Special Weather Statement, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
342 PM EDT Wed Jul 28 2021

.SYNOPSIS...
Isolated strong storms are possible this afternoon across the
southwest portion of central PA and may produce locally
damaging wind gusts. The risk of severe storms has increased on
Thursday with a wind damage and isolated tornado threat possible.
A northwest breeze will bring cooler and less humid air into
the area on Friday which will set the stage for a beautiful
start to the weekend.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
The forecast area will be split from northwest to southeast this
evening as a frontal boundary is draped from roughly Erie to
Philadelphia. Along and to the southwest of this line, a few
showers have developed and will track to the southeast through
sunset.

Severe potential is lower this evening but will monitor for any
potential strong cells.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Better model agreement on the evolution of upstream convection
combined with new model data has resulted in an increased risk
of severe storms on Thursday; SPC has expanded the SLGT risk
SWO focused over south-central PA highlighted by a 5% tornado
prob.

Remnants of an MCS currently over the midwest will affect the
area Thursday morning. If this cloud cover limits precip to a
stratiform rain for a period, that may limit some of the
convective potential. Otherwise, low level shear and low LCL
heights, especially over the southeast portion of our forecast
area, would inidicate the potential for strong storms.

Improving conditions are expected in the wake of the cold FROPA
Thursday night with much drier air poised to arrive on Friday
via refreshing NW breeze. Look for a nice end to the week with
partly sunny skies and low humidity. The dry/low PW airmass will
set the stage for a rather cool Friday night/AM Saturday with
minTs ranging from the mid 40s over the NW Alleghenies to the
mid 50s across the southeast valleys.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Dry and seasonably cool conditions look to settle in for the end
of the week into the first half of the weekend. Northwest flow
aloft in the wake of an upper trough axis and surface ridge
moving out of the Great Lakes into the Ohio Valley will lead to
cool/dry air advection on Friday as clouds lift/break up through
the afternoon. Will likely see widespread temperatures in the
mid-upper 40s by Saturday morning across a good portion of
central PA, with low-mid 50s across the middle/lower Susquehanna
Valley and farther west along the Mason-Dixon line.

Shortwave trough pushing south across Ontario on Saturday will
lead to backing flow aloft as modest return flow sets up for
late Saturday and Sunday, spelling the return of shower chances
across the Alleghenies late Saturday. A better shot for showers/storms
will exist for all of central PA on Sunday as a surface low
moves across Lake Ontario.

Much of Monday should remain dry, outside of a few lingering
early day showers across the northern tier. Another upper low
looks to dig into the western Great Lakes/Midwest into Tuesday,
which will once again lead to increasing moisture and subsequent
shower/storm chances into midweek. Below normal temperatures
look to remain the rule, with highs generally in the low 70s
north to low 80s south and lows spanning the 50s with low 60s in
the lower Susquehanna Valley.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
Mainly VFR, though showers and storms will be possible
this afternoon mainly for southern PA. MVFR restrictions will
be possible in TSRA. More widespread convection likely on
Thursday with a FROPA crossing W to E.

Outlook...

Thu...Widespread TSRA impacts.

Fri & Sat...No sig wx expected.

Sun...Chance of a shower or thunderstorm.

&&

.CLIMATE...
It's been a wet July in some parts of central PA. Through July
27th, the monthly precipitation at Harrisburg is 7.99 inches
which currently ranks 2021 as the 9th wettest July on record.

&&

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

&&

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl/Tyburski
SHORT TERM...Steinbugl/Tyburski
LONG TERM...Guseman/Ross
AVIATION...Ross/Wagner
CLIMATE...

Hazardous Weather Outlook
National Weather Service State College PA
511 AM EDT Wed Jul 28 2021

PAZ004>006-010>012-037-041-042-045-046-049>053-057>059-066-290915-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Tioga-
Northern Lycoming-Sullivan-Southern Clinton-Southern Lycoming-Union-
Snyder-Montour-Northumberland-Columbia-Dauphin-Schuylkill-Lebanon-
Lancaster-
511 AM EDT Wed Jul 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...Thursday through Tuesday.

Severe thunderstorms with a damaging wind and isolated tornado threat
are possible Thursday afternoon and evening. Locally heavy rainfall
is also possible and may produce isolated flooding.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ017>019-024>028-033>036-056-063>065-290915-
Clearfield-Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-
Mifflin-Juniata-Somerset-Bedford-Fulton-Franklin-Perry-Cumberland-
Adams-York-
511 AM EDT Wed Jul 28 2021

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and tonight.

Isolated strong to marginally severe thunderstorms with locally
damaging winds are possible during the afternoon and early evening.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Severe thunderstorms with a damaging wind and isolated tornado threat
are possible Thursday afternoon and evening. Locally heavy rainfall
is also possible and may produce isolated flooding.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

MRS

Special Weather Statement
National Weather Service State College PA
442 PM EDT Wed Jul 28 2021

PAZ024-033-282130-
Somerset PA-Cambria PA-
442 PM EDT Wed Jul 28 2021

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF SOMERSET AND CAMBRIA
COUNTIES UNTIL 530 PM EDT...

At 441 PM EDT, Doppler radar indicated a strong thunderstorm near
Westmont, moving southeast at 25 mph.

Wind gusts up to 50 mph are possible.

Locations impacted include...
Johnstown, Westmont, Windber, Belmont, Geistown, Southmont, Boswell,
Dale, Davidsville, Paint, Jerome, Scalp Level, Daisytown, Tire Hill,
Elim, Lorain, Brownstown, Jennerstown, Hooversville and Stoystown.

LAT...LON 4037 7899 4022 7870 4006 7900 4020 7912
TIME...MOT...LOC 2041Z 309DEG 22KT 4033 7906

Travis

Special Weather Statement
National Weather Service State College PA
443 PM EDT Wed Jul 28 2021

PAZ065-282130-
York PA-
443 PM EDT Wed Jul 28 2021

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF YORK COUNTY UNTIL 530
PM EDT...

At 442 PM EDT, Doppler radar indicated a strong thunderstorm over
West York, moving south at 20 mph.

Wind gusts up to 40 mph are possible.

Locations impacted include...
York, Weigelstown, Red Lion, Spry, Dallastown, Shiloh, East York,
West York, Grantley, Tyler Run-Queens Gate, Emigsville, Glen Rock,
North York, Jacobus, Yoe, Cross Roads, Loganville, New Salem,
Winterstown and Seven Valleys.

LAT...LON 3998 7683 4002 7674 3982 7654 3976 7681
TIME...MOT...LOC 2042Z 339DEG 16KT 3997 7677

DeVoir

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
510 PM EDT WED JUL 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     TSTM WND DMG     2 WSW YORK              39.95N 76.76W
07/28/2021                   YORK               PA   FIRE DEPT/RESCUE

            ROOF BLOWN OFF OF STRUCTURE AND MULTIPLE
            WIRES DOWN.

&&

QRM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
522 PM EDT WED JUL 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0450 PM     TSTM WND DMG     2 WSW YORK              39.95N 76.76W
07/28/2021                   YORK               PA   FIRE DEPT/RESCUE

            ROOF BLOWN OFF OF STRUCTURE AND MULTIPLE
            WIRES DOWN.

&&

QRM

Special Weather Statement
National Weather Service State College PA
535 PM EDT Wed Jul 28 2021

PAZ035-036-282230-
Fulton PA-Franklin PA-
535 PM EDT Wed Jul 28 2021

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF FULTON AND FRANKLIN
COUNTIES UNTIL 630 PM EDT...

At 535 PM EDT, Doppler radar indicated a strong thunderstorm over
Fort Littleton, moving south at 15 mph.

Pea size hail and wind gusts up to 50 mph are possible.

Locations impacted include...
St. Thomas, McConnellsburg, Fort Loudon and Fort Littleton.

LAT...LON 3987 7802 4010 7806 4012 7798 4011 7796
      3992 7779
TIME...MOT...LOC 2135Z 339DEG 15KT 4008 7800

DeVoir

Special Weather Statement
National Weather Service State College PA
622 PM EDT Wed Jul 28 2021

PAZ036-282300-
Franklin PA-
622 PM EDT Wed Jul 28 2021

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF FRANKLIN COUNTY UNTIL
700 PM EDT...

At 621 PM EDT, Doppler radar indicated a strong thunderstorm over St.
Thomas, moving southeast at 20 mph.

Wind gusts up to 50 mph are possible.

Locations impacted include...
Waynesboro, Greencastle, St. Thomas, Wayne Heights, Rouzerville,
Marion, Maugansville, State Line, Middleburg, Quincy, Warrenton,
Williamson and Upton.

LAT...LON 3990 7787 3993 7777 3976 7746 3972 7746
      3972 7778
TIME...MOT...LOC 2221Z 321DEG 19KT 3989 7780

DeVoir