639
FXUS61 KPBZ 141743
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
143 PM EDT WED OCT 14 2026
WHAT HAS CHANGED
SPATIAL COVERAGE OF SHOWERS AND STORMS WEDNESDAY AFTERNOON HAS
SHIFTED A BIT FARTHER NORTH. TIMING OF COLD FRONT PASSAGE FRIDAY HAS
SLOWED A BIT.
KEY MESSAGES
1) FIRST OF TWO COLD FRONTS THIS WEEK SWEEPS THROUGH ON WEDNESDAY.
2) STRONGER LATE-WEEK COLD FRONT RETURNS SHOWERS, GUSTY WIND,
AND TEMPERATURES MORE LIKE THAT OF MID-NOVEMBER.
DISCUSSION
KEY MESSAGE 1...
A SLOW MOVING COLD FRONT FINALLY GETS A KICK AND MOVES THROUGH OUR
AREA NORTH TO SOUTH THIS AFTERNOON SHOWERS AND A FEW STORMS. SOME
STORMS COULD GET A BIT ON THE STRONGER SIDE, BUT THE PRIMARY
LIMITING FACTOR TO THAT WILL BE A DISPLACED INSTABILITY AXIS
FROM THE HIGHEST SHEAR. THE BELT OF STRONGEST MID-LEVEL FLOW,
AND THUS DEEP LAYER SHEAR, WILL BE IN THE NORTHERN HALF OF OUR
AREA. THE BEST OPPORTUNITY FOR HEATING AND BETTER INSTABILITY
WILL BE IN THE SOUTHERN HALF OF OUR AREA IN THE THINNER CLOUD
COVER OUT AHEAD OF THE FRONT. REFS JOINT PROBABILITY FOR >500
J/KG OF SBCAPE AND >30 KNOTS OF SHEAR TO CAPTURE THE BEST
OVERLAP OF PARAMETERS HAS SHIFTED A BIT FARTHER NORTHWEST IN
SEVERAL ITERATIONS OF RUNS WITH AROUND 60- 90% FROM EASTERN OH,
THROUGH FAR SOUTHWESTERN PA, AND INTO NORTHERN WV. A HANDFUL OF
RECENT HRRR AND RRFS MPAS RUNS FAVOR A SLIGHTLY SLOWER MOVING
FRONT AND THUS STORMS FIRING A BIT FARTHER NORTH, WHICH IS
FALLING MORE IN LINE WITH THE REFS SHIFT, SO THIS COULD BE A
TREND TO NOTE THROUGH THE DAY TODAY. SO, THIS WILL BE THE AREA
TO WATCH FOR STORMS TO GET MORE FEISTY AND BRING A LOW-END
DAMAGING WIND THREAT COINCIDENT WITH SPC'S MARGINAL RISK. HAIL
SEEMS LESS LIKELY WITH THINNER CAPE PROFILES WITHIN THE HAIL
GROWTH ZONE AND A TOO SHALLOW EQUILIBRIUM LEVEL CAPPING UPDRAFTS
BEFORE THEY CAN MAXIMIZE ON HAIL GROWTH. WITH LACKING LOW LEVEL
LAPSE RATES PROGGED BY THE LATEST RAP, WE'D LIKELY NEED TO SEE
THE DEEP LAYER SHEAR ORGANIZE AND CONGEAL THE STORMS INTO
CLUSTERS TO CAPITALIZE ON THE WIND THREAT. CAN'T ENTIRELY RULE
OUT SOME FLASH FLOOD CONCERN WHICH WOULD BE A BIT MORE
CONCERNING IF STORMS DO FIRE FARTHER NORTH AND IMPACT
SOUTHWESTERN PENNSYLVANIA WHERE TWO ROUNDS OF STORMS ALREADY
WENT THROUGH EARLIER IN THE MORNING AND PRECONDITIONED THE
GROUND, BUT THAT'S STILL FAVORED IN SOUTHERN OH AND NORTHERN WV.
KEY MESSAGE 2...
THE MOST IMPACTFUL SYSTEM ARRIVES ON FRIDAY USHERING IN STRONG WIND
GUSTS, WELL BELOW NORMAL TEMPERATURES, AND SHOWERS. WHILE SOME
UNCERTAINTY REMAINS AMONG ENSEMBLES PRIMARILY OWING TO TIMING AND,
TO A LESSER EXTENT, DEPTH OF THE MID-LEVEL TROUGH, CONFIDENCE IN ALL
THREE IMPACTS REMAINS HIGH. DEEP SURFACE LOW PRESSURE WILL PULL A
COLD FRONT THROUGH THE AREA ON FRIDAY WITH A TIGHT PRESSURE
GRADIENT, 10+ DAM 500 MB HEIGHT FALLS IN 12 HOURS, AND STRONG LOW-
LEVEL COLD ADVECTION.
FOR THE WIND THREAT, THE COMBINATION OF THE TIGHT GRADIENT AND
MIXING INTO A 40-45 KNOT LOW LEVEL JET SHOULD RESULT IN WIDESPREAD
GUSTS OF 35-45 MPH. THEY'LL BE STRONGER ACROSS OUR HIGHER ELEVATION
REMAINS UP TO ~60%. THE ALREADY LOW PROBABILITY OF ADVISORY CRITERIA
IN THE LOWLANDS HAS DECREASED A BIT TO ONLY AROUND 20-40%, SO WHILE
STILL NOT LIKELY, NOT ENTIRELY OUT OF THE QUESTION EITHER. EASTERN
TUCKER COUNTY RUNS AN ELEVATED PROBABILITY FOR HIGH WIND WARNING
CRITERIA GUSTS >58 MPH ALSO UP TO ~60%. WIND HEADLINES FOR THE
RIDGES WILL LIKELY COME INTO CONSIDERATION WITHIN THE NEXT 24-36
HOURS.
STRONG COLD ADVECTION IN POST-FRONTAL NORTHWEST FLOW WILL BOTTOM OUT
ENSEMBLE MEAN 850 MB TEMPERATURES TO AROUND -2 TO -4C. AN
UNSEASONABLY COLD AIR MASS WILL SETTLE IN FOR THE FIRST HALF OF
THE WEEKEND PROVIDING THE POTENTIAL FOR TWO NIGHTS OF FROST AND
FREEZE. FRIDAY NIGHT, IT LOOKS LIKE A FREEZE OR BUST AS WIND
WILL REMAIN ELEVATED IN THE POST-FRONTAL REGIME. SO, WHILE
PROBABILITIES FOR <36F LOWS ARE HIGH, ESPECIALLY OUTSIDE OF
URBAN AREAS, NOT TOO CONCERNED ABOUT WIDESPREAD FROST. PROBS FOR
<32F (AND AN UNCONDITIONAL FREEZE) SNEAK UP TO 40-50% ALONG AND
NORTH OF I-80, SO THAT'LL BE THE AREA TO WORRY ABOUT ON FRIDAY
NIGHT. SATURDAY DAYTIME HIGHS WILL FEEL MORE LIKE THOSE OF MID
TO LATE NOVEMBER ONLY WARMING TO NEAR 50 DEGREES WITH 40S IN THE
ELEVATION. THE GRADIENT WILL RELAX SOME SUNDAY NIGHT ALLOWING
WIND TO SLACKEN AND SKIES WILL CLEAR. THIS SHOULD POINT TOWARD
SATURDAY NIGHT BEING THE COLDEST AREAWIDE, AND POSSIBLY THE
FIRST SHOT FOR THE PITTSBURGH CLIMATE SITE TO DIP TO 32F OR
LOWER SINCE MAY 2ND. WITH BETTER RADIATIONAL COOLING CONDITIONS
AMID A DRY, COLD AIRMASS, THE DEW POINT COULD ESSENTIALLY BE THE
FLOOR FOR LOWS, AND THIS SUGGESTS WIDESPREAD LOW TO MID 30S AND
UPPER 20S. A WIDESPREAD FROST IS LIKELY. PROBABILITY FOR A
FREEZE RANGES FROM 40-80% IN EASTERN OH, NORTHERN WV, AND
WESTERN PA, WITH THE HIGHEST VALUES AWAY FROM URBAN AREAS AND IN
THE HIGHER ELEVATION. EXPECT THAT WE'LL BE LOOKING AT SOME
COMBINATION OF FROST/FREEZE HEADLINES ON TOP OF WIND HEADLINES
AS WELL.
TWO ROUNDS OF PRECIP ARE POSSIBLE BOTH ALONG THE FRONT ITSELF AND
THEN IN THE WRAP AROUND COLD ADVECTION ACROSS THE LAKES ON SATURDAY.
STRONG FLOW AMID THE DYNAMIC SYSTEM COULD DRIVE SOME "POWER SHOWERS"
ACCOMPANYING FROPA ON FRIDAY BRINGING ENHANCED GUSTS WITH THEM
PROVIDED THEY'RE ABLE TO GET TALL ENOUGH TO TAP INTO THE 40-50 KNOTS
A FEW THOUSAND FEET OFF THE GROUND. THIS WILL BE DEPENDENT ON THE
TIMING OF THE FRONT HAS FLUCTUATED BETWEEN EARLY MORNING AND EARLY
AFTERNOON. EARLIER WOULD POSE LESS POTENTIAL FOR STRONG GUSTS
ACCOMPANYING THE SHOWERS, LATER WOULD POSE MORE. IT WOULDN'T REQUIRE
A WHOLE LOT OF DEPTH TO THE UNSTABLE LAYER TO GET THINGS MIXED DOWN,
SO WILL CERTAINLY REQUIRE MONITORING. THEN, CONTINUED COLD ADVECTION
IN NORTHWEST FLOW LIKELY RESULTS IN SOME LAKE EFFECT AND UPSLOPE
PRECIP LATE FRIDAY INTO EARLY SATURDAY. FOR MOST, THIS WILL BE A
COOL, WINDY SCATTERED RAIN/GRAUPEL SHOWER SETUP. FOR SOME, THE FIRST
NOVELTY SNOWFLAKES OF THE SEASON AREN'T OUT OF THE QUESTION. GROUND
TEMPERATURES WILL BE TOO WARM TO SEE IT STICK, AND THERE'S SOME
QUESTION TO THE REMAINING DEPTH OF THE MOISTURE AND WHETHER OR NOT
IT'S DEEP ENOUGH TO GENERATE SNOWFLAKES OR SITS IN THE FAVORED
SUPERCOOLED LIQUID REGION. ENSEMBLE 850 MB TEMPERATURES SUGGEST THE
COLDEST TO THE NORTH AND EAST WITH A COLDER OUTLIER EXTENDING
FARTHER WEST. SO THE MOST FAVORED AREA TO SEE SOME WHITE STUFF
FALLING SHOULD BE THE HIGHEST ELEVATIONS OF PA AND WV AND THE FAR
REACHES OF OUR NORTHERN TIER OF COUNTIES, UNLESS THE OUTLIER
SOLUTION COMES TO FRUITION AND COLDER AIR FILTERS IN FARTHER
WEST.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
THE FRONTAL BOUNDARY IS SINKING ACROSS OH/PA THIS AFTERNOON, AND
MAY BE POSITIONED THROUGH IDI, AND JUST NORTH OF PIT AND PHD. A
BAND OF STRATUS IMPACTING FKL/DUJ LIES NORTH OF I-80, AND THESE
LOW CEILINGS SHOULD LINGER INTO THE EVENING BEFORE IMPROVING
SLIGHTLY.
ADDITIONAL SHOWER AND THUNDERSTORM DEVELOP IS FORECAST AHEAD OF
THE SINKING BOUNDARY. THIS IS MAINLY EXPECTED TO IMPACT THE
TERMINALS NEAR AND SOUTH OF I-70 (HLG/ZZV/MGW), AND THIS IS
WHERE TEMPO THUNDERSTORMS HAVE BEEN INCLUDED THIS AFTERNOON.
SHOWERS HAVE BEEN INCLUDED AT PIT AND AGC JUST AHEAD OF THE
FRONT, BUT CANNOT TOTALLY RULE OUT ANOTHER RUMBLE OF THUNDER.
ANY STORM WILL BE CAPABLE OF GUSTY WIND (30-40 KNOTS MOST LIKELY
AT STRONGEST AT ANY TERMINAL), AS WELL AS IFR-PRODUCING
DOWNPOURS AND LIGHTNING. BEHIND THE FRONT, MVFR CEILINGS ARE
EXPECTED TO CONTINUE TO DROP FROM NORTH TO SOUTH. PAST MIDNIGHT,
RAIN COVERAGE WILL DROP OFF, BUT CEILING CONFIDENCE BEGINS TO
FALL OFF. GUIDANCE INDICATES SOME IMPROVEMENT TO LOW-END VFR IS
POSSIBLE, AND FOLLOWED THIS FOR NOW GIVEN THE ARRIVAL OF DRIER
AIR FROM THE NORTH, BUT COULD EASILY SEE THIS IMPROVEMENT
HAPPENING MORE SLOWLY OR NOT AT ALL. IMPROVEMENT IS LESS LIKELY
OVERNIGHT SOUTH OF I-70 AS THE FRONT'S PROGRESS STARTS TO SLOW.
CANNOT RULE OUT IFR CEILINGS AND SOME FOG AS WELL, PARTICULARLY
AT MGW.
THE FRONT MAY BEGIN TO ADVANCE BACK NORTH AS A WARM BOUNDARY
AFTER SUNRISE ON THURSDAY. SHOWER CHANCES THROUGH 18Z APPEAR
RELATIVELY LOW, BUT MVFR CEILINGS MAY CREEP BACK NORTH AGAIN
THROUGH THE DAY AS WIND SLOWLY VEERS TO NORTHEAST.
OUTLOOK...
THAT WARM FRONT SHOULD RETURN SHOWER AND POSSIBLE THUNDERSTORM
CHANCES LATER IN THE DAY THROUGH THURSDAY NIGHT, ALONG WITH
CONTINUED CEILING RESTRICTIONS. A STRONG COLD FRONT IS EXPECTED
TO CROSS THE REGION FROM W-E FRIDAY, WITH SHOWERS AND W-NW WIND
GUSTS FROM 30-40KT. GUSTS FROM 40-45 KT ARE POSSIBLE ACROSS THE
HIGHER TERRAIN.
VFR SHOULD RETURN SATURDAY AND SUNDAY AS WIND DIMINISHES UNDER
BUILDING HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...MLB
AVIATION...CL
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