Area Forecast Discussion
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FXUS61 KCTP 291423
Area Forecast Discussion
National Weather Service State College PA
1023 AM EDT Thu Sep 29 2016
A widespread moderate to locally heavy rain event will continue
through tonight. Minor flooding impacts are likely across the
southern half 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/...
2.5 to 3.5 inch amounts trickling in across southern tier from
overnight rainfall...right on track with forecasts for this event.
Dry slot with high clouds peeling off to the east spells
transition to low topped open cellular activity propogating from
southeast to northwest today...a more showery regime 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. Strong upslope
flow still moderate PW transport along with some elevated
instability will maintain a favorable environment for heavy
rain/efficient rainfall processes through this afternoon, while
increasingly diffluent flow aloft supports some training bands in
addition to the trend to low topped open cellular character. As
the upper low settles a little further south, backing flow should
shift the heavy rain focus back toward the upslope regions of the
Laurel Highlands this afternoon into tonight.
Still calling for widespread 2-4" over the flood watch area with
locally 4-6" most likely across 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.
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
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.
.LONG TERM /MONDAY 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
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
Increasingly moist easterly flow will will produce low cigs and
rain across central Pa today. Model soundings and latest SREF
output support predominantly IFR cigs through this evening at the
higher terrain airfields, including KBFD, KUNV, KAOO and KJST. At
the lower elevation airfields, predominantly MVFR cigs are
expected today at KIPT, KMDT and KLNS. However, periodic IFR is
likely this morning associated with bouts of heavier rain.
Fri-Sat...Low cigs/showers likely, mainly w mtns.
Sun...AM low cigs possible.
Mon...Showers/cig reductions possible at KBFD.
Flood Watch through Friday morning for PAZ024>028-033>036-056-