Special Weather Statement, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
234 PM EDT Thu Sep 9 2021

.SYNOPSIS...
Much cooler temperatures aloft, associated with an upper
level trough, will move east across the region this afternoon
through the midday hours Friday. This large scale weather
feature aloft will create clouds and scattered to numerous
showers this afternoon and early this evening across the
mountains of the west.

High pressure will then slowly build over the area through the
weekend, with mainly dry weather and fairly seasonable
temperatures.

&&

.NEAR TERM /THROUGH TONIGHT/...
Small, short-lived, but numerous SHRA and a few TSRA have popped
over the wrn mtns and are moving ESE. Most cells living only
15-20 mins before passing on the baton. We did get a very decent
downpour at the office with a gust to 39mph on the roof and
37mph at Beaver Stadium (We Are...windy). This first volley of
forcing/short wave aloft will likely start dying down in 3-4 hrs
as the sun gets lower. There is another spoke of vort in the
axis of the trough, but it will arrive too late in the day to do
much of anything past Warren/McKean Cos. Will keep PoPs in the
nrn mtns for the first part of the night. Everyone else should
clear out at first. The drier air and clouds and some light NW
wind will try to keep fog from forming, but the cooler temps
and partly cloudy sky overnight could allow the deeper valleys
of the central mtns to fog up. However, the hill tops will
likely not fog due to a bit of wind lasting most of the night.
We have kept min temps close to blended guid there. Normally,
we would undercut them a little on a night with better/more
clearing and less wind expected. Mins will run from the u40s to
the m50s. THV might get close to 50F if they calm down for more
than an hour.

&&

.SHORT TERM /FRIDAY/...
The upper trough axis will have swung past our longitude by
morning. Rising heights on Friday and breezy NW sfc wind will
combine to decrease the morning clouds over the NW and lead to
a mostly sunny and dry, but also slightly chilly, day. Maxes of
m60s to l70s will be 1F to 10F below normals.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Heading into the weekend, a warming trend is expected as surface
high pressure drifts just south of the Commonwealth and winds
turn from northerly on Friday to westerly on Saturday and then
southerly by Sunday. By Sunday afternoon, temperatures will top
out at about 10 degrees above average, corresponding to sensible
high temperatures in the upper 70s to mid 80s.

The bulk of med range guidance tracks a dying cold front into
the region late this weekend into early next week. Some
disagreement is seen in med range guidance to the expected
southern progress of the moisture-starved front. The front looks
like it will stretch out W-E -- but at what latitude? The
southward progression of this boundary will ultimately determine
the chance for precipitation along and north of US-6 on Sunday
and Monday afternoons, but have kept only slight chance PoPs in
at this time.

By Tuesday and Wednesday, considerable uncertainty
remains in how progressive the upper level flow pattern will be,
and whether there will be upper level troughiness or more
ridging. At some point during the middle of next week, a surface
cold front will traverse the region, but until then, have kept higher
PoPs generally in the afternoons/early evenings, with the
higher values north rather than south. The high heights (590+
dam 5H ridge) over the SE coast and western Atlantic Ocean will
try to suppress storms ahead of the front, though increasingly
unsettled weather will be the story through mid week.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
The SHRA around the area this aftn will be confined mainly to
the wrn and nrn mtns, and could make a brief (<1hr) reduction to
MVFR where they do form. Have added VCSH to almost all
locations, but the most likely place to get vis/cig reduction
from one would be JST/AOO/UNV. Just had one here at the office
(close to UNV) with a G39mph right at 18Z. It appears that UNV
didn't take the brunt of the cell. Shows just how localized
these showers/storms are. No *widespread* restrictions to
MVFR/IFR are expected until tonight over the mtns (BFD/JST)
where MVFR cigs may return.

The SHRA will dissipate this evening as the sun goes away. Fog
could form if the cool air can settle into the deeper valleys
of the nrn and central mtns. However, dewpoints in the u40s-
l50s, lower clouds and some wind will help thwart a more
widespread fog. The lower/MVFR clouds and any fog should
dissipate early Fri AM and leave a mostly sunny and VFR day. It
will be gusty with a 8-12KT NW wind and gusts close to 20KT on
the hill tops. There is just a small (20pct) chc of a SHRA up
close to LE generally N of BFD where the warmer lake water and
cooler temps aloft could cause a taller cloud or two.

Outlook...

Sat-Sun...AM valley fog poss. Otherwise VFR.

Mon-Tues...PM SHRA and associated restrictions possible north.
Otherwise VFR.

&&

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

&&

SYNOPSIS...Jurewicz/Lambert
NEAR TERM...Dangelo
SHORT TERM...Jurewicz/Lambert/Fitzgerald
LONG TERM...Dangelo/Banghoff
AVIATION...Dangelo

Hazardous Weather Outlook
National Weather Service State College PA
356 AM EDT Thu Sep 9 2021

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-100800-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin-
Juniata-Somerset-Bedford-Fulton-Franklin-Tioga-Northern Lycoming-
Sullivan-Southern Clinton-Southern Lycoming-Union-Snyder-Montour-
Northumberland-Columbia-Perry-Dauphin-Schuylkill-Lebanon-Cumberland-
Adams-York-Lancaster-
356 AM EDT Thu Sep 9 2021

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service State College PA
500 PM EDT Thu Sep 9 2021

PAZ036-063-064-092130-
Adams PA-Franklin PA-Cumberland PA-
500 PM EDT Thu Sep 9 2021

...A strong thunderstorm will impact portions of northwestern Adams,
southeastern Franklin and southwestern Cumberland Counties through
530 PM EDT...

At 459 PM EDT, Doppler radar was tracking a strong thunderstorm over
St. Thomas, moving southeast at 15 mph. Other strong storms were
forming to the northeast of this storm.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Chambersburg, Waynesboro, Greencastle, Guilford, St. Thomas,
Fayetteville, Mont Alto, Scotland, Marion, Williamson, Quincy and
Penn State Mont Alto.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3987 7785 4001 7770 4002 7727 3972 7759
      3972 7768
TIME...MOT...LOC 2059Z 305DEG 6KT 3992 7777

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Martin

Special Weather Statement
National Weather Service State College PA
515 PM EDT Thu Sep 9 2021

PAZ058-059-092200-
Lebanon PA-Schuylkill PA-
515 PM EDT Thu Sep 9 2021

...A strong thunderstorm will impact portions of Lebanon County
through 600 PM EDT...

At 514 PM EDT, Doppler radar was tracking a strong thunderstorm over
Harper Tavern, moving east at 35 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Lebanon, Palmyra, Annville, Cornwall, Myerstown, Campbelltown,
Pleasant Hill, Sand Hill, Newmanstown, Lebanon South, Cleona, Avon,
Richland, Fredericksburg, Schaefferstown, Quentin, Harper Tavern,
Lickdale, Kleinfeltersville and Fort Indiantown Gap.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4056 7609 4052 7626 4051 7632 4043 7633
      4036 7620 4032 7615 4025 7659 4035 7663
      4042 7663 4049 7642 4044 7633 4052 7633
      4060 7608 4057 7607
TIME...MOT...LOC 2114Z 254DEG 29KT 4037 7656

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Martin