305
FXUS61 KPBZ 291227
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
827 AM EDT SAT MAR 29 2025
SYNOPSIS
MAINLY DRY AND WARM TODAY. SHOWER AND STORM THREAT INCREASES
SUNDAY INTO MONDAY, AHEAD OF A PASSING COLD FRONT. MUCH COOLER
BY TUESDAY.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- SLIGHT RAIN SHOWER CHANCES BUT LARGELY DRY
- WELL ABOVE AVERAGE TEMPERATURES
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RADAR RETURNS HAVE INCREASED IN COVERAGE THIS MORNING AS A WEAK
MID-LEVEL WAVE AND FAVORABLE JET DYNAMICS OVERLAP, BUT SUB-CLOUD
DRY AIR IS PREVENTING MOST OF THIS FROM REACHING THE GROUND WITH
SURFACE DEW POINT DEPRESSIONS OF 15-20 DEGREES. A FEW OBS OF
LIGHT RAIN HAVE BEEN REPORTED, BUT WITHOUT SUFFICIENT SATURATION
OF THE LOWER LEVELS AND WEAK LIFT, NOT EXPECTING MUCH MORE THAN
A FEW HUNDREDTHS OF AN INCH FROM THIS STUFF THIS MORNING AND IT
SHOULD EXIT BY NOONTIME OR SO. THE SURFACE WARM FRONT AND BEST
LOW LEVEL CONVERGENCE IS ANALYZED OFF TO OUR NORTH, AND LOCALLY
OUR 12Z SOUNDING SHOWS INCREASED MOISTURE IN THE 700-550 MB
LAYER SUPPORTING THE THICKENING OF MID-LEVEL CLOUD COVERAGE THAT
WILL PERSIST THROUGH THE DAY TODAY.
500MB HEIGHTS WILL SLOWLY RISE AS AN AREA OF HIGH PRESSURE
ALOFT DRIFTS OVER THE ATLANTIC OFF THE SOUTHEASTERN US COAST. AS
THE RIDGE AMPLIFIES, THIS WILL HELP TO PUSH THE WARM FRONT
FURTHER NORTH, ROBBING THE AREA OF ANY LOW-LEVEL FORCING. A
SCATTERED SHOWER IS POSSIBLE OVER THE I-80 CORRIDOR TODAY WITH A
CROSSING SHORTWAVE TROUGH RIDING OVER TOP OF THE RIDGE.
HOWEVER, THE WAVE WILL BE WEAK AND MOISTURE WILL STILL BE
LACKING.
THE REGION WILL BE WELL INTO THE WARM SECTOR TODAY, SO EXPECT
HIGH TEMPERATURES 20 TO 25 DEGREES ABOVE NORMAL. CLOUD COVERAGE
WILL BE THE ONLY THING HAMPERING AFTERNOON HIGH TEMPERATURES AS
STOUT SOUTHWEST FLOW PROMOTES WARM ADVECTION. NBM PROBS FOR MAXT
>75 ARE 60 TO 100% SOUTH OF I-80, SO WILL BUMP HIGH
TEMPERATURES ABOVE THE NBM MEAN POINTING TOWARD LOCATIONS FROM
PITTSBURGH AND SOUTH FLIRTING WITH 80 DEGREES.
SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/
KEY MESSAGES:
- SHOWER/STORM CHANCES INCREASE SUNDAY AND MONDAY
- UNCERTAINTY TO SEVERE THREAT AND TIMING OF FRONT
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RIDGE WILL SLOWLY BREAK DOWN ON SUNDAY AS A SHORTWAVE TROUGH,
STREAKING NORTHEASTWARD IN THE SOUTHWESTERLY FLOW ALOFT, WILL
CROSS THE REGION SUNDAY AFTERNOON. EXPECT AN AREA OF SHOWERS TO
DEVELOP AHEAD OF THE WAVE AND SPREAD ACROSS THE UPPER OHIO
VALLEY SUNDAY MORNING. SHOWERS WILL LIKELY CONTINUE THROUGH MOST
OF THE DAY AS A PLUME OF DEEP MOISTURE WILL DRIVE NORTHEASTWARD
ON THE WESTERN FLANK OF THE EASTWARD DRIFTING RIDGE. DONT SEE
MUCH ATMOSPHERIC DESTABILIZATION UNTIL LATE IN THE DAY, SO
WOULD THINK THE RISK FOR THUNDERSTORMS WOULD INCREASE DURING THE
LATE AFTERNOON AND THROUGH THE EVENING. THE INSTABILITY IS NOT
OVERLY IMPRESSIVE (200-500 J/KG) WITH THE STRONGEST BUOYANCY
OVER PORTIONS OF EASTERN OHIO. THE HEADACHE WILL BE THAT AN
UPPER LEVEL DRY SLOT WILL PASS OVER THE REGION SUNDAY EVENING
WHICH MAY LEAD TO A DECREASE IN ACTIVITY FOR A PORTION OF THE
EVENING AND OVERNIGHT HOURS.
THE BIG QUESTIONS COME SUNDAY NIGHT AND MONDAY MORNING. THE COLD
FRONTS EASTERN PROGRESSION WILL SLOW SUNDAY NIGHT AS THE RIDGE
WILL NOT EASILY GIVE WAY AND THE MAIN TROUGH AXIS WILL BE WELL
TO THE NORTHWEST OF THE SURFACE BOUNDARY. SINCE WE EXPECT MUCH
OF THE CONVECTION TO BE DRIVEN BY THE SURFACE FRONT, IT MAY BE
TOO FAR WEST TO HAVE THAT MUCH OF AN INFLUENCE UNTIL VERY LATE
SUNDAY NIGHT OR EVEN MONDAY. THE OTHER ISSUE IS THAT MOST, IF
NOT ALL OF THE MODEL DATA, IS IN AGREEMENT THAT THE ATMOSPHERE
WILL STABILIZE SUNDAY NIGHT, WHICH COULD FORCE THE CONVECTION
ALONG THE FRONT TO BE FORCED TO AN AREA WITH HIGHER BUOYANCY.
MODELS ARE PORTRAYING A SCENARIO WHERE THE CONVECTION OVER
WESTERN OHIO WILL DIVE SOUTHEASTWARD TOWARD KY AN TN, WHERE MUCH
MORE UNSTABLE AIR WILL REST. THIS COULD LEAD TO AN OUTCOME
WHERE WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA GET
CLIPPED WITH STRONGER STORMS. STILL A LOT OF UNCERTAINTY ON THE
THREAT FOR STRONG TO SEVERE STORMS SUNDAY NIGHT AND WHERE THEY
MAY IMPACT.
FRONT WILL FINALLY BEGIN TO MOVE EASTWARD AT A FASTER PACE
MONDAY MORNING AS THE MAIN TROUGH AXIS WILL DIG INTO THE MIDWEST
AND GIVE THE FRONT A PUSH. THE RISK FOR SHOWERS AND STORMS WILL
CONTINUE THROUGH MONDAY, AS THE BOUNDARY FINALLY DOES EXIT TO
THE EAST MONDAY EVENING. MODELS ARE SHOWING SOME DESTABILIZATION
ON MONDAY AHEAD OF THE BOUNDARY, SO THE RISK FOR STRONG TO
SEVERE STORMS WILL CONTINUE, BUT UNCERTAINTY REMAINS HIGH.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL BOTH SUNDAY AND
MONDAY.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
KEY MESSAGES:
- A COOL-DOWN IS MOST LIKELY MONDAY NIGHT INTO TUESDAY.
- ABOVE AVERAGE TEMPERATURES WEDNESDAY THROUGH FRIDAY.
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DRY AND COOLER CONDITIONS ARE EXPECTED TUESDAY WITH ANOTHER WARM
UP BEGINNING ON WEDNESDAY. ABOVE NORMAL TEMPERATURES ARE THEN
EXPECTED THROUGH THE END OF THE WEEK WITH AN UNSETTLED WEATHER
PATTERN RETURNING ON WEDNESDAY.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
RECENT TREND IN ACARS SOUNDINGS IS SHOWING MOISTENING OF THE
MID-LEVELS SUPPORTING THE INCREASE IN CLOUD COVERAGE AND CIGS
JUST BELOW 10KFT WHICH WILL LIKELY HOLD ON FOR MOST OF THE DAY
TODAY. VFR IS EXPECTED TO BE THE RULE THROUGH TONIGHT. THE
POSSIBLE EXCEPTION REMAINS THE LOW CHANCE (~30%) FOR ISOLATED
SHOWERS ACROSS THE REGION TODAY TRAVELING ALONG A SPOKE OF MID-
LEVEL PVA; THE BEST CHANCE FOR THIS WOULD BE AT FKL/DUJ. HI RES
MODELS ARE BOUNCING BACK AND FORTH, BUT HAVE SOME EXTENT OF
DEVELOPMENT, SO HAVE INTRODUCED A PROB30 AT THOSE TWO SITES THIS
AFTERNOON.
LLWS CONCERNS REMAIN AT ALL PORTS AS DECOUPLED SURFACE WINDS
REMAIN LIGHT UNDERNEATH AN IMPRESSIVE 40-60KT LOW-LEVEL JET.
LLWS CONCERNS BEGIN TO ERODE NEAR 15Z AS THE CORE OF THE JET
FRACTURES. OUR LOW-LEVEL INVERSION IS LIKELY TO BREAK NEAR THE
SAME TIME AND KICK OFF GUSTY WIND (NEAR 30 KTS) MIXING DOWN TO
THE SURFACE FOR MUCH OF THE AFTERNOON HOURS.
AS A DIGGING CENTRAL CONUS TROUGH SHUNTS THE MID-LEVEL RIDGE
OFF TO THE EAST TONIGHT, BACKING SOUTHWESTERLY FLOW WILL
PROMOTE MOISTURE ADVECTION SATURATING THE PROFILE AND LOWERING
CIGS INTO SUNDAY MORNING. MVFR PROBS INCREASE TOWARD THE END OF
THE CURRENT TAF PERIOD, AND IT'S POSSIBLE THAT RESTRICTIONS
INITIALLY COME FROM VIS AS THE COLUMN SATURATES AND CLOUD BASES
THEN LOWER.
OUTLOOK...
RESTRICTIONS IN RAIN ARE LIKELY LATE SATURDAY NIGHT
INTO EARLY SUNDAY AFTERNOON AS AN UPPER LEVEL TROUGH MOVES
ACROSS THE REGION. SHOWER AND THUNDERSTORM POTENTIAL INCREASES
SUNDAY NIGHT AND MONDAY WITH THE APPROACH AND PASSAGE OF A COLD
FRONT. VFR RETURNS TUESDAY UNDER HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...22
NEAR TERM...22/MLB
SHORT TERM...22
LONG TERM...22
AVIATION...MLB/AK
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