165
FXUS61 KPBZ 061757
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1257 PM EST FRI MAR 6 2026
WHAT HAS CHANGED
THE PREVIOUS FLOOD WARNING AND DENSE FOG ADVISORY HAVE BEEN LET
GO. SEVERE TIMING IS TRENDING PERHAPS A LITTLE EARLIER ON
SATURDAY BUT THE OVERALL LOOK AND THREATS REMAIN SIMILAR,
FAVORING DAMAGING WIND GUSTS, WITH HAIL AND AN ISOLATED TORNADO
OR TWO POSSIBLE. IF ANYTHING, AVAILABLE INSTABILITY SEEMS TO BE
ON THE RISE, WITH MEAN CAPE VALUES ON THE UPTICK.
KEY MESSAGES
1) SEVERE THUNDERSTORMS POSSIBLE SATURDAY
2) NEXT RAIN/STORM CHANCES LOOK TO BE TUESDAY/WEDNESDAY NEXT
WEEK
DISCUSSION
KEY MESSAGE 1...
AN AMPLIFIED ALBEIT POSITIVELY TILTED TROUGH IS EXPECTED TO
MOVE THROUGH THE MIDWEST AND ADVANCE ON THE REGION SATURDAY. AT
THE SURFACE, A DEEPENING LOW WILL CLIMB OUT OF THE CENTRAL
PLAINS AND THROUGH THE GREAT LAKES. THIS LOW WILL PUSH A PRE-
FRONTAL TROUGH AND COLD FRONT THROUGH OUR REGION WITH SHOWERS
AND THUNDERSTORMS FOCUSED ALONG THEM. STORMS ALONG THE INITIAL
PRE- FRONTAL TROUGH LOOK LIKE THEY COULD BE STRONG TO SEVERE.
AT THIS TIME THERE ARE SOME NOTABLE DIFFERENCES IN THE MODEL
DEPICTIONS OF THE TIMING OF THIS SYSTEM, WITH QUICKER MODELS
LIKE THE HRRR FAVORING AN ARRIVAL INTO PITTSBURGH IN THE EARLY
AFTERNOON HOURS AND SLOWER MODELS LIKE THE NAM FAVORING LATE
AFTERNOON. THE TREND IN MOST MODELS THOUGH HAS BEEN PUSHING
TOWARDS EARLIER TIMING. THIS TIMING COULD BE RATHER IMPORTANT IN
DICTATING HOW MUCH CLEARING AND HEATING WE ARE ABLE TO ACHIEVE
BETWEEN WHAT COULD BE A POTENTIALLY DISRUPTIVE MORNING ROUND OF
SHOWERS MOVING THROUGH AND THE ACTUAL LINE OF STORMS.
CAPE ESTIMATES HAVE RISEN IN RECENT MODEL RUNS AND THE HREF
SUPPORTS BETWEEN 500-1000 J/KG AVAILABLE, WHILE A REASONABLE
HIGHER SOLUTION (MORE HEATING AND/OR A LARGER BREAK BETWEEN
STORMS) WOULD SUPPORT CAPE VALUES BETWEEN 1000-1500 J/KG.
SFC-6KM SHEAR IS BETWEEN 35-45 KTS AND LARGELY UNIDIRECTIONAL
OUT OF THE SOUTHWEST. IF THE BOUNDARY ORIENTS MORE SW-NE THEN
THIS FLOW PROMOTES UPSCALE GROWTH AND A QUICKER CONGEALING INTO
A LINE OF STORMS RAISING THE WIND THREAT AND FOCUSING THE
TORNADO THREAT INTO SECTORS OF THE LINE THAT CAN SURGE MORE DUE
EASTWARD. IF THE BOUNDARY IS SLIGHTLY MORE DUE S-N ORIENTED THEN
UPDRAFTS WILL PROPAGATE ABOUT 45 DEGREES OFF OF THE
UNIDIRECTIONAL SHEAR VECTORS SUPPORTING A LONGER PERIOD OF
DISCRETE STORM MODES AND A MUCH GREATER INGESTION OF STREAMWISE
VORTICITY INTO THE UPDRAFTS RAISING THE TORNADO THREAT. AT THIS
TIME, ALL THREATS REMAIN IN PLAY, BUT BOUNDARY ORIENTATION WILL
PLAY A LARGE ROLE INTO JUST HOW MUCH OF A TORNADO THREAT WE SEE.
THE STORM PREDICTION CENTER HAS MAINTAINED THEIR PREVIOUS
SLIGHT RISK (LEVEL 2 OUT OF 5) FOR SEVERE THUNDERSTORMS ON
SATURDAY.
RAINFALL AMOUNTS ARE LIKELY LARGELY BETWEEN 0.25-0.75 INCHES
ACROSS THE AREA, WITH THE HIGHEST TOTALS IN MORE FOCUSED SWATHS
ALONG THUNDERSTORM TRACKS. WITH LARGELY DRY WEATHER TODAY AND
TONIGHT, SOME DRAINING AND RECEDING OF WATER FROM THE PREVIOUS
DAYS COULD HELP TO MITIGATE FURTHER FLOOD ISSUES TOMORROW. THE
RATHER QUICK FORWARD SPEED OF THESE STORMS PROMOTES HEAVY BUT
BRIEF DOWNPOURS FOR ANY ONE LOCATION AS THE LINE CROSSES.
KEY MESSAGE 2...
AFTER A RATHER DRY LATE SUNDAY THROUGH MONDAY PERIOD, THERE ARE
INDICATIONS THAT A NORTHERN STREAM SHORTWAVE COULD EJECT AND
PHASE WITH A SOUTHERN STREAM CLOSED LOW LOCKED INTO THE FOUR
CORNERS REGION. THIS OPENING WAVE THEN PRESSES EASTWARD DURING
THE TUESDAY/WEDNESDAY TIMEFRAME.
ENSEMBLES ARE IN SEEMINGLY GOOD AGREEMENT ON THIS SOLUTION
RETURNING RAIN AND POSSIBLY STORMS TO THE REGION. HOWEVER, THE
COMPLEX SITUATION OF PHASING BETWEEN THE SHORTWAVE AND LOW COULD
LEAD TO SOME STARK CHANGES IN TIMING DIFFERENCES PRESENTED IN
THE CLUSTERED ENSEMBLES.
THERE IS STILL A LOT TO COME INTO LINE FOR THIS SYSTEM, BUT
MACHINE LEARNING SOLUTIONS ARE ALREADY TRYING TO PICK UP ON WHAT
COULD BE LOW END SEVERE CHANCES DURING THE TUESDAY/WEDNESDAY
TIMEFRAME NEXT WEEK.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
MVFR STRATOCU AND GENERALLY LIGHT SOUTHWEST WINDS PREVAIL THIS
AFTERNOON, WITH IMPROVEMENT TO VFR EXPECTED FROM SOUTH TO NORTH
BY EVENING. SOME PATCHY FOG IS POSSIBLE AGAIN OVERNIGHT,
PRIMARILY IN SHELTERED VALLEYS. HOWEVER, MOST TERMINALS WILL
SEE WINDS REMAINING IN THE 5-10 KNOT RANGE WHICH SHOULD HELP
PREVENT DECOUPLING AND WIDESPREAD FOG DEVELOPMENT.
A ROUND OF SHOWERS AND PERHAPS A FEW RUMBLES OF THUNDER WILL BE
POSSIBLE IN THE 10Z-15Z TIMEFRAME SATURDAY MORNING. THESE MAY
ALSO BE ACCOMPANIED BY A RETURN OF CIG RESTRICTIONS. A GENERAL
LULL IN CONVECTION MAY SEPARATE THE MORNING ROUND FROM THE
HEAVIER THUNDERSTORMS THAT ARE FORECAST TO MOVE THROUGH SATURDAY
AFTERNOON/EVENING (JUST BEYOND THE CURRENT TAF PERIOD), BUT
PROBABILITIES FOR A FEW WIDELY SCATTERED SHOWERS OR STORMS
REMAIN HIGH ENOUGH TO MAINTAIN PROB30S THROUGH LATE MORNING AND
EARLY AFTERNOON. WITH THE ONSET OF HEATING/MIXING AFTER SUNRISE,
SOUTHWEST WINDS WILL ALSO INCREASE WITH GUSTS TO 20-25 KNOTS
POSSIBLE.
OUTLOOK...
THUNDERSTORMS ARE LIKELY SATURDAY AFTERNOON AND EVENING WITH A
CROSSING COLD FRONT. A FEW STORMS COULD BE STRONG TO SEVERE. VFR
AND QUIETER WEATHER IS EXPECTED SUNDAY AND MONDAY WITH BUILDING
HIGH PRESSURE. RESTRICTIONS WITH RAIN LIKELY RETURN TUESDAY
INTO WEDNESDAY.
CLIMATE
RECORD OR NEAR RECORD HIGHS ARE POSSIBLE ON SATURDAY. HERE ARE
THE RECORDS FOR STATIONS AROUND THE AREA FOR MARCH 7TH. EVEN IF
RECORD HIGH TEMPERATURES ARE NOT SET, HIGH TEMPERATURES ON
SATURDAY WILL BE AROUND 30 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR.
RECORD...... FORECAST HIGH
KPIT: 76/1983 75
KDUJ: 64/2016 69
KHLG: 74/2009 76
KPHD: 75/2000 74
KZZV: 77/2009,1983 75
KMGW: 79/1995,1983 78
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...AK
AVIATION...CERMAK/RACKLEY
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