560
FXUS61 KBUF 301045
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
645 AM EDT THU JUL 30 2026
WHAT HAS CHANGED
THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS WITH PERIODS OF
HEAVY RAINFALL IS INCREASING THIS WEEKEND, ESPECIALLY SATURDAY
NIGHT INTO SUNDAY.
KEY MESSAGES
1) INCREASINGLY DRIER CONDITIONS RETURN THROUGH FRIDAY.
2) PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED FRIDAY NIGHT
THROUGH THIS WEEKEND.
3) CURRENT ODDS FAVOR DRY WEATHER THIS MONDAY THROUGH TUESDAY.
DISCUSSION
KEY MESSAGE 1...INCREASINGLY DRIER CONDITIONS RETURN THROUGH
FRIDAY.
A VERTICALLY-STACKED LOW AT THE SURFACE AND ALOFT WOBBLES
NE'WARD FROM THE LONG ISLAND AND SOUTHERN NEW ENGLAND AREA TO
THE CANADIAN MARITIMES THIS MORNING THROUGH FRIDAY. SIMULTANEOUSLY,
A RIDGE AT THE SURFACE AND ALOFT BUILDS FROM THE WESTERN GREAT
LAKES AND VICINITY SO THAT BY SUNSET FRIDAY EVENING, THE SURFACE
RIDGE AXIS SHOULD BECOME LOCATED NEAR LONG ISLAND AND LAKE
CHAMPLAIN. ISOLATED TO SCATTERED RAIN SHOWERS ASSOCIATED WITH
THE LOW PRESSURE SYSTEM'S WEAKENING WARM CONVEYOR BELT
UNDERGOING MOIST ISENTROPIC ASCENT AND CONVERGENCE/MOIST ASCENT
IN THE LOW'S LOW-LEVEL CYCLONIC CIRCULATION WILL IMPACT OUR CWA
FROM ROUGHLY THE GENESEE RIVER VALLEY AND POINTS TO THE EAST
THROUGH ABOUT 8 AM EDT THIS MORNING. THE CONVECTION WILL EXIT
OUR CWA SLOWLY LATER THIS MORNING THROUGH EARLY EVENING AS THE
LOW PRESSURE SYSTEM DEPARTS NE'WARD. SHOWER COVERAGE WILL BE
GREATEST THIS AFTERNOON THROUGH EARLY EVENING AS WEAK BOUNDARY
LAYER DESTABILIZATION VIA DAYTIME HEATING OCCURS. ISOLATED
THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EARLY EVENING,
WHEN THE AFOREMENTIONED LOW-LEVEL CONVERGENCE/MOIST ASCENT MAY
RELEASE SUFFICIENT BOUNDARY LAYER CAPE. OTHERWISE, FAIR WEATHER
IS EXPECTED THROUGH FRIDAY AS THE AFOREMENTIONED RIDGE BUILDS
FROM THE WEST AND IS ACCOMPANIED BY STABILIZING SUBSIDENCE.
GIVEN THE PROJECTED WEATHER PATTERN EVOLUTION AT THE SURFACE
AND ALOFT, WEAK LOW-LEVEL CAA THROUGH TONIGHT IS EXPECTED TO
TRANSITION TO WEAK LOW-LEVEL WAA ON THE SYNOPTIC-SCALE BY
FRIDAY. HIGHS SHOULD REACH THE 70'S TO 80F LATE THIS AFTERNOON.
CONSIDERABLE CLEARING OF SKY, LOWER HUMIDITY AT/NEAR THE
SURFACE, AND WEAK SURFACE WINDS SHOULD PERMIT EFFICIENT
RADIATIONAL COOLING AND ALLOW LOWS TO REACH MAINLY THE 50'S TO
LOWER 60'S AROUND DAYBREAK FRIDAY. RIVER VALLEY STEAM FOG IS
EXPECTED AROUND DAYBREAK IN THE WESTERN SOUTHERN TIER, FINGER
LAKES, AND THE SAINT LAWRENCE AND BLACK RIVER VALLEYS. WITH THE
DEPARTURE OF THE LOW ALOFT AND ITS ASSOCIATED COOL POOL, LATE
AFTERNOON HIGHS SHOULD RECOVER TO SEASONABLE LEVELS (MAINLY
UPPER 70'S TO MID 80'S) ON FRIDAY.
KEY MESSAGE 2...PERIODIC SHOWERS AND THUNDERSTORMS ARE EXPECTED
FRIDAY NIGHT THROUGH THIS WEEKEND.
THE ABOVE-MENTIONED RIDGE AT THE SURFACE AND ALOFT SHOULD EXIT
E'WARD FRIDAY NIGHT AS A SHORTWAVE TROUGH APPROACHES FROM THE
UPPER MIDWEST AND VICINITY. MAINLY FAIR WEATHER IS EXPECTED.
HOWEVER, A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER LAKE
ONTARIO, THE NIAGARA FRONTIER, AND VICINITY SINCE MOIST
ISENTROPIC ASCENT AHEAD OF THE SHORTWAVE TROUGH AXIS MAY RELEASE
SUFFICIENT ELEVATED CAPE. LOWS SHOULD REACH MAINLY THE MID 50'S
TO MID 60'S AROUND DAYBREAK SATURDAY. ON SATURDAY, THE
AFOREMENTIONED RIDGE SHOULD CONTINUE TO EXIT E'WARD AS THE
SHORTWAVE TROUGH AXIS ADVANCES TOWARD THE WESTERN GREAT LAKES.
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS SHOULD DEVELOP
ALONG THE LAKE ONTARIO LAKE BREEZE FRONT AND ESPECIALLY THE LAKE
ERIE LAKE BREEZE FRONT AND THE LAKE ERIE/LAKE ONTARIO LAKE
BREEZE CONVERGENCE ZONE NEAR THE NIAGARA ESCARPMENT SATURDAY
AFTERNOON AND EARLY EVENING AS THE BOUNDARY LAYER DESTABILIZES
WEAKLY TO MODERATELY VIA DAYTIME HEATING AND LOW-LEVEL
WARM/MOIST AIR ADVECTION FROM THE GULF AND SOUTHERN GULF STREAM.
PERIODS OF HEAVY RAINFALL ARE EXPECTED AS PWAT VALUES RISE TO
UNUSUALLY-HIGH VALUES. TRAINING SHOWERS/THUNDERSTORMS ARE
POSSIBLE ALONG THE LAKE ERIE LAKE BREEZE FRONT SOUTH AND EAST
OF THE LAKE, WHERE SW'ERLY AND FAIRLY WEAK MEAN MID-LEVEL FLOW
SHOULD EXHIBIT A LARGE COMPONENT PARALLEL TO THE LAKE BREEZE
FRONT. LOCALIZED FLASH FLOODING MAY BECOME A CONCERN. PRIMARILY
WEAK DEEP-LAYER BULK SHEAR SHOULD CURB SEVERE STORM POTENTIAL.
LATE AFTERNOON HIGHS SHOULD REACH MAINLY THE UPPER 70'S TO MID
80'S.
THE SHORTWAVE TROUGH AXIS SHOULD ADVANCE FROM NEAR THE WESTERN
GREAT LAKES TO NEAR THE NY/NEW ENGLAND BORDER SATURDAY NIGHT
THROUGH SUNDAY NIGHT. AT THE SURFACE, A COLD FRONT ACCOMPANYING
THE SHORTWAVE DISTURBANCE SHOULD DRIFT SE'WARD ACROSS OUR CWA
SATURDAY NIGHT THROUGH SUNDAY EVENING. BEHIND THE SHORTWAVE
TROUGH AXIS AND FRONT, A RIDGE AT THE SURFACE AND ALOFT SHOULD
BUILD FROM THE UPPER MIDWEST AND VICINITY THROUGH DAYBREAK
MONDAY. ADDTIONAL PERIODS OF SHOWERS AND THUNDERSTORMS ARE
EXPECTED SATURDAY NIGHT THROUGH SUNDAY EVENING AS WEAK TO
MODERATE INSTABILITY, INCLUDING ELEVATED CAPE, IS RELEASED BY
CONVERGENCE/MOIST ASCENT ALONG THE FRONT AND MOIST-ISENTROPIC
ASCENT AHEAD OF THE SHORTWAVE TROUGH AXIS. UNUSUALLY-HIGH PWAT'S
WITHIN THE LOW-LEVEL WARM/MOIST AIR ADVECTION REGIME FROM THE
GULF AND/OR SOUTHERN GULF STREAM SHOULD ALLOW CONVECTION TO
PRODUCE PERIODS OF HEAVY RAINFALL. SW'ERLY MEAN MID-LEVEL FLOW
SHOULD EXHIBIT A LARGE COMPONENT PARALLEL TO THE SYNOPTIC FRONT
AND ALLOW CONVECTION TO TRAIN. THUS, LOCALIZED FLASH FLOODING
SHOULD REMAIN A CONCERN. DEEP-LAYER BULK SHEAR STRENGTHENING TO
MODERATE TO STRONG MAGNITUDES MAY SUPPORT STRONGER STORMS
SATURDAY NIGHT THROUGH SUNDAY NIGHT, BUT THE POTENTIAL FOR
STRONGER STORMS WILL BE CONTINGENT ON MULTIPLE FACTORS,
INCLUDING THE MAGNITUDE OF INSTABILITY. FAIR WEATHER SHOULD
RETURN TO OUR CWA BY DAYBREAK MONDAY AS STABILIZING SUBSIDENCE
ACCOMPANIES THE AFOREMENTIONED RIDGE. LOWS SHOULD REACH MAINLY
THE LOWER TO MID 60'S OVERNIGHT SATURDAY NIGHT AND BE FOLLOWED
BY HIGHS IN THE 70'S ON SUNDAY. LOWS SHOULD THEN REACH MAINLY
THE MID 50'S TO LOWER 60'S AROUND DAYBREAK MONDAY AS A SOMEWHAT
COOLER AND DRIER AIR MASS OVERSPREADS OUR AREA BEHIND THE COLD
FRONT.
KEY MESSAGE 3...CURRENT ODDS FAVOR DRY WEATHER THIS MONDAY
THROUGH TUESDAY.
CURRENT ODDS FAVOR DRY WEATHER THIS MONDAY THROUGH TUESDAY AS
THE RIDGE BUILDS AND THEN CRESTS E'WARD ACROSS WESTERN AND
CENTRAL NY. HIGHS IN THE 70'S TO 80F ON MONDAY SHOULD BE
FOLLOWED BY LOWS IN THE 50'S TO LOWER 60'S AROUND DAYBREAK
TUESDAY. LOW-LEVEL WAA ON THE WESTERN FLANK OF THE SURFACE
PORTION OF THE RIDGE SHOULD CONTRIBUTE TO HIGHS REBOUNDING TO
MAINLY THE 80'S ON TUESDAY. NOTE: THE POTENTIAL FOR ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD INCREASE TUESDAY
NIGHT THROUGH THIS WEDNESDAY DUE, IN PART TO A N'WARD WARM FRONT
PASSAGE TUESDAY NIGHT AS THE RIDGE EXITS E'WARD AND THE
APPROACH OF ANOTHER SHORTWAVE TROUGH AND COLD FRONT FROM THE
WESTERN GREAT LAKES AND VICINITY ON WEDNESDAY. TEMPERATURES
SHOULD BE NEAR OR ABOVE AVERAGE.
AVIATION /12Z THURSDAY THROUGH MONDAY/
AT THE SURFACE, A LOW WOBBLES NE'WARD FROM THE SOUTHERN NEW
ENGLAND AREA TO THE CANADIAN MARITIMES AS A HIGH PRESSURE RIDGE
BUILDS INTO WESTERN AND CENTRAL NY FROM THE WESTERN GREAT LAKES
THROUGH 12Z/FRI. PRIMARILY VFR AND FAIR WEATHER ARE EXPECTED
DURING THE TAF PERIOD. HOWEVER, WIDESPREAD CEILINGS NEAR 2KFT TO
5KFT AGL AND ISOLATED TO SCATTERED RAIN SHOWERS WITH BRIEF MVFR
VISIBILITY ASSOCIATED WITH THE LOW PRESSURE SYSTEM WILL EXIT
SLOWLY E'WARD FROM THE GENESEE RIVER VALLEY AND POINTS EAST IN
OUR AREA THROUGH ~23Z/THURS. ISOLATED THUNDERSTORMS WITH BRIEF
IFR/LIFR ARE POSSIBLE THIS AFTERNOON THROUGH ~23Z/THURS IN THE
EASTERN LAKE ONTARIO REGION, BUT THE PROBABILITY OF ONE OR MORE
STORMS IMPACTING KART IS LOW.
CONSIDERABLE CLEARING OF SKY AND EASING OF SURFACE WINDS WILL
CONTRIBUTE TO THE DEVELOPMENT OF STEAM MIST/FOG OVER WATERWAYS
IN THE WESTERN SOUTHERN TIER, FINGER LAKES, AND EASTERN LAKE
ONTARIO REGION LATE THIS EVENING AND ESPECIALLY FROM 04Z THROUGH
12Z/FRI. VISIBILITY, INCLUDING VERTICAL VISIBILITY, SHOULD BE
AS LOW AS IFR TO LIFR IN THE MIST/FOG.
OUTLOOK...
FRIDAY...DRY WEATHER AND MAINLY VFR EXPECTED. ANY LINGERING
MIST OR FOG SHOULD DISSIPATE BY 14Z.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...PERIODIC SHOWERS AND
THUNDERSTORMS WITH MVFR TO LIFR EXPECTED, ESPECIALLY SATURDAY
NIGHT THROUGH SUNDAY EVENING.
MONDAY...MAINLY VFR AND DRY WEATHER EXPECTED. HOWEVER, ISOLATED
SHOWERS AND THUNDERSTORMS WITH NON-VFR ARE POSSIBLE IN THE
AFTERNOON AND EARLY EVENING ALONG LAKE BREEZE BOUNDARIES.
MARINE
A HIGH PRESSURE RIDGE BUILDS E'WARD ACROSS EASTERN LAKE ERIE AND
LAKE ONTARIO THROUGH TONIGHT AS A TROUGH EXITS TOWARD NEW
ENGLAND AND THE CANADIAN MARITIMES. NW'ERLY TO N'ERLY WINDS
AROUND 5 TO 15 KNOTS THIS MORNING BECOME VARIABLE AROUND 5 TO 10
KNOTS THIS AFTERNOON THROUGH TONIGHT. WAVES OF 3 FEET OR LESS
ARE EXPECTED THROUGH THIS EARLY AFTERNOON BEFORE SUBSIDING TO 2
FEET OR LESS. THE RIDGE SHOULD EXIT SLOWLY E'WARD ON FRIDAY
THROUGH SATURDAY AS WINDS REMAIN VARIABLE AROUND 5 TO 10 KNOTS
AND WAVES REMAIN 2 FEET OR LESS. WINDS SHOULD TREND ONSHORE
DURING THE LATE MORNING THROUGH EARLY EVENING HOURS OF FRIDAY
AND SATURDAY DUE TO LAKE ERIE AND LAKE ONTARIO LAKE BREEZE
DEVELOPMENT.
DURING SATURDAY NIGHT THROUGH SUNDAY NIGHT, A COLD FRONT AND
INVERTED SURFACE TROUGH SHOULD SWEEP SE'WARD ACROSS EASTERN LAKE
ERIE AND LAKE ONTARIO, AND CAUSE MAINLY S'ERLY TO SE'ERLY WINDS
AROUND 5 TO 10 KNOTS TO SHIFT TO MAINLY NE'ERLY TO N'ERLY. WAVES
ARE EXPECTED TO REMAIN 2 FEET OR LESS. BEHIND THE FRONT, VARIABLE
WINDS AROUND 5 TO 10 KNOTS AND WAVES OF 2 FEET OR LESS ARE
EXPECTED THIS MONDAY AS A RIDGE BUILDS FROM THE WESTERN GREAT
LAKES.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
DISCUSSION...JASZKA
AVIATION...JASZKA
MARINE...JASZKA
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