069
FXUS61 KPBZ 130125 AAA
AFDPBZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
925 PM EDT THU JUN 12 2025
SYNOPSIS
WARM AND HUMID CONDITIONS CONTINUE THROUGH FRIDAY. DAILY
THUNDERSTORM CHANCES LINGER THROUGH THE MIDDLE OF NEXT WEEK
WITH HEAVY RAINFALL AND LOW SEVERE WEATHER CHANCES.
NEAR TERM /UNTIL 6 AM FRIDAY MORNING/
KEY MESSAGES:
- MAINLY DRY OVERNIGHT
---------------------------------------------------------------
A SURFACE COLD FRONT WAS ANALYZED FROM JUST SOUTH OF DUJ, TO
BTP, TO NORTH OF PHD. THE FRONT WILL CONTINUE TO DRIFT SOUTH
OVERNIGHT BEFORE STALLING ACROSS THE REGION ON FRIDAY. CAPPING
ALOFT AND A LACK OF SIGNIFICANT MOISTURE WITH THE FRONT
PRECLUDED ANY PRECIP FROM DEVELOPING THIS EVENING, AND THIS
SHOULD CONTINUE OVERNIGHT.
THE 00Z PIT SOUNDING SHOWED THE CAP AT AROUND 800MB. DRY AIR WAS
ALSO OBSERVED THROUGH MOST OF THE COLUMN, WITH HIGH LEVEL
MOISTURE INCREASING WITH THE CIRRUS OVERSPREADING THE REGION.
OVERNIGHT LOWS ARE EXPECTED TO BE AROUND 5 DEGREES ABOVE
AVERAGE.
SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/
KEY MESSAGES:
- DAILY THUNDERSTORM CHANCES WITH HEAVY RAINFALL THREAT FRIDAY
AND SATURDAY.
- TEMPERATURES DIPPING CLOSER TO NORMAL BUT STILL HUMID WITH
WARM OVERNIGHT LOWS.
----------------------------------------------------------------
A MORE ACTIVE FRIDAY AND WEEKEND IS IN STORE AS THE AFOREMENTIONED
BOUNDARY REMAINS STALLED AND WIGGLING OVER OUR AREA. A RENEWED PUSH
OF SOUTHERLY FLOW ON FRIDAY WILL PUMP PWAT VALUES AROUND 1.5". THE
BOUNDARY WILL LIFT NORTH AS A WARM FRONT AND LEAVE OUR AREA IN THE
OPEN WARM, MOIST SECTOR. THICK CLOUD COVER SHOULD PREVENT NOTABLE
DESTABILIZATION, BUT SKINNY MUCAPE AROUND THE 400-800 J/KG
RANGE COUPLED WITH WEAK FLOW AND PWATS PUSHING THE 90TH
PERCENTILE OF CLIMATOLOGY WILL POINT TOWARD A LOCALLY HEAVY
RAINFALL AND FLASH FLOODING THREAT. SOME SCATTERED SHOWERS MAY
BE AROUND IN THE MORNING WITH LOW PROBABILITY THUNDER, BUT MORE
WIDESPREAD THUNDERSTORM DEVELOPMENT IS LIKELY AFTER 12 OR 1PM
WITH ACHIEVEMENT OF CONVECTIVE TEMPERATURES. EXACT PLACEMENT OF
INITIATION WILL BE TOUGH TO FORECAST, AND FURTHER DEVELOPMENT
MAY BE TIED TO COLD POOL/OUTFLOW BOUNDARY PROGRESSION. HREF
PROBABILITY FOR >1"/HOUR RATES IN ANY GIVEN HOUR FROM 12PM-6PM
IS UP TO 50%.
SATURDAY LOOKS TO BE A SIMILAR SETUP TO FRIDAY THOUGH WITH A
POTENTIALLY HIGHER HEAVY RAINFALL THREAT. PWAT VALUES RISE A BIT
MORE WITH HIGH PROBABILITY FOR >1.5" AND 40-60% CHANCE OF >1.75". IN
TURN, DCAPE VALUES WILL BE LOWER GIVEN A MORE MOIST COLUMN, SO THE
SEVERE WEATHER THREAT WILL BE LOWER. STILL, A 50-80% CHANCE OF >500
J/KG OF SBCAPE, HIGHEST SOUTH OF PITTSBURGH, AND CONTINUED WEAK DEEP
LAYER FLOW WILL PROVIDE A GOOD ENVIRONMENT FOR MORE SLOW MOVING
AFTERNOON CONVECTION. WITH THE POTENTIAL FOR FRIDAY TO PRIME
THE GROUND FOR THE NEXT ROUND ON SATURDAY, WPC HAS KEPT THE
ENTIRE AREA IN A MARGINAL RISK (1/4) FOR EXCESSIVE RAINFALL.
GIVEN THE CLOUD COVER AND HIGHER PRECIPITATION PROBABILITY,
TEMPERATURES WILL DIP CLOSER TO NORMAL OVER THE WEEKEND BUT STILL
REMAIN QUITE HUMID WITH DEW POINTS IN THE UPPER 60S AND LITTLE
RELIEF AT NIGHT WITH LOWS IN THE 60S.
LONG TERM /SUNDAY THROUGH THURSDAY/
KEY MESSAGES:
- PRECIPITATION CHANCES CONTINUE INTO NEXT WEEK.
- TEMPERATURES FAVORED TO CLIMB ABOVE SEASONAL NORMALS.
-------------------------------------------------------------------
BY SUNDAY, SURFACE LOW PRESSURE IS FAVORED TO DEVELOP ACROSS THE
OHIO VALLEY AS AN UPPER WAVE APPROACHES. THIS WILL BEGIN TO PUSH THE
STALLED BOUNDARY TO THE EAST BUT PRECIPITATION CHANCES STILL
CONTINUE AS IT SLIDES BY. LATEST CLUSTERED ENSEMBLE RUNS HAVE
TRENDED DEEPER AND SLIGHTLY SLOWER WITH THE UPPER WAVE
PROGRESSION, AND IN THIS SCENARIO, SUNDAY MAY SEE CONTINUED
FLOODING AND LOW SEVERE THREATS. IF A FASTER SCENARIO (LOWER
PROBABILITY) TAKES HOLD, BOTH OF THOSE THREATS WOULD LOWER AND
TEMPERATURES WOULD BE COOLER.
TEMPERATURES ARE FAVORED TO RISE AGAIN THROUGHOUT THE WEEK AND
EVENTUALLY END UP BACK ABOVE NORMAL, BUT DAILY RAIN CHANCES CONTINUE
WITH PASSING WAVES OF LOW PRESSURE. UNCERTAINTY GROWS BY MID-WEEK
WITH SPREAD IN MAXTS AROUND 5-8 DEGREES. THE PATTERN LOOKS TO REMAIN
ACTIVE WITH MACHINE LEARNING GUIDANCE POINTING TOWARD LOW END SEVERE
CHANCES THROUGH THE END OF THE WEEK.
AVIATION /01Z FRIDAY THROUGH TUESDAY/
HIGH PRESSURE CONTINUES
TO BE THE DOMINANT WEATHER FEATURE MAINTAINING VFR CONDITIONS WITH
ONLY SOME PASSING CIRRUS AND UPPER-LEVEL SMOKE EXPECTED. LIGHT AND
VARIABLE WIND EXPECTED TODAY INTO THE OVERNIGHT TIME PERIOD.
PROBABILITY OF SHOWERS AND STORMS WILL LIKELY INCREASE AFTER 17Z
FRIDAY WITH A PASSING LOW PRESSURE DISTURBANCE AND WILL CONTINUE
INTO THE OVERNIGHT TIME PERIOD.
ISOLATED STORMS MAY HAVE A DOWNBURST POTENTIAL BETWEEN 17Z TO 21Z
AND CREATE STRONG WIND GUSTS. GIVEN THAT CONVECTION IS DISORGANIZED,
CONFIDENCE ON SPECIFIC TERMINAL IMPACTS REMAINS LOW, SO VCTS AND
PROB30S ARE CURRENTLY FORECASTED TO REPRESENT THE UNCERTAINTY.
OUTLOOK...
WEAK DISTURBANCES WITHIN THE UPPER FLOW WILL BRING
INCREASED CHANCES FOR PRECIPITATION AND ASSOCIATED MVFR RESTRICTIONS
OVER THE WEEKEND.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...MLB
NEAR TERM...WM
SHORT TERM...MLB
LONG TERM...MLB
AVIATION...HEFFERAN/LUPO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page