Latest Area Forecast Discussion for Central PA

Here is the latest Area Forecast Discussion for Central PA

This text statement is the latest forecast reasoning from the NWS in State College, PA

See the links at the bottom of the page for previous issuances/versions of the statement as well as our other text statements.

578
FXUS61 KCTP 201136
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
736 AM EDT Sun Jun 20 2021

.SYNOPSIS...
Very warm and muggy conditions expected for Father`s Day with an
isolated strong thunderstorm possible in the afternoon. Heat and
humidity will peak on Monday with a slight risk of severe storms.
Showers exit on Tuesday followed by cooler and more comfortable
weather through midweek. Temperatures return to seasonal levels
by late week with an increasing chance of rain into next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
0730AM/1130Z: Radar trends show showers fading over the northern
tier with complex of t-storms over extreme SW PA tracking toward
the Laurel Highlands by 14Z. Fog/shallow stratus (some locally
dense) will dissipate within the next 1-2 hours giving way to a
mix of clouds and sunshine.

Previous Discussion: 445 AM EDT Sun Jun 20 2021

Warm front lifts north of the PA/NY border this afternoon with
cloud breaks/diurnal heating expected to fuel isolated to
scattered convection. Despite very weak synoptic forcing, fcst
CAPE/shear profiles are supportive of isolated strong to
marginally severe storms capable of strong/locally damaging
wind gusts. The initial SPC D1 SWO is now MRGL for most of the
area (risk of level 1 out of 5; increased from non-severe or
general thunder d/d).

Any lingering late-day convection should fizzle out by 06Z. Much
of CPA is fcst to stay dry into early Monday morning in between
a modestly strengthening sfc low tracking through the Great
Lakes and TD/TS Claudette reaching the NC OBX around 12Z Mon.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
No change to the D3 to D2 SPC SLGT risk SWO for Monday.

Isolated to scattered severe storm risk on Monday afternoon and
evening will be driven by amplifying large scale trough and low
level convergence along the attendant cold front and pre-frontal
trough. Rich low level moisture (dewpoints 65-70F) will reside
ahead of the front, and diurnal heating/instability combined
with frontal forcing and sufficient deep-layer shear should
support organized (linear) storm clusters/lines capable of
producing strong to locally damaging winds.

Heat+Humidity peaks on Monday with max temperatures in the mid
80s to low 90s and max heat index (HX) values forecast to reach
the mid to upper 90s across the central and southeast valleys.
Forecast max temperatures are a solid 5-10F above average and
approach near-record territory in some areas (within 5F at
STCP1).

Convection should gradually weaken Monday night due to the loss
of heating and increasing CINH. Minimum temperatures will have
the most spread in recent nights thanks to the cold front
bisecting the area with lows ranging from the mid 50s in the NW
mtns to around 70F in the southeast/Lower Susq. metro areas.

Showers are likely early Tuesday across the southeast zones
before exiting the CWA by 00Z Wed. Temps will trend much cooler
on Tuesday with 24hrMaxT deltas of -15 to -25F lower vs. Monday.
Cool trend continues into Tuesday night with surge of
abnormally low PWAT air sending minTs down into the 40-55F
range or about -10F below late June climo.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Temps moderate through midweek with dry conditions. Surface
high pressure will move to the east later in the week with
warmer, more humid air moving in from the south.

A cold front will approach from the west next weekend, but there
is still a great deal of uncertainty with the timing of that
front and precipitation it will bring.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Restrictions in fog/low stratus should trend VFR by 14Z. Focus
will shift toward isolated to scattered t-storms into the
afternoon. The fcst coverage/duration continues to preclude
anything more than VCTS.

Outlook...

Monday-Tuesday...more widespread showers/storms possible
areawide.

Wednesday and Thursday...widespread VFR.

&&

.CLIMATE...
Astronomical Summer (solstice) begins at 1132 PM EDT Sunday June
20th.

&&

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

&&

$$
SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Guseman/Travis
AVIATION...Steinbugl/Colbert
CLIMATE...Steinbugl

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