Monday, April 24, 2017, 10:42 PM EDT
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Area Forecast Discussion
||Wed, Dec 31, 7:00pm EST
FXUS61 KCTP 241910
Area Forecast Discussion
National Weather Service State College PA
310 PM EDT Mon Apr 24 2017
A storm system over the southeastern states will begin to make
slow progress northward along the coast over the next several
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Rain continues to advance from the south. Showers remain
scattered as lower atmosphere is fairly dry. Have tried to
refine the timing and northward extent of the rain and opaque
cloud cover for the near term. Overall, the timing is similar
between all the guidance. QPF will be light today, on the order
of a tenth of an inch or less south of I-80 and a tenth to
quarter of an inch south of the turnpike. Maxes should be above
normals in the north but below normal in the south. Temps
through southern and central PA are in low 60s where the mainly
sunny Northern portion of PA has reached the 70s.
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
The guidance is very consistent with timing and placement of the
major features. Deep easterly flow will slide up the coast into
PA through the short term period. Moisture will slowly
infiltrate the lower levels and rainfall will become more
widespread overnight into Tuesday morning. The confidence in
occurrence of the decent rain is highest tomorrow afternoon,
especially through the eastern half of the region. However, the
tilt of the trough which the upper low is associated with is a
little fuzzy. With a more- negative tilt it may move a little
faster, and bands of rain may move more quickly. This would
probably keep the rain lighter at any one location. Looking at
latest plumes keep precip total/accumulation around 0.5 through
the period. Most of this rain should be out of stable profiles,
so thunder and big totals are not likely. Temps will be
seasonably mild overnight tonight. Maxes on Tues will be
homogeneous in the u50s to low 60s in the far northwest where
skies will see some sun.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
The upper low is progged to take a right turn as or even before
it gets to our latitude. As it pulls away to the east, the
chance of rain drops off Tuesday night. It will get warm fast.
It should feel like summer through the second half of the week.
As the 500 hPa low fills and the attendant low moves to our
northeast the chance of rain should fall off Wednesday into
Wednesday evening. Our 850 hPa temperatures will rise rapidly
Wednesday and it should be noticeably warmer Wednesday relative
to Monday and Tuesday.
Thursday into Saturday the 850 hPa temperatures will be well
above normal, mainly in the 14 to 16C range and we will be on
the western edge of a rather impressive early season subtropical
Thursday through at least Saturday should be very warm and
humid. We should have several days with high temperatures around
80. Thursday into Friday will see the passage of large upper
level trough. Have left broad POPS as this trough will move a
corresponding front through.
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
High pressure and associated dry air mass over Pennsylvania will
keep widespread VFR conditions and light winds through the
afternoon over much of PA. Low pressure lifting up the east
coast will spread lowering clouds and spotty light rain into
southern Pa through late this afternoon. The dry air in the low
levels should keep conditions VFR. However, model soundings and
SREF prob charts suggest MVFR conditions will become likely by
this evening across southern Pa, with IFR even possible at
AOO/JST. Overnight tonight into tomorrow IFR and lower cigs are
possible encroaching from the south to the north beginning
around 06Z. Expect IFR possible at most TAF sites and possibly
continuing into tomorrow afternoon.
Tue...Rain/low CIGs likely.
Wed...AM rain/low CIGs possible.
Thu...AM fog possible. PM tsra impacts possible.
Fri...PM tsra impacts possible.