906
FXUS61 KBUF 041813
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
213 PM EDT MON MAY 4 2026
WHAT HAS CHANGED
SLIGHT ADJUSTMENTS MADE TO PRECIP CHANCES TONIGHT AND TUESDAY,
MAINLY TO INDICATE THE POTENTIAL FOR A BREAK IN THE PRECIP ACROSS
WNY TUESDAY MORNING.
KEY MESSAGES
1) WARMER AND BREEZY/WINDY CONDITIONS INTO TUESDAY, WITH MUCH COOLER
TEMPERATURES RETURNING BY MIDWEEK.
2) INCREASINGLY ACTIVE WEATHER RETURNS TONIGHT AND TUESDAY, WITH
ANOTHER SOAKING RAINFALL EXPECTED LATER TUESDAY INTO WEDNESDAY.
DISCUSSION
KEY MESSAGE 1...WARMER AND BREEZY/WINDY CONDITIONS INTO TUESDAY,
WITH MUCH COOLER TEMPERATURES RETURNING BY MIDWEEK.
THROUGH TUESDAY, THE GREAT LAKES WILL REMAIN SANDWICHED BETWEEN A
RELOADING LONGWAVE TROUGH ACROSS CENTRAL/EASTERN CANADA MOVING INTO
THE NORTHERN TIER OF THE CONUS, AND A DEVELOPING BERMUDA HIGH IN THE
ATLANTIC. DEEP SOUTHWESTERLY FLOW ACROSS THE MISSISSIPPI VALLEY
BETWEEN THESE FEATURES WILL CONTINUE TO ADVECT AN AIRMASS WITH 850MB
TEMPS BETWEEN +7C AND +10C INTO THE REGION THROUGH, LIKELY PEAKING
THIS EVENING THROUGH EARLY TUESDAY MORNING. THIS WILL CONTINUE TO
SUPPORT SFC TEMPERATURES ABOVE NORMAL FOR EARLY MAY THROUGH AT LEAST
TONIGHT, THOUGH FOR THE FINGER LAKES REGION LIKELY THROUGH TUESDAY
AS WELL.
IN THE SAME ENVIRONMENT, A TIGHT PRESSURE GRADIENT WILL ALLOW
SEVERAL LLJ SEGMENTS TO CROSS INTO THE REGION, SUPPORTING BREEZY TO
LOCALLY WINDY CONDITIONS THROUGH AT LEAST THE FIRST HALF OF TUESDAY.
WHILE THIS LLJ WILL PEAK IN STRENGTH BETWEEN 40-50KTS AT 925MB,
SEVERAL FACTORS WILL BE WORKING AGAINST THE POTENTIAL FOR DEEPER
MIXING TO THE SURFACE...MAINLY THE WARM/NEUTRAL ADVECTIVE PATTERN,
UNFAVORABLE DIURNAL TIMING, AND INCREASING CLOUDS/PRECIP COVERAGE.
SOME MODELS (NAMELY THE NAM & CANADIAN) ARE A BIT MORE CONCERNING
WITH A STRONGER JET THAT IS ORIENTED UP THE LONG AXIS OF LAKE ERIE
AND ST. LAWRENCE VALLEY, WHICH WOULD SUGGEST NEAR ADVISORY-LEVEL
GUSTS ESPECIALLY ACROSS THE LATTER. THINKING THE OTHER FACTORS WILL
PRECLUDE THIS FROM HAPPENING, THOUGH GUSTS OF 30-40MPH ARE STILL
PROBABLE NORTHEAST OF THE LAKES AT TIMES UNTIL TUESDAY AFTERNOON.
THE WARMTH AND GUSTY WINDS WILL DIMINISH WITH THE PASSAGE OF A SLOW-
MOVING BUT STRONG COLD FRONT BETWEEN TUESDAY AFTERNOON AND EVENING.
850MB TEMPS WILL FALL TO AROUND 0C IN THE IMMEDIATE POST-FRONTAL
ENVIRONMENT, WITH WEAK COLD ADVECTION INSIDE THE IMPINGING LONGWAVE
TROUGH SLOWLY KNOCKING SEVERAL MORE DEGREES OFF THIS METRIC THROUGH
THE REST OF THE WEEK. THIS WILL TRANSLATE TO SURFACE HIGH TEMPS
FALLING BACK INTO THE 40S AND 50S FROM MIDWEEK ONWARDS, THOUGH SOME
DEGREE OF WARMING MAY OCCUR OVER THE WEEKEND. NOT OUT OF THE
QUESTION THAT ANOTHER ROUND OF FROST/FREEZE HEADLINES IS NEEDED AT
NIGHT WITH LOWS IN THE 30S EXPECTED.
KEY MESSAGE 2...INCREASINGLY ACTIVE WEATHER RETURNS TONIGHT AND
TUESDAY, WITH ANOTHER SOAKING RAINFALL EXPECTED LATER TUESDAY INTO
WEDNESDAY.
THE AFOREMENTIONED NORTHERN TROUGH, COLD FRONT AND LLJ SEGMENTS AS
DESCRIBED IN KEY MESSAGE (1) WILL INCREASE THE AMOUNT OF SYNOPTIC-
SCALE FORCING ACROSS THE EASTERN GREAT LAKES TONIGHT THROUGH MUCH OF
WEDNESDAY. THE DEEP SOUTHWESTERLY FLOW ACROSS THE MISSISSIPPI VALLEY
WILL ALSO ADVECT A DEEP PLUME OF PWATS 1-1.5" INTO THIS ENVIRONMENT,
WHICH WILL BE AMPLE FUEL TO SUPPORT YET ANOTHER SOAKING RAINFALL
ACROSS THE REGION. THERE WILL LIKELY BE A FEW SHOWERS OR ISOLATED
THUNDERSTORMS TONIGHT ON THE NOSE OF THE STRONGEST LLJ SEGMENT,
THOUGH THE MAIN TIMEFRAME FOR SOAKING SHOWERS AND EMBEDDED
THUNDERSTORMS WILL BE TUESDAY AFTERNOON THROUGH EARLY WEDNESDAY AS
INSTABILITY AND FORCING GROWS AHEAD OF THE COLD FRONT.
STILL QUITE A BIT OF UNCERTAINTY IN THE DETAILS HERE AS MODELS
CONTINUE TO STRUGGLE WITH THE TIMING OF THE FRONT AND THE MORE
WEAKLY FORCED ENVIRONMENT TONIGHT AND EARLY TUESDAY. MULTIPLE WAVES
OF LOW PRESSURE ARE EXPECTED TO RIDE UP ALONG THE FRONT AS THE MAIN
SFC LOW UNDERGOES A COMPLEX INTERACTION WITH A SECONDARY LOW UP NEAR
THE HUDSON STRAIT. THIS WILL LIKELY CAUSE THE THERMAL GRADIENT TO
TIGHTEN AND OVERALL FRONTAL PROGRESSION TO SLOW CONSIDERABLY AS IT
MOVES THROUGH THE FORECAST AREA, THE SETUP FOR WHICH IS PROVING
RATHER SENSITIVE FOR THE MODELS. THIS WILL ALSO INFLUENCE THE
STRENGTH AND POSITION OF THE OVERHEAD JET, WHICH WILL IN TURN
DETERMINE SHEAR MAGNITUDES NECESSARY FOR MORE ORGANIZED CONVECTION
TO FORM. IN THE MOST PESSIMISTIC SCENARIOS, THE FRONTAL PROGRESSION
IS SLOWER WHICH PLACES THE STRONGER JET ENERGY AND GROWING
INSTABILITY ACROSS THE FINGER LAKES AND NORTH COUNTRY TUESDAY
AFTERNOON. CANNOT RULE OUT THIS SCENARIO WHICH MAY SPARK A COUPLE OF
STRONG TO SEVERE STORMS IN THE REGION.
OTHERWISE, RAINFALL AMOUNTS BETWEEN TONIGHT AND EARLY WEDNESDAY ARE
EXPECTED TO AVERAGE BETWEEN 0.75-1.25" IN MOST AREAS, THOUGH THERE
WILL LIKELY BE A SWATH OF TOTALS CLOSER TO 1.5" IN THE CORRIDOR
BETWEEN THE SOUTHERN TIER, FINGER LAKES AND TUG HILL REGION. LOCALLY
HIGHER TOTALS WILL BE POSSIBLE DEEPENING ON HOW CONVECTION EVOLVES
THROUGHOUT THE DAY TUESDAY.
AVIATION /18Z MONDAY THROUGH SATURDAY/
VFR CONDITIONS TODAY WITH PARTLY TO MOSTLY SUNNY SKIES THROUGH THE
EARLY EVENING HOURS. SOUTHWEST WINDS OF 10 TO 20 KTS WILL HAVE GUSTS
TO THE 25 TO 35 KT RANGE THROUGH THE AFTERNOON, WITH THE STRONGEST
SUSTAINED WINDS AND GUSTS NORTHEAST OF LAKE ERIE.
TONIGHT, FLIGHT CONDITIONS WILL REMAIN MAINLY VFR FOR THE START OF
THE EVENING BEFORE MID LEVEL CLOUDS AND EVENTUALLY SOME LOW LEVEL
CLOUDS MOVE INTO THE REGION. THIS WILL BRING PERIODS OF MVFR CIGS TO
THE HIGHER TERRAIN SOUTH OF BUFFALO FIRST DURING THE EVENING HOURS
AND THEN TO THE FAR WESTERN NY TERMINALS WITHIN A FEW HOURS OF
DAYBREAK ON TUESDAY MORNING. SCATTERED SHOWERS AND A FEW
THUNDERSTORMS WILL BE POSSIBLE THROUGH THE NIGHT. EARLIER GUSTY
WINDS WILL WEAKEN AS DAYTIME HEATING DIMINISHES. WITH A LLJ STILL
OVER THE REGION, THIS WILL RESULT IN LLWS OVER PORTIONS OF THE AREA
TONIGHT.
TUESDAY, MAINLY MVFR CIGS EXPECTED, WITH SOME LOWER CLOUD BASES TO
IFR OVER THE HIGHER TERRAIN SOUTH OF BUFFALO. A FEW SHOWERS WILL
LINGER INTO THE MORNING HOURS WITH ADDITIONAL DEVELOPMENT OF SHOWERS
AND SOME THUNDERSTORMS DURING THE LATE MORNING INTO THE AFTERNOON.
SHOWERS MAY BRING BRIEF HEAVY DOWNPOURS AT TIMES, CAUSING REDUCTIONS
TO VSBYS, MAINLY DOWN TO THE MVFR RANGE.
OUTLOOK...
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 THROUGH SATURDAY...RESTRICTIONS POSSIBLE WITH INCREASING
CHANCES FOR SHOWERS IN THE AFTERNOON.
MARINE
HIGH PRESSURE WILL TRACK FARTHER OFF THE MID-ATLANTIC COAST THROUGH
THE DAY ON TUESDAY. THE PRESSURE GRADIENT HAS INCREASED OVER THE
REGION BETWEEN THIS AREA OF HIGH PRESSURE AND AN AREA OF LOW
PRESSURE TO THE NORTHWEST. THIS HAS CAUSED GUSTY WINDS ACROSS MOST
OF THE LAND AREAS OF WESTERN AND NORTH CENTRAL NY, WITH THE MORE
STABLE MARINE LAYERS HAVING LESS WINDS. THE PRESSURE GRADIENT WILL
REMAIN STRONG OVER THE REGION THROUGH TUESDAY EVENING BEFORE
WEAKENING TUESDAY NIGHT. A COLD FRONT MOVING THROUGH ON TUESDAY WILL
HELP TO BRING SOME WINDS TO THE SURFACE FOR THE MARINE AREAS WITH
WEAK COLD AIR ADVECTION, BUT THE LOW LEVEL JET IS EXPECTED TO WEAKEN
BEHIND THE FRONT. THIS WILL RESULT IN A MODERATE TO FRESH BREEZE
THROUGH THE DAYTIME HOURS TODAY AND THEN AGAIN EARLY ON TUESDAY.
WINDS ON TUESDAY MORNING MAY BE JUST STRONG ENOUGH TO MEET SCA
CRITERIA, BUT THESE WINDS AND RESULTING WAVES ARE EXPECTED TO BE
OFFSHORE. THE BEST CHANCE FOR SCA LEVEL WINDS/WAVES WILL BE ACROSS
THE WESTERN AND EASTERN PORTIONS OF LAKE ONTARIO.
SHOWERS WITH A FEW THUNDERSTORMS WILL ALSO BE POSSIBLE TONIGHT WITH
A BETTER CHANCE FOR TUESDAY INTO TUESDAY NIGHT.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
DISCUSSION...PP
AVIATION...SW
MARINE...SW
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