013
FXUS61 KPBZ 211756
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
156 PM EDT TUE APR 21 2026
WHAT HAS CHANGED
NO MAJOR CHANGES WERE MADE TO THE FORECAST.
KEY MESSAGES
1) DRY, SEASONABLE WEATHER TODAY WITH CHANCE FOR SHOWERS TONIGHT.
2) CONTINUED WARMER WITH PERIODIC SHOWER CHANCES MID WEEK INTO THE
WEEKEND.
DISCUSSION
KEY MESSAGE 1...
DRY WEATHER IS EXPECTED FOR THE REMAINDER OF TODAY, WITH SOME
INCREASE IN HIGH LEVEL CLOUDS IN WARM ADVECTION. HIGHS ARE MORE
SEASONABLE TODAY.
A SHORTWAVE TROUGH AND WEAKENING SURFACE COLD FRONT IS EXPECTED TO
APPROACH AND CROSS THE REGION TONIGHT INTO TOMORROW MORNING WITH
SHOWERS LIKELY. MINIMAL INSTABILITY (MU CAPE LESS THAN 500 J/KG)
COULD RESULT IN A COUPLE OF EMBEDDED THUNDERSTORMS TONIGHT, WITH
THIS POTENTIAL SHIFTING SOUTH OF PITTSBURGH DURING THE DAY TOMORROW.
KEY MESSAGE 2...
DRY AND WARMER WEATHER IS EXPECTED THURSDAY INTO EARLY FRIDAY AS A
RIDGE BUILDS IN. THE RIDGE SHOULD FLATTEN AND EXIT THE AREA LATER
FRIDAY AS A MARGINALLY ZONAL TYPE FLOW SETTING UP ACROSS MUCH THE
CONUS INTO THE WEEKEND. PERIODIC SHORTWAVES EMBEDDED IN THE FLOW
SHOULD RETURN SHOWER CHANCES TO THE REGION FRIDAY AFTERNOON INTO THE
WEEKEND. AT THIS TIME, IT APPEARS THE MOST LIKELY TIME FOR SHOWERS
IS WITH A SHORTWAVE AND SURFACE WARM FRONT APPROACH AND PASSAGE
FRIDAY NIGHT, FOLLOWED BY A SURFACE COLD FRONT ON SATURDAY. MODEL
ENSEMBLE DATA INDICATE RELATIVELY LOW INSTABILITY AND SHEAR
PARAMETERS, WITH LOW CHANCES FOR THUNDER AND SEVERE STORMS.
LINGERING SHOWER CHANCES CONTINUE, ESPECIALLY EARLY SUNDAY, WITH
ANOTHER WEAK SHORTWAVE PASSAGE.
A WARMING TREND IS EXPECTED FROM WEDNESDAY THROUGH FRIDAY, WITH
HIGHS EVENTUALLY REACHING AROUND 15 DEGREES ABOVE AVERAGE. A RETURN
TO MORE SEASONABLE TEMPERATURES IS EXPECTED AFTER THE PASSAGE OF THE
SATURDAY COLD FRONT.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
PASSING HIGH CLOUDS AND SW WINDS GUSTING TO AROUND 20 KNOTS
CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. A COLD FRONT
DROPS SOUTH THROUGH THE AREA OVERNIGHT, BRINGING RAIN SHOWERS TO
AREA TERMINALS PRIMARILY IN THE 03Z-12Z TIMEFRAME. A COLD FRONT
ENDS SHOWER ACTIVITY AND SHIFTS WINDS TO NW'LY EARLY WEDNESDAY
MORNING. ENSEMBLE PROBABILITIES FOR MVFR CEILINGS INCREASE TO
70-90 PERCENT ACROSS MUCH OF THE REGION FOLLOWING THE FRONTAL
PASSAGE, WITH ONSET TIME FOR THESE LOWER CIGS FALLING ROUGHLY
AROUND 11Z-15Z. PROBABILITIES FOR IFR ARE ALSO HIGH (70-90%) AT
FKL/DUJ, BUT DECREASE SOUTH OF I-80 AND ARE LESS THAN 20% AT ALL
OTHER TERMINALS. IMPROVEMENT BACK TO VFR OCCURS FROM NORTH TO
SOUTH STARTING AT THE TAIL END OF THE 24-HOUR TAF CYCLE, WITH
ALL TERMINALS EXPECTED TO BE BACK TO VFR BY ~21Z WED.
OUTLOOK...
VFR RETURNS WEDNESDAY AFTERNOON/EVENING AND IS FAVORED
THEREAFTER THROUGH THE END OF THE WORK WEEK. ANOTHER COLD FRONT
BRINGS RAIN CHANCES AND RESTRICTIONS BACK TO THE AREA LATE
FRIDAY INTO THE WEEKEND.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...WM/LUPO
AVIATION...CERMAK
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