605
FXUS61 KPBZ 020809
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
409 AM EDT WED APR 2 2025
SYNOPSIS
RAIN AND THUNDERSTORMS RETURN TODAY THROUGH THE END OF THE WEEK.
A FEW STORMS COULD BE STRONG. MULTIPLE DAYS OF RAIN COULD LEAD
TO LOCAL FLOODING ISSUES. A FLOOD WATCH REMAINS IN EFFECT FOR
EASTERN OHIO.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- SHOWERS AND THUNDERSTORMS RETURN WITH A WARM FRONT THIS
AFTERNOON AND A COLD FRONT TONIGHT.
- LOCALLY HEAVY RAINFALL AND SEVERE STORMS ARE POSSIBLE.
- A FLOOD WATCH IS IN EFFECT FOR PORTIONS OF EASTERN OHIO.
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STRONG SURFACE LOW PRESSURE IS EXPECTED TO TRACK ACROSS THE
PLAINS AND UPPER MIDWEST REGION ON WEDNESDAY, AS A WARM FRONT
EXTENDING EAST OF THE LOW LIFTS ACROSS THE UPPER OHIO VALLEY
REGION. A VORTICITY MAXIMUM IN SW FLOW ALOFT WILL CROSS THE
REGION AT THE SAME TIME, SUPPORTING A WAVE OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. INSTABILITY WILL BE ELEVATED,
WITH A STRONG INVERSION PROGGED ABOVE THE SURFACE AS 850MB
TEMPERATURES WARM TO ABOVE 10C. DESPITE MEAGER MUCAPE (AROUND
500 J/KG), STRONG SHEAR IN PLACE WILL SUPPORT THE POTENTIAL FOR
HAIL IN STORMS DURING THE INITIAL WAVE THIS AFTERNOON. WITH THE
DEPARTURE OF THE FIRST WAVE, A MAINLY DRY EVENING IS EXPECTED
UNDER WEAK SUBSIDENCE BEHIND THE AFOREMENTIONED VORT MAX.
HOWEVER, GUSTY NON-THUNDERSTORM WINDS OUT OF THE SOUTHEAST WILL
CONTINUE, ESPECIALLY IN AREAS JUST WEST OF THE LAUREL HIGHLANDS
AND NORTHERN WV RIDGES WHERE DOWNSLOPING ENHANCEMENT COULD
SUPPORT GUSTS OVER 40 MPH. DESPITE EVEN STRONGER WINDS ALOFT,
WIND DIRECTION AND INVERSION HEIGHTS STILL APPEAR SUBOPTIMAL FOR
ANYTHING STRONGER REACHING THE SURFACE.
SHOWERS AND THUNDERSTORMS WILL INCREASE AGAIN OVERNIGHT AS A
COLD FRONT AND SHORTWAVE TROUGH APPROACH. SIGNIFICANT SHEAR IS
PROGGED TO STILL BE IN PLACE AS THE FRONT APPROACHES. THE
POTENTIAL FOR SEVERE STORMS WILL INCREASE LATE AS THE FRONT
APPROACHES, THOUGH THE AVAILABLE INSTABILITY COULD BE A
LIMITING FACTOR. THE BEST CHANCE FOR SUFFICIENT SURFACE-BASED
INSTABILITY TO SUPPORT SEVERE WEATHER WILL BE OVER EASTERN OHIO.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
KEY MESSAGES:
- SHOWERS AND THUNDERSTORMS CONTINUE THROUGH THE REST OF THE
WEEK AS A FRONT STALLS NEAR THE LOCAL AREA.
- SOME STORMS COULD BE STRONG TO SEVERE ON THURSDAY.
- A FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF EASTERN OHIO.
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THE FORWARD PROGRESS OF THE FRONT IS EXPECTED TO SLOW ON THURSDAY
AS IT BECOMES MORE PARALLEL TO THE SOUTHWESTERLY DEEP-LAYER
FLOW. UNCERTAINTY IN THE EXACT POSITION OF THE FRONT EXISTS,
WHICH WILL IMPACT AREAS WHERE HEAVY RAIN FALLS AND ALSO WHICH
AREAS HAVE THE POTENTIAL FOR SEVERE STORMS. AT THIS TIME, THE
SOUTHERN HALF OF THE AREA (AND ESPECIALLY SOUTH OF I-70) IS
FAVORED FOR HAVING A MORE CONDUCIVE ENVIRONMENT FOR ORGANIZED
DEEP CONVECTION AND SEVERE POTENTIAL. THIS CONTINUES TO BE
HIGHLIGHTED IN THE STORM PREDICTION CENTER'S SLIGHT RISK AREA
(LEVEL 2 OF 5) GENERALLY SOUTH OF A LINE FROM ZANESVILLE, OH TO
INDIANA, PA. THE FRONT IS PROGGED TO DRIFT SOUTH OF THE AREA
LATE THURSDAY OR THURSDAY NIGHT, WHICH WILL LEAD TO A DECREASE
IN POPS FROM NORTH TO SOUTH DURING THAT TIME AS THE PRIMARY
AXIS OF SHOWERS AND THUNDERSTORMS SHIFTS SOUTH OF THE MASON-
DIXON. THIS IS ALSO THE WINDOW WHEN THE STRONGEST UPPER FORCING
FOR LARGE-SCALE ASCENT EXITS THE REGION, FURTHER SUPPORTING A
BRIEF DECREASE IN HEAVY RAIN AND THUNDERSTORM POTENTIAL
(ESPECIALLY NORTH OF I-70) DURING THE DAY FRIDAY.
YET ANOTHER SURFACE LOW IS THEN EXPECTED TO TRACK NE OUT OF THE
MISSISSIPPI VALLEY REGION FRIDAY NIGHT, RETURNING THE FRONT
NORTHWARD INTO THE LOCAL AREA. SHOWERS AND THUNDERSTORMS ONCE
AGAIN INCREASE IN COVERAGE AS THE FRONT AND SURFACE LOW MOVE
ACROSS THE UPPER OHIO VALLEY REGION FRIDAY NIGHT INTO EARLY
SATURDAY. THE SEVERE WEATHER POTENTIAL SHOULD BE LIMITED DUE TO
WEAK INSTABILITY, HOWEVER LOCALLY HEAVY RAIN AND SUBSEQUENT
FLOODING POTENTIAL WILL RETURN.
LONG TERM /SATURDAY THROUGH TUESDAY/
KEY MESSAGES:
- SHOWERS/THUNDERSTORMS WITH POTENTIAL FOR HEAVY RAINFALL
CONTINUE THROUGH SATURDAY NIGHT.
- A FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF EASTERN OHIO
THROUGH SATURDAY NIGHT.
- A COLD FRONT MOVES THROUGH SUNDAY, BRINGING AN END TO THE
HEAVY RAIN AND STORM THREAT.
- COLDER NEXT WEEK WITH LIGHTER RAIN/SNOW CHANCES EACH DAY.
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SHOWERS AND THUNDERSTORMS CONTINUE THROUGH THE DAY SATURDAY AS
THE SURFACE LOW TRACKS THROUGH THE AREA, YET IS STILL UNABLE TO
EFFECTIVELY MOVE THE STALLED FRONTAL BOUNDARY. HOWEVER, ON
SUNDAY A LARGE UPPER LOW PUSHING EASTWARD ACROSS CANADA IS
FINALLY ABLE TO SHUNT THE SURFACE RIDGE THAT HAD BEEN FIRMLY
PLANTED OVER THE SOUTHEAST CONUS COAST. THIS IS FINALLY ABLE TO
SHIFT THE PATTERN ENOUGH TO ALLOW A COLD FRONT TO ADVANCE
THROUGH THE AREA AND OFF TO THE EAST, BRINGING AN END TO THE
HEAVY RAIN AND STORM POTENTIAL BY SUNDAY NIGHT. AN UPPER TROUGH
IS THEN EXPECTED TO PERSIST ACROSS THE NE CONUS EARLY NEXT WEEK,
RESULTING IN COOLER TEMPS AND DAILY RAIN/SNOW CHANCES, ALBEIT
NOT NEARLY AS INTENSE AS WHAT WE'RE EXPERIENCING THIS WEEK.
AVIATION /08Z WEDNESDAY THROUGH SUNDAY/
HIGH CONFIDENCE VFR THROUGH 14Z WEDNESDAY UNDER THE INFLUENCE OF
HIGH PRESSURE SE OF THE REGION. AN APPROACHING UPPER LEVEL TROUGH
FROM THE WEST WILL INCREASE AREA CIRRUS AND SLOWLY INTRODUCE LOWER
MID LEVEL DECKS. TIGHTENING OF THE SURFACE GRADIENT BETWEEN 13Z-18Z
WEDNESDAY WILL FAVOR 20-30KT ESE WIND GUSTS THROUGH THE END OF THE
TAF PERIOD, WITH POTENTIAL (20-30%) FOR 35-40KT GUSTS AT DOWNSLOPE
TERMINAL LOCATIONS (LBE/DUJ).
PASSAGE OF A WARM FRONT BETWEEN 17Z-23Z WEDNESDAY IS EXPECTED TO
GENERATE A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS, WITH MOISTURE
CONVERGENCE AIDING MAINLY MVFR CIG GENERATION. CONFIDENCE IS FAIRLY
HIGH ON THE TIMING, WITH ANY THUNDERSTORM DURATION LIKELY LIMITED TO
2 HOURS. DURING THIS WARM FRONTAL PASSAGE, FKL AND DUJ ARE FORECAST
TO DROP DOWN TO THE LOWER END OF MVFR (BETWEEN 1000 - 20000 FEET).
BY 00Z, RESTRICTIONS WILL BE TEMPORARILY LIFTED AT ALL TERMINALS. BY
06Z ON THURSDAY, A LINE OF SHOWERS AND THUNDERSTORMS AHEAD OF A COLD
FRONT IS EXPECTED TO ENTER THE REGION AND START DROPPING CEILING
HEIGHTS IN EASTERN OHIO.
OUTLOOK...
SHOWERS AND THUNDERSTORMS WILL CROSS THE REGION THURSDAY
MORNING INTO THE EARLY AFTERNOON AHEAD OF AN ADVANCING COLD FRONT.
ONCE THE LINE OF SHOWERS IS THROUGH THE AREA EARLY TOMORROW
EVENING, THERE MAY BE A BRIEF PERIOD OF LIFTED CEILING
RESTRICTIONS. THE FRONT WILL STALL NEAR THE REGION BY LATE
TOMORROW NIGHT.
THIS WILL BRING A CONTINUED ACTIVE WEATHER PATTERN AS MULTIPLE
UPPER LEVEL WAVES ARE FORECAST TO OVERRUN THE OHIO VALLEY
REGION. EXPECT MULTIPLE PERIODS OF HEAVIER RAIN AND FAIRLY
WIDESPREAD RESTRICTIONS THROUGH THE WEEKEND.
HYDROLOGY
THE POTENTIAL FOR HEAVY RAINFALL WILL EXIST BEGINNING TONIGHT
AND CONTINUING INTO SUNDAY. AT THIS TIME, AREAS ACROSS OHIO HAVE
THE POTENTIAL TO SEE THE HEAVIEST RAINFALL, WHERE A FLOOD WATCH
HAS BEEN ISSUED. CURRENT NBM VALUES INDICATE A 60 PERCENT
CHANCE OR GREATER OF AT LEAST 2 INCHES OF RAIN OVER A 72 HR
PERIOD IN THIS REGION, WITH LESSER PROBABILITIES FURTHER EAST.
THE EXACT LOCATION OF HEAVY RAIN WILL DEPEND ON THE POSITION OF
A QUASI STATIONARY SURFACE FRONT. 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. CURRENT
ENSEMBLE RIVER FORECAST PROJECTIONS ALSO FOCUS THE MOST
SIGNIFICANT RIVER RISES ACROSS OHIO.
WILL MONITOR FURTHER TRENDS FOR ANY FUTURE ADJUSTMENTS TO THE
WATCH.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...FLOOD WATCH FROM THIS EVENING THROUGH SUNDAY MORNING FOR
OHZ039-040-048-049-057>059-068-069.
WV...NONE.
SYNOPSIS...CERMAK/HEFFERAN
NEAR TERM...CERMAK/HEFFERAN
SHORT TERM...CERMAK/WM
LONG TERM...CERMAK/WM
AVIATION...FRAZIER/LUPO
HYDROLOGY...WM
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