Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 261950
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
350 PM EDT Wed Jul 26 2017

.SYNOPSIS...
A cold front will push across the area Thursday night and
Friday morning. The front will likely stall along the Maryland
border for Friday. Heavy rain is possible Friday and Friday
night. A much cooler airmass will overspread the commonwealth
over the weekend and dry and slightly cooler than normal
weather will last into mid-week.

&&

.NEAR TERM /UNTIL 11 PM THIS EVENING/...
Still some clouds across the region this afternoon. Took
out mention of showers.

Overall a nice summer evening.

&&

.SHORT TERM /11 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Did cut back QPF some on Thursday.

SPC cut back on slight risk area.

Best instability to the south, while cold front further north on
Thursday, so expect 2 areas of showers and storms. One with the
front to the north, and one late, with low pressure moving
east.

Main chance of heavier rain will be later on Friday, but a
complex situation, as upper lvl low lags the sfc low, and models
may suffer from convective feedback.

DSS briefing and HWO updated.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Main story in the long term is the change from a muggy, stormy,
and wet day on Friday to a very dry and fair pattern for the
rest of the term. A strong short wave trough is slated to push
across the Great Lakes and Ohio Valley Friday. This should help
to deepen at least one ripple of low pressure along an old
front. The front will be over srn PA or MD at first and heavy
rain is possible. WPC hydro outlook for Fri-night is for a SLGT
risk of excessive rainfall. QPF from some output is over 3
inches total for the southern third to half of the area. Plumes
from GEFS have averages of at least 2 inches there. Lighter
amounts are fcst for the northern half of the area. Convection
and mean westerly flow aloft and light winds at the low levels
seem likely to produce much higher point amounts.

The trough rounds the base of a long-wave trough after it passes
our longitude, and clears things out nicely. This should happen
sometime Sat. Will linger POPs in the S for the day Sat, but go
very dry and sunny/clear for the next 2-3 days. Scattered
diurnal convection may then start to pop up - esp in NY state
Tues/Wed. But, the risk of a shra/tsra in PA is very low until
at least Wed as the humidity rises back to more-August like
values.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
Conditions VFR now.

Some fog possible late tonight. However, clouds will
be moving in late, so limited fog to the southeast late
for a few hours.

Some chance of showers and storms on Thu, but nothing
widespread. Used VCSH for now.

More widespread showers and storms on Friday will be
possible.

.OUTLOOK...

Fri...Scattered SHRA north with more numerous and heavier
SHRA/TSRA across the south.

Sat-Mon...No sig wx.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Dangelo
NEAR TERM...Martin
SHORT TERM...Martin
LONG TERM...Dangelo
AVIATION...Martin


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