423
FXUS61 KCTP 131827
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
227 PM EDT WED MAY 13 2026
WHAT HAS CHANGED
* THUNDERSTORM INITIATION UNDERWAY ACROSS WESTERN PA. SEVERAL
REPORTS OF FREQUENT LIGHTNING AND PEA SIZE HAIL THUS FAR.
KEY MESSAGES
1) A LINE OF THUNDERSTORMS THIS AFTERNOON AND EVENING PRECEDES
UNSEASONABLY COOL THURSDAY. THUNDERSTORMS MAY CONTAIN GUSTY
WINDS AND SMALL HAIL.
2) SIGNIFICANT SUMMERLIKE WARMUP RAMPS INTO EARLY NEXT WEEK
WITH THE HIGHEST TEMPERATURES OF THE YEAR SO FAR.
DISCUSSION
KEY MESSAGE 1: A LINE OF THUNDERSTORMS THIS AFTERNOON AND
EVENING PRECEDES UNSEASONABLY COOL THURSDAY. THUNDERSTORMS MAY
CONTAIN GUSTY WINDS AND SMALL HAIL.
A SEASONABLY STRONG UPPER LEVEL TROUGH WILL DIG THROUGH THE
GREAT LAKES/OHIO VALLEY TODAY AND DEVELOP INTO A CLOSED LOW OVER
THE NORTHERN MID-ATLANTIC AND SOUTHERN NEW ENGLAND REGION BEFORE
EJECTING TO THE NORTHEAST ON FRIDAY. THE ASSOCIATED SFC LOW
MOVING EAST FROM LOWER MICHIGAN TOWARD NORTHERN NEW YORK WILL
DRAG A TRAILING COLD FRONT ACROSS THE ALLEGHENIES THIS AFTERNOON
AND EVENING. STEEPENING MIDLEVEL LAPSE RATES, ESPECIALLY IN
NORTH CENTRAL AND NW PA, WILL SUPPORT CONVECTION WITH FREQUENT
LIGHTNING AND MOSTLY PEA TO DIME SIZE HAIL, ALTHOUGH SOME OF THE
STRONGEST CELLS COULD CONTAIN QUARTER SIZE HAIL. SUFFICIENT
(30-40KT) DEEP LAYER SHEAR AND STEEPENING LOW LEVEL LAPSE RATES
SUPPORT A MARGINAL WIND THREAT AS WELL.
THE HREF/REFS SHOW THE PRIMARY FRONTAL BAND EXITING THE EASTERN
PORTION OF THE CWA AFTER 14/03Z. IF THERE IS SOME CLEARING
OVERNIGHT (BEST CHANCE FROM THE SUSQ RIVER EASTWARD), MOIST LOW
LEVELS CLOUD RESULT IN PATCHY FOG INTO EARLY THU AM. PLENTY OF
CLOUDS LINGERING ACROSS THE WESTERN HIGHLANDS SHOULD PROHIBIT
FOG IN THAT AREA.
SCATTERED SHOWERS LINGER INTO THURSDAY BENEATH THE UPPER LOW.
THURSDAY WILL BE THE COLDEST DAY OF THE WEEK. MAX TEMPS WILL BE
UNSEASONABLY COOL AND QUITE CHILLY FOR MID MAY WITH HIGHS IN
THE 45-60F RANGE OR 10 TO 20 DEGREES BELOW THE HISTORICAL
AVERAGE (FREQUENT 20-25 MPH WIND GUSTS WILL ONLY ADD TO THE
CHILL).
CONDITIONS WILL DRY OUT ON FRIDAY WITH DAYTIME HIGHS REBOUNDING
+10-20 DEGREES VS. THURSDAY.
KEY MESSAGE 2: SIGNIFICANT SUMMERLIKE WARMUP RAMPS INTO EARLY
NEXT WEEK WITH THE HIGHEST TEMPERATURES OF THE YEAR SO FAR.
AFTER A COOL START TO MAY, GUIDANCE CONTINUES TO SIGNAL A
SIGNIFICANT WARMUP ON THE HORIZON FOR THIS WEEKEND INTO EARLY
NEXT WEEK. THIS LARGE SCALE PATTERN SHIFT SHOULD DELIVER A
RATHER SUDDEN WARM SURGE WITH MAX TEMPS PROJECTED TO REACH WELL
INTO THE 80S AND EVEN LOWER 90S. DAILY RECORD HIGHS MAY BE
CHALLENGED BASED ON THE CURRENT FCST MONDAY AND TUESDAY.
THERE MAY BE SOME POTENTIAL HEATRISK CONSIDERATIONS LOOMING FOR
EARLY NEXT WEEK. THIS STEMS NOT ONLY WITH THE FORECAST HIGH
TEMPERATURES, BUT ALSO FROM AN ACCLIMATION PERSPECTIVE
ESPECIALLY AFTER A RATHER COOL STRETCH OF WEATHER DURING THE
FIRST HALF OF MAY. PROBABILISTIC HEATRISK SHOWS >50% ODDS FOR
MODERATE OR HIGHER LEVELS ACROSS SOUTH CENTRAL PA WITH FCST
HEAT INDEX VALUES STARTING TO EXCEED 95F MONDAY AND TUESDAY.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
EXPECT TSRA ACTIVITY TO PICK UP FROM NW TO SE ALONG AND AHEAD OF
A COLD FRONT. BFD WILL SEE A GLANCING BLOW FROM A THUNDERSTORM BY
19Z, WITH SMALL HAIL AND STRONG GUSTY WINDS POSSIBLE ESPECIALLY
JUST NORTH OF THE AIRFIELD. TSRA WILL THEN BE POSSIBLE AT JST,
AOO, UNV, AND IPT BY LATE AFTERNOON TO EARLY EVENING. STORMS
WILL BE ON A WEAKENING TREND AS THE ARRIVE IN MDT/LNS AFTER 00Z.
AS THE UPPER LEVEL LOW DROPS TO THE SOUTH TONIGHT INTO THURSDAY,
MOISTURE WILL WRAP AROUND THE LOW. THIS WILL RESULT IN LOW
STRATUS AND SHOWERS ESPECIALLY ACROSS THE MOUNTAINS. A BRIEF
WINDOW FOR CLEARING LATER TONIGHT IN THE EAST MAY RESULT IN
PATCHY FOG ALONG AND EAST OF THE SUSQ RIVER. LOW STRATUS WILL
RESULT IN CIG RESTRICTIONS IN THE WESTERN AIRFIELDS ALL DAY
THURSDAY, POTENTIALLY DROPPING AS LOW AS LIFR AT BFD AND JST
LATER TONIGHT INTO EARLY THURSDAY.
CONDITIONS WILL IMPROVE LATER ON FRIDAY, AS THE LOW MOVES AWAY
FROM THE AREA.
OUTLOOK...
THU...LINGERING CLOUDS AND SHOWERS WITH RESTRICTIONS NORTH/WEST
AND IMPROVEMENT SOUTHEAST.
FRI...VFR LIKELY.
SAT-MON...VFR IS LIKELY MUCH OF THE TIME, ALTHOUGH BRIEF
RESTRICTIONS ARE POSSIBLE WITH ISOLATED AFTERNOON/EVENING
SHOWERS AND THUNDERSTORMS.
CLIMATE
RECORD LOW TEMPERATURE OF 25 DEGREES WAS TIED (1963) AT
BRADFORD YESTERDAY.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...COLBERT
KEY MESSAGES...STEINBUGL/COLBERT
DISCUSSION...STEINBUGL/COLBERT
AVIATION...COLBERT/MARTIN
CLIMATE...STEINBUGL
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