096
FXUS61 KPBZ 160616
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
216 AM EDT THU APR 16 2026
WHAT HAS CHANGED
FOR TODAY, THERE HAS BEEN A SLIGHT EASTWARD SHIFT IN THE
MARGINAL RISK AREA, WHICH NOW ENCOMPASSES VIRTUALLY ALL OF THE
FORECAST AREA. OTHERWISE, THERE WERE NO MAJOR CHANGES TO THE
FORECAST.
KEY MESSAGES
1) A MARGINAL RISK (LEVEL 1 OF 5) OF SEVERE THUNDERSTORMS EXISTS
FOR THIS AFTERNOON AND EVENING, WITH DAMAGING WIND GUSTS THE
PRIMARY THREAT. A BREAK IN THE CONVECTION PATTERN IS EXPECTED
FRIDAY.
2) A STRONGER COLD FRONT IS EXPECTED TO CROSS SATURDAY AFTERNOON
AND EVENING, WITH ANOTHER ROUND OF STRONG TO POTENTIALLY SEVERE
THUNDERSTORMS. DAMAGING WIND AGAIN APPEARS TO BE THE MOST LIKELY
THREAT.
3) MUCH ABOVE-NORMAL TEMPERATURES CONTINUE UNTIL THE SATURDAY
COLD FRONT PASSAGE. BEHIND IT, TEMPERATURES CRASH TO MUCH
BELOW-NORMAL LEVELS. FROST/FREEZE CONCERNS RETURN BY EARLY NEXT
WEEK, AND EVEN A FEW SUNDAY NIGHT SNOWFLAKES ARE POSSIBLE.
DISCUSSION
KEY MESSAGE 1...
AFTER A MORNING LULL, ANOTHER ROUND OF STRONG TO POTENTIALLY SEVERE
THUNDERSTORMS IS FORECAST THIS AFTERNOON AND EVENING. SURFACE LOW
PRESSURE CROSSES MICHIGAN INTO SOUTHERN ONTARIO TODAY, DRAGGING A
WEAK FRONT ACROSS THE UPPER OHIO VALLEY. A TRAILING MID-LEVEL
SHORTWAVE CROSSING THE LOWER GREAT LAKES SHOULD SPARK A ROUND OF
ISOLATED TO SCATTERED THUNDERSTORMS BY MID-AFTERNOON ACROSS CENTRAL
OHIO, WITH COVERAGE SLOWLY INCREASING INTO THE LATE AFTERNOON/EARLY
EVENING AS ACTIVITY CROSSES OUR REGION.
THE ENVIRONMENT WILL BE A LITTLE LESS FAVORABLE THAN WEDNESDAY FOR
SEVERE STORMS. ALTHOUGH DEEP-LAYER SHEAR OF AROUND 40 KNOTS WILL BE
PRESENT, INSTABILITY SHOULD BE SOMEWHAT LESS PRONOUNCED, TOPPING OUT
IN THE 500-1000 J/KG RANGE. FACTORS SUCH AS INCREASED CLOUD COVER,
LOWER DEWPOINTS, AND WEAKER MID-LEVEL LAPSE RATES ALL CONTRIBUTE TO
THIS LOWER LEVEL OF BUOYANCY. THE POOR LAPSE RATES POINT TO LOWER
HAIL POTENTIAL, WHILE WEAK TO ABSENT LOW-LEVEL CURVATURE TO
HODOGRAPHS WITH UNIFORM COLUMN SOUTHWEST FLOW SUGGEST LITTLE TORNADO
THREAT. THIS LEAVES ISOLATED DAMAGING WIND AS THE MOST LIKELY IMPACT
FROM THE STRONGER STORMS, ESPECIALLY IF THEY ORGANIZE INTO
CLUSTERS/SHORT LINES. SPC HAS MAINTAINED A MARGINAL RISK (LEVEL 1 OF
5) FOR THE FORECAST AREA.
A SECOND SHORTWAVE DIGGING ACROSS THE TENNESSEE VALLEY WILL HELP TO
DISLODGE WHAT HAS BEEN A STUBBORN SOUTHEAST CONUS RIDGE THURSDAY
NIGHT AS THE AFTERNOON AND EVENING SHOWERS AND STORMS WORK THEIR WAY
OUT AFTER SUNSET. BEHIND THIS WAVE, A BRIEF PERIOD OF MID-LEVEL
RIDGING SHOULD ALLOW FOR A BREAK FROM THE DAILY THUNDERSTORM
ACTIVITY FOR MOST OF FRIDAY AND FRIDAY NIGHT.
KEY MESSAGE 2...
A STRONGER COLD FRONT IS STILL SLATED TO CROSS DURING THE
AFTERNOON/EVENING HOURS OF SATURDAY. THIS BOUNDARY WILL PROVIDE THE
MOST FOCUSED LIFT OF THE PAST SEVERAL DAYS, WHICH COULD BE BETTER
FOR CONVECTIVE ORGANIZATION. THE MAIN QUESTION WITH THIS BOUNDARY
REMAINS TIMING, WHICH WOULD HAVE IMPLICATIONS ON HOW MUCH
INSTABILITY CAN BUILD ACROSS OUR REGION. THIS WILL DEPEND AT LEAST
IN PART ON THE SPEED AND ORIENTATION OF THE ASSOCIATED 500MB
SHORTWAVE TROUGH. ENSEMBLE CLUSTERS SUGGEST SOME FAIRLY MINOR
DIFFERENCES IN STRENGTH AND TIMING WITH THIS WAVE AS WELL AS THE
SURFACE BOUNDARY. HOWEVER, EVEN A 3-6 HOUR DIFFERENCE HAS NOTABLE
EFFECTS ON THE POTENTIAL LOCATION AND SEVERITY OF ANY ASSOCIATED
CONVECTION, AND THUS THE OVERALL IMPACT LEVEL REMAINS UNCERTAIN.
MACHINE-LEARNING GUIDANCE FROM NCAR AND CSU DO HIGHLIGHT OUR REGION
FOR AT LEAST SOME SEVERE STORM POTENTIAL. ENSEMBLE SOUNDINGS DURING
THAT PERIOD DEPICT GENERALLY POOR MID-LEVEL LAPSE RATES AND MODEST
LOW-LEVEL HODOGRAPH CURVATURE, SUGGESTING DAMAGING WIND GUSTS
CURRENTLY APPEAR TO BE THE MOST LIKELY IMPACT.
KEY MESSAGE 3...
MUCH ABOVE-NORMAL TEMPERATURES CONTINUE INTO SATURDAY AHEAD OF
THE EXPECTED STRONG COLD FRONT. TODAY, THE APPROACHING MID-LEVEL
TROUGH WILL BEGIN TO KNOCK DOWN THE ANOMALOUS 500MB HEIGHTS,
WHICH WERE ABOVE THE 95TH PERCENTILE YESTERDAY BUT WILL BE
MERELY AROUND 90TH PERCENTILE BY AFTERNOON. MORE ABUNDANT CLOUDS
WILL ALSO KEEP TEMPERATURES A BIT MORE IN CHECK. HIGH
TEMPERATURES IN THE LOWER 80S REMAIN FAVORED FOR MANY AREAS
SOUTH OF I-80, BUT RECORDS WILL LIKELY REMAIN A BIT OUT OF
REACH. ALL CLIMATE SITES HAVE 30 PERCENT OR LOWER CHANCES OF
TYING/BREAKING MARCH 16TH STANDARDS. MEANWHILE, RECORD WARM
MINIMUMS FOR TODAY ARE MORE IN JEOPARDY, WITH ALL CLIMATE
LOCATIONS SAVE ZZV HAVING A 70% OR GREATER CHANCE OF OCCURRENCE.
RIDGING RETURNS FRIDAY, BUT WITH LOWER ABSOLUTE 500MB HEIGHTS,
THUS RECORDS ARE NOT LIKELY. THERE MAY BE SOME MODEST POTENTIAL
TO APPROACH RECORDS ON SATURDAY, ESPECIALLY IF THE FRONT IS
LATER THAN CURRENTLY PROJECTED, ALLOWING FOR A LONGER PERIOD OF
WARM SOUTHWEST FLOW. NBM PROBABILITIES OF 80 OR WARMER MAY BE A
BIT OVERSTATED, BUT MUCH OF THE AREA FROM PITTSBURGH SOUTH
SHOULD HAVE AT LEAST A 50/50 SHOT OF REACHING THAT LEVEL.
MEANWHILE, BEHIND THE FRONT, THE SCRIPT FLIPS, AND NORTHEAST
CONUS TROUGHING LEADS TO DAYTIME HIGH TEMPERATURES SOME 10-15
DEGREES BELOW NORMAL FOR SUNDAY AND MONDAY, BEFORE APPROACHING
CLIMATOLOGY ON TUESDAY. FROST/FREEZE PRODUCTS MAY NEED TO BE
ISSUED BY EARLY NEXT WEEK, AND SOME SUNDAY NIGHT SNOWFLAKES ARE
A POSSIBILITY.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AREAWIDE VFR IS EXPECTED UNDER MID-LEVEL CLOUDS THROUGH THE
OVERNIGHT AND MORNING HOURS. CONTINUED ISOLATED SHOWERY ACTIVITY
IS EXPECTED FOR FKL/DUJ THROUGH ABOUT SUNRISE TODAY. CLOUD
DECKS WILL BEGIN TO LOWER IN THE AFTERNOON HOURS IN FRONT OF AN
APPROACHING COLD FRONT, BUT VFR CIGS ARE EXPECTED TO HOLD FIRM.
A LINE OF BROKEN STRONG TO SEVERE STORMS ARE EXPECTED ALONG THE
COLD FRONT. THESE STORMS CAN BRING BRIEF BOUTS OF MVFR
RESTRICTIONS OR A FEW DIPS TO IFR. IT IS POSSIBLE FOR THERE TO
BE 2 LINES OF STORMS, WITH ONE ALONG A PRE-FRONTAL TROUGH.
ALTOGETHER, CAMS ARE IN GOOD AGREEMENT ON A ~20Z APPROACH
TOWARDS THE PA/OH BORDER. TIMING HAS BEEN BROKEN DOWN WITH
PREVAILING GROUPS SHOWING THE GREATLY INCREASED CONFIDENCE IN
TIMING OF THESE STORMS AS OPPOSED TO PRIOR DAYS.
BEHIND THE COLD FRONT VFR CIGS CAN RETURN IN VCSH OR LIMITED
VCTS ACTIVITY BEFORE CIGS ARE EXPECTED TO BEGIN TO FALL AS WE
APPROACH SUNRISE ON FRIDAY.
WINDS WILL BE GUSTY ACROSS THE REGION THURSDAY, WITH SWERLY
GUSTS BETWEEN 20-25 KTS FOR MOST PORTS AHEAD OF THE FRONTAL
PASSAGE. BEHIND THE FRONT, WINDS SHIFT TO MORE WESTERLY AND
REMAIN GUSTY FOR A COUPLE HOURS BEFORE SUBSIDING.
OUTLOOK...
FRIDAY SHOULD BE MOSTLY DRY FOLLOWING THURSDAY EVENING'S WEAK
FRONTAL PASSAGE. HOWEVER, ANOTHER LOW PRESSURE SYSTEM AND A
STRONGER COLD FRONT APPROACH THE AREA ON SATURDAY, RETURNING
SHOWER AND THUNDERSTORM CHANCES (AND ASSOCIATED RESTRICTIONS) TO
THE REGION THROUGH THE WEEKEND. DRY WEATHER AND VFR CONDITIONS
ARE THEN FAVORED AS WE HEAD INTO EARLY NEXT WEEK WITH A PATTERN
SHIFT FOLLOWING THE WEEKEND COLD FRONT.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...CL
AVIATION...CERMAK/AK
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