993
FXUS61 KPBZ 260657
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
257 AM EDT MON MAY 26 2025
SYNOPSIS
HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD INTO NEW YORK AND
PENNSYLVANIA AND BRING DRY WEATHER FOR MEMORIAL DAY. LOW
PRESSURE MOVING INTO THE MIDDLE MISSISSIPPI RIVER VALLEY TUESDAY
WILL LIFT INTO THE GREAT LAKES ON WEDNESDAY BRINGING WET
WEATHER TO THE UPPER OHIO RIVER VALLEY. AN UPPER LEVEL TROUGH IS
EXPECTED TO KEEP CONDITIONS COOL AND WET FOR THE REMAINDER OF
THE WEEK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- DRY AND PLEASANT WEATHER EXPECTED FOR MEMORIAL DAY
-------------------------------------------------------------------
CALM WINDS MOST AREAS AND CLEAR SKIES IN THE NORTHERN TWO-THIRDS
HAS ALLOWED EXCELLENT RADIATIONAL COOLING AND FOG PRODUCT IS
PICKING UP RIVER VALLEY FOG ALONG THE ALLEGHENY RIVER IN
FOREST/VENANGO/CLARION COUNTIES. EXPECT THAT TO EXPAND SLOWLY
SOUTH THROUGH DAYBREAK BEFORE A QUICK BURNOFF BY 8 AM OR SO.
HEALTHY 500 MB HEIGHT RISES OF ABOUT 60 METERS TODAY WILL BRING
CONTINUED SUBSIDENCE ALONG WITH 850 MB TEMPS WARMING ABOUT 3C TO
ABOUT 8C. WITH MORE SUNSHINE THAT SHOULD PUSH US UP CLOSER TO
NORMAL IN THE LOWER 70S.
SURFACE HIGH OVER GREAT LAKES WILL SETTLE OVER NEW YORK STATE
TONIGHT. READINGS WILL BE CLOSE TO NORMAL AS THICKENING HIGH
CLOUDS PREVENT BIGGER TEMPERATURE FALLS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
KEY MESSAGES:
- WET WEATHER RETURNS LATER TUESDAY INTO WEDNESDAY
----------------------------------------------------------------
SHORT WAVE TROUGH OVER THE SOUTHERN PLAINS STARTS TO PHASE WITH
DEEPENING UPPER LOW OVER MINNESOTA AREA ON TUESDAY AND TUESDAY
NIGHT, WITH HEIGHT FALLS SPREADING INTO THE OHIO RIVER VALLEY.
UPPER LOW THEN MOVES INTO WISCONSIN ON WEDNESDAY. THIS SHOULD
RESULT IN A SURFACE LOW MOVING FROM THE MIDDLE MISSISSIPPI RIVER
VALLEY TUESDAY INTO INDIANA TUESDAY NIGHT AND MICHIGAN ON
WEDNESDAY.
850-700 MB WARM ADVECTION PUSHES INTO OHIO AND WEST VIRGINIA
TUESDAY AFTERNOON AND ACROSS THE AREA TUESDAY NIGHT BRINGING
RAIN. AIRMASS MAY GET UNSTABLE ENOUGH BY WEDNESDAY TO ALLOW FOR
SOME THUNDER BUT THE THREAT OF SEVERE WEATHER AND HEAVY RAINFALL
IS RATHER LOW.
NBM 25TH PERCENTILE PQPF IS 0.50-1.00" WITH 75TH PERCENTILE OF
1.00-2.00". HOWEVER, HOURLY RATES DON'T APPEAR TO BE MUCH MORE
THAN 0.10 TO 0.25" SO IMPACTS FROM RAINFALL APPEARS TO BE
MINIMAL.
LONG TERM /THURSDAY THROUGH SUNDAY/
KEY MESSAGES:
- TEMPERATURE UNCERTAINTY IS RATHER HIGH ESPECIALLY OVER THE
WEEKEND
- READINGS SHOULD BE CLOSER TO SEASONAL NORMALS OVERALL
- DAILY SHOWER CHANCES LATE WEEK INTO THE WEEKEND
-------------------------------------------------------------------
ENSEMBLE GUIDANCE COMING INTO A BIT BETTER AGREEMENT THAT UPPER
LOW WILL OPEN UP AS A TROUGH ON THURSDAY AND MOVE FROM MICHIGAN
TO SOUTHWEST ONTARIO AS UPPER RIDGE BUILDS OVER NORTHERN ROCKY
MOUNTAINS. A RATHER DEEP UPPER TROUGH THEN IS SHOWN TO DIG SOUTH
ACROSS ONTARIO AND HEAD FOR GREAT LAKES ON FRIDAY.
THIS TROUGH THEN SWINGS EAST ACROSS NORTHEAST ON SATURDAY AND
THEN HEIGHTS BUILD OVER THE UPPER OHIO RIVER VALLEY ON SUNDAY.
SHOWERS WILL BE POSSIBLE THROUGHOUT THE PERIOD ESPECIALLY DURING
THE DIURNAL CYCLE WHEN CONVECTION IS POSSIBLE. WHILE THE MEAN
TEMPERATURES WILL BE CLOSE TO NORMAL, UNCERTAINTY WITH THE DEPTH
OF THE UPPER TROUGH LEADS TO RATHER HIGH SPREADS OF POTENTIAL
OUTCOMES ESPECIALLY BY THE WEEKEND. NBM 10TH PERCENTILE MAXT ARE
IN THE 60S, WHILE 90TH PERCENTILE ARE IN THE 80S.
BECAUSE HEIGHTS WILL BE RISING IN THE PLAINS AND HEAT ALSO
BUILDING, THAT WARM AIR WILL EVENTUALLY PUSH INTO THE OHIO
VALLEY BUT PROBABLY NOT UNTIL NEXT WEEK. THE MOST LIKELY
SCENARIO IS FOR TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL UNDER
THE UPPER TROUGH WITH DIURNAL CLOUDS AND SHOWERS PREVENTING
TEMPERATURES FROM CLIMBING MUCH.
AVIATION /06Z MONDAY THROUGH FRIDAY/
TEMPORARY VISIBILITY RESTRICTIONS TO AT LEAST MVFR IN FOG ARE
POSSIBLE FOR FKL AND DUJ THIS MORNING, WITH PROBABILITIES OF
VIS LESS THAN MVFR AROUND 40% TO 60%, THOUGH, MUCH LIKE LAST
NIGHT, FOG WILL FOLLOW AN ALL-OR-NOTHING PATTERN FOR FKL/DUJ;
TEMPORARY DENSE FOG COULD NOT BE RULED OUT. ELSEWHERE, FOG IS
POSSIBLE, BUT GENERALLY UNLIKELY (<10%) WITH A SHORTER RADIATIVE
COOLING PERIOD IN WAKE OF MID-CLOUDS.
VFR IS FAVORED FOR MOST WITH HIGH CONFIDENCE AFTER 13Z.
CLEARING MID- DECKS WILL GIVE WAY TO SCATTERED HIGH CLOUDS
TODAY, INCREASING IN COVERAGE SLIGHTLY TOWARD THE END OF THE TAF
PERIOD. WIND WILL REMAIN LIGHT TO CALM AND GENERALLY OUT OF THE
NORTHEAST WITH HIGH CONFIDENCE.
OUTLOOK...
MAINLY VFR CONDITIONS ARE FORECAST INTO TUESDAY. LOW PRESSURE
TRACKING UP THE OHIO VALLEY EVENTUALLY BRINGS RAIN CHANCES AND
RESTRICTIONS BACK TO THE LATER TUESDAY INTO WEDNESDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...CRAVEN
NEAR TERM...CRAVEN
SHORT TERM...CRAVEN
LONG TERM...CRAVEN
AVIATION...MILCAREK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page