300
FXUS61 KBUF 170650
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
250 AM EDT SUN AUG 17 2025
SYNOPSIS
A COLD FRONT WILL BRING A ROUND OF SHOWERS AND A FEW THUNDERSTORMS
TODAY, FOLLOWED BY COOLER WEATHER FOR THE START OF THE WORK WEEK. AN
AREA OF LOW PRESSURE WILL APPROACH THE GREAT LAKES REGION THROUGH
MID-WEEK BRINGING A PERIOD OF UNSETTLED WEATHER.
NEAR TERM /THROUGH TONIGHT/
A ROBUST SHORTWAVE TROUGH AND PLUME OF DEEP MOISTURE OVER THE
CENTRAL GREAT LAKES WILL MOVE ACROSS THE EASTERN GREAT LAKES REGION
THIS MORNING. REGIONAL RADAR SHOWS SHOWERS AND THUNDERSTORMS ACROSS
SOUTHERN ONTARIO, WITH ORGANIZED CONVECTION JUST WEST OF LAKE
ONTARIO EARLY THIS MORNING.
A COLD FRONT IS CO-LOCATED WITH THE CONVECTION AND THE COMBINATION
OF DEEP LAYER ASCENT AND MOISTURE WILL SUPPORT SHOWERS AND
THUNDERSTORMS ACROSS WESTERN AND NORTH-CENTRAL NY TODAY. BUILDING
HIGH PRESSURE FROM THE NORTH AS THE COLD FRONT MOVES INTO THE SAINT
LAWRENCE VALLEY SHOULD WEAKEN ORGANIZED CONVECTION NORTH OF LAKE
ONTARIO EARLY THIS MORNING. THEREFORE, RAINFALL AMOUNTS WILL BE
WIDELY SCATTERED ACROSS THE EASTERN LAKE ONTARIO REGION TODAY.
THE COLD FRONT WILL MOVE ACROSS THE FORECAST AREA FROM NORTH TO
SOUTH BETWEEN 10AM AND 4PM TODAY. IN REGARDS TO THE THUNDERSTORM
POTENTIAL, INSTABILITY IS EXPECTED TO CLIMB TO 500 J/KG SOUTH OF THE
FRONT THIS AFTERNOON. MID-LEVEL LAPSE RATES AND 0-6KM SHEAR ARE
WEAK, RESULTING IN A VERY LOW POTENTIAL FOR SEVERE THUNDERSTORMS
TODAY. THERE IS A RISK OF HEAVY RAINFALL ACROSS WESTERN NY TODAY DUE
TO THE HIGH PWATS, HOWEVER THIS IS VERY LOCALIZED AND DUE TO
ABNORMALLY DRY WEATHER AS OF THE LAST FEW WEEKS, HYDRO CONCERNS ARE
VERY LOW. THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS
WESTERN NY TO THE FINGER LAKES REGION. RAINFALL AMOUNTS WILL AVERAGE
0.25-0.50" ACROSS WESTERN NY. RAINFALL AMOUNTS WILL BE LESS
THAN 0.25" ACROSS THE EASTERN LAKE ONTARIO REGION.
COOL, DRY NORTHEAST FLOW WILL RESULT IN A DRY NIGHT. LOW
TEMPERATURES WILL FALL TO THE UPPER 40S TO LOW 50S ACROSS THE TUG
HILL REGION TO THE 50S ACROSS WESTERN NY.
SHORT TERM /MONDAY THROUGH WEDNESDAY/
AN AREA OF HIGH PRESSURE CENTERED OVER THE ON/QC PROVIDENCE BORDER
WILL BRING FAIR DRY WEATHER THROUGH AT LEAST MONDAY NIGHT. PARTLY TO
MOSTLY SUNNY CONDITIONS ARE EXPECTED FOR THE DAY, WITH SOME
AFTERNOON FAIR WEATHER CU POSSIBLE INLAND FROM THE LAKES. A COOL
CANADIAN AIRMASS BEHIND TODAYS PASSING COLD FRONT WILL HELP LIMIT
TEMPERATURES ON MONDAY TO JUST BELOW NORMAL FOR MOST OF THE FORECAST
AREAS, AND AMONG THE COOLEST AFTERNOON HIGHS THE AREA HAS
EXPERIENCED IN THE PAST FEW WEEKS. HIGH TEMPERATURES ON MONDAY WILL
RANGE FROM NEAR 70 OVER THE HIGHER TERRAIN TO NEAR 80 IN THE LOWER
ELEVATIONS. HUMIDITY LEVELS WILL ALSO DROP TO VERY COMFORTABLE
LEVELS AS WELL. MORNING NORTHEAST WINDS OF AROUND 5 TO 16 MPH
(STRONGEST NEAR THE LAKES) WILL WEAKEN THROUGH THE DAY.
MONDAY NIGHT THROUGH TUESDAY, GUIDANCE STARTS TO INCREASE THE
POTENTIAL FOR SHOWERS TUESDAY MORNING/AFTERNOON ACROSS THE AREA WITH
AN INVERTED TROUGH OVER THE REGION. THERE STILL REMAINS A LARGE
SPREAD IN COVERAGE AND OVERALL POTENTIAL FOR SHOWERS. WITH THIS IN
MIND, LIMITING POPS TO LOWER END CHANCE FOR NOW, WITH THE BEST
CHANCE FOR SHOWERS TUESDAY AFTERNOON.
TUESDAY NIGHT THROUGH WEDNESDAY, SHOWERS WILL PUSH INTO THE WNY AREA
TUESDAY EVENING AND EXPAND EAST AS A SHORTWAVE TROUGH TRACKS
SOUTHEAST OUT OF CANADA AND ACROSS THE REGION. SOME OF THE GLOBAL
MODELS ARE DRIER THAN THE HIGHER RESOLUTION GUIDANCE THROUGH TUESDAY
NIGHT AND CONTINUE THE DRIER TREND THROUGH THE DAY ON WEDNESDAY.
WITH THE HIGHER RESOLUTION GUIDANCE ONLY GOING THROUGH TUESDAY NIGHT
AT THIS POINT, UNCERTAINTY STILL EXISTS WITH THE WEDNESDAY RAIN
POTENTIAL AND WILL CERTAINLY NEED TO BE MONITORED.
TEMPERATURES WILL WARM SOME FOR TUESDAY AND WEDNESDAY AFTERNOON,
ESPECIALLY SOUTH OF LAKE ONTARIO WHERE HIGHS WILL REACH THE MID 70S
TO LOW 80S. EAST OF LAKE ONTARIO, TEMPERATURES WILL REMAIN SIMILAR
TO MONDAYS VALUES FROM NEAR 70 TO THE UPPER 70S. AFTERNOON HIGHS
WILL BE SIMILAR FOR BOTH TUESDAY AND WEDNESDAY.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/
SHOWERS ACROSS THE AREA WILL PUSH OUT FROM WEST TO EAST WEDNESDAY
EVENING/NIGHT AS THE TROUGH TRACKS TOWARD NEW ENGLAND. MAINLY DRY
CONDITIONS ARE EXPECTED FROM LATER WEDNESDAY NIGHT THROUGH FRIDAY
NIGHT AS HIGH PRESSURE OVER THE MIDWEST AND UPPER GREAT LAKES BUILDS
EAST TO THE COAST THROUGH THE LATE WEEK.
A COLD FRONT EXTENDING SOUTH FROM A SFC LOW NEAR JAMES BAY WILL
APPROACH AND CROSS THE REGION ON SATURDAY, BRINGING THE NEXT CHANCE
FOR SHOWERS AND THUNDERSTORMS. GUIDANCE IS ACTUALLY IN PRETTY GOOD
AGREEMENT FOR THE COLD FRONT CROSSING SATURDAY MORNING/AFTERNOON.
HOWEVER, THERE IS STILL A BIT SPLIT ON HOW QUICKLY SHOWERS MOVE OUT
DURING THE SECOND HALF OF THE WEEKEND WITH A LINGERING TROUGH
CONTINUING THE SHOWER POTENTIAL WITH SOME OF THE MODELS.
NEAR TO BELOW NORMAL TEMPERATURES THURSDAY WILL WARM THROUGH
SATURDAY TO ABOVE NORMAL.
AVIATION /07Z SUNDAY THROUGH THURSDAY/
VFR CONDITIONS WILL PERSIST EARLY THIS MORNING. A PLUME OF DEEP
MOISTURE AHEAD OF A SHORTWAVE TROUGH WILL MOVE INTO WESTERN AND
NORTH-CENTRAL NY THIS MORNING. UPSTREAM CONVECTION WILL APPROACH THE
REGION OVERNIGHT, WITH ADDITIONAL CONVECTION FORMING AHEAD OF A COLD
FROM ACROSS WESTERN NY TODAY. FLIGHT CONDITIONS WILL FALL TO MVFR AS
DEEPER MOISTURE MOVES INTO THE REGION. THE COLD FRONT WILL MOVE FROM
NORTH TO SOUTH ACROSS THE REGION, AND WINDS WILL BECOME OUT OF THE
NORTHEAST. DRIER AIR WILL FILTER INTO THE REGION AND FLIGHT
CONDITIONS WILL IMPROVE BACK TO VFR LATE THIS AFTERNOON AND PERSIST
OVERNIGHT.
OUTLOOK...
MONDAY...VFR.
TUESDAY AND TUESDAY NIGHT...MAINLY VFR WITH SCATTERED SHOWERS AND
THUNDERSTORMS WITH ASSOCIATED BRIEF/LOCAL CIG/VSBY RESTRICTIONS.
WEDNESDAY...LOCALIZED CIG/VSBY RESTRICTIONS POSSIBLE ESPECIALLY
EARLY IN THE DAY, OTHERWISE MAINLY VFR WITH DECREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS.
THURSDAY...VFR.
MARINE
WINDS AND WAVES WILL INCREASE ON BOTH LAKE ERIE AND ONTARIO TODAY AS
A COLD FRONT CROSSES THE REGION. WINDS WILL SHIFT TO THE NORTHEAST
BEHIND THE FRONTAL PASSAGE AND INCREASE TO 15 TO 25 KNOTS, HIGHEST
ON LAKE ONTARIO. SMALL CRAFT HEADLINES WILL LIKELY BE NEEDED ON LAKE
ERIE LATE TODAY THROUGH MONDAY MORNING AND ON LAKE ONTARIO TONIGHT
THROUGH MONDAY.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
SYNOPSIS...HSK/TMA
NEAR TERM...HSK
SHORT TERM...SW
LONG TERM...SW
AVIATION...HSK
MARINE...HSK/TMA
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