950
FXUS61 KPBZ 071120
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
720 AM EDT MON JUL 7 2025
SYNOPSIS
SHOWERS AND STORMS TODAY ALONG A SLOW MOVING COLD FRONT COULD
RESULT IN HEAVY RAIN WITH LOCALIZED FLOODING POSSIBLE. THE
BOUNDARY STALLS TUESDAY AND AN UNSETTLED PATTERN WILL BRING
DAILY RAIN CHANCES THROUGHOUT THE WEEK ALONG WITH NEAR NORMAL
TEMPERATURES.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- HOT ON TODAY WITH HEAT INDICES IN THE UPPER 90S.
- SLOW MOVING SHOWERS AND STORMS WITH A HEAVY RAINFALL AND LOW-
END SEVERE WEATHER THREAT.
- SLIGHT RISK FOR EXCESSIVE RAINFALL COVERS MUCH OF THE AREA.
---------------------------------------------------------------
AN UPPER TROUGH IS NOSING ITS WAY INTO THE OHIO VALLEY AND BEGINNING
TO FLATTEN AS IT DOES SO. THE TIMING OF THIS TROUGH IS LIKELY TO
KICK CHANTAL'S REMNANTS OUT TO OUR EAST AND IMPACTS FROM THE
REMAINING RAIN BANDS ARE NOT EXPECTED ACROSS OUR REGION.
ARRIVING IN TANDEM WITH THE UPPER TROUGH IS A WEAK COLD FRONT
DRAPING DOWN FROM A LOW SLIDING THROUGH SOUTHERN CANADA. AHEAD OF
THIS FRONT, WARM AND MOIST ADVECTION CONTINUE IN SOUTHWESTERLY FLOW.
THIS GIVES THE REGION ANOTHER CHANCE TO SEE HIGH TEMPERATURES OVER
90 DEGREES (60-90% SOUTH OF I-80, TEMPERED FURTHER NORTH DUE TO
INCREASING CLOUD COVERAGE). HEAT INDICES ARE EXPECTED TO CLIMB ONCE
AGAIN AND MANY AREAS CAN CLIMB INTO THE MID TO UPPER 90S WITH A
COUPLE OF URBAN AREAS AND VALLEYS STRIKING 100 DEGREES. HEAT
ADVISORY CRITERIA ARE NOT EXPECTED TO BE MET ON A WIDESPREAD OR
LONG TERM BASIS AND THUS NO HEAT HEADLINES ARE ANTICIPATED.
A COUPLE OF SHOWERS MAY BE SEEN ACROSS THE REGION IN THE MORNING IN
WEAK PRE-FRONTAL CONVERGENCE BUT WIDESPREAD DEVELOPMENT OF SHOWERS
AND STORMS WAITS UNTIL THE AFTERNOON HOURS. HEAVY RAIN LOOKS TO
REMAIN THE PRIMARY THREAT FROM THESE STORMS AS PWATS ARE EXPECTED TO
SURGE NORTH OF 1.75 INCHES, WARM CLOUD DEPTHS TOP 12,000 FEET,
MUCAPE RISES ABOVE 1500 J/KG AND WEAK FLOW WITH BOUNDARY PARALLEL
MOTION VECTORS ALLOW FOR UPSCALE GROWTH ALONG THE FRONT. HREF
PROBABILITIES FOR RAINFALL RATES OVER 1"/HR SHOW UP ACROSS MUCH OF
THE REGION BUT ARE AT THEIR HIGHEST (NEAR 60%) IN OUR NORTHWESTERN
COUNTIES. ISOLATED BUT NON ZERO PROBABILITIES OF RAINFALL RATES OVER
2"/HR SHOW ACROSS THE REGION AS WELL.
TOTAL AMOUNTS THROUGH MONDAY NIGHT EXHIBIT A 40-70% PROBABILITY OF
ONE INCH, AND A 15-30% PROBABILITY OF TWO INCHES AGAIN WITH HIGHEST
CHANCES NORTH OF PITTSBURGH. WITH SOME TIME TO RECOVER SINCE OUR
LAST HEAVY RAIN EVENT, THE AREA WON'T BE QUITE AS HYDROPHOBIC, BUT
SOIL MOISTURES ARE STILL ELEVATED, SO A FLASH FLOOD RISK IS
CERTAINLY THERE. THE NEW DAY 1 EXCESSIVE RAINFALL OUT LOOK HAS MUCH
OF THE REGION IN A SLIGHT RISK (2/4).
THE OTHER MENTION WILL BE A LOW-END SEVERE RISK AS A MARGINAL RISK
(1/5) EXTENDS SOUTH FROM OUR NORTHERN BORDER TO THE MASON DIXON
LINE. WITH THE AFOREMENTIONED DESTABILIZATION, WE'LL HAVE THE
INSTABILITY IN PLAY, BUT SHEAR WILL BE WEAK OVERALL (<20 KNOTS DEEP
LAYER). THIS POINTS TOWARD A WATER LOADED DOWNBURST THREAT GIVEN THE
PWATS, ESPECIALLY IN ANY AREAS THAT WOULD SEE JUST A BIT OF MID-
LEVEL DRIER AIR INTRUSION AND NUDGE UP IN DCAPE (MODEL SOUNDINGS
ALREADY SUPPORT DCAPE OVER 1000 J/KG). HAIL THREAT IS NEARLY NULL
GIVEN THE HIGH MOISTURE CONTENT AND WEAK SHEAR BOTH DETRIMENTAL TO
HAIL GROWTH.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
KEY MESSAGES:
- BOUNDARY SLOWS AND STALLS ACROSS NORTHERN WV MAINTAINING DAILY
PRECIP CHANCES
- PWATS REMAIN ELEVATED NEAR THE BOUNDARY CONTINUING OUR HEAVY
RAIN CHANCE INTO MIDWEEK
----------------------------------------------------------------
THE BOUNDARY IS EXPECTED TO STALL OUT SOUTH OF PITTSBURGH ON TUESDAY
AND LINGER THERE THROUGH MIDWEEK. BEHIND THE BOUNDARY TEMPERATURES
ARE EXPECTED TO COME BACK DOWN TO NEAR NORMAL VALUES FOR THIS TIME
OF YEAR. NEAR AND ALONG THE BOUNDARY POPS AND PWATS WILL REMAIN
ELEVATED. SHOWERS AND STORMS ARE EXPECTED TO FIRE DIURNALLY EACH
AFTERNOON AND EVENING ALONG THE STALLED BOUNDARY. THIS CONTINUES OUR
RISK FOR HEAVY RAIN INTO MIDWEEK AND MARGINAL RISKS FOR EXCESSIVE
RAINFALL (1/4) REMAIN ACROSS OUR SOUTHERN COUNTIES TUESDAY AND
WEDNESDAY. OUR HIGHEST POPS REMAIN LARGELY SOUTH OF THE MASON DIXON
LINE TUESDAY AND WEDNESDAY ALTHOUGH LOWER END SHOWER AND STORM
CHANCES DRIFT AS FAR NORTH AS PITTSBURGH.
LONG TERM /THURSDAY THROUGH SUNDAY/
KEY MESSAGES:
- STALLED BOUNDARY PLAGUES THE AREA WITH DAILY PRECIP CHANCES
THROUGH THE END OF THE WEEK
- ANOTHER SYSTEM FAVORED TO MOVE IN OVER THE WEEKEND.
-------------------------------------------------------------------
A DEVELOPING AREA OF LOW PRESSURE TRACKS ACROSS THE GREAT LAKES LATE
THIS WEEK AND PUSHES THE BOUNDARY BACK NORTH AS A WARM FRONT
BRINGING RAIN CHANCES NORTH WITH IT. ADDITIONAL WAVES OF LOW
PRESSURE RIDE ALONG THIS BOUNDARY AND CONTINUE RAIN CHANCES THROUGH
THE END OF THE WEEK. THE BOUNDARY FINALLY LOOKS TO MOVE OUT OF THE
REGION THIS WEEKEND AS ANOTHER LOW TRAVERSES THE GREAT LAKES AND
COULD BRING RENEWED RAIN CHANCES THIS WEEKEND. TEMPERATURES ARE
EXPECTED TO REMAIN NEAR NORMAL THROUGH THE END OF THE PERIOD WITH
CLOUD COVER AND RAIN CHANCES EACH DAY.
AVIATION /11Z MONDAY THROUGH FRIDAY/
VFR CONDITIONS WITH SOME MID TO HIGH LEVEL CLOUDS EXPECTED
THROUGH THIS MORNING. WILL THEN LIKELY SEE SOME CU POP AS LOWER
LEVELS BEGIN TO MIX AND WIND PICKS UP OUT OF THE SOUTHWEST.
OVERALL, WINDS WILL VEER MORE WESTERLY DURING THE AFTERNOON
AHEAD OF A SLOW-MOVING FRONT.
THE MENTIONED FRONT, WHICH WILL CROSS IN THE AFTERNOON TO
EVENING HOURS, WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS
THAT WILL BE CAPABLE OF BOTH HEAVY RAIN AND A DAMAGING WIND
RISK. EXACT LOCATION OF A HEAVIER STORM IS DIFFICULT TO PIN DOWN,
SO HAVE INCLUDED PROB30S WITH VIS REDUCTION AND INCLUSION OF
GUSTIER WIND FOR EACH SITE DURING THE MOST LIKELY TIMEFRAME.
OUTSIDE OF ANY SHOWERS AND STORMS, VFR IS LIKELY TO PREVAIL.
A REDUCTION TO IFR OR LOWER IS INCREASINGLY POSSIBLE IN A COLD
ADVECTION REGIME WITH LINGERING NEAR-SURFACE MOISTURE BEHIND
THE FRONT TUESDAY MORNING, ESPECIALLY IN AREAS THAT SEE
THUNDERSTORMS TODAY. HREF PROB OF IFR IS UP TO 60-80% MOSTLY
ONLY IN AREAS THAT IT THINKS WILL SEE PRECIP TODAY AND MUCH
LOWER ELSEWHERE, BUT IN REALITY THAT PROBABILITY IS LIKELY
REPRESENTATIVE FOR ANYWHERE THAT SEES PRECIP TODAY.
OUTLOOK...
RESTRICTIONS WILL GRADUALLY IMPROVE HEADED INTO TUESDAY MORNING
WITH MIXING, BUT AN UNSETTLED PATTERN WILL CONTINUE FOR MUCH OF
THE REST OF THE WEEK AS MONDAY'S COLD FRONT SLOWS AND STALLS.
DIURNALLY DRIVEN STORM CHANCES WILL GOVERN CONDITIONS THE REST
OF THE WEEK WITH PERIODIC AFTERNOON AND EVENING IMPACTS
POSSIBLE EACH DAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...MLB/AK
NEAR TERM...CERMAK/AK
SHORT TERM...AK
LONG TERM...AK
AVIATION...MLB
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