838
FXUS61 KPBZ 050754
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
354 AM EDT SAT APR 5 2025
SYNOPSIS
AN ACTIVE PATTERN CONTINUES THROUGH THE WEEKEND WITH MULTIPLE
ROUNDS OF SHOWERS AND THUNDERSTORMS. SEVERE STORMS ARE POSSIBLE
TODAY. MUCH COLDER TEMPERATURES NEXT WEEK.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF THE REGION.
- RISK FOR SHOWERS AND STORMS CONTINUE TODAY WITH A COLD FRONT.
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UPPER LEVEL HEIGHTS WILL BEGIN TO SLOWLY TUMBLE THIS MORNING AS
A SHORTWAVE TROUGH MOVE ACROSS OHIO. THE SURFACE COLD FRONT
WILL LAG BEHIND THE MORNING WAVE, WITH THE BOUNDARY MOVING INTO
WESTERN OHIO AS THE MORNING PROGRESSES. THE FRONT WILL TAKE THE
ENTIRE DAY TO MOVE ACROSS THE REGION AS MUCH OF THE UPPER LEVEL
SUPPORT WILL WEAKEN AS IT MOVES NORTHEASTWARD IN THE SOUTHWEST
FLOW ALOFT. UNTIL THE COLD FRONT ARRIVES, THE AREA WILL REMAIN
IN THE WARM SECTOR WHICH SHOULD WORK TO LIMIT CONVECTION.
INSTABILITY WILL BE LIMITED AGAIN TODAY AS WELL. COULD SEE A
BREAK IN WIDESPREAD ACTIVITY FOR AWHILE AFTER THE MORNING
CONVECTION MOVES THROUGH. THEN THINGS RAMPING BACK UP AS THE
COLD FRONT APPROACHES.
EVEN THOUGH WE WILL HAVE CLOUDS AND RAIN, TEMPERATURES WILL BE
WELL ABOVE NORMAL TODAY.
SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/
KEY MESSAGES:
- A COLD FRONT ON SUNDAY WILL FINALLY BRING AN END TO THE HEAVY
RAINFALL THREAT.
- MUCH COLDER MONDAY WITH LATE DAY RAIN/SNOW SHOWERS.
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SHOWERS AND SOME THUNDERSTORMS WILL CONTINUE TONIGHT AND EARLY
SUNDAY AS LOW PRESSURE CROSSES, BUT THE STALLED FRONT REMAINS.
RAPID HEIGHT FALLS ON SUNDAY WILL FINALLY SHUNT THE SURFACE
RIDGE OVER THE SOUTHEAST AND ALLOW A COLD FRONT TO CROSS THE
AREA BY SUNDAY NIGHT/EARLY MONDAY -- FINALLY BRINGING AN END TO
WIDESPREAD RAINFALL. AS TEMPERATURES COOL BEHIND THE FRONT,
LINGERING PRECIPITATION MAY BRIEFLY TRANSITION TO SNOW FOR AREAS
NORTH OF PITTSBURGH AND IN THE RIDGES SUNDAY AFTERNOON AND
OVERNIGHT. GIVEN THE WARM/WET GROUND, ANY ACCUMULATION WILL BE
MINIMAL.
STRONG COLD AIR ADVECTION AND NORTHWEST FLOW MONDAY WILL PUSH
HIGH TEMPERATURES BACK DOWN TO BELOW NORMAL VALUES. SOME BRIEF
IMPROVEMENT IN OUR WEATHER IS POSSIBLE MONDAY AFTERNOON BEFORE A
SECOND COLD FRONT WILL BRING THE RISK FOR PRECIPITATION LATE IN
THE DAY.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
KEY MESSAGES:
- IMPRESSIVE COLD SHOT TUESDAY.
- DRY WEATHER BRIEFLY RETURNS MIDWEEK BEFORE ADDITIONAL
PRECIPITATION CHANCES BY LATE WEEK.
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COLDEST AIR WILL MOVE THROUGH THE REGION ON TUESDAY. SCATTERED
SNOW SHOWERS ARE POSSIBLE IN THE NORTHWEST FLOW, MAINLY OVER THE
I-80 CORRIDOR AND THE RIDGES. HIGH TEMPERATURES TUESDAY WILL BE
15 TO 20 DEGREES BELOW NORMAL.
UPPER TROUGHING IS EXPECTED TO PERSIST THROUGH MIDWEEK,
RESULTING IN BELOW NORMAL TEMPERATURES. DRY WEATHER LOOKS TO
RETURN BRIEFLY MIDWEEK WITH HIGH PRESSURE BEFORE ADDITIONAL RAIN
CHANCE WITH A SYSTEM LATE WEEK.
AVIATION /08Z SATURDAY THROUGH WEDNESDAY/
LARGELY VFR SHOWERS UNDER VFR DECKS HAVE CONTINUED NORTH OF I-70
THIS EVENING. SOUTH OF I-70, PROXIMITY TO A SFC TROUGH AND MORE
ABUNDANT MOISTURE HAS KEPT CIGS BELOW 1000FT. THIS STATUS QUO
IS LARGELY EXPECTED TO HOLD OVERNIGHT UNTIL AFTER 06Z WHEN
FRONTS AND TROUGHS BEGIN TO SURGE NORTH WITH A SFC LOW ADVANCING
THROUGH THE OH VALLEY.
THIS MOVEMENT WILL LIKELY SPARK ANOTHER ROUND OF SHOWERS AND
EMBEDDED THUNDERSTORMS ACROSS THE REGION THROUGH THE REMAINDER
OF THE OVERNIGHT HOURS AND INTO THE MORNING. MODEL UNCERTAINTY
IN EXACT PLACEMENT AND TIMING REMAINS HIGH. THE BEST FORCING
REMAINS CLOSER TO THE LOW AND A LOW-LEVEL JET TO THE NORTH AND
WEST OF PIT. THIS MAKES STORMS FAR LESS OF A CERTAINTY FOR HLG
AND MGW WHERE VCTS HAS BEEN INCLUDED IN THE TAFS.
AS CONVECTIVE ACTIVITY SURGES NORTH CIGS IN THE SOUTH ARE
EXPECTED TO RISE AND MANY MODELS SUPPORT VFR CONDITIONS
ESTABLISHING THEMSELVES IN THE WARM SECTOR BENEATH THE SURGING
WARM FRONT. HOW FAR THIS CLEARING GETS REMAINS A LARGER QUESTION
WITH MODELS SHOWING THE LINE NEAR/JUST SOUTH OF PIT/AGC.
OUTLOOK... THE UPPER OHIO RIVER VALLEY REMAINS POSITIONED
BETWEEN A MOUNTAIN WEST TROUGH AND EAST COAST RIDGE THAT WILL
FOSTER MULTIPLE ROUNDS OF MODERATE TO LOCALLY HEAVY RAIN AND
THUNDERSTORMS THROUGH SUNDAY MORNING. TIMING AND SHAPE OF EACH
PASSING SHORTWAVE TROUGH REMAINS VARIABLE, WHICH CAN ALTER THE
AXIS OF HEAVIEST PRECIPITATION AND LOWEST CLOUDS. CONTINUED
LIMITED WINDOWS OF VFR AND DRY CONDITIONS ARE EXPECTED THROUGH
THE PERIOD AS THE PATTERN CONTINUES TO FAVOR BOUTS OF MVFR/IFR
RESTRICTIONS IN ANY HEAVIER RAIN SHOWERS AND OCCASIONAL
THUNDERSTORMS.
HEAVY RAIN IS LIKELY TO BREAK SUNDAY INTO MONDAY AS AN UPPER-
LEVEL TROUGH IMPINGES UPON THE AREA, SWITCHING US OVER TO A
COOLER PATTERN FEATURING PERIODIC RAIN/SNOW CHANCES. THIS
PATTERN SWITCH LIKELY MEANS A CONTINUED PERIOD OF RESTRICTIONS.
HYDROLOGY
THE POTENTIAL FOR HEAVY RAINFALL CONTINUES THROUGH SUNDAY. AT
THIS TIME, AREAS ACROSS OHIO HAVE THE POTENTIAL TO SEE THE
HEAVIEST RAINFALL, WHERE A FLOOD WATCH CONTINUES. CURRENT NBM
VALUES INDICATE A 40 TO 60 PERCENT CHANCE OF 2 INCHES OF RAIN
OVER A 72 HR PERIOD IN THIS REGION. THE EXACT LOCATION OF THE
HEAVIEST RAIN WILL DEPEND ON THE POSITION OF A QUASI-STATIONARY
SURFACE FRONT AND HOW MUCH CONVECTION DEVELOPS TODAY AND SUNDAY.
PRECIPITABLE WATER IS EXPECTED TO REMAIN ELEVATED THROUGH
SUNDAY, WITH SOME PERIODIC JET ENHANCED ASCENT. EVEN AFTER THE
HEAVY RAIN POTENTIAL ENDS, RIVER LEVELS WILL LIKELY REMAIN
ELEVATED FOR A FEW DAYS.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...FLOOD WATCH THROUGH SUNDAY MORNING FOR PAZ021-029-031-073>076.
OH...FLOOD WATCH THROUGH SUNDAY MORNING FOR OHZ039-040-048>050-
057>059-068-069.
WV...FLOOD WATCH THROUGH SUNDAY MORNING FOR WVZ001>004-012-021-509-
510.
SYNOPSIS...22
NEAR TERM...22
SHORT TERM...RACKLEY/22
LONG TERM...RACKLEY/22
AVIATION...AK
HYDROLOGY...
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