328
FXUS61 KBUF 221021
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
621 AM EDT FRI MAY 22 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES TO THE FORECAST.
KEY MESSAGES
1) BELOW NORMAL TEMPERATURES CONTINUE THROUGH SATURDAY.
2) A WIDESPREAD SOAKING RAIN IS EXPECTED LATE TONIGHT THROUGH
SATURDAY NIGHT.
DISCUSSION
KEY MESSAGE 1...BELOW NORMAL TEMPERATURES CONTINUE THROUGH SATURDAY.
SURFACE HIGH PRESSURE IS STRETCHED FROM LAKE SUPERIOR TO SOUTHERN
QUEBEC THIS MORNING. MOSTLY CLEAR SKIES AND CALM WINDS ARE
SUPPORTING A FAVORABLE SETUP FOR RADIATIONAL COOLING ACROSS CENTRAL
AND NORTH CENTRAL NY. FURTHER WEST, A SLIGHT PRESSURE GRADIENT
ACROSS FAR WESTERN NY SHOULD PREVENT TEMPERATURES FROM FALLING INTO
THE MID-30S IN THAT AREA. A FROST ADVISORY IS IN EFFECT FOR
JEFFERSON, OSWEGO, LEWIS, AND ALLEGANY COUNTIES THROUGH 8AM THIS
MORNING WHERE SENSITIVE VEGETATION MAY BE HARMED IF NOT PROTECTED.
THIS COOL, DRY AIRMASS WILL SHIFT EAST OF THE REGION TODAY. A LIGHT
RETURN FLOW WILL MOVE INTO THE AREA, WITH TEMPERATURES REBOUNDING
INTO THE 60S TO LOW 70S IN DOWNSLOPE REGIONS.
MID TO HIGH LEVEL CLOUDS WILL INCREASE FROM SOUTH TO NORTH TODAY AS
THE NEXT SYSTEM APPROACHES. WIDESPREAD RAIN IS EXPECTED ON SATURDAY,
BRINGING TEMPERATURES BACK BELOW NORMAL.
KEY MESSAGE 2...A WIDESPREAD SOAKING RAIN IS EXPECTED LATE TONIGHT
THROUGH SATURDAY NIGHT.
OUR WINDOW OF DRY WEATHER WILL COME TO AN END THIS WEEKEND AS AN
AREA OF LOW PRESSURE CURRENTLY OVER THE LOWER MISSISSIPPI VALLEY
MOVES NORTH, REACHING THE GREAT LAKES REGION SATURDAY. WARM AIR
ADVECTION AND INCREASING MOISTURE WILL RESULT IN SHOWERS MOVING INTO
WESTERN LATE FRIDAY NIGHT, WITH STEADY RAIN MOVING INTO THE WESTERN
SOUTHERN TIER BY EARLY SATURDAY MORNING.
A SHORTWAVE TROUGH WILL CATCH UP WITH THE SURFACE LOW OVER THE OHIO
VALLEY SATURDAY, AND DEEP SOUTHERLY FLOW WILL ADVANCE NORTHWARD WITH
ANOMALOUSLY HIGH PWATS STRETCHING FROM THE OHIO VALLEY INTO WESTERN
NY. WIDESPREAD MODERATE RAIN WILL SPREAD ACROSS WESTERN NY THROUGH
SATURDAY AFTERNOON, REACHING THE FINGER LAKES REGION AND CENTRAL NY
LATE SATURDAY AFTERNOON. A STRONG AREA OF HIGH PRESSURE OVER THE
CANADIAN MARITIMES IS EXPECTED TO MAINTAIN MOSTLY DRY CONDITIONS
ACROSS THE TUG HILL REGION AND NORTH COUNTRY SATURDAY. A VERY TIGHT
THERMAL GRADIENT AND LOW-LEVEL JET WILL MOVE INTO FAR WESTERN NY
SATURDAY AFTERNOON. ENHANCED RAINFALL IS POSSIBLE WHERE A STRONG LOW-
LEVEL JET INTERACTS WITH A VERY MOIST AIRMASS. NBM GUIDANCE HAS
LOWERED QPF AMOUNTS IN THIS REGION, HOWEVER BASED ON DYNAMICS AND
MOISTURE CONTENT A PERIOD OF HEAVY RAINFALL REMAINS POSSIBLE.
THE SURFACE LOW IS EXPECTED TO OCCLUDE AND AS IT MOVES NORTHWARD
INTO LOWER MICHIGAN AND LAKE HURON SATURDAY NIGHT. FORCING AND DEEP
MOISTURE WILL MOVE EASTWARD WHILE THE LOW-LEVEL THERMAL GRADIENT
LOOSENS ACROSS THE LAKE ONTARIO REGION. THE GREATEST QPF IS EXPECTED
TO FOLLOW THIS GRADIENT NEAR LAKE ONTARIO SATURDAY NIGHT. DRIER AIR
WILL MOVE INTO THE WESTERN SOUTHERN TIER THROUGH SATURDAY NIGHT. THE
CURRENT FORECAST INCLUDES RAINFALL AMOUNTS OF 0.75-1.5" ACROSS THE
WESTERN NEW YORK, WITH THE HIGHEST AMOUNTS ACROSS THE NIAGARA
FRONTIER LATE FRIDAY NIGHT THROUGH SATURDAY NIGHT. LOWER RAINFALL
AMOUNTS ARE EXPECTED ACROSS THE EASTERN LAKE ONTARIO REGION AND 0.25-
0.50". THIS AMOUNT OF RAINFALL HAS THE POTENTIAL TO CAUSE PONDING
AND MINOR FLOODING OF LOW LYING AREAS ACROSS WESTERN NY. RISES ON
RIVERS AND CREEKS IS EXPECTED, BUT WIDESPREAD FLOODING IS NOT
EXPECTED.
WIND GUSTS UP TO 30 MPH ARE EXPECTED ACROSS WESTERN NY
SATURDAY, AND ACROSS NORTH-CENTRAL NY ON SATURDAY NIGHT AS THE
LOW- LEVEL JET MOVES OVERHEAD. THERE IS A POSSIBILITY OF HIGHER
WIND GUSTS, REACHING UP TO 40 MPH IN DOWNSLOPE REGIONS.
SUBSIDENCE AND DRIER AIR WILL MOVE INTO AREA FROM WEST TO EAST
SUNDAY, LEADING TO IMPROVING CONDITIONS.
AVIATION /10Z FRIDAY THROUGH TUESDAY/
WIDESPREAD VFR CONDITIONS WILL PREVAIL AS SURFACE HIGH PRESSURE
MOVES ACROSS THE REGION THROUGH THIS EVENING. EAST TO NORTHEAST
WINDS WILL INCREASE TO 10-15 KNOTS TODAY.
AS SURFACE HIGH PRESSURE SLIDES FURTHER EAST, LOW PRESSURE WILL
SLIDE NORTHEAST OUT OF THE GULF TOWARDS THE OHIO VALLEY, SUPPORTING
MID-LEVEL CLOUDS EXPANDING FROM SOUTHWEST TO NORTHEAST LATE
FRIDAY. MVFR CONDITIONS WILL MOVE INTO THE WESTERN SOUTHERN TIER
LATE TONIGHT.
OUTLOOK...
SATURDAY...MVFR/VFR DETERIORATING TO MVFR/IFR WITH WIDESPREAD RAIN
SHOWERS.
SUNDAY...MVFR/IFR WITH RAIN SHOWERS IN THE MORNING, THEN IMPROVING
TO VFR.
MONDAY...MAINLY VFR WITH A CHANCE OF RAIN SHOWERS.
TUESDAY... MAINLY VFR.
MARINE
NORTHEAST WINDS WILL CONTINUE ON THE LAKES TODAY. WINDS ARE EXPECTED
TO MOSTLY STAY BELOW 15 KNOTS, HOWEVER WINDS MAY REACH 20 KNOTS
ACROSS WESTERN LAKE ONTARIO WHICH MAY RESULT IN A BRIEF PERIOD OF
SMALL CRAFT CONDITIONS.
A STRONGER PRESSURE GRADIENT DEVELOPS LATE FRIDAY NIGHT AND SATURDAY
AS A WAVE OF LOW PRESSURE AND A WARM FRONT MOVES INTO THE GREAT
LAKES. EASTERLY WINDS WILL INCREASE TO 15 TO 25 KNOTS ON THE WESTERN
END OF LAKE ONTARIO WITH SMALL CRAFT AND BEACH HAZARDS HEADLINES
LIKELY DURING THIS TIME PERIOD. WINDS WILL TREND WEAKER ON LAKE ERIE.
BUF WATCHES/WARNINGS/ADVISORIES
NY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ006>008-021.
MARINE...NONE.
DISCUSSION...HSK
AVIATION...EAJ/HSK
MARINE...HSK
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