Area Forecast Discussion
Issued by NWS State College, PA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
221
FXUS61 KCTP 280642
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
242 AM EDT SUN AUG 28 2016

.SYNOPSIS...
A warm front extending along the Ohio...Pennsylvania border will
push east into the region this morning...followed by the passage
of a weak cold front tonight and Monday morning. This pair of
frontal systems will bring scattered showers and thunderstorms
to mainly the northwest half of the state this afternoon and
tonight. Another period of warmer than normal and mainly dry
weather will follow for Monday into early Wednesday. A stronger
cold front will move southeast across the commonwealth Wednesday
followed by a refreshingly cooler airmass with low humidity
Thursday through Saturday.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
Tranquil conditions prevail across the region early this morning
with moderate sfc dewpoints in the low-mid 60s and just some
patches of mid and high clouds drifting northeast. The current sfc
dewpoints will mark the low temp in many locations. Some locations
across the northern mtns could see some localized low clouds and
patchy fog for an hour or two around sunrise.

A few stray showers could brush the far nw zones during the mid
to late morning hours as a warm front moves over that region with
enhanced uvvel and theta-e advection focused near the nose of a 30
kt swrly llj.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM MONDAY/...
Will have to monitor the situation for potential isolated...strong
to svr tsra across the central and nrn mtns of the state this
afternoon and early evening.

Very warm air aloft (8-9C at 700 mb) during the day today may
make it hard to fire up many showers or storms. However...a
ribbon of 1.5-2 inch PWAT air...the approaching warm/cold frontal
tandem...and an elongated mid/upper shear axis will combine to
bring a band of 1500-2500 j/kg sfc-based cape and sfc-6km wsw bulk
shear of around 25-30 kts across NW PA later today and this
evening.

SPC has expanded their Marginal Risk for SVR slightly south and
east today to cover practically all of the nrn mtns...and a
smaller portion of the central mtns today...within the fairly
narrow warm sector.

Gusty (and highly localized damaging) westerly winds will
accompany some of the stronger storms in the 18Z Sunday - 01Z
Monday period in the MRGL Risk area.

Above normal temps will continue today with similar maxes (or
perhaps just a few deg f lower than Sat`s across the Susq Valley).
Highs expected to range from the mid 80s (mtns) to near 90F in the
Lower Susq Valley.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
The extended period looks like it will feature a transition from
a persistent upper-level ridge over the eastern United States to
a weak upper-level trough by mid to late week. As a result,
above-normal temperatures through the Tuesday-Wednesday timeframe
will transition to near or a little below normal by the end of the
period.

A weakening cold front will push slowly SE through the
Commonwealth Sunday night into Monday morning accompanied by
isolated to scattered showers/thunderstorms. The frontal
boundary is expected to wash out near or just south of the
Mason/Dixon line during the day Monday. Abundant low-level
moisture, mesoscale convergence and some orographic lift/heating
via the east to NE low level flow regime across the mountains of
SW PA will focus the best chance for showers and scattered
thunderstorms there Monday afternoon.

Monday night through Wed morning looks to be dry with generally
light wind and just the possibility of patchy early morning valley
fog.

Medium range guidance agrees with a second-stronger cold front
pushing SE across the area Wednesday afternoon or early Thursday,
with a renewed chance for showers and thunderstorms.

This front will be followed by a cool-down for the end of next
week. Max temps should be mainly in the 70s Thursday into the
weekend over the northern and western higher terrain, with low to
mid 80s elsewhere as an upper trough amplifies from central
Quebec...to the Mid Atlantic Piedmont.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Local visibility restrictions in BR/FG possible 06-12z, otherwise
VFR. Followed last nights obs trends for TEMPO usage for 28/06z
scheduled TAFs. Patchy fog will dissipate by 13z.

Scattered TS forecast to develop across the NW 1/2 of the airspace
this afternoon. Added VCTS to KBFD and PROB30 group to KJST. Model
guidance suggests convection generally stays northwest of KCBE-
KHZL line. Expect any TS to weaken/dissipate by 00-03z. With
surface winds expected to remain light and variable, local
visibility restrictions are possible into early Monday morning.

Outlook...

Mon...VFR. Isold PM TS possible southern 1/4 airspace.

Tue...Patchy AM fog, then VFR.

Wed...Sct PM TS impacts possible.

Thu...No sig wx expected.

&&

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

&&

$$
SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Lambert
LONG TERM...La Corte
AVIATION...Steinbugl



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.