Special Weather Statement, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
619 AM EDT Tue Sep 28 2021

.SYNOPSIS...
A cold front will bring scattered showers and thunderstorms to
central Pennsylvania through this evening. A dry and seasonal
weather pattern is expected for the rest of the week with some
chilly nights as the calendar flips from September to October.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Amplifying upper level trough and approaching cold front are
enhancing the coverage of shower activity over western/central
PA this morning. As expected, elevated MUCAPE of ~1000+ J/kg
has sprouted embedded isold to sct thunder as coverage expands
through the Central and South Central Mountains. This all thanks
to robust llvl moisture advection fed by a potent low level jet
along with falling heights ahead of the sharp upper trough.
Some cells may grow tall enough to support small hail and brief
heavy rainfall rates, but believe most will be well below
severe levels. Ahead of the front and upper trough, southwest
breeze kept things quite mild overnight and into this morning.
Sfc temps are mostly in the lower to middle 60s across central
and western PA. Over the Ridge and Valley Region/Lower Susq,
some decoupling briefly allowed temperatures to fall off into
the 50s, but they too have warmed back into the lower 60s as
showers approach.

Lead vort max and first round of showers and embedded thunder
will push through southeast half of the forecast area between
12Z- 16Z. Behind this feature, another round of convection is
possible along the cold front, as it pushes from the central
mountains around 18Z to the southern tier counties by early
evening, for which SPC has maintained a MRGL risk area. A tiny
sliver of far southern Lancaster County is included in SPCs new
SLGT risk area, which debuted in the 06z issuance.

Expect a mainly cloudy day for most, in between the rounds of
showers and thunderstorms. Breaks in the cloud cover over the
south and especially southeast may fuel a few strong tstorms
with the FROPA late this afternoon or early evening. Conditions
should dry out from northwest to southeast by Tuesday evening.
Highs will vary from the 60s in the northern tier to the upper
70s in the south central valleys.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Lingering light showers and storms along the PA/MD border this
evening will end or shortly past sunset. Drier and cooler air
shifts southward over the rest of central PA by late tonight,
and expect lows more typical of late September by Wednesday
morning, ranging from the lower 40s north to the lower 50s
southeast. Canadian surface high pressure builds into the area
on Wednesday, bringing seasonable to slightly below average
temperatures, NW flow, and mostly sunny skies.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Pleasant conditions will last from Wednesday night to Saturday.
Temperatures these nights will be on the chilly side, and we
could very well dip into the 30s across the Northern Mountains
with radiational cooling under clear skies. The coldest night
should be Thursday night, when surface high builds over the
area. Wouldn't be surprised to see the first frost of the season
Friday morning in the cooler valleys of the Alleghenies.

Models are coming to somewhat more of a consensus on the
evolution and positioning of an upper level low over New
England mid-late next week. The low will most likely linger over
New Brunswick/Northern New England through early next week.
During this time a surface low develops over the central US and
will begin to track towards our area by late weekend/early next
week. Still lots of uncertainty this far out but at least
chance POPs by late this upcoming weekend and early next week.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
Widely scattered showers and thunderstorms are beginning to
develop as of 07z Tue and will likely continue from west to east
across central PA through Tue afternoon ahead of an approaching
cold front. LLWS remains in the fcst into early Tuesday as a
40kt westerly LLJ moves overhead. Expect sub- VFR conditions
along and behind the front over the northwest 1/2 of the
airspace into early Tuesday with some marginal improvement
likely by afternoon. VFR conditions return later tomorrow
afternoon and evening as the cold front clears out.

Outlook...

Wed-Fri...AM valley fog, then VFR.

&&

.CLIMATE...
Harrisburg's latest 90-degree day on record is Oct. 7 in the
1941. With summer in the rearview mirror and given the fall
pattern going forward, it's probably safe to say that there
won't be any more 90 degree days this year.

So in 2021, Harrisburg likely finishes with 34 days where the
maximum temperature was >= 90F. That ties 2010 and 1955 with the
14th highest on record. The top 3 are 1966 (60), 1944 (48), and
1943 (46). h/t @ajuklo for the callout on Twitter.

More interestingly, 2021 currently ranks 2nd for the number of
days with minimum temperatures >= 70F in Harrisburg. The top 3
are 2020 (50), 2021 (48), and 2016 (42). 8 of the top 10 years
are in the 2000s. Those warm summer nights...

&&

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

&&

SYNOPSIS...DeVoir/Steinbugl
NEAR TERM...DeVoir/Fitzgerald
SHORT TERM...DeVoir/Fitzgerald/Steinbugl
LONG TERM...Fitzgerald/Wagner
AVIATION...Colbert/Gutierrez
CLIMATE...

Hazardous Weather Outlook
National Weather Service State College PA
419 AM EDT Tue Sep 28 2021

PAZ004>006-012-028-035-037-041-042-045-046-049>053-290830-
Warren-McKean-Potter-Northern Clinton-Juniata-Fulton-Tioga-
Northern Lycoming-Sullivan-Southern Clinton-Southern Lycoming-Union-
Snyder-Montour-Northumberland-Columbia-
419 AM EDT Tue Sep 28 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...Wednesday through Monday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PAZ010-011-017>019-024>027-033-034-290830-
Elk-Cameron-Clearfield-Northern Centre-Southern Centre-Cambria-Blair-
Huntingdon-Mifflin-Somerset-Bedford-
419 AM EDT Tue Sep 28 2021

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and tonight.

Isolated hail is possible in scattered thunderstorms this morning.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PAZ036-056>059-063>066-290830-
Franklin-Perry-Dauphin-Schuylkill-Lebanon-Cumberland-Adams-York-
Lancaster-
419 AM EDT Tue Sep 28 2021

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and tonight.

Isolated hail and gusty winds are possible in strong thunderstorms
this afternoon and early evening.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

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
536 AM EDT Tue Sep 28 2021

PAZ024-025-033-034-281015-
Bedford PA-Somerset PA-Blair PA-Cambria PA-
536 AM EDT Tue Sep 28 2021

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN BEDFORD...
NORTHEASTERN SOMERSET...SOUTHWESTERN BLAIR AND SOUTHWESTERN CAMBRIA
COUNTIES THROUGH 615 AM EDT...

At 535 AM EDT, Doppler radar was tracking a strong thunderstorm over
Geistown, moving east at 25 mph.

HAZARD...Wind gusts up to 45 mph, heavy rain and pea size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Johnstown, Westmont, Windber, Belmont, Portage, Geistown, Southmont,
Vinco, Dale, East Conemaugh, Osterburg, Salix-Beauty Line Park,
Davidsville, Beaverdale-Lloydell, Paint, Lilly, South Fork, Scalp
Level, Sidman and St. Michael.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4022 7899 4039 7896 4045 7848 4017 7849
TIME...MOT...LOC 0935Z 271DEG 21KT 4032 7884

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

DeVoir

Special Weather Statement
National Weather Service State College PA
545 AM EDT Tue Sep 28 2021

PAZ024>027-281030-
Blair PA-Cambria PA-Huntingdon PA-Mifflin PA-
545 AM EDT Tue Sep 28 2021

...STRONG THUNDERSTORMS WILL IMPACT CENTRAL HUNTINGDON...SOUTHWESTERN
MIFFLIN...BLAIR AND NORTHEASTERN CAMBRIA COUNTIES THROUGH 630 AM
EDT...

At 544 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Blandburg to Gallitzin. Movement was east
at 35 mph.

HAZARD...Wind gusts up to 45 mph, heavy rain and pea size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Altoona, Huntingdon, Hollidaysburg, Tyrone, Roaring Spring, Mount
Union, Martinsburg, Lakemont, Bellwood, Patton, Cresson, Gallitzin,
Loretto, Williamsburg, Duncansville, Tipton, Lilly, Sankertown,
Allensville and Blandburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4042 7863 4054 7874 4062 7865 4071 7858
      4065 7776 4019 7795
TIME...MOT...LOC 0944Z 286DEG 29KT 4067 7847 4048 7854

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

DeVoir

Special Weather Statement
National Weather Service State College PA
614 AM EDT Tue Sep 28 2021

PAZ035-036-281100-
Fulton PA-Franklin PA-
614 AM EDT Tue Sep 28 2021

...STRONG THUNDERSTORMS WILL IMPACT FRANKLIN AND NORTHEASTERN FULTON
COUNTIES THROUGH 700 AM EDT...

At 613 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Fort Littleton to near Fort Loudon to near
Big Cove Tannery. Movement was east at 35 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Chambersburg, Waynesboro, Shippensburg, Greencastle, Guilford, St.
Thomas, Fayetteville, Mont Alto, Mercersburg, Scotland,
McConnellsburg, Marion, Fort Loudon, Fort Littleton, Roxbury, Upper
Strasburg, Willow Hill, Fannettsburg, Orrstown and Quincy.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3984 7803 3999 7797 4011 7796 4010 7791
      4006 7787 4012 7782 4013 7757 4010 7756
      4007 7753 4005 7753 4000 7749 3995 7746
      3976 7752
TIME...MOT...LOC 1013Z 280DEG 32KT 4009 7792 3998 7791 3986 7799

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

DeVoir

Special Weather Statement
National Weather Service State College PA
743 AM EDT Tue Sep 28 2021

PAZ006-037-281215-
Potter PA-Tioga PA-
743 AM EDT Tue Sep 28 2021

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN POTTER AND
NORTHWESTERN TIOGA COUNTIES THROUGH 815 AM EDT...

At 743 AM EDT, Doppler radar was tracking a strong thunderstorm near
Genesee, moving southeast 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 vegetation possible.

Locations impacted include...
Westfield, Genesee, Harrison Valley, Knoxville and Ulysses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4196 7743 4173 7757 4192 7798 4200 7800
      4200 7770
TIME...MOT...LOC 1143Z 294DEG 29KT 4196 7781

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

Evanego