717
FXUS61 KBUF 032337
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
737 PM EDT SUN MAY 3 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES HAVE BEEN MADE WITH THIS UPDATE.
KEY MESSAGES
1) WARMER AND BREEZY CONDITIONS PREVAIL THROUGH TUESDAY WITH COOLER
TEMPERATURES RETURNING BY MIDWEEK.
2) INCREASINGLY ACTIVE WEATHER RETURNS MONDAY NIGHT/TUESDAY, WITH
WIDESPREAD SHOWERS/A FEW STORMS LATER TUESDAY THROUGH WEDNESDAY.
DISCUSSION
KEY MESSAGE 2...WARMER AND BREEZY CONDITIONS PREVAIL THROUGH
TUESDAY WITH COOLER TEMPERATURES RETURNING BY MIDWEEK.
DEEP LONGWAVE UPPER LEVEL TROUGHING WILL CONTINUE TO PULL AWAY FROM
NEW ENGLAND AND ACROSS THE CANADIAN MARITIMES THROUGH MONDAY NIGHT.
A FEW SHORTWAVE TROUGHS EMBEDDED IN THE BROAD RESIDUAL TROUGHING
ACROSS CANADA AND THE NORTHERN TIER WILL HAVE THEIR SOUTHWARD EXTENT
SUPPRESSED BY AN AN EXPANSE OF HIGH PRESSURE RIDING ACROSS THE
SOUTHEASTERN QUADRANT OF THE CONUS AND WESTERN ATLANTIC. AS THE
EASTERN GREAT LAKES REMAIN SANDWICHED BETWEEN THESE FEATURES,
DEEPENING SOUTHWESTERLY FLOW ACROSS THE MISSISSIPPI VALLEY WILL
CONTINUE TO ADVECT WARMER AIR INTO THE REGION. 850MB TEMPS WILL
LIKELY REMAIN IN THE SINGLE DIGITS (C) THOUGH TOP OUT JUST SHY OF
+10C MONDAY EVENING THROUGH EARLY TUESDAY. THIS WILL TRANSLATE TO
SEASONABLY COOL TEMPERATURES TODAY RISING TO A FEW DEGREES ABOVE
SEASONAL AVERAGES MONDAY THROUGH TUESDAY.
THE PRESSURE GRADIENT BETWEEN THE AFOREMENTIONED NORTHERN TROUGHING
AND SOUTH/SOUTHEASTERN RIDGING WILL MAINTAIN A STIFF SOUTHWESTERLY
SURFACE BREEZE ACROSS THE REGION AS WELL. A BIT OF A TRICKIER
FORECAST HERE AS THE STRENGTH OF THE OVERHEAD LLJ WILL NOT BE STEADY-
STATE. THE WARM ADVECTION PATTERN SHOULD GENERALLY LIMIT THE EXTENT
THIS JET MIXES TO THE GROUND, WHILE MODEL GUIDANCE SUGGESTS THE LLJ
INCREASES LATE THIS EVENING AND AGAIN MONDAY NIGHT, WHICH IS ALSO
NOT IDEAL FOR MIXING. THE END RESULT SHOULD BE A PERSISTENT BREEZE
THROUGH AT LEAST TUESDAY WHICH IS STRONGEST NORTHEAST OF BOTH LAKES,
PARTICULARLY ACROSS THE NIAGARA FRONTIER WHERE GUSTS 25-35MPH ARE
LIKELY. OVERALL CONFIDENCE IN GUST POTENTIAL IS LOWER LATER TUESDAY
AS ENSEMBLE GUIDANCE INDICATES A MUCH HIGHER SPREAD IN 850MB WINDS
AHEAD OF A SLOW-MOVING COLD FRONT, WHICH IS LIKELY CAUSED BY
DIFFERENCES IN BOTH TIMING AND STRENGTH OF THE LLJ.
BEHIND THIS COLD FRONT, SHORTWAVE PHASING WITHIN THE NORTHERN TROUGH
WILL EFFECTIVELY RELOAD IT ACROSS THE NORTHEAST AND CAUSE POLAR
CONTINENTAL AIR FROM CANADA TO SPILL SOUTHWARD ACROSS THE GREAT
LAKES. THIS WILL CAUSE ANOTHER PROLONGED STRETCH OF COOLER
TEMPERATURES TUESDAY NIGHT THROUGH THE REST OF THE WEEK.
KEY MESSAGE 2...INCREASINGLY ACTIVE WEATHER RETURNS MONDAY NIGHT/
TUESDAY, WITH WIDESPREAD SHOWERS/A FEW STORMS LATER TUESDAY THROUGH
WEDNESDAY.
THE NORTHERN TROUGH WILL FURTHER IMPINGE ON THE EASTERN GREAT LAKES
AS A BERMUDA HIGH IS PUSHED FURTHER NORTHEASTWARD INTO THE ATLANTIC
MONDAY NIGHT THROUGH WEDNESDAY. THIS WILL FORCE A CLOSED MID-LEVEL
CYCLONE FROM WESTERN ONTARIO PROVINCE THIS EVENING TO JAMES BAY BY
EARLY TUESDAY. THIS SYSTEM WILL FORCE A COLD FRONT INTO THE GREAT
LAKES REGION DURING THIS TIMEFRAME, THOUGH COMPLEX PHASING WILL THEN
OCCUR WITH A SECONDARY LOW NEAR THE LABRADOR SEA AND THE HUDSON
STRAIT THROUGH WEDNESDAY. THIS WILL RESULT IN THE FRONT SLOWING DOWN
SUBSTANTIALLY WITH A TIGHTENING THERMAL GRADIENT AS SEVERAL
ADDITIONAL WAVES OF LOW PRESSURE RIDE NORTHEAST ALONG THE BOUNDARY.
IN TERMS OF SENSIBLE WEATHER, THIS WILL RESULT IN INCREASING CHANCES
FOR SHOWERS MONDAY NIGHT THROUGH THE FIRST HALF OF TUESDAY ACROSS
THE FORECAST AREA. THEN, YET ANOTHER WIDESPREAD SOAKING RAINFALL IS
LIKELY LATER TUESDAY THROUGH THE FIRST HALF OF WEDNESDAY, WITH A
CHANCE FOR EMBEDDED THUNDERSTORMS TUESDAY AFTERNOON. BASIN-AVERAGED
RAINFALL AMOUNTS IN THE BALLPARK OF 0.75" TO 1.25" THROUGH WEDNESDAY
SEEMS PROBABLE BASED ON MID AND LONG RANGE ENSEMBLES, THOUGH THE
DETERMINISTIC GUIDANCE IS SHOWING A FAIR AMOUNT OF SPREAD IN THE
FINER DETAILS OF THE COLD FRONT'S EVOLUTION. LOCALLY HIGHER AMOUNTS
WILL CERTAINLY BE POSSIBLE ESPECIALLY IF AND WHERE CONVECTION
ENHANCES RAINFALL RATES. PWATS AND OVERALL INSTABILITY SEEM LOW
ENOUGH SUCH THAT FLOODING AND/OR SEVERE WEATHER DO NOT APPEAR
LIKELY, BUT WILL CONTINUE TO MONITOR.
AVIATION /00Z MONDAY THROUGH FRIDAY/
VFR WILL CONTINUE TO PREVAIL THROUGH MONDAY AS SEVERAL WARM FRONTAL
SEGMENTS MOVE INTO THE REGION, BRINGING PERIODS OF MID LEVEL CLOUDS.
A FEW SHOWERS MAY APPROACH THE SOUTHERN LAKE ONTARIO SHORELINE
(KBUF/KIAG/KROC) BETWEEN 21Z AND 02Z, THOUGH CIGS/VSBYS WILL LIKELY
REMAIN IN VFR RANGE. A BRIEF WINDOW OF MVFR CIGS MAY ACCOMPANY A FEW
SHOWERS IN THE NORTH COUNTRY BETWEEN 02Z AND 06Z THIS EVENING AND
AGAIN MONDAY MORNING, WITH LOWER CONFIDENCE IN TIMING.
A PERSISTENT BUT WAVERING LLJ WILL MAINTAIN A STIFF SOUTHWESTERLY
BREEZE ACROSS THE REGION THROUGH TONIGHT. GUSTS OF 20-25KTS CAN BE
EXPECTED IN MOST AREAS THROUGH THIS EVENING, WITH GUSTS AROUND 30KTS
POSSIBLE AT KBUF/KIAG. GUSTS WILL BECOME MORE ISOLATED TO AREAS NEAR
THE LAKES TONIGHT, THOUGH SIMILARLY EXPAND IN COVERAGE MONDAY.
OUTLOOK...
MONDAY NIGHT...VFR/MVFR. INCREASING CHANCES FOR SHOWERS.
TUESDAY...MVFR. COVERAGE OF SHOWERS INCREASES, WITH A FEW
THUNDERSTORMS POSSIBLE IN THE AFTERNOON
TUESDAY NIGHT...MAINLY IFR WITH WIDESPREAD RAIN.
WEDNESDAY...IMPROVEMENT TO MVFR/VFR POSSIBLE WITH STEADY RAIN
TAPERING OFF. LOW-END CHANCE FOR SHOWERS LINGERS.
THURSDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
FRIDAY...RESTRICTIONS POSSIBLE WITH INCREASING CHANCES FOR SHOWERS
IN THE AFTERNOON.
MARINE
THROUGH TUESDAY HIGH PRESSURE WILL SLIDE EAST FROM THE APPALACHIANS
INTO THE WESTERN ATLANTIC, WHILE DEVELOPING LOW PRESSURE TRACKS
ACROSS NORTHERN ONTARIO AND QUEBEC. A SLOW-MOVING COLD FRONT WILL
THEN CROSS OUR REGION LATER TUESDAY. PERIODS OF MODERATELY BRISK
SOUTHWESTERLY FLOW IS EXPECTED AT TIMES AHEAD OF THIS FRONT,
BRINGING THE LIKELIHOOD FOR ROUNDS OF NEAR-SCA TO SCA CONDITIONS.
THESE ARE MOST LIKELY ACROSS LAKE ERIE, THE UPPER NIAGARA RIVER, AND
THE EASTERN END OF LAKE ONTARIO GIVEN THE ONSHORE WIND COMPONENT.
A FEW THUNDERSTORMS AND LOCALLY HIGHER WINDS/WAVES WILL ALSO BE
POSSIBLE ON TUESDAY WITH THE APPROACH AND PASSAGE OF THE SLOW-MOVING
COLD FRONT.
CLIMATE
OUR VERY WET SPRING CONTINUED THROUGH THE MONTH OF APRIL...WITH BOTH
BUFFALO AND WATERTOWN POSTING APRILS THAT WERE AMONG THE TOP 10
WETTEST ON RECORD. THE MONTHLY PRECIPITATION TOTALS FOR OUR THREE
CLIMATE SITES WERE AS FOLLOWS:
BUFFALO - 5.58" (6TH WETTEST ON RECORD)
ROCHESTER - 4.08" (TIED FOR 14TH WETTEST ON RECORD)
WATERTOWN - 5.16" (5TH WETTEST ON RECORD)
COUPLED WITH THE EXTREMELY WET MARCH...THE ABOVE RESULTED IN
COMBINED MARCH-APRIL PRECIPITATION TOTALS THAT WERE EITHER THE
WETTEST OR 2ND WETTEST ON RECORD. FOR OUR THREE CLIMATE SITES, THESE
WERE AS FOLLOWS:
BUFFALO - 11.91" (WETTEST ON RECORD - PREVIOUS WETTEST 11.80"/1991)
ROCHESTER - 9.97" (2ND WETTEST ON RECORD, BEHIND ONLY 11.73"/1873)
WATERTOWN - 9.79" (WETTEST ON RECORD - PREVIOUS WETTEST 8.43"/2011)
NOTE THAT PERIODS OF RECORD GO BACK TO JANUARY 1871 FOR BUFFALO AND
ROCHESTER, AND MAY 1949 FOR WATERTOWN.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR LEZ020-040-041.
DISCUSSION...PP
AVIATION...AR/PP
MARINE...JJR/PP
CLIMATE...JJR
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