS ARE FAIRLY SLOW AT 10-15 KT SO THIS
WILL HAVE TO BE WATCHED. WPC HAS KEPT THE SLIGHT RISK ERO FOR
THE WESTERN MOHAWK VALLEY AND FAR SOUTHERN ADKS , WITH A
MARGINAL RISK FOR THE REST OF THE REGION. RAINFALL RATES OF OVER
1" PER HOUR WITH TOTAL RAINFALL AMOUNTS GENERALLY AROUND 0.5 TO
1.5", WITH SOME LOCALLY HIGHER AMOUNTS OF 2-3" NOT OUT OF THE
QUESTION WHERE ANY TRAINING OCCURS. SO, ISOLATED TO POSSIBLY
SCATTERED INSTANCES OF FLASH FLOODING CAN'T BE RULED OUT,
ALTHOUGH POTENTIAL FOR MAIN STEM RIVER FLOODING LOOKS VERY LOW
(<10%). WITH JUST ISOLATED TO POSSIBLY SCATTERED FLASH FLOOD
THREAT AND SOME UNCERTAINTY IN EXACT TRACK OF THE MCS, DID NOT
FEEL A FLOOD WATCH IS WARRANTED AT THIS TIME.
THURSDAY FORECAST REMAINS SOMEWHAT NEBULOUS, AND WILL LIKELY DEPEND
ON EXACTLY HOW THE OVERNIGHT CONVECTION EVOLVES. MOST NUMERICAL
GUIDANCE SUGGESTS THAT OUR SOUTHERN AREAS COULD DESTABILIZE THURSDAY
AFTERNOON, ESPECIALLY IF THE CONVECTION IS A LITTLE SLOWER TO TRACK
E/SE OF OUR REGION. DEEP-LAYER SHEAR STILL LOOKS IMPRESSIVE WITH 35-
45 KT. SO, PARAMETER SPACE ON PAPER APPEARS FAVORABLE FOR SEVERE
WEATHER, BUT MID-LEVEL DRYING AND SUBSIDENCE MAY HELP TO
COUNTERACT CI AND LIMIT THE SEVERE THREAT. THIS WOULD BE
ESPECIALLY TRUE IF THE OVERNIGHT CONVECTION PUSHES FURTHER SOUTH
OF OUR REGION THURSDAY MORNING. SPC WAS LEANING TOWARDS THIS
SOLUTION WITH THEIR OVERNIGHT D3 CONVECTIVE OUTLOOK, OPTING TO
KEEP US IN GENERAL THUNDER. HOWEVER, GIVEN THE CONDITIONAL
SEVERE THREAT, EXPANSION OF THE MARGINAL RISK FURTHER NORTH INTO
OUR AREA REMAINS POSSIBLE.
KEY MESSAGE 3...THURSDAY NIGHT INTO FRIDAY, THE FRONT FINALLY PUSHES
WELL SOUTH OF OUR REGION, THUS ENDING THE THREAT FOR SEVERE WEATHER
THROUGH THE REMAINDER OF THE FORECAST PERIOD. AN UPPER TROUGH/ULL
NEARBY COULD LEAD TO A FEW ISOLATED SHOWERS FRIDAY INTO THE WEEKEND,
ESPECIALLY FOR EASTERN AREAS WHERE THERE ARE SOME HINTS FOR AN
INVERTED TROUGH TO DEVELOP AS SFC LOW PRESSURE TRACKS INTO THE GULF
OF MAINE. HIGH PRESSURE THEN BUILDS DOWN FROM THE NORTH BEHIND THE
DEPARTING ULL FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT
WEEK, RESULTING IN DRY CONDITIONS AREA-WIDE. TEMPERATURES LOOKS TO
REMAIN NEAR TO SLIGHTLY BELOW NORMAL WITH LOW-LEVEL NORTHERLY
FLOW.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
THROUGH 18Z WEDNESDAY...MVFR CIGS IN PLACE TO START THE PERIOD
EARLY THIS EVENING. OTHER THAN SOME PATCHY DRIZZLE, THERE WILL
BE A FEW -SHRA MOVING ACROSS KPOU THROUGH AROUND 02Z. OTHERWISE,
IT WILL BE MAINLY DRY THROUGH THE REST OF THE 24 HOUR TAF
PERIOD. CIGS WILL GRADUALLY LOWER TO IFR LEVELS BY LATER THIS
EVENING AND LAST THROUGH THE NIGHT INTO WEDNESDAY MORNING. VSBYS
WILL GENERALLY BE VFR, WITH PERIODS OF MVFR ASSOCIATED WITH SOME
MIST TONIGHT. CIGS ARE EXPECTED TO IMPROVE TO MVFR LEVELS BY
WEDNESDAY AFTERNOON. WINDS WILL BE VARIABLE AROUND 5 KT OR LESS
TONIGHT, BECOMING SOUTHEAST AROUND 5-10 KT ON WEDNESDAY.
OUTLOOK...
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA.
THURSDAY: HIGH OPERATIONAL IMPACT. DEFINITE SHRA...TSRA.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
ALY WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
DISCUSSION...35
AVIATION...07
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