Scientific Forecaster Discussion
fxus61 kctp 211537
Area forecast discussion
National Weather Service State College PA
1137 am EDT Sat Sep 21 2019
A ridge of high pressure will remain in place until a cold front
provides a brief cool down early next week. After high pressure
returns for Tuesday and Wednesday, another cold front will move
our way for Thursday and Friday.
Near term /until 6 PM this evening/...
A weak shortwave topping the big-burly upper ridge over the
eastern US may be just enough to spark a stray shower or
thunderstorm over western areas this afternoon. Otherwise what
we will see is the surface high slip off to our southeast allowing a
moistening southerly flow to return to the region. Dewpoints
that have been in the refreshing 40s and 50s will start to creep
up into the 60s, adding a bit of humidity to the afternoon
warmth that will range from the mid and upper 70s over the
northern tier to the mid 80s over the lower susq valley.
The warmth and increasing humidity will lead to CAPES in the
1500-2000j range across our SW zones this afteroon and early
evening. This instability will support isolated showers and
perhaps a stray thunderstorm near and to the SW of a line from
kfig to kaoo and khgr. Slight chance pops seem the order of the
day given the very isolated portrayals of the various cams for
the afternoon and evening.
Short term /6 PM this evening through 6 am Sunday/...
heights and temps aloft will rise again tonight and Sunday,
leading to a fair conditions at night and mostly sunny and a
pleasantly warm early autumn day with temps well into the 70s
across the northern and western mtns, and at least the mid 80s
in the southeast zones. It will feel more humid as sfc dewpoints rise
to the 60-65f range on Sunday. High temps will stay anomalously
warm tonight through Sunday with mins in the low 60s running
about 10 deg f warmer than normal in most of central and ern PA
but as much as 15 deg f or so across the western mtns of PA.
Long term /Sunday through Friday/...
the models are coming into agreement on the tracking of a cold
front that will move through the area Monday. This system will
likely be accompanied by a round of generally light showers. It
should move through the region quickly with a return to fair and
slightly warmer than seasonable weather Tue/Wed. High pressure
should build southeast from the grt lks mid next week.
Aviation /16z Saturday through Wednesday/...
Satellite shows the early fog has all melted away leaving
widespread VFR with a light variable breeze.
An increase in low level moisture should result in scattered
cumulus this afternoon with a spotty/isolated shower possible
across the western 1/2 of the airspace.
Valley fog is likely to redevelop tonight with local
restrictions into early Sunday morning.
Sun...am fog. VFR.
Mon...sct showers/isold T-storms as a cold front crosses the
Tue...MVFR cigs possible north/west.
Wed...VFR/no sig wx.
autumn officially arrives at 3:50 a.M. EDT, on Monday, sept. 23.
near term...la corte/Lambert