Scientific Forecaster Discussion
fxus61 kctp 202254
Area forecast discussion
National Weather Service State College PA
654 PM EDT Tue Aug 20 2019
it will remain very warm and humid through Wednesday. A warm
front lifting north across the state today will provide the
focus scattered, mainly afternoon showers and thunderstorms.
A pair of cold fronts will push southeast through the state late
Wednesday into early Thursday bringing cooler and much less
humid air will that will last into the weekend.
Near term /until 6 am Wednesday morning/...
sb convective available potential energy exceeding 1500 j/kg providing more than enough juice
for ongoing scattered storms over the lower susq this evening.
Some have gotten quite tall with 50dbz over 40k feet in southern
Dauphin County this hour, prompting a severe warning. No
significant damage reports received thus far. Very weak deep
layer shear is preventing storms from reaching the next level,
but still concerned for a localized microburst given the height
of some of these storms and dd CAPES over 1000 j/kg.
Only an isolated shower or thunderstorm will be seen elsewhere
across the souther half of central PA through dark. Activity
will decrease after dark, with another warm/muggy night on tap
for tonight. However, another isolated shower or thunderstorm
can't be ruled out overnight.
Min temps will be in the 60s...to around 70f in the southeast.
Short term /6 am Wednesday morning through 6 PM Wednesday/...
Wednesday will see slightly higher probability for active
convection, mainly during the afternoon and evening as a more
vigorous upper shortwave and associated cold front pushes
southeast through the County Warning Area late in the day and evening.
Storm Prediction Center has a broader marginal risk covering the majority of our County Warning Area on
Wednesday, at the SW edge of a fairly large slight risk area
across upstate New York and western New England.
Long term /Wednesday night through Tuesday/...
secondary surface cfront and cfa dropping southeast from the glakes
Thursday should trigger a few afternoon showers/thunderstorms and rain across
mainly the southeast half of PA. 700 mb temps will likely cool off by
at least 2-3c during the day Thursday.
Look for refreshingly cooler Max temps Thursday ranging from the
low to mid 70s over the northern mtns to the l-M 80s in the susq
valley. Rain risk will linger across south central PA on Friday
as the frontal boundary continues to sink southward into the
southern mid Atlantic.
A sprawling area of Canadian high pressure should bring a
multi-day stretch of fair weather to central PA Saturday to
Monday. Temperatures will be near average with pleasant and
warm afternoons and comfortably cool nights.
Aviation /00z Wednesday through Sunday/...
widespread VFR will continue into the evening, with only brief
restrictions this afternoon at terminals affected by the roaming
showers and thunderstorms.
Areas of low clouds and fog will form once again overnight,
before burning off within a couple of hours of sunrise Wed.
Showers and thunderstorms will once again boil up for Wednesday
afternoon and evening associated with a cold front. They will
have the potential to bring brief restrictions, gusty winds and
Thu...PM thunderstorms southeast 1/2.
Fri...chance of showers southern 1/4.
Sat-sun...am fog possible.