Severe Thunderstorm Watch 496

Issued

Sep 13, 2021, 5:53 PM EDT (21:53 UTC)

Expired

Sep 13, 2021, 8:54 PM EDT

In force

3 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

Counties Cameron County, PA, Centre County, PA, Clarion County, PA, Clearfield County, PA, Clinton County, PA, Columbia County, PA, Elk County, PA, Forest County, PA, Jefferson County, PA, Lycoming County, PA, McKean County, PA, Montour County, PA, Northumberland County, PA, Potter County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Tioga County, PA, Union County, PA, Venango County, PA

The State College radar (KCCX), 76 km from the middle of the area, began a volume at 21:56 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

5%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1738 Severe potential...watch unlikelySep 13, 4:11 PM EDT
• Mesoscale Discussion 1739 Severe thunderstorm watch 496Sep 13, 7:07 PM EDT

948 
WWUS20 KWNS 132150
SEL6  
SPC WW 132150
PAZ000-140500-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 496
NWS Storm Prediction Center Norman OK
550 PM EDT Mon Sep 13 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Northern and central Pennsylvania

* Effective this Monday afternoon and Tuesday morning from 550 PM
  until 100 AM EDT.

* Primary threats include...
  Scattered damaging wind gusts to 70 mph likely
  Scattered large hail events to 1.5 inches in diameter possible

SUMMARY...A growing cluster of thunderstorms in northwestern PA may
continue to expand and organize as it moves east-southeastward down
a frontal zone, offering damaging to severe gusts and sporadic large
hail.  Isolated severe hail/gusts also are possible from
thunderstorms ahead of the main cluster, also on either side of the
front.

The severe thunderstorm watch area is approximately along and 35
statute miles north and south of a line from 20 miles north of
Franklin PA to 35 miles east southeast of Williamsport PA. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU6).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
29045.

...Edwards

Severe Thunderstorm Watches in Pennsylvania, 2021Every severe thunderstorm watch in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.