373
FXUS61 KBUF 031855
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
255 PM EDT THU SEP 3 2026
WHAT HAS CHANGED
THE SPC MAINTAINS A MARGINAL RISK OF SEVERE THUNDERSTORMS
CAPABLE OF PRODUCING DAMAGING STRAIGHT-LINE WIND GUSTS ACROSS
SOUTHERN PORTIONS OF CHAUTAUQUA AND CATTARAUGUS COUNTIES FOR
THIS AFTERNOON INTO EVENING.
KEY MESSAGES
1) PERIODIC, ISOLATED TO SCATTERED RAIN SHOWERS AND
THUNDERSTORMS EXPECTED THROUGH FRIDAY NIGHT.
2) QUIETER WEATHER EXPECTED THIS LABOR DAY WEEKEND.
DISCUSSION
KEY MESSAGE 1...PERIODIC, ISOLATED TO SCATTERED RAIN SHOWERS
AND THUNDERSTORMS EXPECTED THROUGH FRIDAY NIGHT.
CYCLONIC W'ERLY TO NW'ERLY FLOW ALOFT AND EMBEDDED SHORTWAVE
TROUGHS IMPACT OUR REGION THROUGH FRIDAY NIGHT. AT THE SURFACE,
A SECONDARY COLD FRONT SHOULD SWEEP SE'WARD THROUGH WESTERN AND
CENTRAL NY THIS EVENING THROUGH ABOUT DAYBREAK FRIDAY MORNING.
THIS FRONT WILL BE PRECEDED BY A RATHER HUMID AIR MASS
ORIGINATING OVER THE GULF. BEHIND THE FRONT, A HIGH PRESSURE
RIDGE ASSOCIATED WITH A COOLER AND LESS HUMID AIR MASS WILL
BUILD FROM NORTHERN ON AND VICINITY THROUGH FRIDAY NIGHT. HIGHS
WILL REACH THE LOWER 70'S TO LOWER 80'S LATE THIS AFTERNOON AND
BE FOLLOWED BY OVERNIGHT LOWS IN MAINLY THE MID 50'S TO MID 60'S
AROUND DAYBREAK FRIDAY. FRIDAY WILL FEATURE LATE AFTERNOON
HIGHS IN THE 70'S. OVERNIGHT LOWS SHOULD REACH MAINLY THE UPPER
40'S TO UPPER 50'S AROUND DAYBREAK SATURDAY. PARTIAL CLEARING,
LINGERING LOW-LEVEL MOISTURE, AND WEAK SURFACE WINDS SHOULD
YIELD LOCALIZED STEAM FOG IN THE RIVER AND LAKE VALLEYS EAST OF
LAKE ONTARIO, IN THE FINGER LAKES, AND IN THE WESTERN SOUTHERN
TIER AROUND DAYBREAK FRIDAY AND SATURDAY, RESPECTIVELY.
PERIODIC, ISOLATED TO SCATTERED, AND ORGANIZED SHOWERS AND
THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON THROUGH FRIDAY
EVENING, ESPECIALLY FROM THE NIAGARA FRONTIER TO NORTHERN CAYUGA
COUNTY AND POINTS SOUTH (GREATEST POTENTIAL FROM SOUTHERN ERIE
COUNTY TO SOUTHWESTERN ONTARIO COUNTY AND FARTHER SOUTH), AS
DEEP-LAYER BULK SHEAR REMAINS MODERATE TO STRONG AND WEAK TO
MODERATE CAPE, INCLUDING ELEVATED CAPE, IS RELEASED BY THE
FOLLOWING: MOIST ISENTROPIC ASCENT AHEAD OF SHORTWAVE TROUGH
AXES; LOW-LEVEL CONVERGENCE/MOIST ASCENT ALONG THE SECONDARY
COLD FRONT AND SURFACE TROUGH AXES ATTENDANT TO THE SHORTWAVE
TROUGHS; DOWNSHEAR OUTFLOW BOUNDARIES INTERACTING FAVORABLY WITH
AMBIENT LOW-LEVEL VERTICAL WIND SHEAR. WHILE THE SEVERE
CONVECTIVE WEATHER RISK IS MUCH GREATER IN NE OH AND NW PA,
CANNOT RULE-OUT A FEW SEVERE THUNDERSTORMS IMPACTING SOUTHERN
PORTIONS OF CHAUTAUQUA AND CATTARAUGUS COUNTIES LATE THIS
AFTERNOON INTO THIS EVENING. IF SEVERE STORMS OCCUR, DAMAGING
STRAIGHT-LINE WIND GUSTS ARE EXPECTED TO BE THE MAIN HAZARD DUE
TO THE AFOREMENTIONED INSTABILITY AND DEEP-LAYER BULK SHEAR
COMBINED WITH THE FOLLOWING: MODERATE DCAPE DUE TO DIURNAL
CONVECTIVE MIXING OF THE BOUNDARY LAYER AND STEEPENING LOW-LEVEL
LAPSE RATES THROUGH THIS LATE AFTERNOON AND THEN GRADUAL
BOUNDARY LAYER STABILIZATION/REDUCTION OF DCAPE THIS EVENING AS
NOCTURNAL COOLING OCCURS AT A SOMEWHAT SLOW RATE IN THE
WARM/MOIST SECTOR. PERIODS OF HEAVY RAIN ARE EXPECTED,
ESPECIALLY WITH SHOWERS AND STORMS IN THE WARM SECTOR, DUE TO
THE AFOREMENTIONED RICH LOW-LEVEL MOISTURE ORIGINATING OVER THE
GULF. LOCALIZED FLASH FLOODING CANNOT BE RULED-OUT WHERE
MULTIPLE ROUNDS OF HEAVY RAIN-PRODUCING SHOWERS/STORMS MANAGE TO
OCCUR. FAIR WEATHER IS EXPECTED CWA-WIDE AFTER MIDNIGHT FRIDAY
NIGHT AS THE AFOREMENTIONED SURFACE RIDGE CONTINUES TO BUILD
INTO OUR REGION, THE RIDGE ALOFT BEGINS TO BUILD FROM THE UPPER
MIDWEST, AND STABILIZING SUBSIDENCE BECOMES MORE EXTENSIVE AND
STRENGTHENS OVER WESTERN AND CENTRAL NY.
KEY MESSAGE 2...QUIETER WEATHER EXPECTED THIS LABOR DAY WEEKEND.
CURRENT ODDS FAVOR FAIR WEATHER THIS SATURDAY THROUGH LABOR DAY
AS THE SURFACE RIDGE SETTLES S'WARD AND OVER OUR REGION AND THE
RIDGE ALOFT CONTINUES TO BUILD FROM THE UPPER MIDWEST. HOWEVER,
ISOLATED RAIN SHOWERS MAY IMPACT THE EASTERN LAKE ONTARIO
REGION AT TIMES ON SATURDAY AND SUNDAY AS SHORTWAVE TROUGHS
EMBEDDED IN THE NW'ERLY FLOW ALOFT IMPACT THAT PART OF OUR CWA.
NEAR-AVERAGE TO SLIGHTLY BELOW-AVERAGE DAILY HIGH AND LOW
TEMPERATURES ARE EXPECTED THROUGH LABOR DAY AS THE AFOREMENTIONED
RIDGE IS ACCOMPANIED BY A COOLER AND DRIER AIR MASS. MAINLY
CLEAR SKY AND WEAK OR CALM SURFACE WINDS SHOULD YIELD STEAM FOG
IN THE RIVER AND LAKE VALLEYS EAST OF LAKE ONTARIO, IN THE
FINGER LAKES, AND IN THE WESTERN SOUTHERN TIER AROUND DAYBREAK
EACH DAY.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
AN EAST-WEST ORIENTED COLD FRONT LOCATED OVER LAKE ONTARIO
STRETCHING EAST INTO THE NORTH COUNTRY EARLY THIS AFTERNOON IS
TRYING TO PRESS SLOWLY SOUTHWARD, BUT ULTIMATELY WILL LIKELY NOT
MAKE MUCH MORE IN THE WAY OF SOUTHWARD PROGRESS THROUGH AT LEAST THE
FIRST HALF OF TONIGHT. EXPECT MAINLY SCT-BKN DIURNAL CU (MAINLY
LOWER-END VFR/SOME MARGINAL MVFR) THIS AFTERNOON ACROSS MOST SITES
SOUTH OF LAKE ONTARIO, WITH CHANCES FOR SHOWERS AND ISOLATED STORMS
FROM MID AFTERNOON THROUGH THIS EVENING, ESPECIALLY TOWARD THE
WESTERN SOUTHERN TIER. DRY WEATHER WITH FEW-SCT LOWER-END DIURNAL CU
DECKS EXPECTED EAST OF LAKE ONTARIO.
HIGH PRESSURE CENTERED OVER HUDSON BAY WILL START TO BUILD SOUTH,
HELPING TO FINALLY FORCE THE COLD FRONT, STILL SOMEWHERE IN THE
VICINITY OF THE SOUTHERN LAKE ONTARIO SHORELINE FURTHER SOUTH. THIS
WILL HELP SUPPRESS THE NORTHERN EDGE ANY LINGERING SHOWER ACTIVITY A
BIT FURTHER SOUTH ACROSS POINTS MAINLY SOUTH OF I-90. THE MAIN
ISSUES TONIGHT WILL BE THE DEVELOPMENT OF STRATUS AND FOG,
ESPECIALLY ACROSS THE HIGHER TERRAIN SOUTH OF LAKE ONTARIO, WHERE
PLENTIFUL LOW LEVEL MOISTURE WILL REMAIN IN PLACE AHEAD OF THE
SURFACE COLD FRONT WITH IFR/LIFR CIGS EXPECTED TO DEVELOP (INCLUDING
KJHW). SOME LOWER-END VFR/MVFR WILL ALSO BE POSSIBLE FROM KBUF/KIAG
OVER TO KROC.
CANADIAN HIGH PRESSURE WILL CONTINUE TO BUILD FURTHER SOUTH TOWARD
THE REGION, HELPING TO PUSH THE SLOW-MOVING COLD FRONT FURTHER
SOUTH, NEARING THE NY/PA LINE AT SOME POINT LATER FRIDAY. THIS WILL
ALLOW MOST AREAS TO REMAIN AT OR IMPROVE TO VFR FRIDAY AS SUBSIDENCE
AND DRIER AIR ASSOCIATED WITH SAID HIGH PRESSURE BUILDS FURTHER
SOUTH INTO THE GREAT LAKES REGION. THE EXCEPTION WILL BE TOWARD THE
SOUTHERN TIER, WHERE CLOSER PROXIMITY TO THE SURFACE COLD FRONT MAY
ALLOW MVFR/LOWER-END VFR CIGS TO HANG ON INTO THE AFTERNOON HOURS,
ALONG WITH THE CHANCE FOR A FEW MORE SCATTERED SHOWERS AND STORMS.
OUTLOOK...
FRIDAY NIGHT THROUGH MONDAY...MAINLY VFR. RIVER VALLEY FOG WITH
LOCAL IFR EACH LATE NIGHT AND EARLY MORNING ACROSS THE SOUTHERN TIER.
TUESDAY...MAINLY VFR WITH A SLIGHT CHANCE OF SHOWERS.
MARINE
WINDS AROUND 5 TO 15 KNOTS AND WAVES OF 3 FEET OR LESS ARE
EXPECTED THROUGH THIS TUESDAY FOR EASTERN LAKE ERIE AND LAKE
ONTARIO. A SECONDARY COLD FRONT WILL SWEEP SE'WARD ACROSS THE
LAKES THIS EVENING THROUGH THE PREDAWN HOURS OF FRIDAY MORNING
AND CAUSE SW'ERLY TO W'ERLY WINDS TO VEER TO NW'ERLY TO N'ERLY.
BEHIND THE FRONT, A RIDGE BUILDS FROM NORTHERN ON AND VICINITY
THROUGH LABOR DAY AND WILL BE ACCOMPANIED BY VARIABLE WINDS.
THAT RIDGE SHOULD EXIT S'WARD MONDAY NIGHT AND BE FOLLOWED BY
ANOTHER COLD FRONT SWEEPING S'WARD ACROSS THE LAKES. VARIABLE
WINDS AHEAD OF THE FRONT SHOULD BECOME MAINLY NE'ERLY TO E'ERLY
BEHIND THE FRONT. MAINLY NE'ERLY TO E'ERLY WINDS SHOULD PERSIST
ON TUESDAY AS ANOTHER RIDGE BUILDS FROM NEAR JAMES BAY.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
DISCUSSION...JASZKA
AVIATION...JM
MARINE...JASZKA
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