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000
FXUS61 KCTP 291839
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
239 PM EDT Thu Sep 29 2016

.SYNOPSIS...
Showery conditions will prevail through tonight...with additional
moderate to locally heavy rainfall possible over the higher
elevations of the southern tier of central Pennsylvania through
early Friday. Only minor flooding impacts are likely across the
southern portions of central PA. Unsettled weather with
occasional lighter rain showers will persist into the weekend with
a gradual drying trend by early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
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2.5 to 3.5 inch amounts feel across southern tier overnight
through midday...with higher amounts likely on the east facing
slopes occurred across the southern tier. Flooding threat
remains...albeit low...with upslope areas susceptible to any
persistent upslope or training convective showers over the next
18 hours which could add another 1 to as much as 2 inches in some
spots.

Dry slot opver western PA with high cloud covering eastern brought
transition to low topped open cellular activity propagating from
southeast to northwest today. Thus a more showery regime took over
with times of little or no rainfall and other times with brief
moderate to heavy rates accumulating a few tenths of an inch at
time.

Moderate PW transport along with some elevated instability will
maintain a favorable environment for mdt-heavy rain/efficient
rainfall processes through this evening, while increasingly
diffluent flow aloft supports some training bands in addition to
the trend to low topped open cellular character. In
fact...training bands have organized over nrn VA/MD at mid
afternoon and are moving into the Laurels and South Central
Mountains...as anticipated earlier.

Still expecting storm totals of 2-4" over the remaining flood
watch area with locally 5"+ possible aloing the east-facing slopes
and highest terrain. Very dry antecedent conditions resulting in
3-6hr FFG values of 4+ inches along with below normal stream flows
should help to mitigate flooding to some extent, however if the
higher end amounts are realized flooding impacts/runoff issues
could become more serious.
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&&

.SHORT TERM /FRIDAY/...
The upper low continues to double back to MI on Friday before
slowly tracking eastward into the Lower Great Lakes over the
weekend. Strong E-SE LLJ and above normal PW along with
associated forcing on east/southeast side of upper low favors
scattered to numerous lighter rain showers through the period. The
mid range models are keying in on a mid level short wave trough
that could possibly increase rainfall rates and amounts through
Central PA as it is coupled with the LLJ and the PWATS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
The trend for early next week is toward dry weather as the
stubborn upper low is finally is kicked to the northeast by
upstream amplifying trough over the Nation`s mid section. High
pressure should regain control of the large scale pattern. FWIW
the 29/00z GFS is much faster vs. the ECMWF with the projected
path of TC Matthew, with the system nearing the NC coast by
Thursday morning.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
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Low cigs and shra persist across PA through Friday. Expect
predominantly IFR cigs through tonight at the higher terrain
airfields, including KBFD, KUNV, KAOO and KJST. At the lower
elevation airfields, while mvfr with sporadic ifr expected farther
north.

Outlook...

Fri-Sat...Low cigs/showers likely, mainly w mtns.

Sun...AM low cigs possible.

Mon...Showers/cig reductions possible at KBFD.

Tue...Fair.
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&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Friday morning for PAZ025-026-033>036-064-
065.

&&

$$
SYNOPSIS...DeVoir/Steinbugl
NEAR TERM...DeVoir/Steinbugl
SHORT TERM...DeVoir/Ceru/Steinbugl
LONG TERM...Steinbugl
AVIATION...DeVoir/Fitzgerald