644
FXUS61 KBUF 211722
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
122 PM EDT TUE JUL 21 2026
WHAT HAS CHANGED
MINOR CHANGES TO THE FORECAST WITH THIS UPDATE.
KEY MESSAGES
1) SCATTERED STRONG TO SEVERE THUNDERSTORMS CONTINUE THROUGH THIS
EVENING WITH STRONG WINDS AS THE MAIN HAZARD.
2) COOL WEDNESDAY, WITH A CHANCE OF LINGERING SHOWERS AHEAD OF
A GRADUAL WARM UP THROUGH THE REMAINDER OF THE WEEK.
DISCUSSION
KEY MESSAGE 1...SCATTERED STRONG TO SEVERE THUNDERSTORMS CONTINUE
THROUGH THIS EVENING WITH STRONG WINDS AS THE MAIN HAZARD.
SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS AFTERNOON HAVE SPREAD
ACROSS THE LAKE ONTARIO REGION ON BOTH SIDES OF THE INTERNATIONAL
BORDER ASSOCIATED WITH A COMPACT SHORTWAVE NOTED ON GOES WV IMAGERY
LIFTING JUST NORTH OF TORONTO. THIS IS ALL WHILE EARLIER STORMS
ACROSS THE SOUTHERN TIER OUTRAN THE AXIS OF STRONGEST INSTABILITY
LEADING TO A SWATH OF STRATIFORM PRECIPITATION LINGERING.
REGARDLESS, SEVERE THUNDERSTORMS WERE STILL OBSERVED THIS MORNING
WITH GUSTY WINDS LEADING TO DOWNED TREES AND SMALL HAIL REPORTED.
CLEARING SKIES MOVING INTO WESTERN NY EARLY THIS AFTERNOON PER GOES
SATELLITE IMAGERY WILL HELP POTENTIALLY REFUEL THE ATMOSPHERE FOR
THE NEXT ROUND OF STRONG TO SEVERE THUNDERSTORMS.
ONGOING DEVELOPMENT IN EASTERN MI AND SOUTHWESTERN ON WITHIN AN AREA
OF 2000 J/KG OF MLCAPE AND 40 KT OF BULK SHEAR CLOSER TO THE COLD
FRONT WILL BE WORTH MONITORING AS IT MOVES EAST TOWARDS WESTERN NY
LATER THIS AFTERNOON INTO EARLY THIS EVENING. ADDITIONALLY,
SOUTHWESTWARD EXPANSION OF THE ONGOING CONVECTION NEAR TORONTO ALONG
THE PREFRONTAL TROUGH ASSOCIATED WITH THE AFOREMENTIONED
SHORTWAVE WILL ALSO NEED CLOSE MONITORING AS ATMOSPHERIC
DESTABILIZATION CONTINUES. THESE STORMS WILL PROGRESS EASTWARD
ACROSS WESTERN AND NORTH-CENTRAL NY THROUGH THE AFTERNOON AND
EVENING.
STRONG WINDS AND HEAVY RAINFALL WILL CONTINUE TO BE THE PRIMARY
HAZARD WITH THESE STORMS. PWAT VALUE REPORTED FROM THE KBUF 12Z
SOUNDING WAS 1.50" AND WARM CLOUD DEPTHS EXCEED 10 KFT. HOWEVER,
FAST STORM MOTIONS AND LINE NORMAL MOTIONS, AS OBSERVED WITH EARLIER
STORMS, WOULD LIMIT HEAVY RAINFALL DURATIONS. ADDITIONALLY, THE
HIGHEST DCAPE VALUES REMAIN IN SOUTHWESTERN ON AND WILL BE LESS THAN
WHAT WAS ANALYZED EARLIER ACROSS THE NIAGARA FRONTIER AROUND THE
TIME OF SEVERE WIND DAMAGE REPORTED.
HEADED INTO LATE THIS EVENING, LINGERING SHOWERS AND A FEW RUMBLES
OF THUNDER MAY CONTINUE UNTIL THE COLD FRONT PASSES THROUGH WESTERN
NY AROUND MIDNIGHT AND EARLY WEDNESDAY MORNING FOR NORTH-CENTRAL NY.
KEY MESSAGE 2...COOL WEDNESDAY, WITH A CHANCE OF LINGERING
SHOWERS AHEAD OF A GRADUAL WARM UP THROUGH THE REMAINDER OF THE
WEEK.
COOLER WEATHER IS EXPECTED WEDNESDAY AS THE UPPER LEVEL LOW BEGINS
TO EXIT TO THE NORTHEAST. WITH 850MB TEMPS DROPPING AROUND 6-8 DEGC,
AFTERNOON HIGHS WILL STRUGGLE TO REACH 70 DEGF AS MOST LOCATIONS
WILL BE AROUND 10 DEGF BELOW NORMAL FOR LATE JULY. ADDITIONALLY, A
SECONDARY SHORTWAVE WILL ROUND THE BACKSIDE OF THE DEPARTING LOW,
SUPPORTING SCATTERED SHOWERS ALONG WITH THE COOLER AIR ALOFT AND
STEEP LOW-LEVEL LAPSE RATES EXTENDING INLAND FROM THE LAKES UNDER
WEST-NORTHWEST FLOW. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE
LOWER GREAT LAKES LATE WEDNESDAY THROUGH THE REMAINDER OF THE WEEK
LEADING TO DRIER WEATHER AND GRADUALLY WARMING TEMPERATURES
BACK TOWARDS SLIGHTLY ABOVE NORMAL THIS WEEKEND.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS
AFTERNOON AND INTO THIS EVENING WITH THE PASSAGE OF BOTH A WARM
FRONT LIFTING NORTH, FOLLOWED BY A COLD FRONT SLIDING EAST. THIS
BEING SAID, A CONGLOMERATION OF FLIGHT CONDITIONS WILL CONTINUE
THROUGH THIS EVENING, WITH AN IMPROVING TREND OVERNIGHT INTO
WEDNESDAY. FROM THE ROUND OF SHOWERS THAT JUST IMPACTED THE WESTERN
3 TERMINALS (KIAG, KBUF AND KJHW), EXPECT THESE SHOWERS AND EMBEDDED
THUNDERSTORMS CONTINUE EAST INTO KROC WITHIN THE HOUR, AND REACH
KART A COUPLE OF HOURS LATER. ANOTHER LINE OF SHOWERS IS ON OUR
WESTERN DOORSTEP AS OF 17Z, WHICH WILL BRING MORE SHOWERS AND
THUNDER EARLY THIS AFTERNOON. ADDITIONAL, SHOWERS ARE THEN EXPECTED
LATE THIS AFTERNOON AND INTO THE EVENING WITH THE ARRIVAL OF THE
COLD FRONT.
THIS ALL BEING SAID, THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS
THROUGH THIS EVENING, WHERE SOME OF THE THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING DAMAGING WINDS, LARGE HAIL, AND TORRENTIAL
RAIN. BOTH VISIBILITIES AND CEILINGS RESTRICTIONS CAN BE POSSIBLE
AT TIMES.
OTHERWISE, AHEAD OF THE COLD FRONTAL PASSAGE'S ARRIVAL IT WILL BE
BREEZY, WITH A 20-30 KNOT SOUTH-SOUTHWEST WIND GUSTS, ESPECIALLY FOR
KIAG AND KBUF THIS AFTERNOON.
OUTLOOK...
WEDNESDAY...RESTRICTIONS LIKELY WITH LINGERING SHOWERS/ISOLATED
THUNDERSTORMS.
THURSDAY THROUGH SATURDAY...MAINLY VFR.
SUNDAY...VFR/MVFR WITH A CHANCE FOR SHOWERS/THUNDERSTORMS IN THE
AFTERNOON.
MARINE
SOUTHWEST WINDS GUSTING AROUND 30 KT OVER LAKE ERIE AND WESTERN LAKE
ONTARIO WILL CONTINUE THROUGH THIS AFTERNOON WHILE WINDS OVER
EASTERN LAKE ONTARIO WILL VEER TO THE SOUTHWEST. SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGHOUT THE DAY WITH MULTIPLE ROUNDS
AHEAD OF A COLD FRONTAL PASSAGE LATE TONIGHT. BEHIND THE FRONT,
WINDS WILL TURN TO BE OUT OF THE WEST-NORTHWEST AND INCREASE ONCE
AGAIN, ESPECIALLY ACROSS LAKE ONTARIO, HEADED INTO WEDNESDAY. SMALL
CRAFT ADVISORY CONTINUES FOR LAKE ERIE THROUGH TONIGHT AND FOR
PORTIONS OF LAKE ONTARIO THROUGH WEDNESDAY EVENING. CALMER WATERS
ARE EXPECTED LATE THIS WEEK INTO EARLY THIS WEEKEND AS HIGH PRESSURE
BUILDS INTO THE LOWER GREAT LAKES.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR
LOZ042.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THURSDAY FOR LOZ045.
DISCUSSION...BROTHERS
AVIATION...EAJ
MARINE...BROTHERS
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