Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KCTP 232002
Area Forecast Discussion
National Weather Service State College PA
402 PM EDT MON MAY 23 2016
The slow moving storm system that brought rainy cool weather all
weekend will slowly edge away from the region today and Tuesday.
A noticeably warmer and more summer-like pattern is forecast from
mid week into the holiday weekend.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Showers are developing as expected with the more organized band
over Schuykill County. This band is headed toward the Harrisburg
area and showers are forming west of it. There is a good chance of
showers and thunderstorms in the York-Harrisburg-Lancaster area in
the next few hours. HRRR gets these out after about 5-6 PM.
A second band is less organized over central areas and shows less
organization. Cannot rule out isolated showers this afternoon in
central areas through late afternoon.
Farther north and west chance of showers is very low.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Most areas will clear out overnight. In areas of rain this
afternoon increased chance patchy valley fog.
Tuesday looks to be a generally good day. Low probability of
precipitation. Mostly sunny day.
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --Extended guidance continues the idea the development of an eastern
ridge/western trough pattern, bringing the arrival of the first
extended period of summer-like temperatures and humidity.
By Wednesday... central PA will be under rising heights as the
low lifts out and the ridge bulges east. At the same time a
weakening back door cold front will be sliding out of Canada into
the rising heights aloft. The models use this to develop scattered
showers and thunderstorms Wed afternoon and evening. Precip
confidence is never terribly high with surface fronts moving into
By Thursday we will be embedded in a broad wsw flow aloft.
Slightly above normal PWATS support the idea that humidity will
become noticeable over most of the area for the first time this
warm season. It also means we will be susceptible to mainly
afternoon convection pretty much on a daily basis into the
weekend. The limiting factor will be the eventual sharpness of the
upper ridge and how warm we manage to get aloft. The GFS is very
aggressive poking the Bermuda ridge strongly up over the eastern
U.S. Saturday while the ECMWF is a little flatter. The NAEFS is
more in line with the GFS which hints that Saturday could be the
day with smallest convective chances. I don`t have anything more
than chance pops in the extended given the muddy nature of the
ridge and low confidence that it will be able to shield us from
upstream convection that will be embedded in the flow.
The highest confidence part of the forecast is for temperatures to
be above normal through the end of the month.
-- End Changed Discussion --
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
A band of rain showers has developed in southeast areas. The
threat of showers and thunderstorms has increased for KSEG-KMDT-
KLNS-THV area this afternoon as the line of showers to the
northeast is heading toward the region.
MVFR possible in the showers this afternoon. There is a risk of
some more widely scattered showers and storms in central areas
from KIPT to KJST.
Most or all activity should diminish before sunset. Mainly VFR
overnight perhaps patchy MVFR in some valleys.
Tue-Wed...VFR/No sig wx expected.
Thu-Fri...Chance of mainly P.M. showers/tstms.