439
FXUS61 KPBZ 241845
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
245 PM EDT THU APR 24 2025
SYNOPSIS
DRY AND VERY WARM TODAY UNDER HIGH PRESSURE. SHOWER AND
THUNDERSTORM CHANCES INCREASE FRIDAY INTO SATURDAY. ABOVE
AVERAGE TEMPERATURES EXPECTED THROUGH EARLY NEXT WEEK.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- DRY AND VERY WARM TODAY
- ELEVATED FIRE CONCERNS SOUTH OF I-80 IN PA
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HEIGHTS HAVE CONTINUED TO RISE TODAY AS SURFACE HIGH PRESSURE
HOLDS ON. DRY AND WARM CONDITIONS ARE EXPECTED TO CONTINUE
THROUGH TONIGHT. WARM ADVECTION IS RELATIVELY MINOR WITH WEAK
SOUTHERLY FLOW BUT NEARLY FULL SUN UNDER LARGELY CLEAR SKIES
WILL HELP PUSH HIGH TEMPERATURES 15 TO 20 DEGREES ABOVE NORMAL.
EFFICIENT MIXING IS EXPECTED TO LAST THROUGH THE REMAINDER OF
THE AFTERNOON. DEWPOINTS ARE EXPECTED TO DROP THROUGH THE 40S
AND END UP IN THE UPPER 30S IN SOME SPOTS. FULL SUN AND A DRY
SFC LAYER MAKE IT SEEM LIKELY THAT MANY AREAS IN THE RIVER
VALLEYS SOUTH OF I-80 COULD STRIKE 85 TODAY (70+% PROBABILITY).
NBM PROBABILITIES OF AT LEAST 85 DEGREES ARE NORTH OF 80% BOTH
IN DOWNTOWN PITTSBURGH AND AT THE AIRPORT.
WITH CONTINUED DRY WEATHER AND LOW RELATIVE HUMIDITY, THERE
EXISTS AN ELEVATED CHANCE OF FIRE SPREAD ACROSS PA SOUTH OF
I-80 TODAY. WIND IS THE NOTABLE LACKING INGREDIENT AND WILL CURB
AGGRESSIVE GROWTH BUT AN SPS FOR THE RISK HAS BEEN HOISTED FOR
MANY OF OUR PA COUNTIES.
SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/
KEY MESSAGES:
- RISK FOR SHOWERS AND STORMS INCREASES FRIDAY
- SHOWER CHANCES CONTINUE INTO SATURDAY MORNING
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AN UPPER TROUGH IS EXPECTED TO BE MOVING EASTWARD THROUGH THE
CENTRAL CONUS TODAY. A SUBTLE SHORTWAVE WILL DRAG AN ASSOCIATED
SFC LOW THROUGH THE GREAT LAKES LATE TONIGHT AND ACROSS THE
REGION FRIDAY. A WEAK FRONTAL SYSTEM DRAPED OVER THE AREA, AND
INCREASING MOISTURE IN WARM ADVECTION, WILL RETURN SHOWER
CHANCES TO THE REGION BEGINNING LATE TONIGHT.
SHOWER AND THUNDERSTORM CHANCES RISE ACROSS THE AREA FRIDAY AMID
WARM ADVECTION AND PEAK OVERNIGHT WITH THE PASSING COLD FRONT. A
LACK OF STRONG SHEAR AND UPPER-LEVEL SUPPORT LEAD TO A MUDDY
PICTURE OF DISORGANIZED SHOWERS AND THUNDERSTORMS ACROSS THE
REGION WITH A LOW THREAT OF SEVERE WEATHER. SHOWERS ARE EXPECTED
TO END FROM WEST TO EAST SATURDAY MORNING WITH RAINFALL TOTALS
LARGELY BETWEEN 0.25- 0.75 INCHES.
ENSEMBLES PROG THE COLD FRONT AS BEING NEAR/EAST OF OUR CWA
BORDERS AROUND SUNRISE SATURDAY. SATURDAY IS EXPECTED TO BE DRY,
COOLER, AND POSSIBLY BREEZY, WITH A TIGHTENED PRESSURE GRADIENT
BEHIND THE DEPARTING LOW PRESSURE AND ADVANCING HIGH PRESSURE.
LONG TERM /SUNDAY THROUGH THURSDAY/
KEY MESSAGES:
- TROUGH SPEED WILL DETERMINE TIMING OF RETURN TO ABOVE AVERAGE
TEMPS
- ACTIVE WEATHER POSSIBLE NEXT WEEK BUT DEPENDENT ON TROUGH
SPEED
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THE LONGWAVE TROUGH FINALLY PHASES WITH THE SHORTWAVE AS THE
WAVE PACKET EXITS THE EASTERN SEABOARD. CLUSTERED ENSEMBLES
CONTINUE TO SHOW A SIGNAL FOR A QUICKER AND WEAKER TROUGH
EXITING THE EASTERN SEABOARD BY SUNDAY NIGHT. DESPITE THE
INDICATION OF A SLIGHTLY QUICKER EXIT IT SEEMS UNLIKELY THAT
SIGNIFICANT HEIGHT RISES OCCUR DURING THE DAYTIME SUNDAY AND
TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL. SFC HIGH PRESSURE
IS EXPECTED TO CONTINUE DRY CONDITIONS THROUGH TUESDAY.
HEIGHTS AND TEMPERATURES ARE EXPECTED TO CONTINUE TO RISE EARLY
NEXT WEEK AS THE CENTRAL CONUS RIDGE TRANSLATES EASTWARD.
CLUSTERED ENSEMBLES CONTINUE TO STRUGGLE PAINTING A COHESIVE
PICTURE OF EXACTLY HOW QUICKLY OUR STUBBORN TROUGH KICKS
EASTWARD AWAY FROM THE EASTERN SEABOARD, WITH SEVERAL CLUSTERS
STILL SHOWING THE TROUGH CAMPED OUT SOUTH OF ATLANTIC CANADA BY
TUESDAY. MODELING CONTINUES TO HINT AT THE POSSIBILITY OF ACTIVE
WEATHER TIED TO A NEW UPPER TROUGH CROSSING THE CENTRAL CONUS
DURING THE MIDDLE OF NEXT WEEK BUT THE TIMING OF THIS WILL
GREATLY DEPEND ON THE AMPLITUDE AND SPEED OF THE ENTIRE WAVE
PACKET WHICH LARGELY REMAINS IN QUESTION.
AVIATION /19Z THURSDAY THROUGH TUESDAY/
HIGH PRESSURE WILL ENSURE VFR CONDITIONS THROUGH TONIGHT. WINDS
REMAIN LIGHT AND PREDOMINANTLY OUT OF THE SOUTH TO SOUTHEAST.
CAN'T ENTIRELY RULE OUT A COUPLE WIDELY ISOLATED SHOWERS THIS
EVENING, THOUGH CONFIDENCE REMAINS TOO LOW AND COVERAGE TOO
SPARSE TO WARRANT A MENTION AT ANY SPECIFIC SITE (THOUGH BEST
CHANCE CONTINUE TO FOCUS IN EASTER OHIO, AROUND ZZV).
BETTER SHOWER AND THUNDERSTORM CHANCES RETURN AFTER 06Z FRIDAY
WITH INCREASING MID-LEVEL CLOUDS AS LOW PRESSURE APPROACHES. A
GREATER COVERAGE IN SHOWERS OVERSPREADS THE AREA FRIDAY MORNING,
WITH CEILINGS DROPPING TO LOW-END VFR OR POSSIBLY DIPPING TO
MVFR AT ZZV AND BVI BEFORE THE END OF THE TAF PERIOD.
OUTLOOK...
SHOWER AND THUNDERSTORM CHANCES WITH RESTRICTIONS ACCOMPANY THE
PASSAGE OF A LOW PRESSURE SYSTEM FRIDAY INTO SATURDAY MORNING.
THERE IS HIGH CONFIDENCE IN VFR AND DRY WEATHER DEVELOPING BY
SUNDAY UNDER DRIER NORTHWEST FLOW AND BUILDING HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...22/AK
NEAR TERM...AK
SHORT TERM...AK
LONG TERM...AK
AVIATION...CERMAK/RACKLEY
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