Severe Thunderstorm Warning 166, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
210 PM EDT Tue Jul 8 2025

.SYNOPSIS...
* Flash flooding and damaging thunderstorm wind risk this
  afternoon and evening across the southeastern portion of
  central PA
* Similar setup for Wednesday with renewed damaging wind and
  flash flooding risks focused over southeast PA
* Continued seasonably warm and humid with scattered afternoon
  and evening thunderstorms through the weekend

&&

.NEAR TERM /THROUGH TONIGHT/...
Thunderstorms are beginning to develop early this afternoon
along and ahead of an outflow boundary associated with morning
convection that has moved in from the Ohio Valley. As this
convection moves eastward with time through the afternoon, it
will encounter a more unstable and sheared airmass, likely
helping it to take on a more linear mode. With this evolution,
the likelihood of damaging wind gusts will increase.

Pwats eclipsing 2" over southeast PA will support a flash flood
threat where any tstms train. We issued a flood watch starting
18Z today for a portion of the Lower Susquehanna Valley in
coordination with WFO LWX. In addition to the robust and
anomalous pwat values, very efficient warm-rain processes could
lead to rain rates >2"/hr at times resulting in potential
instances of flash flooding.

Ahead of the rain, there also remains some concern for max HX
values to reach or exceed the century mark in parts of the LSV.
However, not thinking that this will be widespread enough to
warrant a Heat Advisory.

Hires models show the majority of showers/storms will shift to
the east before midnight (in fact, most guidance has the bulk of
the convective activity winding down before 8 PM). Min temps
will be a bit cooler than last night, with fog likely forming
in the valleys through the predawn hours Wednesday.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Similar overall synoptic setup on Wednesday & Thursday with
gradual southward shift to the severe t-storm and FF risk areas
coincident with zone of max PW. Conditions will remain humid and
with daytime highs in the 80s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
The forecast for Friday and the weekend is more uncertain, with
some guidance suggesting a break in the unsettled pattern, and
others suggesting active weather continues. An active pattern
would favor continue heat/humidity while a quieter pattern could
support the intrusion of lower dewpoints and more refreshing
conditions.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
Thunderstorms ahead of a slow-moving cold front will continue
to impact the central Pennsylvania airspace over the next couple
of hours, with highest confidence in impacts along a north-
south line extending from UNV to HGR and areas east.
Thunderstorms will bring about localized drops in visibility
with heavy rainfall and frequent lightning near UNV from 18Z-20Z
Tue, MDT/LNS between 19Z-23Z Tue, with lower probabilities of
thunderstorm impacts at airfields at AOO (closer to cold front;
however, non-zero chance from 18Z-19Z) and IPT (best instability
further south; however, non-zero chance between 19Z-21Z). The
most recent guidance does show fair agreement in thunderstorm
potential; however, main difference in timing with regards to
precipitation as the cold front continues to progress eastward
this evening.

In the wake of the cold front, areas that have received locally
heavy rainfall this evening will have higher potential for fog
and widespread visibility restrictions overnight. At this time,
have progged AOO/UNV towards LIFR conditions overnight; however,
model guidance indicates some potential at all airfields except
for MDT/LNS. Have stuck with guidance trends; however, will
have to continue to monitor trends at MDT/LNS with heavy
rainfall and fog potential overnight.

After sunrise on Wednesday (12Z Wed - 18Z Wed), model guidance
shows fair agreement with respect to restrictions being lifted
by 12Z for most airfields. The 18Z TAF package does set the goal
post slightly wider, with widespread restrictions lifting
closer to 13-14Z give some lingering low-level moisture in RAP
model soundings.

Outlook...

Wed...Best chance for storms and restrictions in southern PA.

Thu-Sun...Potential for showers and thunderstorms, mainly
aftn/eve.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Flood Watch until midnight EDT tonight for PAZ057-059-065-066.

&&

SYNOPSIS...Steinbugl/Colbert
NEAR TERM...Steinbugl/Colbert
SHORT TERM...Steinbugl/Colbert
LONG TERM...Lambert/Colbert
AVIATION...NPB

Hazardous Weather Outlook
National Weather Service State College PA
203 PM EDT Tue Jul 8 2025

PAZ006-010>012-017>019-024-025-037-041-042-045-046-091815-
Potter-Elk-Cameron-Northern Clinton-Clearfield-Northern Centre-
Southern Centre-Cambria-Blair-Tioga-Northern Lycoming-Sullivan-
Southern Clinton-Southern Lycoming-
203 PM EDT Tue Jul 8 2025

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This afternoon and tonight.

Isolated strong thunderstorms with gusty winds and locally heavy
rainfall are possible this afternoon.

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

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ056-058-063-064-091815-
Perry-Schuylkill-Cumberland-Adams-
203 PM EDT Tue Jul 8 2025

...SEVERE THUNDERSTORM WATCH 496 IN EFFECT UNTIL 9 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to
weather.gov/StateCollege on the internet for more
information about the following hazards.

   Severe Thunderstorm Watch.

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

Isolated damaging thunderstorm wind gusts are also possible
Wednesday afternoon.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ026>028-033>036-049>053-091815-
Huntingdon-Mifflin-Juniata-Somerset-Bedford-Fulton-Franklin-Union-
Snyder-Montour-Northumberland-Columbia-
203 PM EDT Tue Jul 8 2025

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...Wednesday through Monday.

Isolated damaging thunderstorm wind gusts are also possible
Wednesday afternoon.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ057-059-065-066-091815-
Dauphin-Lebanon-York-Lancaster-
203 PM EDT Tue Jul 8 2025

...FLOOD WATCH IN EFFECT UNTIL MIDNIGHT EDT TONIGHT...
...SEVERE THUNDERSTORM WATCH 496 IN EFFECT UNTIL 9 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to
weather.gov/StateCollege on the internet for more
information about the following hazards.

   Severe Thunderstorm Watch.
   Flood Watch.

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

Isolated damaging thunderstorm wind gusts are also possible
Wednesday afternoon.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ004-005-091815-
Warren-McKean-
203 PM EDT Tue Jul 8 2025

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...Wednesday through Monday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Preliminary Local Storm Report
National Weather Service State College PA
240 PM EDT Tue Jul 8 2025

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

0158 PM     Tstm Wnd Dmg     2 SW Mcalisterville     40.62N 77.30W
07/08/2025                   Juniata            PA   Fire Dept/Rescue

            Tree on wires on 200 block Hower Rd.

&&

MRC

Preliminary Local Storm Report
National Weather Service State College PA
306 PM EDT Tue Jul 8 2025

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

0247 PM     Tstm Wnd Dmg     2 N Dauphin             40.40N 76.93W
07/08/2025                   Dauphin            PA   911 Call Center

            Tree down blocking the roadway on Clarks
            Valley Road.

&&

NPB

Preliminary Local Storm Report
National Weather Service State College PA
313 PM EDT Tue Jul 8 2025

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

0249 PM     Tstm Wnd Dmg     2 SSW Halifax           40.43N 76.95W
07/08/2025                   Dauphin            PA   911 Call Center

            Tree down blocking one lane of Creek Road
            near the intersection of Lehman Road.

&&

NPB