Special Weather Statement, NWS State College, PA

Area Forecast Discussion
National Weather Service State College PA
231 AM EDT Mon Jun 21 2021

.SYNOPSIS...
Very warm and muggy conditions this Father's Day with an
isolated strong thunderstorm possible late this afternoon. Heat
and humidity will peak on Monday with a slight risk of severe
storms. Showers exit on Tuesday followed by cooler and more
comfortable weather through midweek. Temperatures return to
seasonal levels by late week with an increasing chance of rain
into next weekend.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Coverage of thunderstorms will diminish over most of the CWA
overnight, however a couple of thunderstorms may move into the
far northwest late tonight as a decaying line of convection
moves across northern Ohio into northwest PA. Have added patchy
fog to the lower and middle Susquehanna valley and into the
central mountains where it rained in the afternoon and evening.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
D2 SPC SLGT risk SWO continues for Monday.

Isolated to scattered severe storm risk on Monday afternoon and
evening will be driven by amplifying large scale trough and low
level convergence along the attendant cold front and pre-frontal
trough. Rich low level moisture (dewpoints 65-70F) will reside
ahead of the front, and diurnal heating/instability combined
with frontal forcing and sufficient deep-layer shear should
support organized (linear) storm clusters/lines capable of
producing strong to locally damaging winds.

Heat+Humidity peaks on Monday with max temperatures in the mid
80s to low 90s and max heat index (HX) values forecast to reach
the mid to upper 90s across the central and southeast valleys.
Forecast max temperatures are a solid 5-10F above average and
approach near-record territory in some areas (within 5F at
STCP1).

Convection should gradually weaken Monday night due to the loss
of heating and increasing CINH. Minimum temperatures will have
the most spread in recent nights thanks to the cold front
bisecting the area with lows ranging from the mid 50s in the NW
mtns to around 70F in the southeast/Lower Susq. metro areas.

Showers are likely early Tuesday across the southeast zones
before exiting the CWA by 00Z Wed. Temps will trend much cooler
on Tuesday with 24hrMaxT deltas of -15 to -25F lower vs. Monday.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Dry conditions and low humidity expected through midweek as
surface high pressure builds in behind the cold front. The high
will move to the east later in the week with warmer, more humid
air moving in from the south and east.

A cold front will approach from the west next weekend, but there
is still a great deal of uncertainty with the timing of that
front and precipitation it will bring. GFS and ECMWF have been
trending toward a slower solution on the movement of the front
and perhaps event the front stalling over PA next weekend into
early next week. This would result in an unsettled period with
multiple rain chances for central PA through the middle of the
week.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
As of 06z Mon, scattered TSRA has moved out of the area into NY
state. Will continue to monitor upstream convection over Lake
Erie, which may work its way into BFD after 09z, although it is
on a weakening trend so chances are decreasing.

Model guidance continues to indicate that lower clouds will
develop over eastern terminals after 10z
/MDT...IPT...LNS...UNV/. With muggy airmass in place expect
vsbys across Central PA to slip to MVFR for a short while around
sunrise... with possible localized areas of fog bringing vsby
down to IFR.

Widespread coverage of showers/tstms is expected on Monday with
activity spreading from the NW across the CWA by afternoon.
These storms will bring potential for locally strong wind gusts
and torrential rainfall as they impact the area through the
afternoon hours. Peak areal extent of TSRA expected between 18z-
00z.

Outlook...

Monday-Tuesday...more widespread showers/storms possible
areawide.

Wednesday-Friday...widespread VFR.

&&

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

&&

SYNOPSIS...Steinbugl/RXR
NEAR TERM...RXR/Travis
SHORT TERM...Steinbugl/RXR
LONG TERM...Guseman/Travis
AVIATION...Colbert/Wagner

Hazardous Weather Outlook
National Weather Service State College PA
455 AM EDT Sun Jun 20 2021

PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053-
056>059-063>066-210900-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin-
Juniata-Somerset-Bedford-Fulton-Franklin-Tioga-Northern Lycoming-
Sullivan-Southern Clinton-Southern Lycoming-Union-Snyder-Montour-
Northumberland-Columbia-Perry-Dauphin-Schuylkill-Lebanon-Cumberland-
Adams-York-Lancaster-
455 AM EDT Sun Jun 20 2021

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and tonight.

Isolated strong to marginally severe thunderstorms with gusty winds
are possible Sunday afternoon and evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Scattered severe thunderstorms with damaging winds 60 mph or greater
are possible Monday afternoon and evening. Locally heavy rainfall may
produce isolated flooding in poor drainage and urban areas.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report significant hazardous weather.

MRS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1240 AM EDT MON JUN 21 2021

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

0820 PM     TSTM WND DMG     1 NNE MCALISTERVILLE    40.64N 77.27W
06/20/2021                   JUNIATA            PA   911 CALL CENTER

            TREES ON WIRES. OTHER REPORTS OF TREES
            ACROSS ROADS REPORTED IN JUNIATA COUNTY.

&&

AW

Special Weather Statement
National Weather Service State College PA
418 AM EDT Mon Jun 21 2021

PAZ004-210900-
Warren PA-
418 AM EDT Mon Jun 21 2021

...STRONG THUNDERSTORMS WILL AFFECT PARTS OF WARREN COUNTY UNTIL 515
AM EDT...

At 417 AM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 7 miles southwest of Long Point State Park to
near Riceville. Movement was east at 50 mph.

Wind gusts up to 50 mph are possible.

Locations impacted include...
Columbus, Youngsville, Spring Creek, Lottsville, Sugar Grove and Bear
Lake.

LAT...LON 4200 7914 4199 7912 4183 7926 4182 7961
      4196 7961 4200 7960
TIME...MOT...LOC 0817Z 248DEG 43KT 4209 7950 4184 7973

Colbert