076
FXUS61 KBUF 030603
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
203 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 TODAY/
LATEST SURFACE OBS/ANALYSIS SUGGEST THAT THE SURFACE COLD FRONT IS
DRAPED JUST TO OUR NORTH ACROSS LAKES ERIE AND ONTARIO AS OF THIS
WRITING...WITH THIS AFTERNOON'S PASSING WAVE/ROUND OF CONVECTION
HAVING ALREADY LARGELY EXITED OUR REGION TO THE EAST. THE COLD FRONT
WILL GRADUALLY SLIP SOUTHWARD ACROSS OUR REGION THIS EVENING AND MAY
GENERATE A FEW MORE SHOWERS AS IT DOES SO...HOWEVER THE COVERAGE OF
THESE (IF ANY) SHOULD REMAIN FAIRLY LOW GIVEN ONLY WEAK FORCING AND
WANING INSTABILITY.
AS WE PUSH INTO THE OVERNIGHT HOURS...THE FRONT WILL EVENTUALLY
STALL OUT JUST TO OUR SOUTH AS A CONVECTIVELY ENHANCED SHORTWAVE
CURRENTLY OVER THE OHIO VALLEY RIPPLES NORTHEASTWARD ALONG THIS
BOUNDARY. THE INCREASE IN MOISTURE AND LARGE-SCALE ASCENT ATTENDANT
TO THIS FEATURE WILL USHER ANOTHER ROUND OF FAIRLY WIDESPREAD
SHOWERS ACROSS THE AREA LATER TONIGHT AND SATURDAY MORNING...WITH
THE PRECIPITATION THEN POSSIBLY DIMINISHING SOMEWHAT DURING SATURDAY
AFTERNOON AS THIS NEXT WAVE SLIDES EAST OF OUR LONGITUDE...THOUGH
THIS PROCESS WILL PROBABLY BE AT LEAST SOMEWHAT HINDERED BY A
PERSISTENT MOIST NORTHEASTERLY UPSLOPE FLOW OFF LAKE ONTARIO...WHICH
MAY WELL KEEP AT LEAST SOME LIGHT RAIN/DRIZZLE GOING AFTER THE MORE
PERSISTENT SHOWERS WIND DOWN. EVEN IF THERE IS A RELATIVE BREAK IN
THE PCPN...IT WILL BE SHORT-LIVED AS LOW PRESSURE OVER THE OHIO
VALLEY LOOKS TO SEND YET ANOTHER WAVE OF MOISTURE OUR WAY SATURDAY
EVENING. THE BOTTOM LINE IS THAT SATURDAY WILL BE A WET AND COOL
DAY...WITH HIGHS MOSTLY IN THE LOWER TO MID 50S.
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/
A CLOSED LOW WILL SLOWLY MOVE FROM ILLINOIS TO INDIANA THROUGH THE
END OF THE WEEKEND. A PERSISTENT SOUTHERLY FLOW WILL PROVIDE A FEED
OF ATLANTIC MOISTURE ALONG THE EASTERN SEABOARD AND INTO WESTERN AND
NORTH CENTRAL NY. COOL AND UNSETTLED WEATHER WILL BE THE MAIN
WEATHER STORY FOR THE END OF THE WEEKEND INTO THE START OF THE NEXT
WORK WEEK.
AN UPPER LEVEL RIDGE WILL BE STRETCHED ACROSS SOUTHERN CANADA
THROUGH THE WEEKEND. THIS WILL ACT AS A BARRIER, AND MOISTURE
TRANSPORT WILL BE FORCED TO GO LATITUDINAL ACROSS THE GREAT LAKES
REGION AND NEW ENGLAND. THERE WILL BE MULTIPLE SHORTWAVE TROUGHS
MOVING AROUND THE CLOSED LOW AND CONFIDENCE IS LOW TO MEDIUM ON THE
TIMING OF THESE FEATURES. MODELS SUGGEST A SHORTWAVE TROUGH MAY
APPROACH THE CENTRAL APPALACHIANS SATURDAY NIGHT INTO SUNDAY AND
SHOWERS WILL SPREAD NORTHWARD INTO THE FORECAST AREA WITH HIGHER
CONFIDENCE FOR SHOWERS ACROSS WESTERN NY. THE HIGH TO THE NORTH MAY
KEEP THE SAINT LAWRENCE VALLEY AND NORTHERN TUG HILL REGION DRY.
SURFACE BASED INSTABILITY IS LIKELY IN THIS MOISTURE-RICH
ENVIRONMENT AND ANY HEAVY SHOWERS OR THUNDERSTORMS WILL BE CAPABLE
OF HEAVY DOWNPOURS SUNDAY AFTERNOON THROUGH EVENING. COVERAGE WILL
DIMINISH INTO SUNDAY EVENING BUT SHOWERS WILL REMAIN POSSIBLE.
MONDAY, THE SURFACE RIDGE WILL RETREAT SLIGHTLY NORTHWARD. AN
INVERTED TROUGH MAY DEVELOP FROM THE APPALACHIANS INTO THE LAKE ERIE
BASIN. THE LOW LEVEL FLOW WILL BECOME SOUTHEASTERLY AND WARMER AIR
WILL MOVE INTO THE REGION. DAYTIME HEATING WILL AGAIN RESULT IN
SHOWERS AND SCATTERED THUNDERSTORMS TO DEVELOP ACROSS THE REGION.
THERE ARE SOME SIGNALS THAT THE CLOSED LOW WILL SLOWLY MOVE NORTH
ACROSS OHIO MONDAY NIGHT. THIS MAY INCREASE SURFACE CONVERGENCE NEAR
THE SURFACE LOW AND WHILE SHOWERS AND A FEW STRONG THUNDERSTORMS ARE
POSSIBLE, THE THREAT OF HEAVY RAINFALL MAY SHIFT EASTWARD.
THERE IS A RISK FLOODING, MAINLY URBAN OR POOR DRAINAGE IF TRAINING
OF SHOWERS AND STORMS PERSIST ACROSS THE FORECAST AREA. AT THIS
TIME, THERE IS LOW CONFIDENCE IN THE LOCATION OF HEAVIEST RAIN. HIGH
TEMPERATURES WILL BE 5 TO 10 DEGREES BELOW NORMAL ON SUNDAY.
TEMPERATURES SHOULD REBOUND TO NEAR, IF NOT ABOVE NORMAL ON MONDAY.
LONG TERM /TUESDAY THROUGH FRIDAY/
THE PATTERN FINALLY BREAKS MID-WEEK BUT NOT BEFORE THE CLOSED LOW
LUMBERS ACROSS THE NORTHEAST RESULTING IN UNSETTLED WEATHER TO
CONTINUE TUESDAY AND WEDNESDAY. WITH THIS MILDER PATTERN WILL COME
INCREASING INSTABILITY, THAT COUPLED WITH INCREASING LAPSE RATES
UNDER THE POOL OF COLD AIR ALOFT (UPPER LEVEL LOW) DEEPER CONVECTION
WILL BE ENCOURAGED, WITH THUNDERSTORM CHANCES INCREASING THROUGH THE
AFTERNOON AND EVENING HOURS.
SURFACE HIGH PRESSURE SHOULD BUILD INTO THE GREAT LAKES REGION
THURSDAY AND FRIDAY, RESULTING IN DRIER WEATHER AND MORE SUNSHINE.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
FOR THE 06Z 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 BRING SHOWERS, NOW ENTERING THE
WESTERN SOUTHERN TIER, ACROSS OUR REGION THIS MORNING. THESE SHOWERS
WILL LIKELY SLOWLY IMPROVE VISIBILITIES FOR KJHW FROM VLIFR TO IFR
THIS EARLY MORNING.
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. ANOTHER WAVE OF RAIN SHOWERS WILL LIKELY ENTER INTO WNY
TO CLOSE OUT THE TAF CYCLE TONIGHT THAT WILL MAINLY 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
A COLD FRONT WILL SLIP SOUTHEAST ACROSS THE AREA THIS EVENING. IN
ITS WAKE LIGHT TO MODERATE NORTHEASTERLIES CAN THEN BE EXPECTED
OVERNIGHT THROUGH SATURDAY NIGHT, WITH SOME LIGHT TO MODERATE CHOP
ON THE LAKES.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
SYNOPSIS...THOMAS
NEAR TERM...AR/JJR
SHORT TERM...HSK
LONG TERM...HSK/THOMAS
AVIATION...THOMAS
MARINE...AR/JJR
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page