999
FXUS61 KBUF 231021
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
621 AM EDT FRI MAY 23 2025
SYNOPSIS
A BROAD, SLOW MOVING UPPER LEVEL LOW OVER THE NORTHEAST US WILL
CONTINUE TO PRODUCE PERIODS OF LIGHT RAIN, DRIZZLE, AND OVERCAST
SKIES TODAY THROUGH TONIGHT. THIS SYSTEM WILL GRADUALLY MOVE EAST
ACROSS THE CANADIAN MARITIMES OVER THE WEEKEND, WITH A SLOW
IMPROVING TREND. WIDESPREAD RAIN WILL GIVE WAY TO MORE INTERMITTENT
SHOWERS SATURDAY, WITH THE COVERAGE OF SHOWERS TRENDING LOWER BY
SUNDAY. HIGH PRESSURE WILL THEN BUILD INTO THE GREAT LAKES ON
MEMORIAL DAY, WITH MAINLY DRY WEATHER AND SOMEWHAT WARMER
TEMPERATURES.
NEAR TERM /THROUGH TONIGHT/
RADAR IMAGERY SHOWING WIDESPREAD LIGHT RAIN AND DRIZZLE ACROSS
WESTERN NY, THE GENESEE VALLEY, AND WESTERN FINGER LAKES EARLY THIS
MORNING, WITH THE RAIN MORE SPOTTY EAST OF LAKE ONTARIO. THE MOST
WIDESPREAD RAIN WILL CONTINUE TO FOCUS ACROSS THE NIAGARA FRONTIER,
GENESEE VALLEY, AND WESTERN FINGER LAKES THIS MORNING BEFORE MOVING
NORTHEAST AND FILLING IN EAST OF LAKE ONTARIO THIS AFTERNOON.
A LARGE, DEEP MID/UPPER LEVEL LOW STRETCHING FROM THE GREAT LAKES TO
NEW ENGLAND WILL CONTINUE TO DRIFT VERY SLOWLY EAST, BECOMING
CENTERED OVER MAINE BY SATURDAY MORNING. AT THE SURFACE, LOW
PRESSURE WILL DRIFT SLOWLY EAST ACROSS LAKE ONTARIO TODAY BEFORE
DISSIPATING AS A SECONDARY COASTAL LOW MOVES NORTH ALONG THE NEW
ENGLAND COAST. DEEP, MOIST CYCLONIC FLOW WILL CONTINUE ACROSS THE
EASTERN GREAT LAKES TODAY THROUGH TONIGHT. A NORTHWEST TO SOUTHEAST
ORIENTED FRONTAL ZONE AND AXIS OF LOW/MID LEVEL DEFORMATION WILL
CONTINUE TO BE THE PRIMARY FOCUS FOR WIDESPREAD RAINFALL TODAY
THROUGH TONIGHT, WITH THIS FEATURE BECOMING FOCUSED OVER AND
SOUTHEAST OF LAKE ONTARIO TODAY. THIS WILL MAINTAIN WIDESPREAD LIGHT
RAIN AND DRIZZLE FOR MUCH OF THE AREA TODAY INTO THE FIRST HALF OF
TONIGHT BEFORE THE RAIN DIMINISHES SOMEWHAT IN COVERAGE LATE TONIGHT
AS THE BEST FORCING AND MOISTURE BEGIN TO DRIFT EAST.
ACROSS THE WESTERN SOUTHERN TIER, RAIN WILL BECOME MORE INTERMITTENT
AND SHOWERY TODAY AS THE DEFORMATION ZONE MOVES NORTHEAST TOWARDS
LAKE ONTARIO. WNW UPSLOPE FLOW WILL STILL MAINTAIN FREQUENT SHOWERS
ACROSS THE HIGHER TERRAIN JUST INLAND FROM LAKE ERIE, AND STEEPENING
LAPSE RATES WITH MODEST DIURNAL HEATING WILL ALSO RESULT IN
ADDITIONAL SHOWER COVERAGE THIS AFTERNOON.
TEMPERATURES WILL REMAIN WELL BELOW AVERAGE TODAY, WITH HIGHS BARELY
REACHING THE LOWER 50S FOR THE LAKE PLAINS, AND MID TO UPPER 40S
ACROSS HIGHER TERRAIN. THESE VALUES ARE APPROACHING 20F BELOW
AVERAGE FOR LATE MAY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
HEADING INTO THE HOLIDAY WEEKEND, A VERTICALLY STACKED LOW PRESSURE
SYSTEM WILL LIE ACROSS THE EAST COAST OF MAINE, WHILE A WEAK
SHORTWAVE TROUGH WILL TRACK WEST ACROSS THE UPPER GREAT LAKES AND
INTO THE LOWER GREAT LAKES THROUGH THE WEEKEND. THIS BEING SAID,
EXPECT THE CHANCES FOR SHOWERS TO LINGER THROUGHOUT THE WEEKEND,
WITH THE BEST CHANCES OCCURRING EACH AFTERNOON DUE TO INCREASING
INSTABILITY FROM DIURNAL HEATING. ADDITIONALLY A FEW RUMBLES OF
THUNDER CAN'T BE RULED OUT SOUTH OF LAKE ONTARIO ACROSS THE GENESEE
VALLEY.
SHOWERS WILL THEN SCATTER OUT LATE SUNDAY EVENING AND OVERNIGHT WITH
THE LOSS OF DAYTIME HEATING AND A BUILDING RIDGE EDGING INTO THE
EASTERN GREAT LAKES.
THE AIRMASS OVERHEAD WILL CONTINUE TO REMAIN ON THE COOLER SIDE
SUPPORTING DAYTIME HIGHS BELOW NORMAL FOR THE FIRST TWO DAYS OF THE
HOLIDAY WEEKEND.
LONG TERM /MONDAY THROUGH THURSDAY/
MID-LEVEL RIDGING AND CORRESPONDING SURFACE HIGH PRESSURE WILL SLIDE
ACROSS THE EASTERN GREAT LAKES REGION MEMORIAL DAY, WHICH IN TURN
WILL SUPPORT THE BEST DAY TO BE OUTSIDE FOR THE LONG WEEKEND. WHILE
THE WEATHER WILL REMAIN MAINLY DRY, A FEW AFTERNOON SHOWERS INLAND
FROM THE LAKES WILL BE POSSIBLE. ALONG WITH THE NICE WEATHER,
TEMPERATURES MONDAY WILL BE THE WARMEST OF THE HOLIDAY WEEKEND.
ATTENTION THEN TURNS TO THE NEXT MID-LEVEL CLOSED LOW DEVELOPING
ACROSS THE MIDWEST AND GREAT LAKES. MODEL GUIDANCE CONTINUES TO
REMAIN DIVERGED WITH THE TIMING, LOCATION AND STRENGTH OF THIS
FEATURE. THIS BEING SAID, A SLOWER TRACK OF THIS LOW WILL PROMOTE
MORE DRY WEATHER, HOWEVER A QUICKER PACED SYSTEM WILL SUPPORT
INCREASING CHANCES FOR RAIN TO RETURN. FOR NOW HAVE SHOWERS ARRIVING
TUESDAY NIGHT INTO WEDNESDAY MORNING. AS THIS MID-LEVEL LOW THEN
MAKES A PASS ACROSS THE GREAT LAKES MID TO LATE IN THE WEEK, THE
POTENTIAL FOR SHOWERS WILL CONTINUE.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
A BROAD, DEEP UPPER LEVEL LOW WILL CONTINUE TO DOMINATE THE GREAT
LAKES AND NEW ENGLAND THROUGH TONIGHT, SUPPORTING A CONTINUATION OF
RAIN AND LOW CIGS. THE MOST WIDESPREAD RAIN WILL FOCUS OVER WESTERN
NY, THE GENESEE VALLEY, AND WESTERN FINGER LAKES THROUGH THIS
MORNING, THEN GRADUALLY EXPAND NORTHEAST, FILLING IN EAST OF LAKE
ONTARIO THIS AFTERNOON. RAIN ACROSS THE SOUTHERN TIER WILL BECOME
MORE INTERMITTENT AND SHOWERY LATE THIS MORNING THROUGH THE
AFTERNOON. THE MISTY, LIGHT RAIN WILL REDUCE VSBY TO MVFR AND LOCAL
IFR AT TIMES. WIDESPREAD IFR TO LOW END MVFR CIGS WILL CONTINUE
TODAY ACROSS ALL OF WESTERN NY. THE VFR CIGS ACROSS THE NORTH
COUNTRY WILL DETERIORATE TO MVFR THIS MORNING, THEN IFR TO LOW END
MVFR THIS AFTERNOON.
THE WIDESPREAD RAIN WILL LAST INTO THIS EVENING, THEN TEND TO
DIMINISH IN COVERAGE AND INTENSITY OVERNIGHT AS A SURFACE LOW
ASSOCIATED WITH THE UPPER LEVEL LOW MOVES OFF INTO THE CANADIAN
MARITIMES. DESPITE THE DIMINISHING RAIN COVERAGE, ABUNDANT LOW LEVEL
MOISTURE WILL CONTINUE TO SUPPORT WIDESPREAD IFR TO LOW END MVFR
CIGS TONIGHT THROUGH EARLY SATURDAY MORNING.
OUTLOOK...
SATURDAY...SCATTERED TO NUMEROUS SHOWERS. WIDESPREAD IFR/LOW END
MVFR CIGS IN THE MORNING IMPROVING TO VFR/MVFR IN THE AFTERNOON.
SUNDAY...VFR/MVFR WITH SCATTERED SHOWERS.
MONDAY...MAINLY VFR.
TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
MARINE
LOW PRESSURE WILL MOVE SLOWLY EAST ACROSS LAKE ONTARIO TODAY BEFORE
GIVING WAY TO A SECONDARY COASTAL LOW ALONG THE MAINE COAST THIS
EVENING. MODERATE WESTERLIES OF 20+ KNOTS WILL PRODUCE SOLID SMALL
CRAFT ADVISORY CONDITIONS ON LAKE ERIE TODAY INTO THIS EVENING.
THE SURFACE LOW TRAVERSING THE MIDDLE OF LAKE ONTARIO WILL MAKE FOR
AN INTERESTING WIND PATTERN OVER THE LAKE TODAY, WITH E/NE WINDS
OVER THE NORTHERN HALF OF THE LAKE, AND WESTERLIES ALONG THE SOUTH
SHORE OF THE LAKE THAT WILL REACH 15+ KNOTS AT TIMES. THE DIFFERING
WIND DIRECTIONS WILL LIKELY PRODUCE A CHAOTIC WAVE PATTERN OVER THE
LAKE, WITH WAVE PACKETS OF DIFFERING DIRECTION AND PERIOD.
CONDITIONS WILL GENERALLY STAY BELOW SMALL CRAFT ADVISORY CRITERIA,
BUT WILL BE CHOPPY.
LATE TONIGHT AND SATURDAY, EXPECT WESTERLIES OF AROUND 15 KNOTS ON
LAKE ERIE AND LAKE ONTARIO, WITH A MODERATE CHOP BUT JUST BELOW
SMALL CRAFT ADVISORY CRITERIA. SIMILAR CONDITIONS WILL PERSIST
SUNDAY BEFORE HIGH PRESSURE BUILDS INTO THE GREAT LAKES ON MEMORIAL
DAY, WITH LIGHTER WINDS AND LESS WAVE ACTION.
BUF WATCHES/WARNINGS/ADVISORIES
NY...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR NYZ010-019-
085.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LEZ020-040-
041.
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...EAJ
LONG TERM...EAJ
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
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