252
FXUS61 KPBZ 141105
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
705 AM EDT SUN JUN 14 2026
WHAT HAS CHANGED
PASSING COLD FRONT THIS EVENING WILL INCREASE THE POTENTIAL FOR
DAMAGING WIND GUSTS AND TORNADOES ALONG A SQUALL LINE; SPC ADDED
A 2% TORNADO RISK FOR PORTIONS OF THE REGION
KEY MESSAGES
1) STRONG TO SEVERE STORMS EXPECTED THIS AFTERNOON/EVENING WITH
ADVANCING COLD FRONT
2) QUIET WEATHER EXPECTED MONDAY THROUGH EARLY WEDNESDAY;
MONITORING POTENTIAL HAZARDOUS WEATHER ON THURSDAY
DISCUSSION
KEY MESSAGE 1...
PRE-FRONTAL SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE
DEVELOPING TO OUR WEST AND MOVE INTO THE REGION EARLY THIS
MORNING. WARM, MOIST ADVECTION ASSOCIATED WITH SOUTHWESTERLY
FLOW AND PRECIPITATION WILL LIKELY PRIME THE ENVIRONMENT ENOUGH
FOR FAVORABLE STRONG TO SEVERE STORMS ALONG A COLD FRONT THIS
AFTERNOON AND EVENING, MAINLY BETWEEN 2PM AND 8PM.
THE PRIMARY THREAT TODAY WILL BE DAMAGING WIND GUSTS ALONG AND
AHEAD OF THE COLD FRONT, SUPPORTED BY 40-50KTS OF EFFECTIVE
SHEAR. AS A RESULT, SCATTERED TREE DAMAGE AND POWER OUTAGES ARE
POSSIBLE FROM LATE THIS AFTERNOON INTO THE EARLY EVENING HOURS.
THE STORM PREDICTION CENTER HAS ALSO INTRODUCED A 2% TORNADO
RISK. A NUMBER OF MODEL SOUNDINGS SUGGEST SUFFICIENT LOW-LEVEL
STRETCHING OF UPDRAFTS WITH LOWER CLOUD BASES AND SHALLOW
INSTABILITY (3CAPE BETWEEN 100J/KG TO 150J/KG) FOR TORNADIC
DEVELOPMENT.
SMALL HAIL IS POSSIBLE, BUT THE OVERALL THERMODYNAMIC PROFILE
IS NOT FAVORABLE FOR SIGNIFICANT HAIL DEVELOPMENT. FORECAST
SOUNDINGS INDICATE AN ELEVATED FREEZING LEVEL AND A DEEP MOIST
LAYER, BOTH OF WHICH TEND TO LIMIT HAIL GROWTH. CLIMATOLOGICALLY,
UPDRAFTS WOULD LIKELY NEED TO EXCEED 30,000FT TO SUPPORT HAIL
PRODUCTION OF A QUARTER OR BIGGER.
BETWEEN 9PM AND 11PM, THE COLD FRONT IS EXPECTED TO EXIT SOUTHEAST
AND THE THREAT FOR THUNDERSTORMS RAPIDLY DECREASES. A FEW
ISOLATED LIGHT SHOWERS MAY LINGER EARLY MONDAY MORNING BEFORE
DAWN.
KEY MESSAGE 2...
IN THE WAKE OF THE AFOREMENTIONED COLD FRONT, EXPECT DRY AND
BELOW-AVERAGE TEMPERATURES MONDAY AFTERNOON INTO TUESDAY.
LINGERING CLOUDS AND COLD ADVECTION FROM THE NORTHWEST WILL
LIKELY KEEP HIGH TEMPERATURES IN THE UPPER-60S/LOW-70S ON
MONDAY, 10 DEGREES BELOW AVERAGE.
BY THURSDAY, A WARM FRONTAL PASSAGE COULD BRING RISING 500MB HEIGHTS
AND HIGHER DEWPOINTS BACK TO THE REGION. ALONG WITH THIS ARE
INDICATIONS OF ENHANCED FLOW, WITH 45-50 KNOTS AT 700MB AND
85-95 KNOTS AT 500MB ON ENSEMBLE PROGS. THIS COMBINATION
SUGGESTS AN INCREASING RISK OF SEVERE WEATHER ON THIS DAY,
ASSOCIATED WITH A POTENTIAL COLD FRONTAL PASSAGE FROM GREAT
LAKES LOW PRESSURE. MACHINE-LEARNING GUIDANCE FROM NCAR AND CSU
AGREE WITH THIS ASSESSMENT, WITH PROBABILITIES FOR SEVERE
WEATHER INCREASING OVER THE LAST 24 HOURS TO 30% TO 60%. SPC
ALSO HAS ALREADY HIGHLIGHTED THURSDAY FOR THE RISK AS WELL.
GIVEN THE INSTABILITY/SHEAR COMBINATION THAT COULD BE REALIZED,
THIS IS A POTENTIALLY VOLATILE SITUATION THAT COULD PRESENT THE
RISK OF DAMAGING WIND GUSTS AND TORNADOES.
IN ADDITION TO THE SEVERE WEATHER THREAT, MULTIPLE EMBEDDED
SHORTWAVES MAY PROMOTE REPEATED ROUNDS OF PRECIPITATION, RAISING
CONCERNS FOR TRAINING STORMS AND LOCALIZED FLOODING. AT THIS TIME,
THE GREATEST FLOOD RISK APPEARS MORE LIKELY TO FOCUS OVER AREAS JUST
WEST OF THE UPPER OHIO VALLEY, WPC HAS INTRODUCED A "SLIGHT"
RISK FOR FLOODING WITH THIS LATEST FORECAST UPDATE IN CENTRAL
OHIO.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
ISOLATED MORNING SHOWERS/SPRINKLES AHEAD OF A LIKELY DECAYING
STORM CLUSTER NEAR ZZV WILL TAPER OFF AND/OR SHIFT NE THROUGH
18Z AMID WARM, MOIST ADVECTION AHEAD OF THE MAIN ACTIVITY.
OUTSIDE OF THE HEAVIER RAIN IN THE CLUSTER THAT COULD GENERATE
MVFR OR LOWER VISIBILITY, EXPECT VFR THROUGH THIS PERIOD.
SHOWER AND THUNDERSTORMS DEVELOP MAINLY ALONG AN ADVANCING COLD
FRONT THIS AFTERNOON AND EVENING, REACHING NW PA BETWEEN 18Z-21Z
BEFORE CROSSING WEST CENTRAL PA (INCLUDING PIT) BETWEEN 20Z-24Z,
AND EXITING SOUTHEAST BY 01-04Z. THIS CONVECTIVE LINE IS LIKELY
TO FEATURE MVFR CIGS, MVFR TO IFR VSBYS IN HEAVY RAIN, FAIRLY
FREQUENT LIGHTNING, AND GUSTY WINDS GENERALLY IN THE 20 TO 40KT
RANGE. POCKETS OF STRONG STORMS WITHIN THE LINE CAN'T BE RULED
OUT AND WOULD PUSH THE HIGHER END GUST POTENTIAL TOWARDS
50-58KTS. THE BIGGEST UNCERTAINTY IS HOW MANY, IF ANY, SHOWERS
AND THUNDERSTORMS DEVELOP AHEAD OF THE MAIN LINE AND THUS
ALTERING THE TARGETED IMPACT TIMES CURRENTLY IN TAFS.
COLD ADVECTION AND SUBSIDENCE WILL QUICKLY END PRECIPITATION
CHANCES AFTER FRONTAL PASSAGE BUT CURRENTLY FAVORS A FAIRLY
WIDESPREAD MVFR TO PERIODICALLY IFR STRATOCU DECK THAT
DISSIPATES/LIFTS AFTER DAWN MONDAY. THERE IS POTENTIAL FOR LOWER
DECKS AND FOG IF THERE IS SCATTERING OF THE STRATOCU FIELD
ALLOW FOR BRIEF PERIODS OF RADIATIONAL COOLING NEEDED TO FOSTER
THESE LOWER RESTRICTIONS.
OUTLOOK...
HIGH PRESSURE AND SUBSIDENCE RETURN VFR CONDITIONS MONDAY AS THE
CU FIELD TRANSITIONS FROM BROKEN TO FEW BY 00Z. LITTLE CHANGE IN
IMPACTS IS EXPECTED TUESDAY BUT THE APPROACH OF AN ABNORMALLY
DEEP UPPER TROUGH AND SURFACE LOW MID-WEEK WILL CREATE MULTIPLE
ROUNDS OF SHOWERS/THUNDERSTORMS AND ASSOCIATED RESTRICTIONS.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...HEFFERAN
AVIATION...FRAZIER
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