999
FXUS61 KCTP 201744
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
144 PM EDT SUN SEP 20 2026
WHAT HAS CHANGED
* ADJUSTED POPS/WX TO MATCH CURRENT RADAR TRENDS
* MENTIONED HEAVY RAIN ACROSS THE SRN THIRD TODAY
KEY MESSAGES
1) PERIODS OF RAIN TODAY, PERHAPS A FEW THUNDERSTORMS IN THE
SOUTH.
2) RAINY POTENTIAL CONTINUES INTO MUCH OF THIS WEEK, ALTHOUGH
UNCERTAINTY REMAINS IN THE DETAILS. ON THE COOL SIDE AS WELL.
DISCUSSION
KEY MESSAGE 1: PERIODS OF RAIN TODAY, PERHAPS A FEW
THUNDERSTORMS IN THE SOUTH.
AREA OF SHOWERS DEVELOPING OVER FAR SWRN PA MAY SLIDE JUST TO
OUR SOUTH AS FORCING DIPS S. HOWEVER, EARLIER HEAVY RAIN AND RAP
PROGS INDICATE THAT AT LEAST AREAS S OF THE TURNPIKE, IF NOT
RTE 22, COULD HAVE SOME POCKETS OF HEAVY RAIN. THAT IS ALSO THE
AREA THAT RECEIVED THE HEAVIEST RAIN OVERNIGHT. UNCERTAINTY IN
PLACEMENT OF HEAVY RAIN - IF ANYWHERE - IN THE CWA TODAY WILL
LEAN US AWAY FROM A FLOOD WATCH AT THIS POINT IN TIME. HOWEVER,
HEAVY RAIN IS STILL POSSIBLE.
PREV...
A WEAK AREA OF SFC LOW PRESSURE NEAR THE PA-OH BORDER WILL PUSH
EAST THROUGH THE DAY TODAY, RESULTING IN PERIODS OF RAINFALL. A
THUNDERSTORM OR TWO CAN NOT BE RULED OUT ACROSS THE SOUTH. RAIN
WILL BE STEADIEST AND HEAVIEST IN THE MORNING, AND TREND
LIGHTER AND MORE SCATTERED THROUGH THE DAY. ADDITIONAL RAINFALL
AMOUNTS GENERALLY 0.10 - 0.50" WITH LOCALIZED HIGHER AMTS
POSSIBLE IN REPEAT HEAVIER RAINFALL.
-------------------------------------------------------------
KEY MESSAGE 2: RAINY POTENTIAL CONTINUES INTO MUCH OF THIS
WEEK, ALTHOUGH UNCERTAINTY REMAINS IN THE DETAILS. ON THE COOL
SIDE AS WELL.
A LARGE HIGH OVER QUEBEC WILL PUSH SOUTHWARD ON MONDAY, GIVING
THE AREA A CHANCE FOR DRY CONDITIONS, ESPECIALLY ACROSS THE
NORTHERN TIER. HOWEVER, SEVERAL CAMS ARE NOW INDICATING A BATCH
OF LIGHT RAIN WILL MOVE INTO THE LAURELS FROM THE WEST. WINDS
WILL BE FROM THE E TO NE ON MONDAY, GIVING US OUR FIRST TASTE OF
COLD AIR DAMMING WITH HIGHS ONLY IN THE 60S TO NEAR 70.
HEADING INTO TUESDAY AND WEDNESDAY, THE WEDGE OF COLDER AND
MORE STABLE AIR WILL DEEPEN OVER THE AREA THANKS TO BUILDING
HIGH PRESSURE TO THE NORTH. AN UPPER TROUGH APPROACHING FROM THE
WEST WILL PUSH WARMER AIR UP AND OVER THIS COLD WEDGE, LIKELY
RESULTING IN RAIN. IN THIS COLD AIR DAMMING, HIGH TEMPS ARE
EXPECTED TO BE IN THE 50S TO NEAR 60. AT THIS TIME, THE HIGHEST
POPS ARE OVER THE WEST AND SOUTH, GIVEN AN INVERTED TROUGH.
THURSDAY AND FRIDAY MAY END UP DRY, AS A COASTAL STORM DEVELOPS
ALONG THE ATLANTIC COAST AND WRAPS DRY AIR AROUND THE WESTERN
SIDE. HOWEVER, MODEL GUIDANCE IS STILL SHOWING LARGE SPREAD IN
THE EVOLUTION OF A COASTAL SYSTEM REGARDING ITS FORWARD SPEED
AND LOCATION. SLOW MOVING REX BLOCK PATTERNS CAN BE PARTICULARLY
DIFFICULT TO FORECAST.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
SCATTERED RAIN CONTINUES TO PLAGUE THE AIRSPACE THIS AFTERNOON
ALONG WITH OVERCAST SKIES AND LOW CLOUDS. MANY AREAS WILL
CONTINUE TO SEE MVFR OR LOWER CEILINGS THROUGH THE REMAINDER OF
THIS AFTERNOON AND INTO TONIGHT. RAIN WILL BE LIKELY ACROSS ALL
AIRFIELDS OVER THE NEXT 12 HOURS, AND ANY SITE IMPACTED BY
PRECIPITATION WILL SEE A REDUCTION IN VISIBILITY. STRENGTH OF
THESE RAIN SHOWERS REMAINS UNCERTAIN, BUT RADAR RETURNS AS OF
18Z SUGGEST RAIN IS LIGHT OVERALL. TIMING OUT THE MAIN LINE OF
PRECIPITATION, IT IS EXPECTED TO RESUME RAINING OVER THE WESTERN
TERMINALS OF BFD AND JST NEAR 20Z.
TONIGHT LINGERING RAIN AND LOW CEILINGS WILL KEEP FLIGHT
CONDITIONS POOR. THERE IS SOME SUGGESTION FROM THE LAMP AND
NAM-MOS THAT A BRIEF PERIOD OF VFR IS POSSIBLE AT IPT NEAR 09Z,
BUT CONFIDENCE REMAINS LOW WITH THE MORE LIKELY SOLUTION WILL BE
CONTINUED MVFR TO IFR CEILINGS. IMPROVEMENT MONDAY MORNING WILL
BE VERY SLOW, WITH CLOUDS NOT EXPECTED TO FULLY SCATTER TO VFR
CONDITIONS UNTIL THE LATE MORNING/EARLY AFTERNOON.
OUTLOOK...
TUE-THU...RESTRICTIONS POSSIBLE FROM -SHRA/BR AND LOW CEILINGS,
MAINLY S.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...DANGELO/COLBERT
KEY MESSAGES...COLBERT/MARTIN
DISCUSSION...DANGELO/COLBERT/MARTIN
AVIATION...BOWEN
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