604
FXUS61 KPBZ 161745
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
145 PM EDT TUE JUN 16 2026
WHAT HAS CHANGED
CONTINUING TO MONITOR THE POTENTIAL FOR SEVERE WEATHER LATE
WEDNESDAY INTO THURSDAY. CONFIDENCE IN A STRONG CONVECTIVE LINE
LATE WEDNESDAY NIGHT INTO THURSDAY MORNING REMAINS HIGH. THERE
MAY BE A TREND TOWARDS A DRIER SCENARIO WITH LESS DAYTIME
THUNDERSTORMS THURSDAY.
KEY MESSAGES
1) SCATTERED SHOWERS TONIGHT
2) POTENTIAL FOR SEVERE STORMS LATE WEDNESDAY INTO THURSDAY.
GUSTY WIND MAY RESULT FROM EITHER STRONG THUNDERSTORMS OR
DAYTIME MIXING OF STRONG WIND ALOFT.
DISCUSSION
KEY MESSAGE 1...
A SHORTWAVE TROUGH SWINGS ACROSS THE GREAT LAKES AND THE UPPER
OHIO VALLEY TONIGHT, WITH THE AXIS CROSSING OUR REGION AFTER
06Z. MOISTURE REMAINS LIMITED, BUT IS ENOUGH IN CONCERT WITH THE
SUPPORT FOR LIFT TO EXPECT SOME SCATTERED SHOWERS TO ACCOMPANY
THE PASSAGE OF THE DISTURBANCE. ANY PRECIPITATION SHOULD EXIT TO
THE EAST BY 12Z. THE CLOUDS AND LINGERING MIXING SHOULD KEEP LOW
TEMPERATURES MILDER TONIGHT, A BIT CLOSER TO NORMAL THAN THIS
MORNING.
KEY MESSAGE 2...
STRONG SURFACE LOW PRESSURE IS STILL PROGGED TO TRACK ACROSS
MICHIGAN INTO SOUTHERN ONTARIO LATE WEDNESDAY INTO WEDNESDAY
NIGHT. INITIALLY THERE WAS SOME QUESTION AS TO HOW FAR NORTH THE
ASSOCIATED WARM FRONT WOULD TRACK, BUT THERE IS NOW CONSENSUS
THAT IT WILL LIFT WELL NORTH OF THE REGION BY 12Z THURSDAY,
PUTTING OUR REGION FIRMLY IN THE WARM SECTOR DURING THE DAY.
SOME INITIAL SHOWERS/THUNDERSTORMS MAY ACCOMPANY THE WARM FRONT
AS IT CROSSES WEDNESDAY EVENING.
THIS ACTIVITY IS FORECAST TO BE FOLLOWED BY A MORE STOUT
CONVECTIVE LINE OVERNIGHT, CROSSING POTENTIALLY BETWEEN 06Z AND
12Z. THIS LINE IS FORECAST TO FORM IN A VERY VOLATILE CONVECTIVE
ENVIRONMENT TO OUR WEST ACROSS IL/IN, WHERE A SIGNIFICANT SEVERE
WEATHER OUTBREAK IS POSSIBLE. AS THIS LINE MOVES EAST, AVAILABLE
BUOYANCY IS FORECAST TO DECREASE. REFS MEAN SURFACE-BASED CAPE
IS FORECAST TO BE ONLY AROUND 150 J/KG NEAR ZZV AT 06Z THURSDAY,
WITH MUCAPE OF UNDER 500 J/KG. THESE NUMBERS WOULD THEN DECREASE
TOWARD THE EAST. OF NOTE IS THE VERY STRONG WIND FIELD THAT WILL
BE IN PLACE. 850MB WIND OF 50 TO 60 KNOTS AND 500MB WIND OF 60
TO 70 KNOTS IS FORECAST, CONTRIBUTING TO 50 TO 65 KNOTS OF 0-6KM
SHEAR. THE 850MB/500MB WINDS ARE RIGHT AT THE TOP END OF THE
CLIMATOLOGIC RECORD.
ALTHOUGH INSTABILITY WILL BE DECREASING AS NOTED, THIS WIND
FIELD SHOULD BE ABLE TO MAINTAIN THE CONVECTIVE LINE TO SOME
DEGREE AS IT CROSSES, ALTHOUGH IT WILL LIKELY BE WEAKENING WITH
TIME, ESPECIALLY AS IT REACHES WESTERN PA. THE MAIN THREAT WILL
LIKELY BE DAMAGING WIND GUSTS IN THIS SCENARIO. TORNADOES WOULD
BE POSSIBLE AS WELL, ESPECIALLY GIVEN THE LONG AND STRONGLY
CURVED FORECAST HODOGRAPHS. IF WE ARE ABLE TO MAINTAIN A BIT
MORE INSTABILITY AHEAD OF THE LINE, ESPECIALLY IN THE 0-3KM
LAYER, THEN THE TORNADO THREAT MAY INCREASE, AT LEAST INTO
EASTERN OHIO. ALTHOUGH HEAVY DOWNPOURS ARE LIKELY WITH LINE, THE
OVERALL SPEED OF THE COMPLEX SHOULD LIMIT THE FLOODING THREAT.
THE LOW IS EXPECTED TO CONTINUE TO TRACK TO THE NE ACROSS
EASTERN ONTARIO ON THURSDAY, PULLING A COLD FRONT SOUTH ACROSS
THE UPPER OHIO VALLEY REGION. REDEVELOPMENT OF THUNDERSTORMS IS
EXPECTED ALONG THE FRONT, ALTHOUGH HOW NUMEROUS AND STRONG THESE
STORMS WILL BE IS STILL IN QUESTION. A RUSH OF DRY AIR BEHIND
THE OVERNIGHT CONVECTIVE LINE MAY STUNT DEVELOPMENT DURING THE
DAY TO SOME DEGREE, AS COULD LINGERING CLOUD COVER. AT THIS
TIME, ENSEMBLE MODEL PROGS STILL INDICATE THAT THE GREATEST
INSTABILITY SHOULD BE FROM NEAR PITTSBURGH AND AREAS SOUTH,
THOUGH UNCERTAINTY EXISTS DUE TO THE FACTORS LISTED ABOVE. WITH
STRONG SHEAR REMAINING IN PLACE DAMAGING WIND GUSTS AND
TORNADOES WOULD REMAIN AS THREATS. ANY SUCH STORM ACTIVITY
SHOULD THEN DECREASE AFTER SUNSET.
IN THE CASE OF A DRIER SCENARIO, THE REGION MAY STILL END UP
WITH VERY GUSTY WIND. THE WIND FIELD IS MORE TYPICAL OF A
STRONGER WINTERTIME SYNOPTIC SETUP, AND GIVEN THE POTENTIALLY
DEEP MIXING THAT COULD SET UP IN THE DRIER SCENARIO, THE WIND
ALOFT COULD TRANSPORT TO THE SURFACE TO SOME DEGREE, RESULTING
IN MORE NUMEROUS GUSTS OF 35 TO 45 MPH AT LEAST. IN FACT, NON-
THUNDERSTORM GUSTS OF GREATER THAN 45 MPH CANNOT BE RULED OUT,
AND IF THAT POTENTIAL INCREASES, THEN A WIND ADVISORY FOR AT
LEAST A PORTION OF THE AREA MAY BE WARRANTED. THIS WOULD BE
HIGHLY UNUSUAL - OUR OFFICE HAS NOT ISSUED A SUMMERTIME WIND
ADVISORY IN OVER TWO DECADES.
AVIATION /16Z TUESDAY THROUGH SATURDAY/
LARGELY VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS. A
SCATTERED TO BROKEN CUMULUS FIELD OF 5-6 THOUSAND FEET HASS
DEVELOPED UNDER SOME STREAKS OF CIRRUS AHEAD OF THE NEXT
APPROACHING SHORTWAVE. THIS WAVE SHOULD BRING MID LEVEL CLOUDS
AND SCATTERED SHOWERS TO THE REGION OVERNIGHT. INCLUDED VCSH
MENTION FOR MOST TAF SITES, SAVE MGW. MINIMAL INSTABILITY COULD
RESULT IN AN ISOLATED THUNDERSTORM, BUT CHANCES ARE TOO LOW FOR
TAF INCLUSION. SHOWERS SHOULD PULL EAST OF THE REGION BY 12Z.
A LINGERING SCATTERED MID-LEVEL DECK IS EXPECTED, WITH WINDS
VEERING A BIT TOWARDS SOUTHWEST ONCE DAYTIME MIXING COMMENCES.
OUTLOOK...
RESTRICTIONS IN SHOWERS AND THUNDERSTORMS ARE EXPECTED
WEDNESDAY NIGHT INTO THURSDAY, WITH A POTENTIAL FOR SEVERE
STORMS AS WELL. SCATTERED SHOWERS AND LOCALIZED RESTRICTIONS ARE
POSSIBLE FRIDAY WITH A CROSSING SHORTWAVE TROUGH. VFR RETURNS
SATURDAY UNDER BUILDING HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL
AVIATION...CL
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