668
FXUS61 KPBZ 041145
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
745 AM EDT SAT JUL 4 2026
WHAT HAS CHANGED
LITTLE CHANGE AS SEVERE THREATS REMAIN FOR TODAY WHILE
DIMINISHING THROUGH MONDAY WHILE FLOOD RISKS INCREASE.
KEY MESSAGES
1) DAILY THUNDERSTORMS LIKELY THROUGH MONDAY, GENERALLY FAVORING
AFTERNOON AND EVENINGS, WITH VARYING DEGREES OF SEVERE AND FLOOD
THREATS.
2) HOT AND HUMID CONDITIONS CONTINUE SATURDAY, WITH HEAT INDICES
PEAKING WHERE SUNSHINE IS MAXIMIZED.
DISCUSSION
KEY MESSAGE 1...
ENVIRONMENTAL RECOVERY AFTER FRIDAY'S CONVECTIVE ACTIVITY IS
ANTICIPATED BY THIS AFTERNOON, RESULTING IN 1200-2000 J/KG CAPE
AND AROUND 1000 J/KG DCAPE WITH WEAK SHEAR. SIMILAR TO FRIDAY,
ANY THUNDERSTORMS THAT BECOME ORGANIZED WILL UTILIZE THIS
ENVIRONMENT TO CREATE A DAMAGING WIND THREAT (WITH LOWER NOD TO
LARGE HAIL), GENERATED EITHER BY SINGLE-CELL DOWNBURST WINDS OR
VIA ORGANIZED CLUSTER STRAIGHT LINE WINDS. HOW STORMS INITIALLY
FORM AND EVOLVE REMAINS THE LARGER MYSTERY; THIS IS EVIDENCED BY
LARGE VARIANCES AMONG CONVECTIVE-ALLOWING MODELS IN STORM
PLACEMENT, ESPECIALLY IN THE WAKE OF FRIDAY'S ACTIVITY. THIS
DOESN'T EVEN ACCOUNT FOR ALTERATIONS POTENTIALLY CAUSED BY AN
MCS ONGOING ALONG THE MI/IN/OH BORDER THAT MODELS FAVOR
DISSIPATING BY DAWN. THUS, IT MAY NOT BE UNTIL A FEW HOURS
PRIOR DOES A CONSENSUS DEVELOP IN TIMING AND FAVORED AREAS FOR
THE CONVECTIVE THREATS.
AFTER A POTENTIALLY QUIET OVERNIGHT PERIOD, A SIMILAR OUTLOOK OF
UNCERTAINTY REMAINS FOR SUNDAY AS THE UPPER RIDGE CONTINUES ITS
SOUTHEAST SHIFT WHILE UPPER TROUGHING INCHES NEARER. ONE
ASPECT OF HIGHER CONFIDENCE FOR SUNDAY IS INCREASING MOISTURE
PROFILES THAT PUSH PWATS TOWARD THE 95TH PERCENTILE WITH
POTENTIAL WARM- RAIN PROCESSES CREATING HIGHER RAINFALL RATES
AND A FLASH FLOOD RISK; THE OTHER IS THE POTENTIAL FOR EXTRA
CLOUD COVER TO LIMIT BUOYANCY AS DRY AIR ALOFT VANISHES THAT
LENDS TO LOWER DAMAGING WIND PROBABILITIES.
SLOW PASSAGE OF THE UPPER TROUGH WILL MAINTAIN THUNDERSTORM
CHANCES MONDAY WHERE SBCAPE VALUES MAY NEAR 1000 J/KG, PWATS ARE
NEAR THE 90TH PERCENTILE AND SHEAR REMAINS WEAK. THIS SETUP
SIGNALS A LOWER (BUT NON-ZERO) DAMAGING WIND THREAT VERSUS
PREVIOUS DAYS WHILE MAINTAINING A FLASH FLOOD RISK.
KEY MESSAGE 2...
HOT AND HUMID CONDITIONS WILL CONTINUE TODAY, MOST NOTABLY IN
AREAS GENERALLY SOUTH OF I-80 AND WHERE INSOLATION CAN SUSTAIN
LONGEST PRIOR TO THUNDERSTORM DEVELOPMENT. THOUGH AREA HEAT
INDICES MAY NOT QUITE REACH HEADLINE CRITERIA, THE CUMULATIVE
EFFECTS OF PRIOR DAYS PLUS CONTINUED LIMITED NOCTURNAL COOLING
MEANS HEAT-RELATED IMPACTS ARE FAVORED TO CONTINUE. EVENTUALLY
LOWERING OF MAXIMUM TEMPERATURES THROUGH FALLING HEIGHTS AND
CLOUD COVER WILL LOWER THOSE IMPACTS THROUGH MONDAY, BUT LOWER
ELEVATION LOCATIONS MAY STILL SEE HEAT INDICES PEAK IN THE MID
90S.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
THE MORNING ACROSS THE AREA WILL FEATURE SOME IFR AND BELOW CIGS
AT FKL AND DUJ THROUGH AT LEAST 14Z THIA MORNING BEFORE
IMPROVING. AFTER THIS, VFR WILL PREVAIL UNTIL AFTERNOON
CONVECTION PRODUCES SOME RESTRICTIONS INTO THE EVENING. BY THE
20Z TO 21Z TIMEFRAME, SHOWERS AND THUNDERSTORM'S WILL, BEGIN
DEVELOPING TO THE NORTH. EXPECT SIGNIFICANT RESTRICTIONS AT THE
TERMINALS BETWEEN 22Z AND 04Z AS IFR AND BELOW CONDITIONS ARE
POSSIBLE WITHIN THUNDERSTORMS. THE CONVECTION SHOULD BEGIN TO
WEAKEN AND DISSIPATE BY 06Z. THE RESIDUAL MOISTURE WILL ALLOW
FOR FOG AND STRATUS TO DEVELOP BY 08Z AND PERSIST THROUGH THE
END OF THE TAF PERIOD.
OUTLOOK...
VFR FAVORED THROUGH THE WEEKEND OUTSIDE OF CONVECTIVE ACTIVITY
WHILE UPPER RIDGING SHIFTS SOUTHEAST AMID THE APPROACH/PASSAGE
OF AN UPPER LEVEL TROUGH. EACH DAY SEES INCREASING THUNDERSTORM
CHANCES THAT ARE CAPABLE OF IFR HEAVY RAIN AND GUSTY, ERRATIC
WINDS.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ007-013-014-
020-022-077.
EXTREME HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR PAZ021-
029-031-073-075.
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ039>041-
048>050.
EXTREME HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR
OHZ057>059-068-069.
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ001.
EXTREME HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR
WVZ002>004-012-021-509.
DISCUSSION...FRAZIER
AVIATION...SHALLENBERGER
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