299
FXUS61 KBUF 171721
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
121 PM EDT SUN AUG 17 2025
SYNOPSIS
A COLD FRONT WILL BRING A ROUND OF SCATTERED SHOWERS AND A FEW
THUNDERSTORMS THROUGH THIS AFTERNOON, 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 MONDAY/
A COLD FRONT CURRENTLY DROP SOUTH INTO THE REGION. SCATTERED SHOWERS
HAVE REDEVELOPED ALONG AND AHEAD OF THE BOUNDARY. HEATING WILL
LIKELY BRING AT LEAST SOME RISK FOR ISOLATED THUNDERSTORMS THIS
AFTERNOON. BEHIND THE PASSAGE OF THE FRONT, A COOL, DRY NORTHEAST
FLOW WILL RESULT IN A DRY NIGHT TONIGHT. LOW TEMPERATURES WILL FALL
TO THE UPPER 40S TO LOWER 50S ACROSS THE TUG HILL REGION TO THE
50S ACROSS WESTERN NEW YORK.
AN AREA OF CANADIAN HIGH PRESSURE BUILDING INTO THE REGION WILL
BRING A FAIR AND COOLER DAY MONDAY, WITH HIGH TEMPERATURES IN
THE 70S, WITH SOME UPPER 60S FOR THE HIGHER TERRAIN.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/
DRY AND COMFORTABLE WEATHER WILL CONTINUE TO PREVAIL MONDAY NIGHT
THROUGH MUCH OF TUESDAY AS SFC HIGH PRESSURE DRIFTS SOUTHEAST ACROSS
QUEBEC TO THE CANADIAN MARITIMES. TEMPERATURES WILL BE WARMER
COMPARED TO MONDAY THOUGH STILL WITHIN A FEW DEGREES OF AVERAGE FOR
MID-AUGUST. A POSITIVELY TILTED MID-LEVEL SHORTWAVE AND ASSOCIATED
INVERTED SFC TROUGH DRIFTING SOUTHEAST ACROSS THE GREAT LAKES WILL
THEN INTERSECT A PLUME OF ATLANTIC-BASED MOISTURE ADVECTING
NORTHWARD FROM THE APPALACHIANS TO INCREASE CHANCES FOR SHOWERS
ACROSS THE FORECAST AREA LATE TUESDAY THROUGH WEDNESDAY. FAIRLY
LARGE RUN-TO-RUN INCONSISTENCIES NOTED AMONG THE DETERMINISTIC
MODELS REGARDS TO IN COVERAGE, TIMING AND INTENSITY OF PRECIP DURING
THIS TIMEFRAME THOUGH GLOBAL AND NBM ENSEMBLES HAVE A MORE DISTINCT
TREND TOWARDS A DRIER OVERALL FORECAST. WHILE THERE MAY BE JUST
ENOUGH ELEVATED INSTABILITY PRESENT FOR A FEW THUNDERSTORMS,
GUIDANCE HAS LIKEWISE TRENDED DOWNWARDS WITH THIS POTENTIAL AS WELL.
MID TO UPPER LEVEL RIDGING BUILDING BACK ACROSS THE GREAT LAKES WILL
CAUSE AN EXPANSE OF SFC HIGH PRESSURE TO BUILD BACK SOUTHWARD ACROSS
ON/QC PROVINCES AND NEW ENGLAND MOVING INTO WEDNESDAY NIGHT. THIS
WILL CAUSE PRECIP CHANCES TO TAPER OFF OVERNIGHT, THOUGH CAN'T RULE
OUT SOME LINGERING SPOTTY SHOWERS WITH LINGERING LOW LEVEL MOISTURE
AND TROUGH AXIS CROSSING THE REGION.
LONG TERM /THURSDAY THROUGH SATURDAY/
A PROGRESSIVE WEDGE OF SFC HIGH PRESSURE WILL BUILD SOUTH INTO THE
REGION FROM CANADA THURSDAY AS LONGWAVE TROUGHING SHIFTS EAST TO NEW
ENGLAND. OUTSIDE OF A FEW STRAY SHOWERS ACROSS THE SOUTHERN TIER OR
FINGER LAKES THURSDAY, MAINLY DRY WEATHER WILL RETURN THROUGH AT
LEAST EARLY SATURDAY WITH A MODEST WARMING TREND.
A DEEP CLOSED LOW MOVING SOUTHEAST ACROSS ONTARIO PROVINCE WILL THEN
CAUSE A PAIR OF FRONTAL BOUNDARIES TO MOVE THROUGH THE REGION OVER
THE WEEKEND. THIS WILL BRING ANOTHER ROUND OF SHOWER/TSTORM CHANCES
TO THE FORECAST AREA, THOUGH MODELS REMAIN SOMEWHAT SPLIT ON THE
EXTENT AND PLACEMENT OF NORTHWARD MOISTURE ADVECTION IN THE WARM
SECTOR SATURDAY AND THE TIMING OF THE MAIN COLD FRONT BETWEEN LATER
SATURDAY AND SUNDAY.
TEMPS OVER THE WEEKEND WILL LARGELY DEPEND ON THE TIMING OF THIS
FRONT, THOUGH BASED ON CURRENT MODEL GUIDANCE CONSENSUS A NOTABLE
COOLDOWN SHOULD OCCUR BY SUNDAY.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
A COLD FRONT DROPPING SOUTH THROUGH THE REGION WILL BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH ABOUT 22Z. MVFR
CONDITIONS ARE LIKELY AS A COLD FRONT MOVES FROM NORTH TO SOUTH,
AND WINDS WILL BECOME NORTHEAST. DRIER AIR WILL FILTER INTO THE
REGION AND FLIGHT CONDITIONS WILL IMPROVE BACK TO VFR LATE THIS
AFTERNOON AND PERSIST OVERNIGHT. NORTHEAST GRAIDENT FLOW MAY BE
JUST ENOUGH TO KEEP FOG FROM DEVELOPING OVERNIGHT, WITH LOW
(10-20%) CONFIDENCE IN ANY RESTRICTIONS.
OUTLOOK...
MONDAY...VFR.
TUESDAY AND TUESDAY NIGHT...MAINLY VFR. ISOLATED SHOWERS.
WEDNESDAY...LOCALIZED CIG/VSBY RESTRICTIONS POSSIBLE ESPECIALLY
EARLY IN THE DAY, OTHERWISE MAINLY VFR WITH DECREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS.
THURSDAY AND FRIDAY...VFR.
MARINE
A COLD FRONT WILL CROSS THE REGION THROUGH THIS AFTERNOON. WINDS
WILL SHIFT TO THE NORTHEAST BEHIND THE FRONTAL PASSAGE AND
INCREASE TO 15 TO 25 KNOTS, HIGHEST ON LAKE ONTARIO. SMALL CRAFT
HEADLINES ARE IN EFFECT ON LAKE ERIE WEST OF DUNKIRK THROUGH
MONDAY MORNING AND ON LAKE ONTARIO THROUGH MONDAY.
BUF WATCHES/WARNINGS/ADVISORIES
NY...BEACH HAZARDS STATEMENT THROUGH MONDAY AFTERNOON FOR
NYZ003>006.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT MONDAY FOR LOZ042.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT MONDAY FOR LOZ043>045.
SYNOPSIS...HSK/TMA
NEAR TERM...TMA
SHORT TERM...PP
LONG TERM...PP
AVIATION...HSK/TMA
MARINE...HSK/TMA
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