Special Weather Statement, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
257 PM EDT Thu Aug 3 2017

.SYNOPSIS...
Warm and more humid conditions will prevail until a strong cold
front moves through Friday night, bringing cooler and drier
conditions for the weekend. Unseasonably cool weather will
continue into early next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Weak forcing over the region today with the main frontal
boundary draped up north of the area. Dewpoints have rebounded
back to near 70F in the SE with above normal PWATs across
central PA. CAPE around 1000J has already begun kicking off
showers/sct tstms mainly over the western and northern ridges,
and these will persist through the afternoon. Activity looks to
shift to the east late this afternoon through mid evening, with
latest guidance bringing best chance for a TSTM in the lower
Susq from 23-03z. Much like yesterday, deep layer shear is
pretty weak, limiting severe threat somewhat with mainly
disorganized convection and brief downpours and strong wind
gusts the biggest threat.

Convection will begin to wane with the loss of heating, with
the second half of the overnight seeing just isolated
showers/thunderstorms left over and a redevelopment of valley
fog. Lows will be in the 60s and it will feel muggy over much
of the region.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
Models are in good agreement with an unseasonably strong cold
front on the doorstep of western PA by late Friday afternoon.
They also agree in generating impressive instability with the
added ingredient of increasing deep layer shear later in the day.
The area is outlooked for a SLIGHT risk of severe storms, and
at first glance it looks like the main cold front will be
entering the region after max heating with waning instability.
But the guidance is hinting at a pre-frontal trough developing
over west-central PA which is used to act as a focus for
developing convection during the afternoon. Additionally, the
GFS/ECMWF paint a relatively broad area of enhanced low level
EHI's by afternoon and evening which should support scattered
supercells and even an isolated tornado. So anticipate scattered
convection to kick off in the early afternoon with the main show
later in the day through the evening.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Following the cold front, Saturday will turn significantly
cooler with just the chance of a few showers/thunderstorms as
the still strong mid summer sun and relatively cold air aloft
combine to support steepening lapse rates with daytime heating.
With the upper shortwave expected to begin shearing out to our
north, models suggest the best chance for a shower will be over
the higher elevations of the west and north.

Sunday will be dry and unseasonably cool as high pressure slides
over the state. The cooler than normal conditions look to
continue for much of next week.

A new shortwave is made to approach for Monday. The ECMWF
shows a stronger trough and even a well developed surface low
racing through the state during the day. The GEFS shows a weaker
inverted surface trough and a much flatter wave aloft. The
ECENS agrees with its deterministic counterpart showing a well
organized surface low. A model blend for POPs yields a fairly
wet day as the new surge of showers pushes through the area
during the day.

Drier air is slated to return for midweek as the frontal system
is moved off to our east. From Wed-Thu there is some
disagreement with rainfall potential. The GFS/GEFS are wetter
under a flatter upper zonal flow regime while the ECMWF keeps
us mainly dry until the end of the week. Too early to tease out
the details at this time.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR conditions today except in scattered SHRA/TSRA this
afternoon into early evening.

Valley fog forms again tonight bringing scattered restrictions
to the usual spots.

More organized and widespread activity expected on Friday into
Friday night with scattered convection ahead and more numerous
thunderstorms accompanying the cold front.

.OUTLOOK...
Fri...Stronger and more widespread storms possible with front,
mainly late.
Sat-Sun...No sig wx.
Mon...Showers likely, chance of thunderstorms.
Tue...Chance of showers.

&&

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

&&

SYNOPSIS...La Corte/RXR
NEAR TERM...RXR
SHORT TERM...
LONG TERM...La Corte
AVIATION...RXR

Hazardous Weather Outlook...UPDATED
National Weather Service State College PA
1229 PM EDT Thu Aug 3 2017

PAZ004>006-010-011-017-024-033-041630-
Warren-McKean-Potter-Elk-Cameron-Clearfield-Cambria-Somerset-
1229 PM EDT Thu Aug 3 2017

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This Afternoon and Tonight.

The probability for widespread hazardous weather is low.

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

Severe thunderstorms with damaging winds 60 mph or greater and
large hail exceeding 1 inch in diameter are possible Friday
afternoon and evening.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ012-018-019-025>028-034>037-041-042-045-046-049>053-056-057-063-
064-041630-
Northern Clinton-Northern Centre-Southern Centre-Blair-Huntingdon-
Mifflin-Juniata-Bedford-Fulton-Franklin-Tioga-Northern Lycoming-
Sullivan-Southern Clinton-Southern Lycoming-Union-Snyder-Montour-
Northumberland-Columbia-Perry-Dauphin-Cumberland-Adams-
1229 PM EDT Thu Aug 3 2017

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This Afternoon and Tonight.

Strong to severe thunderstorms with gusty winds, hail and locally
heavy rainfall are possible during the afternoon and evening.

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

Severe thunderstorms with damaging winds 60 mph or greater and
large hail exceeding 1 inch in diameter are possible Friday
afternoon and evening.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ058-059-065-066-041630-
Schuylkill-Lebanon-York-Lancaster-
1229 PM EDT Thu Aug 3 2017

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This Afternoon and Tonight.

Strong to severe thunderstorms with gusty winds, hail and locally
heavy rain are possible during the afternoon and evening.

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

Strong to severe thunderstorms with damaging winds, hail and locally
heavy rainfall are possible Friday afternoon and evening.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

MS

Special Weather Statement
National Weather Service State College PA
1257 PM EDT THU AUG 3 2017

PAZ005-006-011-031800-
McKean PA-Potter PA-Cameron PA-
1257 PM EDT THU AUG 3 2017

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF MCKEAN...POTTER...AND
CAMERON COUNTIES UNTIL 200 PM EDT...

At 1256 PM EDT, Doppler radar indicated a strong thunderstorm over
Elk River, moving northeast at 20 mph.

Pea size hail and winds in excess of 40 mph are possible.

Locations impacted include...
Keating Summit, Denton Hill State Park, Port Allegany, Roulette,
Lyman Run State Park, Coudersport, Elk River, Betula, Sizerville,
Austin, Sweden Valley and Ski Denton Ski Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4172 7770 4149 7837 4153 7843 4154 7842
      4160 7842 4160 7848 4161 7849 4195 7820
TIME...MOT...LOC 1656Z 231DEG 19KT 4157 7834

Lambert

Special Weather Statement
National Weather Service State College PA
151 PM EDT THU AUG 3 2017

PAZ034-031830-
Bedford PA-
151 PM EDT THU AUG 3 2017

...SPECIAL WEATHER STATEMENT...

At 150 PM EDT, Doppler radar indicated a strong thunderstorm over
Buffalo Mills. This storm was drifting slowly eastward at 5 mph.

Pea size hail and winds in excess of 30 mph are possible.

Locations impacted include...
Bedford, Buffalo Mills, Cessna, Schellsburg and Manns Choice.

LAT...LON 3993 7872 4000 7877 4002 7876 4012 7854
      4003 7838 3992 7840
TIME...MOT...LOC 1750Z 241DEG 3KT 3998 7864

RXR

Special Weather Statement
National Weather Service State College PA
159 PM EDT THU AUG 3 2017

PAZ063-064-031830-
Adams PA-Cumberland PA-
159 PM EDT THU AUG 3 2017

...SPECIAL WEATHER STATEMENT...

At 159 PM EDT, Doppler radar indicated a strong thunderstorm near
Pine Grove Furnace. This storm was nearly stationary.

Pea size hail and winds in excess of 30 mph are possible.

Locations impacted include...
Pine Grove Furnace, Aspers, Gardners, Bendersville and Idaville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3993 7741 4002 7744 4012 7730 4003 7718
      3995 7720
TIME...MOT...LOC 1759Z 253DEG 2KT 4000 7737

RXR

Special Weather Statement
National Weather Service State College PA
205 PM EDT THU AUG 3 2017

PAZ012-018-031830-
Northern Centre PA-Northern Clinton PA-
205 PM EDT THU AUG 3 2017

...SPECIAL WEATHER STATEMENT...

At 205 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Keating to near Clarence. Movement was
northeast at 20 mph.

Pea size hail and brief wind gusts in excess of 30 mph are possible.

Locations impacted include...
Westport, Glen Union, Renovo, Keating and South Renovo.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Minor flooding may develop. Do not drive into water covering the
roadway.

Persons in campgrounds should consider seeking sturdy shelter until
these storms pass.

&&

LAT...LON 4127 7758 4107 7794 4115 7804 4116 7805
      4128 7792 4141 7774
TIME...MOT...LOC 1805Z 227DEG 16KT 4126 7785 4113 7794

Lambert

Special Weather Statement
National Weather Service State College PA
301 PM EDT THU AUG 3 2017

PAZ064-031930-
Adams PA-
301 PM EDT THU AUG 3 2017

...SPECIAL WEATHER STATEMENT...

At 300 PM EDT, Doppler radar indicated a strong thunderstorm over
Cashtown. This storm was nearly stationary.

Pea size hail and winds in excess of 30 mph are possible.

Locations impacted include...
Aspers, Cashtown, Arendtsville, McKnightstown, Biglerville and
Bendersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3992 7746 4002 7729 4002 7727 3997 7718
      3989 7718 3984 7741
TIME...MOT...LOC 1900Z 238DEG 3KT 3990 7735

RXR