523
FXUS61 KPBZ 040458 AAB
AFDPBZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1258 AM EDT FRI APR 4 2025
SYNOPSIS
AN ACTIVE PATTERN CONTINUES THROUGH THE WEEKEND WITH MULTIPLE
ROUNDS OF SHOWERS AND THUNDERSTORMS. SEVERE STORMS WILL BE
POSSIBLE SATURDAY.
NEAR TERM /THROUGH TODAY/
KEY MESSAGES:
- FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF EASTERN OHIO.
- SHOWERS CONTINUE OVERNIGHT.
- BREAK FROM THE WIDESPREAD RAIN UNTIL LATER THIS AFTERNOON.
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BIGGEST QUESTION FOR THE OVERNIGHT IS WHERE WILL THE MAIN AXIS
OF HEAVIER RAINFALL WILL SETUP. SEEING POSITIONAL DIFFERENCES
IN THE CAM SOLUTIONS AS WELL AS THE BLENDED DATA. WILL BE USING
CURRENT CONDITIONS AND PAST RAINFALL TO GAUGE WHICH MODELS HAVE
A BETTER HANDLE ON A STARTING POINT. SOME FACTORS THAT WILL COME
INTO PLAY OVERNIGHT. WHAT HAPPENS TO THE CONVECTION OVER KY?
CURRENTLY IT IS HAVING A DIFFICULT TIME SPREADING NORTH AND
EAST. LATEST MESOANALYSIS FROM SPC SHOWS VERY LITTLE INSTABILITY
OVER MUCH OF OUR FORECAST AREA. SOME OF THE QPF AMOUNTS FROM
THE CAM MODELS WOULD REQUIRE CONVECTION TO DEVELOP OVER THE
REGION TONIGHT. THIS DOES NOT APPEAR AS LIKELY WITH SO LITTLE
INSTABILITY, THE STALLED BOUNDARY SOUTH OF THE AREA, AND BEING
THAT IT IS NIGHT TIME. ANOTHER FACTOR WOULD BE THE BROAD SURFACE
HIGH MOVING ACROSS THE GREAT LAKES. THE HIGH IS PREVENTING THE
SURFACE BOUNDARY FROM MOVING BACK NORTHWARD. LOOKING AT NBM
PROBS FOR AMOUNTS THAT THE CAMS ARE SHOWING OVERNIGHT > 1 INCH
THEY RANGE FROM 10 TO 30% SOUTH OF PITTSBURGH WITH THE HIGHER
PROBS RIGHT ALONG THE SOUTHERN BORDER. WILL BE WATCHING HOW
THINGS EVOLVE OVERNIGHT, BUT THINK THE HEAVIER RAINFALL SHOULD
REMAIN MOSTLY SOUTH OF THE FORECAST AREA.
A SHORTWAVE TROUGH WILL QUICKLY MOVE EASTWARD ACROSS NORTHERN WV
THIS MORNING. THIS WAVE WILL SUPPRESS THE STALLED FRONT A BIT
FURTHER SOUTH, PUSHING THE AXIS OF RAINFALL SOUTH OF THE REGION.
HELPING WILL BE A BROAD SURFACE HIGH THAT WILL DRIFT ACROSS THE
GREAT LAKES REGION THIS MORNING. THIS HIGH WILL PUSH DRIER AND
SOMEWHAT COOLER AIR SOUTHWARD. NOT ONLY WILL THIS SUPPRESS THE
RAIN FURTHER SOUTH, BUT THE LOWER CLOUD DECK MAY ALSO SHIFT
SOUTH ALLOWING FOR SOME SUNSHINE THIS AFTERNOON, GENERALLY NORTH
OF I-70.
UPPER LEVEL HEIGHT RISES ARE EXPECTED THIS AFTERNOON AS A LARGE
UPPER LOW DIGS SOUTH OF THE FOUR CORNERS REGION AND A LARGE
500MB HIGH MOVES OVER THE SOUTHEASTERN US. THE RIDGING WILL PUSH
THE SURFACE HIGH TO THE NORTHEAST AND ALLOW THE STALLED FRONT TO
BEGIN TO SLOWLY MOVE NORTHWARD FROM THE MID-ATLANTIC REGION AS
EVENING APPROACHES. THE INCREASE IN SUBSIDENCE SHOULD ALLOW FOR
MUCH OF THE REGION TO REMAIN DRY FOR MOST OF THE DAY. THE
EXCEPTION WOULD BE AREAS SOUTH OF I-70 WHICH MAY SEE SHOWERS
AND STORMS LATER THIS AFTERNOON AS THE AFOREMENTIONED SURFACE
BOUNDARY STARTS TO HEAD NORTHWARD.
HIGH TEMPERATURES TODAY SHOULD BE JUST ABOVE SEASONAL AVERAGES.
ADDITIONALLY, IF THE CLOUD DECK DOES MOVE FURTHER SOUTH THE
EARLY APRIL SUN COULD BUMP THOSE TEMPERATURES A COUPLE OF
DEGREES WARMER.
SHORT TERM /TONIGHT THROUGH SUNDAY/
KEY MESSAGES:
- ROUNDS OF SHOWERS AND THUNDERSTORMS CONTINUE INTO THE WEEKEND.
- A FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF EASTERN OHIO.
- SEVERE WEATHER IS POSSIBLE SATURDAY.
- A COLD FRONT ON SUNDAY WILL FINALLY BRING AN END TO THE HEAVY
RAINFALL THREAT.
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ANOTHER SURFACE LOW IS EXPECTED TO TRACK NE OUT OF THE
MISSISSIPPI VALLEY REGION TONIGHT, PUSHING THE FRONT BACK NORTH
THIS TIME AS A WARM FRONT. SHOWERS AND THUNDERSTORMS ONCE AGAIN
INCREASE IN COVERAGE AS THE FRONT AND SURFACE LOW MOVE ACROSS
THE UPPER OHIO VALLEY REGION INTO EARLY SATURDAY. HOWEVER, IF
THE FRONT MOVES FAR ENOUGH NORTH, WE MAY SEE A BREAK IN THE
ACTIVITY LATE TONIGHT AND SATURDAY MORNING AS THE MAIN MOISTURE
PLUME WILL BE FORCED NORTHWARD AND THE AREA WILL BE WELL INTO
THE WARM SECTOR.
A SECOND ROUND OF THUNDERSTORMS IS THEN EXPECTED SATURDAY
AFTERNOON/EVENING AHEAD OF A CROSSING COLD FRONT. CAMS ARE
HINTING AT SEVERE WEATHER POTENTIAL WITH THIS ROUND OF POSSIBLY
DISCRETE STORMS, AND MODELED HODOGRAPHS SUGGEST AT LEAST
MARGINAL TORNADO THREAT.
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO SATURDAY NIGHT AS
LOW PRESSURE CROSSES, BUT THE STALLED FRONT REMAINS. FLOODING
POTENTIAL WILL INCREASE ON SATURDAY WITH REPEATED ROUNDS OF
HEAVY RAINFALL ON AN ALREADY SATURATED GROUND. RISES ARE
EXPECTED ON AREA RIVERS.
ENSEMBLE CLUSTERS AGREE ON RAPID HEIGHT FALLS SUNDAY. THIS WILL
FINALLY SHUNT THE SURFACE RIDGE, THAT HAD BEEN FIRMLY PLANTED
OVER THE SOUTHEAST CONUS COAST, AND ALLOW A COLD FRONT TO
ADVANCE THROUGH THE AREA AND OFF TO THE SOUTH LATE SUNDAY,
BRINGING AN END TO THE HEAVY RAIN AND STORM POTENTIAL.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/
KEY MESSAGES:
- COLDER NEXT WEEK WITH LIGHTER RAIN/SNOW CHANCES EACH DAY.
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WEAK SURFACE LOW PRESSURE, CROSSING OUT OF THE GREAT LAKES WILL
AID IN STRONG NORTHWESTERLY FLOW BEHIND THE FRONT MONDAY INTO
TUESDAY. THIS COULD BRING A ADDITIONAL FEW SHOWERS TO THE REGION
ON TUESDAY.
UPPER TROUGHING IS EXPECTED TO PERSIST THROUGH MIDWEEK,
RESULTING IN BELOW NORMAL TEMPERATURES AND DAILY RAIN/SNOW
CHANCES, ALBEIT NOT NEARLY AS INTENSE AS WHAT WE'RE EXPERIENCING
THIS WEEK.
AVIATION /06Z FRIDAY THROUGH TUESDAY/
VFR CLOUD DECKS ARE OBSERVED ACROSS A MAJORITY OF THE REGION AT THIS
TIME. A COLD FRONT IS CURRENTLY LINGERING JUST OUTSIDE OF OUR REGION
IN CENTRAL OH. THIS FRONT IS EXPECTED TO MOVE THROUGH THE REGION
THIS EVENING AND OVERNIGHT AND MVFR PROBABILITIES PICK UP QUICKLY
BEHIND THIS FRONT (JUMPING TO >70% FOR ALL PORTS SAVE FKL/DUJ BY
03Z). IFR PROBABILITIES FOR ALL PORTS SAVE FKL/DUJ PEAK NORTH OF 60%
BY 06Z.
AREAS OF RAIN AND EMBEDDED SHOWERS ARE MOVING ACROSS MUCH OF THE
REGION AT THIS TIME. THESE SHOWERS ARE LARGELY OCCURING IN THE VFR
REALM BUT HEAVIER SHOWERS ARE EXPECTED THIS EVENING WITH THE CHANCE
TO BRING MVFR RESTRICTIONS AND THE POSSIBILITY OF BOUTS OF IFR VIS.
THUNDERSTORMS ARE NOT OUT OF THE QUESTION AS THERE IS SOME ELEVATED
INSTABILITY THIS EVENING. THIS CHANCE WOULD BE HIGHEST SOUTH FOR MGW
AND TO A LESSER EXTENT HLG, HOWEVER THIS WAS NOT VIEWED AS HIGH
ENOUGH TO INCLUDE AT ALL IN THE TAFS BUT THE POSSIBILITY IS WORTH
NOTING.
OUTLOOK... THE UPPER OHIO RIVER VALLEY WILL REMAIN POSITIONED
BETWEEN A CENTRAL PLAINS TROUGH AND ATLANTIC RIDGE THAT WILL FOSTER
MULTIPLE ROUNDS OF MODERATE TO LOCALLY HEAVY RAIN THROUGH MONDAY
MORNING. TIMING AND SHAPE IN EACH WAVE REMAINS VARIABLE, WHICH MAY
ALTER THE AXIS OF HIGHEST PRECIPITATION RATES AND AREAS OF GREATEST
RESTRICTIONS. AVIATION CUSTOMERS SHOULD ANTICIPATE LIMITED WINDOWS
OF VFR AND DRY CONDITIONS THROUGH THE PERIOD AS THE PATTERN FAVORS
MVFR/IFR RESTRICTIONS, HEAVIER RAIN SHOWERS AND OCCASIONAL
THUNDERSTORMS.
A DEEPENING UPPER LEVEL TROUGH MAY OVERTAKE THE REGION EARLY NEXT
WEEK, SHIFTING TOWARDS A COLDER PATTERN FEATURING PERIODIC RAIN/SNOW
CHANCES AND CONTINUED CEILING RESTRICTIONS.
HYDROLOGY
THE POTENTIAL FOR HEAVY RAINFALL WILL EXIST 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 70 PERCENT CHANCE OR GREATER OF AT LEAST 2
INCHES OF RAIN OVER A 72 HR PERIOD IN THIS REGION. LESSER
PROBABILITIES EXIST FURTHER EAST, THOUGH A TREND UP HAS BEEN
NOTED IN THE LATEST ENSEMBLE GUIDANCE AND WILL NEED TO BE
MONITORED FOR ANY POTENTIAL EXPANSION OF THE FLOOD WATCH. THE
EXACT LOCATION OF THE HEAVIEST 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 THROUGH SUNDAY MORNING FOR OHZ039-040-048-049-
057>059-068-069.
WV...NONE.
SYNOPSIS...RACKLEY/22
NEAR TERM...22
SHORT TERM...RACKLEY/22
LONG TERM...RACKLEY
AVIATION...AK
HYDROLOGY...
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