224
FXUS61 KBUF 071721
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
121 PM EDT MON SEP 7 2026
WHAT HAS CHANGED
MINOR CHANGES TO THE FORECAST WITH THIS UPDATE.
KEY MESSAGES
1) DRY WEATHER WILL PREVAIL THROUGH TUESDAY NIGHT.
2) A COLD FRONT WILL CROSS THE EASTERN GREAT LAKES WEDNESDAY THROUGH
WEDNESDAY NIGHT, PRODUCING SHOWERS AND THUNDERSTORMS.
DISCUSSION
KEY MESSAGE 1...DRY WEATHER WILL PREVAIL THROUGH TUESDAY NIGHT.
HIGH PRESSURE WILL SETTLE SOUTH INTO THE MID ATLANTIC STATES TONIGHT
BEFORE DRIFTING OFF THE EAST COAST BY TUESDAY NIGHT. A SURFACE RIDGE
EXTENDING BACK INTO PA AND WESTERN NY WILL MAINTAIN DRY WEATHER FOR
MOST OF THE AREA THROUGH TUESDAY NIGHT. A SHARPENING MID LEVEL TROUGH
CROSSING THE CANADIAN MARITIMES WILL PUSH A BACKDOOR COLD FRONT
SOUTH ACROSS NORTHERN NY AND NEW ENGLAND, BUT ANY SHOWERS ASSOCIATED
WITH THIS FRONT SHOULD REMAIN NORTH AND EAST OF JEFFERSON AND LEWIS
COUNTIES LATE TONIGHT THROUGH TUESDAY MORNING.
RIVER VALLEY FOG WILL DEVELOP ONCE AGAIN ACROSS THE SOUTHERN TIER
AND FINGER LAKES LATE TONIGHT AND PERSIST THROUGH MID MORNING
TUESDAY.
KEY MESSAGE 2...A COLD FRONT WILL CROSS THE EASTERN GREAT LAKES
WEDNESDAY THROUGH WEDNESDAY NIGHT, PRODUCING SHOWERS AND
THUNDERSTORMS.
A MID LEVEL TROUGH WILL MOVE FROM FAR NORTHWEST ONTARIO WEDNESDAY TO
NORTHERN QUEBEC BY THURSDAY, WITH THE SOUTHERN EXTENT OF HEIGHT
FALLS AND A BELT OF ENHANCED LOW/MID LEVEL FLOW SPREADING EAST
ACROSS THE GREAT LAKES. LARGE SCALE FORCING FOR ASCENT WILL ARRIVE
LATER WEDNESDAY AND WEDNESDAY EVENING AHEAD OF THE TROUGH, WITH LOW
LEVEL CONVERGENCE BECOMING ENHANCED ALONG A PRE-FRONTAL TROUGH AND
LAKE BREEZE BOUNDARIES WEDNESDAY AFTERNOON AND EVENING. A NARROW
PLUME OF RICH MOISTURE WILL BE CAPTURED AND ADVECTED NORTHEAST INTO
OUR REGION JUST AHEAD OF THE SYSTEM, WITH SURFACE DEWPOINTS RISING
INTO THE 65-70F RANGE AND PWATS BRIEFLY EXCEEDING 2 INCHES.
THE QUALITY OF MOISTURE AND ADEQUATE DYNAMICS WILL SUPPORT AN AREA
OF SHOWERS AND SCATTERED THUNDERSTORMS CROSSING THE REGION FROM
NORTHWEST TO SOUTHEAST, PEAKING IN COVERAGE LATE WEDNESDAY AFTERNOON
AND EVENING. THE HIGH PWAT ENVIRONMENT WILL SUPPORT TORRENTIAL
DOWNPOURS IN ANY STORMS, ALTHOUGH THE PROGRESSIVE NATURE OF THE
SYSTEM SHOULD KEEP THE FLOOD RISK RELATIVELY LOW.
MODERATE DEEP LAYER SHEAR WILL OVERSPREAD THE AREA WEDNESDAY, BUT
INSTABILITY IS FORECAST TO REMAIN WEAK WITH VERY WARM MID LEVELS AND
POOR LOW/MID LEVEL LAPSE RATES. THE LACK OF STRONGER INSTABILITY
WILL LIKELY HOLD DOWN THE SEVERE WEATHER RISK.
AVIATION /18Z MONDAY THROUGH SATURDAY/
DIURNAL CUMULUS WILL CONTINUE INLAND FROM THE LAKES THROUGH LATE
AFTERNOON WITH VFR BASES. TONIGHT, MAINLY CLEAR TO PARTLY CLOUDY
SKIES WILL CONTINUE. RIVER VALLEY FOG WILL DEVELOP OVERNIGHT AND
LAST THROUGH MID MORNING TUESDAY ACROSS THE SOUTHERN TIER AND FINGER
LAKES WITH LOCAL IFR/LIFR. VFR WILL PREVAIL FOR THE REST OF TUESDAY
ONCE THE FOG BURNS OFF ACROSS THE SOUTHERN TIER.
OUTLOOK...
WEDNESDAY...VFR/MVFR. SHOWERS AND A FEW THUNDERSTORMS, MAINLY LATER
IN THE AFTERNOON THROUGH WEDNESDAY EVENING. LOCAL/BRIEF IFR IN
THUNDERSTORMS.
THURSDAY...MVFR CIGS EARLY, IMPROVING TO VFR. A SMALL CHANCE OF
A FEW SHOWERS ACROSS THE SOUTHERN TIER.
FRIDAY THROUGH SATURDAY...MAINLY VFR.
MARINE
HIGH PRESSURE WILL PROVIDE LIGHT WINDS AND MINIMAL WAVE ACTION
THROUGH TUESDAY.
SOUTHERLY WINDS WILL INCREASE LATE TUESDAY NIGHT AS THE PRESSURE
GRADIENT TIGHTENS BETWEEN HIGH PRESSURE DRIFTING OFF THE EAST COAST
AND LOW PRESSURE MOVING INTO NORTHWEST ONTARIO. WINDS WILL BECOME
SOUTHWEST AND INCREASE FURTHER WEDNESDAY AS A COLD FRONT APPROACHES,
WITH WINDS AND WAVES INCREASING TO SMALL CRAFT ADVISORY CRITERIA
LATER WEDNESDAY THROUGH WEDNESDAY NIGHT ON BOTH LAKES AS THE COLD
FRONT CROSSES THE REGION. ELEVATED WINDS AND WAVES WILL PERSIST
THROUGH THURSDAY BEHIND THE DEPARTING COLD FRONT BEFORE WINDS
DIMINISH FRIDAY.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
DISCUSSION...HITCHCOCK
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
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