743
FXUS61 KBUF 090132
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
932 PM EDT TUE SEP 8 2026
WHAT HAS CHANGED
ADJUSTED POP'S UPWARD, OVERALL, AND MADE MINOR EDITS TO QPF
FROM ABOUT DAYBREAK THROUGH EARLY EVENING ON WEDNESDAY TO
ACCOUNT FOR LATEST TRENDS IN OBS, INCLUDING UPSTREAM OBS, AND
NWP MODEL GUIDANCE.
KEY MESSAGES
1) A COLD FRONT WILL CROSS THE EASTERN GREAT LAKES WEDNESDAY THROUGH
WEDNESDAY NIGHT, PRODUCING SHOWERS AND SCATTERED THUNDERSTORMS. A
FEW STORMS MAY BE SEVERE WITH ISOLATED DAMAGING WIND GUSTS THE
PRIMARY HAZARD.
2) A FEW SHOWERS MAY LINGER THURSDAY MAINLY ACROSS THE SOUTHERN
TIER, WITH DRY WEATHER RETURNING FRIDAY THROUGH SATURDAY.
DISCUSSION
KEY MESSAGE 1...A COLD FRONT WILL CROSS THE EASTERN GREAT LAKES
WEDNESDAY THROUGH WEDNESDAY NIGHT, PRODUCING SHOWERS AND SCATTERED
THUNDERSTORMS. A FEW STORMS MAY BE SEVERE WITH ISOLATED DAMAGING
WIND GUSTS THE PRIMARY HAZARD.
INCREASINGLY MOIST ISENTROPIC ASCENT ALOFT, AHEAD OF THE NEXT
LOW PRESSURE SYSTEM, WILL ALLOW WIDESPREAD CLOUD COVER,
INITIALLY IN THE MID/UPPER-LEVELS, TO LOWER AND THICKEN INTO
WIDESPREAD LOW-LEVEL CLOUDS GENERALLY FROM WEST TO EAST BETWEEN
ABOUT DAYBREAK AND MIDDAY WEDNESDAY. PERIODIC AND ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BLOSSOM AND
OVERSPREAD OUR REGION GENERALLY FROM WEST TO EAST BEGINNING
AROUND DAYBREAK AND CONTINUING THROUGH WEDNESDAY AFTERNOON AS
WEAK TO MODERATE CAPE, INCLUDING ELEVATED CAPE, IS RELEASED BY
THE FOLLOWING: THE ISENTROPIC ASCENT WITH A MOISTURE TAP TO THE
GULF; LOW-LEVEL CONVERGENCE/MOIST ASCENT ALONG SURFACE TROUGH
AXES ACCOMPANYING SHORTWAVE TROUGHS EMBEDDED IN W'ERLY
MID/UPPER-LEVEL FLOW; DOWNSHEAR OUTFLOW BOUNDARIES INTERACTING
FAVORABLY WITH AMBIENT LOW-LEVEL VERTICAL WIND SHEAR AMIDST
PRIMARILY MODERATE TO STRONG DEEP-LAYER BULK SHEAR.
THE MAIN AREA OF SHOWERS AND SCATTERED THUNDERSTORMS WILL ARRIVE
LATE WEDNESDAY AFTERNOON THROUGH LATE EVENING AS A BROKEN BAND OF
SHOWERS AND SCATTERED THUNDERSTORMS CROSS THE REGION. A SHARP MID
LEVEL TROUGH WILL CROSS ONTARIO AND QUEBEC, WITH THE SOUTHERN EXTENT
OF HEIGHT FALLS SPREADING EAST ACROSS THE GREAT LAKES AND PROVIDING
SOME LARGE SCALE FORCING FOR ASCENT. THE MAIN FOCUS FOR
CONVECTION WILL BE A PRE-FRONTAL TROUGH THAT IS FORECAST TO
REACH THE EASTERN GREAT LAKES BY EARLY EVENING. THE LOW PRESSURE
SYSTEM WILL CAPTURE A NARROW PLUME OF DEEP MOISTURE, WITH PWAT
VALUES BRIEFLY EXCEEDING 2 INCHES LATE WEDNESDAY JUST AHEAD OF
THE PRE-FRONTAL TROUGH.
ANY THUNDERSTORMS WILL PRODUCE BRIEF DOWNPOURS, BUT FAST STORM
MOTION WILL LIKELY KEEP THE FLOOD RISK LOW. STRONG DEEP-LAYER
BULK SHEAR WILL OVERSPREAD THE AREA WEDNESDAY, WITH BOUNDARY
LAYER FLOW INCREASING TO 40+ KNOTS. POOR MID-LEVEL LAPSE RATES
WILL KEEP INSTABILITY SOMEWHAT LIMITED, BUT THE LATEST NWP MODEL
GUIDANCE SUGGESTS THAT SUFFICIENT INSTABILITY MAY DEVELOP TO
SUPPORT SOME SEVERE THUNDERSTORM RISK FROM LATE AFTERNOON
THROUGH MID TO LATE EVENING. THE LARGELY UNIDIRECTIONAL WIND
PROFILES WILL SUPPORT LOCALIZED DAMAGING WIND GUSTS AS THE
PRIMARY SEVERE CONVECTIVE WEATHER HAZARD.
SHOWERS AND SCATTERED THUNDERSTORMS WILL TAPER OFF FROM NORTHWEST TO
SOUTHEAST OVERNIGHT.
KEY MESSAGE 2...A FEW SHOWERS MAY LINGER THURSDAY MAINLY ACROSS THE
SOUTHERN TIER, WITH DRY WEATHER RETURNING FRIDAY THROUGH SATURDAY.
THE COLD FRONT WILL STALL ACROSS OHIO AND PA THURSDAY AS A WEAK
BAROCLINIC WAVE MOVES EAST DOWN THE BOUNDARY. THIS WAVE WILL PRODUCE
AN AREA OF ORGANIZED RAIN TO OUR SOUTH ACROSS OHIO AND PA. MOST OF
THIS WILL MISS OUR REGION, ALTHOUGH A FEW SHOWERS MAY DEVELOP ACROSS
THE SOUTHERN TIER. OTHERWISE, THE REST OF THE AREA WILL BE MAINLY
DRY THURSDAY WITH A GOOD DEAL OF CLOUD COVER NORTH OF THE FRONTAL
WAVE. THE FRONT WILL THEN ACCELERATE SOUTHEAST AND INTO THE MID
ATLANTIC THURSDAY NIGHT AS HIGH PRESSURE BUILDS INTO THE CENTRAL
GREAT LAKES.
DRY WEATHER AND SUNSHINE WILL RETURN FRIDAY THROUGH SATURDAY AS HIGH
PRESSURE DRIFTS FROM THE GREAT LAKES EAST TO NEW ENGLAND. THE NEXT
CHANCE OF SHOWERS MAY ARRIVE BY SUNDAY AS THE NEXT MID LEVEL TROUGH
AND COLD FRONT MOVE INTO THE GREAT LAKES.
AVIATION /01Z WEDNESDAY THROUGH SUNDAY/
W'ERLY TO NW'ERLY FLOW ALOFT AND EMBEDDED DISTURBANCES AFFECT
WESTERN AND CENTRAL NY THROUGH 00Z/THURS. SIMULTANEOUSLY AND AT
THE SURFACE, A HIGH PRESSURE RIDGE EXITS E'WARD. INITIALLY LIGHT
AND VARIABLE SURFACE WINDS ARE EXPECTED TO BECOME S'ERLY TO
SW'ERLY AROUND 5 TO 15 KNOTS WED MORNING AND THEN PERSIST
THROUGH 00Z/THURS. DIURNAL CONVECTIVE MIXING OF THE BOUNDARY
LAYER TAPPING INTO STRONGER FLOW ALOFT SHOULD ALLOW THESE WINDS
TO GUST UP TO 20 TO 25 KNOTS AT TIMES WED AFTERNOON THROUGH
EARLY EVENING.
DRY WEATHER AND WIDESPREAD VFR ARE EXPECTED FOR THE TIME BEING.
WIDESPREAD CEILINGS, INITIALLY IN THE MID/UPPER-LEVELS, ARE
EXPECTED TO LOWER TO NEAR 4KFT TO 6KFT AGL AND GENERALLY FROM
WEST TO EAST BETWEEN ~10Z/WED AND ~15Z/WED. PERIODIC AND
SCATTERED SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE
AFOREMENTIONED DISTURBANCES SHOULD BLOSSOM AND OVERSPREAD OUR
REGION GENERALLY FROM WEST TO EAST BETWEEN ~11Z/WED AND
~16Z/WED. PERIODIC/SCATTERED SHOWERS/THUNDERSTORMS SHOULD THEN
PERSIST THROUGH 00Z/THURS. BRIEF MVFR TO LIFR AND DOWNPOURS ARE
EXPECTED WITH SHOWERS AND THUNDERSTORMS. SOME STORMS MAY
PRODUCE BRIEF/ERRATIC SURFACE WIND GUSTS UP TO 30 TO 50 KNOTS
WED AFTERNOON THROUGH 00Z/THURS.
OUTLOOK...
WEDNESDAY NIGHT...WIDESPREAD MVFR OR LOWER CEILINGS AND ISOLATED
TO SCATTERED SHOWERS/THUNDERSTORMS EXPECTED.
THURSDAY...MVFR OR LOWER CEILINGS EARLY, IMPROVING TO VFR. A
FEW SHOWERS ARE POSSIBLE ACROSS THE WESTERN SOUTHERN TIER.
FRIDAY THROUGH SATURDAY...MAINLY VFR AND DRY WEATHER EXPECTED.
SUNDAY...MAINLY VFR EXPECTED, BUT SCATTERED SHOWERS ARE
POSSIBLE.
MARINE
LOW PRESSURE WILL TRACK EAST ACROSS HUDSON BAY WEDNESDAY BEFORE
REACHING NORTHERN QUEBEC THURSDAY, WITH A TRAILING COLD FRONT
CROSSING THE LOWER GREAT LAKES WEDNESDAY NIGHT. A BELT OF ENHANCED
WINDS WILL DEVELOP SOUTH OF THE LOW, WITH SOUTHERLY WINDS INCREASING
ON THE LOWER GREAT LAKES TONIGHT, THEN INCREASING FURTHER AND
VEERING TO THE SOUTHWEST WEDNESDAY. WINDS AND WAVES WILL APPROACH
LOW END SMALL CRAFT ADVISORY CRITERIA BY WEDNESDAY AFTERNOON ON BOTH
LAKES, WITH WINDS PEAKING WEDNESDAY EVENING. ELEVATED WINDS AND
WAVES WILL LIKELY CONTINUE THROUGH THURSDAY EVENING ON LAKE ONTARIO.
HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES THURSDAY NIGHT
THROUGH FRIDAY WITH SUBSIDING WINDS AND WAVES.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
DISCUSSION...HITCHCOCK/JASZKA
AVIATION...JASZKA
MARINE...HITCHCOCK
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