725
FXUS61 KBUF 211030
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
630 AM EDT THU MAY 21 2026
WHAT HAS CHANGED
A FROST ADVISORY IS IN EFFECT FOR JEFFERSON AND LEWIS COUNTIES
TONIGHT. RAINFALL AMOUNTS HAVE INCREASED ACROSS WESTERN NY ON
SATURDAY.
KEY MESSAGES
1) BELOW NORMAL TEMPERATURES CONTINUE THROUGH THE END OF THE WEEK.
2) WIDESPREAD SOAKING RAIN FRIDAY NIGHT INTO SATURDAY NIGHT.
DISCUSSION
KEY MESSAGE 1...BELOW NORMAL TEMPERATURES CONTINUE THROUGH SATURDAY.
SURFACE HIGH PRESSURE OVER THE UPPER GREAT LAKES THIS MORNING WILL
MOVE EAST-SOUTHEASTWARD THROUGH THE END OF THE WEEK. THIS COOL AND
DRY AIRMASS WILL MAINTAIN DRY WEATHER ACROSS THE FORECAST AREA
THROUGH FRIDAY.
THE CENTER OF THE SURFACE HIGH WILL MOVE OVER NORTHERN NEW YORK
TONIGHT. MOSTLY CLEAR SKIES AND CALM WINDS WILL PROVIDE A FAVORABLE
SETUP FOR RADIATIONAL COOLING ACROSS THE NORTH COUNTRY. FURTHER
WEST, A SLIGHT PRESSURE GRADIENT ACROSS WESTERN NY SHOULD PREVENT
TEMPERATURES FROM FALLING INTO THE MID-30S IN THAT AREA. LOW
TEMPERATURES WILL RANGE FROM THE MID-30S ACROSS THE NORTH COUNTRY TO
THE UPPER 30S AND LOW 40S ACROSS WESTERN NY. A FROST ADVISORY IS IN
EFFECT FOR JEFFERSON AND LEWIS COUNTIES TONIGHT.
FOLLOWING A COOL DAY TODAY, TEMPERATURES ARE EXPECTED TO RETURN TO
NEAR-SEASONAL NORMALS ON FRIDAY.
KEY MESSAGE 2...WIDESPREAD SOAKING RAIN FRIDAY NIGHT INTO SATURDAY
NIGHT.
AN UPPER LEVEL RIDGE WILL AMPLIFY ACROSS THE OHIO VALLEY AND GREAT
LAKES REGION FRIDAY THROUGH FRIDAY NIGHT. DEEP SOUTHERLY FLOW AHEAD
OF A SURFACE LOW WILL ADVANCE NORTHWARD ACROSS THE OHIO VALLEY, WITH
AN ASSOCIATED WARM FRONT APPROACHING WESTERN NY. WARM AIR ADVECTION
AND INCREASING MOISTURE WILL RESULT IN SHOWERS MOVING INTO WESTERN
NY FRIDAY NIGHT.
A SHORTWAVE TROUGH WILL CATCH UP WITH THE SURFACE LOW OVER THE OHIO
VALLEY, SPREADING WIDESPREAD MODERATE TO HEAVY RAIN ACROSS WESTERN
NY ON SATURDAY. WHILE A STRONG AREA OF HIGH PRESSURE OVER THE
CANADIAN MARITIMES IS EXPECTED TO MAINTAIN MOSTLY DRY CONDITIONS
EAST OF LAKE ONTARIO, ENHANCED RAINFALL IS POSSIBLE IN WESTERN NY
WHERE A LOW-LEVEL JET INTERACTS WITH A VERY MOIST AIRMASS. THOUGH
THERE HAS BEEN UNCERTAINTY IN THE EXACT LOCATION OF THE ENHANCED
RAINFALL. INSTABILITY WILL BE LIMITED IN THIS ENVIRONMENT, HOWEVER A
FEW THUNDERSTORMS CAN'T BE RULED OUT.
THE UPPER LEVEL RIDGE AND SURFACE HIGH WILL MOVE EAST SATURDAY NIGHT
WHILE LARGE SCALE ASCENT AND MOISTURE WILL MOVE INTO THE EASTERN
GREAT LAKES REGION. RAIN SHOWERS WILL CONTINUE ACROSS WESTERN NY
WHILE SPREADING INTO NORTH-CENTRAL NY SATURDAY NIGHT. THE CURRENT
FORECAST INCLUDES RAINFALL AMOUNTS OF 0.75-1.5" ACROSS WESTERN NY
AND 0.25-0.75" ACROSS THE EASTERN LAKE ONTARIO REGION SATURDAY
THROUGH SATURDAY NIGHT. THIS AMOUNT OF RAINFALL HAS THE POTENTIAL TO
CAUSE PONDING AND MINOR FLOODING OF LOW LYING AREAS. RISES ON RIVERS
AND CREEKS IS EXPECTED BUT WIDESPREAD FLOODING IS NOT EXPECTED AT
THIS TIME.
UNFORTUNATELY, AN UPPER LEVEL TROUGH AND LINGERING MOISTURE WILL
MAINTAIN SHOWER CHANCES SUNDAY THROUGH SUNDAY NIGHT, HOWEVER THERE
WILL BE PLENTY OF DRY TIMES.
AVIATION /10Z THURSDAY THROUGH MONDAY/
DESPITE MID TO HIGH LEVEL CLOUDS SPANNING ACROSS THE ENTIRE AREA
TONIGHT, VFR CONDITIONS PREVAIL ACROSS ALL TAF SITES. CLOUD COVER
WILL GRADUALLY STRIP AWAY FROM NORTHWEST TO SOUTHEAST AS THE SURFACE
COLD FRONT TO THE SOUTH PULLS OUT INTO THE ATLANTIC AND SURFACE HIGH
PRESSURE BUILDS OVER THE GREAT LAKES.
SURFACE HIGH PRESSURE WILL THEN GRADUALLY SHIFT EAST INTO THE LOWER
GREAT LAKES TODAY AND TONIGHT, MAINTAINING VFR FLIGHT
CONDITIONS.
OUTLOOK...
FRIDAY...VFR.
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.
MARINE
ELEVATED NORTHEAST WINDS WILL CONTINUE ON LAKE ERIE AND LAKE
ONTARIO, WITH THE STRONGEST WINDS ON THE EASTERN END OF LAKE
ONTARIO. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THIS
REGION THROUGH THIS MORNING. NORTHEAST WINDS WILL PICK UP ON
LAKE ERIE TODAY AND PRODUCE CHOPPY CONDITIONS ESPECIALLY FROM
RIPLEY TO DUNKIRK.
WINDS WILL RELAX AS HIGH PRESSURE BUILDS INTO THE REGION FRIDAY.
A STRONGER PRESSURE GRADIENT DEVELOPS LATE FRIDAY AND SATURDAY
AS A WAVE AND WARM FRONT MOVE 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...BEACH HAZARDS STATEMENT UNTIL 11 AM EDT THIS MORNING FOR
NYZ003>006.
FROST ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT FRIDAY FOR
NYZ007-008.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LOZ043-
044.
DISCUSSION...HSK
AVIATION...EAJ/HSK
MARINE...HSK/TMA
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