148
FXUS61 KBUF 271043
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
643 AM EDT SUN JUL 27 2025
SYNOPSIS
A SLOW-MOVING AREA OF LOW PRESSURE AND ATTENDANT WARM FRONT WILL
BRING INCREASING CHANCES FOR SCATTERED SHOWERS AND STORMS ACROSS
MUCH OF THE AREA EARLY THIS MORNING. SHOWERS AND A FEW THUNDERSTORMS
WILL LINGER PAST DAYBREAK THIS MORNING, THEN TAPER OFF FROM
NORTHWEST TO SOUTHEAST MIDDAY THROUGH MID AFTERNOON AS HIGH PRESSURE
BUILDS ACROSS THE REGION BRINGING DRIER CONDITIONS THAT WILL PERSIST
INTO THE START OF THE NEW WORK WEEK. INCREASINGLY HOT AND HUMID
WEATHER IS SET TO RETURN FOR SUNDAY THROUGH TUESDAY, PEAKING ON
MONDAY.
NEAR TERM /THROUGH TONIGHT/
A VERY HUMID AIRMASS RESIDES ACROSS THE REGION. THE ADVECTED
LAYER PRECIPITABLE WATER (ALPW) PRODUCT DISPLAYS MOISTURE FROM
SURFACE TO 300MB. MESOANALYSIS SHOWS PWATS GREATER THAN 2"
ACROSS THE FORECAST AREA. A SHORTWAVE TROUGH OVER THE EASTERN
GREAT LAKES REGION IS EVIDENT ON WATER VAPOR IMAGERY THIS
MORNING. SHOWERS AND THUNDERSTORMS MOVED ACROSS PORTIONS OF
WESTERN AND NORTH-CENTRAL NY OVERNIGHT AND WILL EXIT TO THE
EAST BY MID-MORNING. LOCATIONS ACROSS SOUTHERN LEWIS COUNTY
RECEIVED ABOUT 2" OF RAINFALL OVERNIGHT. WHILE RAINFALL IS
EXPECTED TO MOVE EAST OF THE AREA, LOCALIZED FLOODING CAN'T BE
RULED OUT IF ANY HEAVY RAIN SETS UP THROUGH MID-MORNING.
A SURFACE TROUGH/WIND SHIFT WILL MOVE THROUGH THE REGION TODAY.
THE MOISTURE AXIS WILL MOVE EAST OF THE REGION AND THE RISK FOR
SHOWERS AND STORMS WILL DIMINISH FROM WEST TO EAST THROUGH LATE
MORNING. MOSTLY DRY WEATHER IS EXPECTED THIS AFTERNOON, WITH A
LOW CHANCE FOR A POP-UP SHOWER ACROSS THE NIAGARA FRONTIER. DRY
WEATHER WILL CONTINUE INTO TONIGHT. PATCHY FOG IS POSSIBLE,
ESPECIALLY IN VALLEY LOCATIONS ACROSS THE WESTERN SOUTHERN TIER.
SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/
BROAD MID-LEVEL RIDGE WILL ANCHOR ACROSS THE SOUTHERN HALF OF THE
CONUS MONDAY THROUGH WEDNESDAY. MEANWHILE, TO THE NORTH ACROSS THE
FAR NORTHERN REACHES OF THE CONUS AND ACROSS MUCH OF CANADA A
SHORTWAVE TROUGH PASSING ACROSS THE EASTERN GREAT LAKES MONDAY NIGHT
WILL CAUSE A LONGWAVE TROUGH TO DIVE SOUTHEAST ACROSS THE UPPER
GREAT LAKES AND INTO THE CENTRAL GREAT LAKES TUESDAY NIGHT AND
WEDNESDAY. INITIALLY AHEAD OF THE TROUGH'S ARRIVAL, A BRIEF PERIOD
OF MID-LEVEL RIDGING WILL PASS ACROSS THE EASTERN GREAT LAKES REGION
MONDAY.
WITH THE RIDGING OVERHEAD MONDAY, SURFACE HIGH PRESSURE WILL WORK
ITS WAY ACROSS THE CENTRAL AND EASTERN GREAT LAKES RESULTING IN A
PERIOD OF DRY WEATHER FOR THE START OF THE WEEK. HOWEVER, A FEW
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS
THE SAINT LAWRENCE DUE TO AN APPROACHING FRONTAL BOUNDARY.
ADDITIONALLY, WITH THE RIDGING ALOFT, 850MB TEMPERATURES WILL WARM
UP TOWARDS +19 TO +20 DEGREES CELSIUS MONDAY SUPPORTING ANOTHER WARM
DAY ON TAP WITH HIGHS IN THE UPPER 80S ACROSS MUCH OF THE REGION AND
SOME LOW TO MID 90S ACROSS THE LAKE PLAINS SOUTH OF LAKE ONTARIO
FROM NIAGARA FALLS TO ROCHESTER AND THE GENESEE VALLEY. THESE WARM
TEMPERATURES COMBINED WITH DEWPOINTS IN THE UPPER 60S TO LOW 70S
WILL SUPPORT HEAT INDICES IN THE LOW TO MID 90S FOR THE NIAGARA
FRONTIER TO THE GENESEE VALLEY.
A WEAK SHORTWAVE TROUGH WILL NOT ONLY ENCOURAGE THE LONGWAVE TROUGH
TO DIVE SOUTHEAST ACROSS THE GREAT LAKES, BUT ALSO INTRODUCE A WEAK
COLD FRONT TO PASS EAST ACROSS THE LOWER GREAT LAKES MONDAY NIGHT
AND TUESDAY RESULTING IN THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS. COVERAGE OF THESE SHOWERS AND THUNDERSTORMS WILL BE
RATHER LIMITED DUE TO THE WEAK NATURE OF THE BOUNDARY AND LOSS OF
UPPER LEVEL SUPPORT WITH TIME. DESPITE ANY AIRMASS CHANGE, THE
AIRMASS WILL BE WEAK AND BRIEF, AND THEREFORE ANOTHER WARM MUGGY DAY
WILL BE ON TAP TUESDAY. HEAT INDICES AGAIN WILL RANGE IN THE LOW TO
MID 90S FOR THE NIAGARA FRONTIER TO THE GENESEE VALLEY.
A SIGNIFICANT PATTERN CHANGE WILL THEN TAKE PLACE WEDNESDAY AS THE
LONGWAVE TROUGH AXIS ENTERS THE CENTRAL AND EASTERN GREAT LAKES,
INTRODUCING A SECONDARY COLD FRONT TO THE AREA AND RESULT BETTER
CHANCES FOR SHOWERS AND THUNDERSTORMS TO PASS ACROSS THE AREA.
LONG TERM /THURSDAY THROUGH SATURDAY/
AFTER THE COLD FRONTAL PASSAGE MID-WEEK, SURFACE HIGH PRESSURE WILL
LIE ACROSS THE GREAT LAKES LATE IN THE WEEK AND INTO THE START OF
THE WEEKEND. ASIDE FROM A FEW LINGERING SHOWERS AND THUNDERSTORMS A
DRYING TREND WILL PERSIST FOR THE END OF THE WEEK AND START OF THE
WEEKEND. ADDITIONALLY WITH THE TROUGH OVERHEAD, EXPECT A COOLER AND
DRIER AIRMASS TO FILTER OVERHEAD, SUPPORTING BELOW NORMAL
TEMPERATURES FOR THE LATER HALF OF THE WEEK.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
A VERY HUMID AIRMASS RESIDES ACROSS WESTERN AND NORTH-CENTRAL NY
TONIGHT. SHOWERS AND A FEW THUNDERSTORMS REMAIN POSSIBLE ACROSS
THE REGION THROUGH LATE MORNING. MVFR/IFR CONDITIONS ARE LIKELY
BEHIND THE RAIN THIS MORNING, THEN IMPROVING TO VFR BY MIDDAY.
A FRONT WITH DRIER AIR WILL MOVE ACROSS THE REGION TODAY.
VFR CONDITIONS SHOULD BE WIDESPREAD ACROSS THE REGION BY MID-
AFTERNOON. DRY WEATHER WILL CONTINUE SUNDAY NIGHT. PATCHY FOG IS
POSSIBLE, WITH HIGHER CONFIDENCE ACROSS VALLEY LOCATIONS.
OUTLOOK...
MONDAY...MAINLY VFR.
TUESDAY THROUGH WEDNESDAY...MAINLY VFR. CHANCE OF SHOWERS/AFTERNOON
THUNDERSTORMS.
THURSDAY...MAINLY VFR.
MARINE
A WAVE OF LOW PRESSURE WILL CROSS THE LOWER GREAT LAKES TONIGHT AND
EARLY SUNDAY. AN ORGANIZED AREA OF RAIN AND STORMS MAY IMPACT THE
LAKES TONIGHT. SOUTHWESTERLY TO WESTERLY BREEZES WILL INCREASE
MODESTLY SUNDAY BEHIND THIS WAVE, WITH SOME LIGHT CHOP DEVELOPING ON
BOTH LAKES.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
SYNOPSIS...HSK
NEAR TERM...HSK
SHORT TERM...EAJ
LONG TERM...EAJ
AVIATION...HSK
MARINE...HSK
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