Special Weather Statement, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
311 PM EDT Fri Jul 16 2021

.SYNOPSIS...
A cold front over the eastern Great Lakes will drift very
slowly to the south tonight and through the upcoming weekend as
several weak waves of low pressure ride northeast along it. The
very warm and humid airmass across Pennsylvania ahead of the
front will help to create numerous showers and scattered
thunderstorms.

Locally heavy rain and isolated strong wind gusts are
likely this evening, and again during the same period Saturday.
Drier air should push south into the northern part of the
Commonwealth on Sunday, though scattered to numerous showers and
a few thunderstorms are likely across the Lower Susquehanna
Valley.

A slow moving upper trough is likely to linger over
the area into much of next week, bringing a reprieve from
excessive humidity and overall drier conditions.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Slow moving front focuses locally heavy afternoon and evening
downpours over the NW and NC mountains through this evening. FFG
values over northern tier counties less than one inch, but 2"+
this afternoon for NW Mountains. Training cells will be watched
closely this evening over the NW Mountains and points east.

Heavy rain threat shifts eastward to include much of the
northern half of central PA overnight, as stalled front slowly
bleeds southward and right entrance region of ULJ focuses
persistent showers and thunderstorms with locally heavy rainfall
there. Flash Flood Watch is in effect for a large portion of
north central PA tonight through Saturday evening with several
rounds of heavy rainfall likely to produce excessive runoff on
nearly saturated surface soil conditions.

Farther south and southeast, diurnal activity will wane after
sunset with a relatively quiet period of time from late tonight
into Saturday morning. Focus for heavy rains shifts southward by
Saturday afternoon as convection fires from the central
mountains eastward through the Middle to Lower Susq River
Valley, and future shifts (eve or mid) will address and
collaborate potential expansion of FLash Flood Watches to
include the Saturday period over the southern and especially
southeastern half of central PA.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Rich moisture plume will stay draped across much of Central PA
Saturday, bringing max coverage and highest intensity of
convective rainfall, and raising potential flood concerns again
for areas that have been very wet lately. WPC coordinated MDT
Excessive Rainfall risk over the region for Saturday.

A cold front will slowly cross PA through the day Saturday,
bringing rounds of showers and storms across the entire area.
The airmass in front of the cold front will be hot and juicy
with PWs will approaching or slightly above 2". Best chance for
flash flooding over the Middle to Lower Susq River Valley comes
Sat afternoon and evening, and later shifts will be
collaborating with our eastern neighbors on further FFA
issuances. After an evening maximum in intensity and coverage,
front drops southeastward and south of the Mason Dixon line by
early Sunday. Showers linger into Sunday morning behind FROPA
but heavy rain threat should be over by then.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Persistent upper level troughing with a mean west-northwest flow
aloft will bring a series of cold fronts through central PA next
week. Timing of these fronts is uncertain with max POPs weighted
toward the afternoon and evening hours. Each front will be
accompanied by scattered showers and t-storms, but with much
lower PWATs (available deep moisture) we expect the probability
of heavy rainfall to remain low. CPC outlooks tilt the odds
toward below average rainfall beyond midweek. SPC has noted that
the overall speed of the flow aloft associated with the broad
upper troughing is fcst to remain rather weak. The weak flow
combined with lack of well-defined shortwave troughs and diffs
with frontal timing favors a low predictability for severe
weather. Lastly, we were keen to utilize a 50/50 weighting of
NBM with the consensus multi-model blend which trends daytime
temps closer to or just below seasonal averages through midweek.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Scattered SHRA and TSRA will develop across the northwest Fri
late morning and afternoon, and spread east/southeast through
the afternoon. Have added VCSH to everywhere except SE
airfields, but most widespread activity is expected in the NW.
Will wait to add VCTS or -TSRA when confidence in timing
increases. VFR will prevail everywhere by Friday afternoon, with
ceilings gradually lowering in the northern mountains
overnight.

Outlook...
Sat...Restrictions possible in SHRA/TSRA
Sun...Showers gradually sag southeast, reductions possible.
Mon-Tue...Isolated to scattered P.M. showers/t-storms.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from 10 PM EDT this evening through Saturday
evening for PAZ004>006-010>012-037-041-042-045-046.

&&

SYNOPSIS...Lambert/DeVoir
NEAR TERM...Lambert/DeVoir
SHORT TERM...Lambert/DeVoir
LONG TERM...Steinbugl
AVIATION...Gartner/Banghoff

Hazardous Weather Outlook
National Weather Service State College PA
455 PM EDT Fri Jul 16 2021

PAZ017>019-024>028-033>036-049-050-056>059-063>066-172100-
Clearfield-Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-
Mifflin-Juniata-Somerset-Bedford-Fulton-Franklin-Union-Snyder-Perry-
Dauphin-Schuylkill-Lebanon-Cumberland-Adams-York-Lancaster-
455 PM EDT Fri Jul 16 2021

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Tonight.

Isolated to scattered strong to severe thunderstorms with gusty
winds and hail are possible through this evening.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Scattered strong to severe thunderstorms with gusty winds and hail
are possible Saturday afternoon and evening. Locally very heavy rain
of over 2 inches may occur in less than one hour where a few
thunderstorms train over the same location.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PAZ004>006-010>012-037-041-042-045-046-051>053-172100-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Tioga-
Northern Lycoming-Sullivan-Southern Clinton-Southern Lycoming-
Montour-Northumberland-Columbia-
455 PM EDT Fri Jul 16 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH SATURDAY EVENING...

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Tonight.

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

   Flash Flood Watch.

Scattered strong to severe thunderstorms with gusty winds and hail
are possible through this evening.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

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

   Flash Flood Watch.

Scattered strong to severe thunderstorms with gusty winds and hail
are possible Saturday afternoon and evening. Locally very heavy rain
of over 2 inches may occur in less than one hour where a few
thunderstorms train over the same location.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
502 PM EDT FRI JUL 16 2021

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

0448 PM     TSTM WND DMG     CLEARFIELD              41.03N 78.44W
07/16/2021                   CLEARFIELD         PA   FIRE DEPT/RESCUE

            LARGE LIMBS DOWN ON ROAD NEAR INTERSECTION
            OF NICHOLS STREET AND WILLIAMS STREET.

&&

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
524 PM EDT FRI JUL 16 2021

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

0520 PM     FLASH FLOOD      2 NE WEST MILTON        41.04N 76.78W
07/16/2021                   NORTHUMBERLAND     PA   TRAINED SPOTTER

            SEVERAL INCHES OF WATER FLOWING ACROSS ROAD
            AT LIMESTONEVILLE RD AND CHURCH RD.

&&

MRC

Special Weather Statement
National Weather Service State College PA
525 PM EDT Fri Jul 16 2021

PAZ058-162145-
Schuylkill PA-
525 PM EDT Fri Jul 16 2021

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF SCHUYLKILL COUNTY UNTIL
545 PM EDT...

At 525 PM EDT, Doppler radar indicated a strong thunderstorm over
Snyders, moving east at 20 mph.

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

Locations impacted include...
Snyders.

LAT...LON 4070 7581 4069 7584 4068 7589 4072 7592
      4081 7588 4081 7587 4074 7576
TIME...MOT...LOC 2125Z 270DEG 17KT 4073 7586

Evanego

Special Weather Statement
National Weather Service State College PA
532 PM EDT Fri Jul 16 2021

PAZ012-018-162200-
Northern Centre PA-Northern Clinton PA-
532 PM EDT Fri Jul 16 2021

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF NORTHERN CENTRE AND
NORTHERN CLINTON COUNTIES UNTIL 600 PM EDT...

At 532 PM EDT, Doppler radar indicated a strong thunderstorm near
Pine Glen, moving east at 30 mph.

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

Locations impacted include...
Snow Shoe, Clarence, Moshannon, Monument, Glen Union and Orviston.

LAT...LON 4130 7759 4113 7753 4105 7770 4101 7800
      4113 7805 4121 7798
TIME...MOT...LOC 2132Z 249DEG 28KT 4112 7797

Evanego

Special Weather Statement
National Weather Service State College PA
544 PM EDT Fri Jul 16 2021

PAZ018-019-045-162215-
Northern Centre PA-Southern Clinton PA-Southern Centre PA-
544 PM EDT Fri Jul 16 2021

...A STRONG THUNDERSTORM WILL AFFECT PARTS OF NORTHERN CENTRE...
SOUTHERN CLINTON...AND SOUTHERN CENTRE COUNTIES UNTIL 615 PM EDT...

At 544 PM EDT, Doppler radar indicated a strong thunderstorm over
Milesburg, moving northeast at 25 mph.

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

Locations impacted include...
Bellefonte, Pleasant Gap, Lamar, Lemont, Zion, Houserville, Mill
Hall, Centre Hall, Milesburg, Millheim, Blanchard, Aaronsburg,
Rebersburg, Madisonburg, Bald Eagle State Park, Mackeyville, Howard
and Beech Creek.

LAT...LON 4090 7739 4082 7781 4103 7786 4105 7770
      4115 7750 4114 7749
TIME...MOT...LOC 2144Z 243DEG 24KT 4096 7776

Evanego

Special Weather Statement
National Weather Service State College PA
601 PM EDT Fri Jul 16 2021

PAZ019-026-027-045-162230-
Southern Clinton PA-Huntingdon PA-Mifflin PA-Southern Centre PA-
601 PM EDT Fri Jul 16 2021

...STRONG THUNDERSTORMS WILL AFFECT PARTS OF SOUTHERN CLINTON...
HUNTINGDON...MIFFLIN...AND SOUTHERN CENTRE COUNTIES UNTIL 630 PM
EDT...

At 601 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Glen Union to Lamar to Whipple Dam State
Park. Movement was east at 25 mph.

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

Locations impacted include...
Lock Haven, Carroll, Woodward, Boalsburg, Pleasant Gap, Lamar,
Burnham, Zion, Mill Hall, Milroy, Avis, Dunnstown, Flemington, Centre
Hall, Castanea, Yeagertown, Millheim, Blanchard, Reedsville and
Aaronsburg.

LAT...LON 4120 7730 4118 7729 4118 7727 4108 7718
      4107 7714 4105 7714 4085 7736 4082 7735
      4064 7750 4065 7790 4098 7765 4106 7769
      4121 7732
TIME...MOT...LOC 2201Z 260DEG 21KT 4119 7765 4099 7756 4068 7785

Evanego