634
FXUS61 KPBZ 130809
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
409 AM EDT SAT JUN 13 2026
WHAT HAS CHANGED
THE THREAT FOR SEVERE THUNDERSTORMS ON SUNDAY CONTINUES, WITH
THE TIMING LARGELY DEPENDENT ON THE POSITION AND PROGRESSION OF
THE COLD FRONT.
KEY MESSAGES
1) ISOLATED RIVER VALLEY FOG IN NORTHERN WV THIS MORNING,
OTHERWISE QUIET TODAY. THE POTENTIAL FOR STRONG TO SEVERE
STORMS IS EXPECTED TOMORROW AFTERNOON AND EVENING WITH A PASSING
COLD FRONT
2) QUIET WEATHER EXPECTED MONDAY THROUGH MID-WEEK; MONITORING
POTENTIAL HAZARDOUS WEATHER ON THURSDAY
DISCUSSION
KEY MESSAGE 1...
CONFIDENCE REMAINS HIGH THAT TRANQUIL AND DRY WEATHER WILL
PERSIST THROUGH THE NEXT 24 HOURS AS HIGH PRESSURE DOMINATES THE
REGION. PATCHY EARLY MORNING FOG REMAINS POSSIBLE SOUTH OF
I-70, PARTICULARLY ALONG THE RIDGES OF WEST VIRGINIA, WHERE
LINGERING LOW-LEVEL MOISTURE AND RADIATIONAL COOLING BENEATH
CLEARING SKIES MAY PROMOTE DEVELOPMENT.
AN APPROACHING UPPER-LEVEL TROUGH AND AN ADVANCING COLD FRONT
WILL INCREASE THE POTENTIAL FOR STRONG TO SEVERE STORMS ON
SUNDAY. SHOWERS AND ISOLATED THUNDERSTORMS MAY BEGIN MOVING INTO
THE REGION AS EARLY AS 7AM TO 9AM FROM THE SOUTHWEST, ASSOCIATED
WITH REMNANT CONVECTION THAT DEVELOPS ACROSS THE PLAINS AND
MIDWEST LATE THIS EVENING. CURRENT EXPECTATIONS ARE THAT
MORNING SHOWERS AND STORMS WILL REMAIN BELOW SEVERE LIMITS, WITH
LIGHTNING POSING THE PRIMARY HAZARD. HOWEVER, LINGERING
CONVECTION COULD HELP ENHANCE INSTABILITY THROUGH THE DAY AHEAD
OF THE APPROACHING COLD FRONT IN THE EVENING, SETTING THE STAGE
FOR STRONGER STORM DEVELOPMENT. HIGH RESOLUTION GUIDANCE SUGGEST
THE PRIME TIME FOR THESE STRONGER UPDRAFTS WOULD BE BETWEEN 2PM
AND 6PM, WITH THE THREAT ENDING WEST TO EAST AS THE COLD FRONT
DRIFTS SOUTHWEST LATE IN THE EVENING.
TORNADOES AND DAMAGING WINDS WILL LIKELY BE THE PRIMARY THREAT
GIVEN EFFECTIVE SHEAR NEAR 40KTS AND THE POTENTIAL FOR LOW CIGS
TO PROMOTE STRETCHING OF ROTATING UPDRAFTS. HAIL COULD OCCUR BUT
GIVEN AN ENHANCED FREEZING LEVEL (13-14KFT), MELTING MAY POSE
A PROBLEM FOR ANYTHING LARGER THAN A QUARTER. ALSO, THERE IS
NOT A TON OF DRY AIR ALOFT GIVEN THE POTENTIAL OF EARLY MORNING
CONVECTION TO PROMPT HAIL GROWTH. EXPECT HEAVY RAINFALL RATES
WITH THIS PASSING DISTURBANCE, PWATS RANGE BETWEEN 1.5-1.8
INCHES. HOWEVER, WITH SUFFICIENT SHEAR, THE FLOOD POTENTIAL
SHOULD REMAIN ON THE LOW SIDE; EXPECT NARROW SWATHS OF HALF TO
ONE INCH OF RAINFALL WITH ADVANCING SHOWERS AND STORMS IN
ISOLATED AREAS.
THE PROBABILITY OF STRONG TO SEVERE STORMS DECREASES BETWEEN 9PM
TO 11PM, AS THE COLD FRONT EXITS EAST.
KEY MESSAGE 2...
THE PROBABILITY OF HAZARDOUS WEATHER REMAINS LOW MONDAY THROUGH
WEDNESDAY IN THE WAKE OF A COLD FRONT. HIGH TEMPERATURES MONDAY
INTO TUESDAY WILL LIKELY TREND BELOW AVERAGE WITH ADVANCING COLD
AIR ALOFT AND LINGERING CLOUDS.
A NOTABLE PATTERN CHANGE IS EXPECTED MIDWEEK (THURSDAY) AS THE
THROUGH OVER THE GREAT LAKES AND NORTHEAST THAT BROUGHT COOLER
CONDITIONS LIFTS NORTH, ALLOWING A WARM AND MORE HUMID AIR MASS
TO RETURN TO THE REGION. THIS SHIFT MAY BRING AN INCREASED RISK
OF SEVERE WEATHER AND FLOODING ACROSS PORTIONS OF THE OHIO
RIVER VALLEY. CURRENT MACHINE LEARNING GUIDANCE INDICATES A
15-40% CHANCE OF SEVERE STORMS EXTENDING FROM INDIANA TO
SOUTHERN NEW YORK, LIKELY DRIVEN BY LONG-RANGE MODEL PROJECTIONS
OF AN UNUSUALLY STRONG LOW-LEVEL JET ON THE ORDER OF 60-70KTS.
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
THE MIDWEST, THOUGH THE EVOLUTION OF THE PATTERN WILL NEED TO
BE MONITORED CLOSELY IN THE COMING DAYS.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
A BRIEF PERIOD OF FOG MAY AFFECT MGW EARLY THIS MORNING DUE TO
LINGERING LOW-LEVEL MOISTURE AND RADIATIONAL COOLING BENEATH
CLEARING SKIES. OTHERWISE, HIGH CONFIDENCE IN VFR CONDITIONS
TODAY INTO EARLY TOMORROW MORNING UNDER HIGH PRESSURE. WINDS
WILL SHIFT FROM THE WEST TO THE SOUTHWEST OVER THE NEXT 24 HOURS
WITH AN APPROACHING TROUGH FROM THE WEST.
OUTLOOK...
MID AND LOW-LVL CLOUDS WILL BUILD EARLY TOMORROW MORNING, MAINLY
AFTER 11Z, WITH WARM AND MOISTURE AIR ADVECTION FROM THE
SOUTHWEST.
SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO ADVANCE INTO
THE REGION BETWEEN 13Z TO 16Z. STRONGER STORMS MAY DEVELOP AHEAD
OR ALONG A COLD FRONT BETWEEN 19Z TO 23Z. MVFR TO IFR CIGS, LOW
VIS, GUSTY WINDS, AND LIGHTNING ARE EXPECTED WITH STORMS.
THUNDERSTORM CHANCE DECREASE BETWEEN 01Z TO 04Z FROM WEST TO
EAST AS THE COLD FRONT EXITS.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...HEFFERAN
AVIATION...HEFFERAN
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