082
FXUS61 KBUF 031042
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
642 AM EDT SAT MAY 3 2025
SYNOPSIS
AN UPPER LEVEL LOW WILL SLOWLY SPIRAL ACROSS THE OHIO VALLEY THIS
WEEKEND, WITH PERIODS OF RAIN SHOWERS ACROSS OUR REGION. COOL
NORTHEAST FLOW OVER LAKE ONTARIO WILL MAINTAIN AIR TEMPERATURES
BELOW NORMAL ACROSS WESTERN NEW YORK. AS THE FLOW BECOMES MORE
EASTERLY AND SOUTHEASTERLY MONDAY A MILDER AND MOIST AIRMASS WILL
PUSH INTO OUR REGION WITH AIR TEMPERATURES SOARING SOME 10-15
DEGREES HIGHER, THOUGH ALSO WITH SHOWERS AND DRENCHING THUNDERSTORMS.
NEAR TERM /THROUGH TONIGHT/
WATER VAPOR IMAGERY DISPLAYS A MID LEVEL SHORTWAVE TROUGH DROPPING
INTO THE MID MISSISSIPPI VALLEY THIS MORNING...AND THIS TROUGH
WILL BECOME CUT OFF FROM THE MAIN FLOW ALOFT, WITH THE SOON TO
BE CLOSED LOW REMAINING OVER THE LOWER OHIO VALLEY THROUGH THE
FORECAST PERIOD.
AT THE SURFACE A WEAKLY DEFINED SURFACE LOW WILL REMAIN IN THE
VICINITY OF KY, WITH A MOISTURE LADEN BAROCLINIC BOUNDARY STRETCHED
NORTHEASTWARD ACROSS THE MID-ATLANTIC AND INTO NEW ENGLAND.
SEVERAL SHORTWAVE TROUGHS ALONG THIS BAROCLINIC BOUNDARY WILL BRING
PERIODS OF RAIN SHOWERS TO OUR REGION, THE FIRST THROUGH THE MORNING
AND AFTERNOON HOURS...WITH ANOTHER SHORTWAVE ROUNDING THE CLOSED LOW
CONTINUING TO PRODUCE SCATTERED SHOWERS OVERNIGHT. BETWEEN THESE TWO
FEATURES WE'LL SEE A BREAK IN THE STEADIER RAIN, THOUGH ABUNDANT
MOISTURE IN THE LOWER LEVELS MAY LEND TO DRIZZLE OR FOG ACROSS THE
HIGHER TERRAIN THIS EVENING AND TONIGHT.
LIGHT NORTHEAST FLOW TODAY, OVER THE COLD LAKE ONTARIO WATERS, WILL
KEEP TEMPERATURES WELL BELOW NORMAL THROUGH THE DAY, WITH
COMMUNITIES ALONG THE SOUTHERN LAKE ONTARIO SHORELINE STRUGGLING TO
MAKE IT INTO THE 50S. SLIGHTLY WARMER TODAY NEAR THE STATE LINE AS
WELL AS EAST OF LAKE ONTARIO.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
MODEL CONSENSUS CONTINUES TO BE LOCKED IN A LARGE CUTOFF UPPER LOW
CENTERED RIGHT OVERHEAD KENTUCKY AND TENNESSEE SUNDAY MORNING. THIS
FEATURE WILL REMAIN NEARLY STATIONARY FOR THE FINISH OF THE WEEKEND
INTO SUNDAY NIGHT. DESPITE BEING CENTERED THAT FAR AWAY FROM US, AS
MENTIONED THIS IS VERY LARGE SYSTEM THAT WILL BE THE MAIN DRIVER OF
THE WEATHER FOR A LARGE CHUNK OF THE EASTERN CONUS, WITH THE
EXCEPTION OF FAR NORTHERN NEW ENGLAND. BACK CLOSER TO HOME, THIS
PLACES WESTERN AND NORTH-CENTRAL NY ON THE NORTHEASTERN PERIPHERY OF
THE SYSTEM. COUNTERCLOCKWISE FLOW AROUND THE LOW WILL PROPAGATE
MULTIPLE WAVES NORTH THEN NORTHWEST ACROSS THE AREA, EACH BRINGING A
PERIOD OF STEADIER, WIDESPREAD SHOWERS WITH IT. LAPSE RATES NOT
IMPRESSIVE SUNDAY, THUS MEAGER INSTABILITY SHOULD MITIGATE MUCH IN
THE WAY OF THUNDER, ALTHOUGH CAN'T RULE OUT A RUMBLE OF THUNDER
ACROSS THE SOUTHERN HALF OF THE AREA SUNDAY AFTERNOON AND EVENING
WHERE A BIT BETTER INSTABILITY MAY DEVELOP. STILL DIFFICULT TO PIN
DOWN TIMING ON AFOREMENTIONED PIECES OF SHORTWAVE ENERGY PINWHEELING
ABOUT THE UPPER LOW, SO IN TERMS OF SENSIBLE WEATHER EXPECT ROUNDS
OF SHOWERS WITH "DRIER" PERIODS IN BETWEEN, BUT STILL THE CHANCE FOR
SCATTERED SHOWERS IN BETWEEN THE MAIN WAVES. CONTINUED NORTHEASTERLY
LOW LEVEL FLOW WILL KEEP IT CHILLY BY EARLY MAY STANDARDS,
ESPECIALLY SOUTH OF LAKE ONTARIO WHERE HIGHS WILL STRUGGLE TO REACH
THE MID 50S. AS AN ADDED BONUS, WINDS WILL ALSO INCREASE FOR SUNDAY
WITH NORTHEASTERLY GUSTS UP TO 25 MPH ALONG THE SOUTHERN LAKE
ONTARIO SHORELINE, SOUTHWEST ACROSS THE NIAGARA FRONTIER.
SOME CHANGES START TO TAKE PLACE FOR THE START OF THE NEW WORK WEEK
AS A TROUGH MOVING EAST ACROSS SOUTH-CENTRAL CANADA STARTS TO
INTERACT WITH THE CUTOFF. THIS WILL CAUSE THE LOW TO INITIALLY
WOBBLE NORTHWARD ACROSS INDIANA AND OHIO MONDAY, BEFORE NUDGING EAST-
NORTHEAST OVER OHIO MONDAY NIGHT. SURFACE REFLECTION WILL TAKE A
SIMILAR TRACK, WITH AN INVERTED TROUGH NOSING NORTHEAST ACROSS
WESTERN NY. THIS FEATURE ALONG WITH DEEPER MOISTURE MOVING INTO THE
AREA AS THE SYSTEM GETS CLOSER, WILL BRING YET ANOTHER UPTICK IN
SHOWERS ACROSS THE AREA FOR MONDAY. IN ADDITION, WITH THE COLD POOL
ALOFT EDGING CLOSER TO THE AREA, INCREASING LAPSE RATES/INSTABILITY
WILL LIKELY LEAD TO MORE IN THE WAY OF CONVECTIVE ACTIVITY BY MONDAY
AFTERNOON AS A NOW SOUTHEASTERLY LOW LEVEL FLOW BOOSTS SURFACE TEMPS
INTO THE UPPER 60S AND LOW 70S, WITH THUNDERSTORMS HAVING THE
POTENTIAL TO PRODUCE LOCALIZED HEAVY DOWNPOURS. THUNDERSTORM
ACTIVITY WILL WIND DOWN THROUGH THE EVENING WITH THE LOSS OF DAYTIME
HEATING, HOWEVER EXPECT SHOWERS TO CONTINUE INTO MONDAY NIGHT. ONE
OTHER NOTE: THOUGH PATTERN/FLOW IS ATYPICAL FOR SEVERE WEATHER,
DECENT AMOUNT OF CAPE BY LATER MONDAY AFTERNOON ALONG WITH SHEAR
VALUES UPWARDS OF 30+ KNOTS MAY YIELD A FEW STRONGER STORMS.
SOMETHING TO WATCH AS WE GET CLOSER.
BASIN AVERAGE RAINFALL AMOUNTS WILL RANGE FROM THREE QUARTERS TO AN
INCH SOUTH OF LAKE ONTARIO FOR THE PERIOD, WITH CLOSER TO A HALF
INCH TOWARD THE NORTH COUNTRY. THERE WILL ALSO LIKELY BE LOCALIZED
HIGHER AMOUNTS FOR AREAS THAT SEE MORE IN THE WAY OF THUNDERSTORM
ACTIVITY.
LONG TERM /TUESDAY THROUGH FRIDAY/
AS THE UPPER LEVEL TROUGH CONTINUES EAST ACROSS SOUTHERN CANADA, IT
WILL CONTINUE TO ENCOURAGE THE STUBBORN CUTOFF UPPER LEVEL LOW TO
PROGRESS EASTWARD ON TUESDAY, MAKING IT INTO WESTERN NY/PA. THE
CUTOFF LOW WILL CONTINUE TO WEAKEN, BECOMING AN OPEN WAVE AND MOVING
EAST INTO NEW ENGLAND BY MID WEEK. THIS WILL YIELD WIDESPREAD
SHOWERS AND A FEW THUNDERSTORMS FOR TUESDAY WITH THE UPPER LOW
PASSING OVERHEAD, FOLLOWED BY SOME LINGERING SCATTERED SHOWERS BY
WEDNESDAY (ESPECIALLY EASTERN AREAS) WITH CYCLONIC FLOW ON THE WEST
SIDE OF THE DEPARTING UPPER LOW STILL HANGING BACK OVER THE AREA.
UNFORTUNATELY, RIGHT ON ITS HEELS WILL BE THE UPPER LEVEL TROUGH
THAT WAS ULTIMATELY RESPONSIBLE FOR KICKING OUT THE STALLED UPPER
LOW. THIS WILL SEND A COLD FRONT THROUGH THE AREA WEDNESDAY NIGHT OR
THURSDAY MORNING BRINGING MORE CHANCES FOR SHOWERS AND A SHOT OF
COOLER AIR. MEDIUM RANGE GUIDANCE IS NOW COMING INTO BETTER
AGREEMENT THAT THIS UPPER LEVEL TROUGH MAY NOW CUTOFF OVER THE
NORTHEAST, POSSIBLY ALLOWING SHOWERS TO LINGER ALL THE WAY THROUGH
THE END OF THE WORK WEEK, ESPECIALLY ACROSS EASTERN AREAS. THIS IS A
LONG WAY OUT, SO STAY TUNED.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
FOR THE 12Z TAFS AN UPSTREAM UPPER LEVEL TROUGH WILL BECOME A
CLOSED, CUTOFF LOW OVER THE OHIO VALLEY, SENDING COPIOUS AMOUNTS
OF MOISTURE OVER OUR REGION...THIS OVER A LOW LEVEL NORTHEAST
FLOW THAT WILL BE CONDUCIVE FOR IFR/LIFR FLIGHT CONDITIONS SOUTH
OF LAKE ONTARIO FROM MID-MORNING AND ON THROUGH THE TAF CYCLE.
A CONVECTIVE SHORTWAVE TROUGH WILL CONTINUE NUMEROUS SHOWERS
FOR THE NEXT 6 TO 12 HOURS ACROSS OUR REGION. VISIBILITIES WILL
LARGELY BE VFR, THOUGH MVFR IN HEAVIER CELLS OR ACROSS THE
HIGHER TERRAIN WHERE SOME PATCHES OF FOG MAY OCCUR.
NORTHEAST FLOW WILL DOMINATE THIS PERIOD, WITH SPEEDS GENERALLY 10
KNOTS OR LESS.
BEHIND THIS SHORTWAVE THERE WILL BE A BRIEF BREAK IN THE RAIN
SHOWERS, THOUGH ABUNDANT LOW LEVEL MOISTURE MAY LINGER SOME PATCHES
OF DRIZZLE INTO THE OVERNIGHT. ANOTHER WAVE OF RAIN SHOWERS
WILL LIKELY ENTER INTO WNY TO CLOSE OUT THE TAF CYCLE TONIGHT
WITH RAIN MAINLY TO BE FOUND SOUTH OF LAKE ONTARIO ALONG A
BAROCLINIC BOUNDARY.
OUTLOOK...
SUNDAY THROUGH TUESDAY...MVFR TO IFR WITH OCCASIONAL SHOWERS. CHANCE
FOR THUNDERSTORMS MONDAY AFTERNOON AND INTO THE OVERNIGHT.
WEDNESDAY...VFR TO MVFR, WITH A CHANCE OF SHOWERS.
MARINE
NORTHEAST FLOW ON THE LAKES TO START THIS WEEKEND AHEAD OF A CLOSED
UPPER LEVEL LOW. AS A SURFACE LOW DEVELOPS THIS NORTHEAST FLOW WILL
INCREASE LATER TONIGHT AND SUNDAY, SUCH THAT CHOPPY WATERS WITH
POSSIBLE SMALL CRAFT ADVISORY WINDS WILL BE FOUND ON LAKE ERIE. THE
WINDS WILL VEER TO EAST SUNDAY NIGHT, WITH POTENTIAL SMALL CRAFT
ADVISORY LEVEL CONDITIONS NOW FOUND ON THE WESTERN LAKE ONTARIO
WATERS.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...JM
LONG TERM...JM
AVIATION...THOMAS
MARINE...THOMAS
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