Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 154, NWS Pittsburgh, PA

July 13, 2021Clarion County, Jefferson County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Jul 13, 2021, 5:08 PM EDT for Clarion County, Jefferson County, Pennsylvania. It was in force for 52 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 13, 2021, 5:08 PM EDT (21:08 UTC)
Expired: Jul 13, 2021, 6:00 PM EDT
In force: 52 min
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Clarion County, PA, Jefferson County, PA

The radar

The State College radar (KCCX), 91 km from the middle of the area, began a volume at 21:07 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 13, 1:37 PM EDT	Severe Thunderstorm Watch	SPC	10 hr

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 9.1 hours before the alert went out and 125 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 107 J/kg
Mixed-layer CIN: -136 J/kg
Mixed-layer LCL: 980 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 84 m²/s²
0-3 km storm-relative helicity: 158 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

171 
WUUS51 KPBZ 132108
SVRPBZ
PAC031-065-132200-
/O.NEW.KPBZ.SV.W.0154.210713T2108Z-210713T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pittsburgh PA
508 PM EDT Tue Jul 13 2021

The National Weather Service in Pittsburgh has issued a

* Severe Thunderstorm Warning for...
  Central Jefferson County in west central Pennsylvania...
  East central Clarion County in west central Pennsylvania...

* Until 600 PM EDT.

* At 508 PM EDT, a severe thunderstorm was located near Brookville,
  moving northeast at 35 mph.

  HAZARD...Wind gusts to 60 mph.

  SOURCE...Radar.

  IMPACT...Expect damage to trees and power lines, resulting in some 
           power outages.

* Locations impacted include...
  Brookville...                     Brockway...
  Summerville...                    Corsica...
  Worthville...                     Knox-Dale...

This includes Interstate 80 in Pennsylvania between mile markers 74
and 89.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to an interior room on the lowest floor of a building.

Please report severe weather by calling 412-262-1988, posting to 
the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. 

&&

LAT...LON 4101 7915 4114 7925 4137 7896 4136 7896
      4126 7874
TIME...MOT...LOC 2108Z 222DEG 29KT 4114 7914 

HAIL...<.75IN
WIND...60MPH
 
$$

3 follow-up statements

519 
WWUS51 KPBZ 132130
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
530 PM EDT Tue Jul 13 2021

PAC031-132139-
/O.CAN.KPBZ.SV.W.0154.000000T0000Z-210713T2200Z/
Clarion PA-
530 PM EDT Tue Jul 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CLARION COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
west central Pennsylvania.

LAT...LON 4111 7913 4117 7919 4137 7896 4136 7896
      4126 7874
TIME...MOT...LOC 2129Z 222DEG 29KT 4127 7898 

$$

PAC065-132200-
/O.CON.KPBZ.SV.W.0154.000000T0000Z-210713T2200Z/
Jefferson PA-
530 PM EDT Tue Jul 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR NORTHERN JEFFERSON COUNTY...

At 529 PM EDT, a severe thunderstorm was located 9 miles northeast of
Brookville, moving northeast at 35 mph.

HAZARD...Wind gusts to 60 mph.

SOURCE...Radar.

IMPACT...Expect damage to trees and power lines, resulting in some 
         power outages.

Locations impacted include...
Brookville...                     Brockway...

This includes Interstate 80 in Pennsylvania between mile markers 75
and 84.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm has a history of producing damaging wind gusts. Move
indoors immediately and stay away from windows!

Please report severe weather by calling 412-262-1988, posting to 
the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. 

&&

LAT...LON 4111 7913 4117 7919 4137 7896 4136 7896
      4126 7874
TIME...MOT...LOC 2129Z 222DEG 29KT 4127 7898 

HAIL...<.75IN
WIND...60MPH
 
$$

235 
WWUS51 KPBZ 132142
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
542 PM EDT Tue Jul 13 2021

PAC065-132200-
/O.CON.KPBZ.SV.W.0154.000000T0000Z-210713T2200Z/
Jefferson PA-
542 PM EDT Tue Jul 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR NORTH CENTRAL JEFFERSON COUNTY...

At 542 PM EDT, a severe thunderstorm was located near Portland Mills,
or 9 miles southwest of Ridgway, moving northeast at 35 mph.

HAZARD...Wind gusts to 60 mph.

SOURCE...Radar.

IMPACT...Expect damage to trees and power lines, resulting in some 
         power outages.

This severe thunderstorm will remain over mainly rural areas of north
central Jefferson County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm has a history of producing damaging wind gusts. Move
indoors immediately and stay away from windows!

Please report severe weather by calling 412-262-1988, posting to 
the NWS Pittsburgh Facebook page, or using Twitter @NWSPITTSBURGH. 

&&

LAT...LON 4124 7901 4128 7906 4137 7896 4136 7896
      4132 7887
TIME...MOT...LOC 2142Z 222DEG 29KT 4135 7889 

HAIL...<.75IN
WIND...60MPH
 
$$

307 
WWUS51 KPBZ 132159 RRA
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
559 PM EDT Tue Jul 13 2021

PAC065-132209-
/O.EXP.KPBZ.SV.W.0154.000000T0000Z-210713T2200Z/
Jefferson PA-
559 PM EDT Tue Jul 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL JEFFERSON COUNTY
WILL EXPIRE AT 600 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until 1100 PM EDT for
west central Pennsylvania.

LAT...LON 4124 7901 4128 7906 4137 7896 4136 7896
      4132 7887
TIME...MOT...LOC 2159Z 222DEG 29KT 4144 7879 

$$

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Pittsburgh, PA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 13, 2:47 PM EDT, 2 hours 21 minutes earlier.

Area forecast discussion, Jul 13, 2:47 PM EDT, 2 hours 21 minutes before

Area Forecast Discussion
National Weather Service Pittsburgh PA
247 PM EDT Tue Jul 13 2021

.SYNOPSIS...
Warm and humid conditions will linger through the week along with
daily shower and thunderstorm chances.

&&

.NEAR TERM /THROUGH TONIGHT/...
The Upr OH rmns under deep southwest flow resulting fm a Midwest
trough and Wrn Atlantic ridge. Shortwaves with that moist, warm flow
continue to spawn sct to nmrs showers and storms. The severe threat
is marginal for the area with warm mid levels prvdg updraft
inhibition; however, effective/deep layer shear has improved fm
yesterday although it is marginal at approx 30kt. Sufficient dry mid
level air is present to support evaporative cooling and hence some
downburst wind. The aforementioned mid level warmth is also
supportive of warm rain process, particularly over areas west of I 79
where moisture depth is better, but, flow is also sufficient for
movement to offset a flash flood threat outside of any local training
that occurs.

Isolated showers/thunderstorms may linger the overnight hours, but
waning instability and declining upr support will inhibit widespread
convective activity.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
The sharpening upper shortwave trough will cross the area on
Wednesday, aiding shower and thunderstorm development once convective
temps are reached late Weds morning and afternoon. Timing of best
upper support will likely keep the most widespread convection across
PA and WV, with lesser extent farther west into OH. More widespread
rain and cloud cover should ease high temperatures by several degrees
Weds afternoon.

Rain chances will diminish Weds night and Thurs as weak mid-lvl
ridging briefly builds across the region. However, drier conditions
will once again boost high temperatures into the upper 80s for much
of the area.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
The next trough will arrive in the Great Lakes/Ohio Valley region by
Friday with a slowly moving cold front eventually crossing on Saturday.
Better rain chances should spread across the area Friday morning and
afternoon in advance of the front, with rain chances lingering for
at least southeast portions of the area into Sunday. Drier weather is
expected Monday into Monday night as high pressure begins to build
across the region.

Even then, temperatures will return to more normal values Sunday and
Monday but look to rebound to above normal values beyond Monday.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Sct to nmrs shra and tsra will affect area terminals through the
evening. Local fog and stratus can be expected once again in the
predawn of Wednesday. More shra/tsra are anticipated on Wednesday
morning, but improvement is indicated thereafter as shortwave
ridging ensues.

.Outlook...
Periodic restrictions with showers and storms, mainly during the
afternoon and evening hours, will be possible through the week.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

Hazardous weather outlook, Jul 13, 1:43 PM EDT, 3 hours 25 minutes before

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
143 PM EDT Tue Jul 13 2021

OHZ039>041-048>050-057>059-068-069-PAZ007-008-013-014-020-021-029-
031-WVZ001>004-012-021-509>514-141745-
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-
Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Lawrence-
Butler-Beaver-Allegheny-Washington-Greene-Hancock-Brooke-Ohio-
Marshall-Wetzel-Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-Preston-
Eastern Preston-Western Tucker-Eastern Tucker-
143 PM EDT Tue Jul 13 2021

This Hazardous Weather Outlook is for east central Ohio, northwest
Pennsylvania, southwest Pennsylvania, western Pennsylvania,
northern West Virginia and the northern panhandle of West Virginia.

.DAY ONE...This afternoon and tonight.

Isolated severe storms are possible with the threat for damaging
wind gusts. Storms may also produce briefly heavy downpours which
could lead to localized flooding.

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

There is a low probability for widespread hazardous weather.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

PAZ009-015-016-022-023-073>076-141745-
Forest-Clarion-Jefferson PA-Armstrong-Indiana-Westmoreland-
Higher Elevations of Westmoreland-Fayette-
Higher Elevations of Fayette-
143 PM EDT Tue Jul 13 2021

...SEVERE THUNDERSTORM WATCH 375 IN EFFECT UNTIL 11 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for northwest Pennsylvania,
southwest Pennsylvania and western Pennsylvania.

.DAY ONE...This afternoon and tonight.

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

   Severe Thunderstorm Watch.

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

There is a low probability for widespread hazardous weather.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

In the hours before

Local storm report, Jul 13, 3:46 PM EDT, 1 hour 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
346 PM EDT TUE JUL 13 2021

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

0339 PM     TSTM WND DMG     1 NNE GREENVILLE EAST   41.41N  80.36W
07/13/2021                   MERCER             PA   911 CALL CENTER

            TREE AND WIRES DOWN ON OLD WILLIAMSON RD NEAR TRACTOR
            SUPPY CO. TREE ALSO ON FIRE.

&&

EVENT NUMBER PBZ2101945

SKH

Local storm report, Jul 13, 3:56 PM EDT, 1 hour 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
356 PM EDT TUE JUL 13 2021

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

0325 PM     TSTM WND DMG     1 WNW GREENCREST PARK   41.35N  80.42W
07/13/2021                   MERCER             PA   911 CALL CENTER

            TREE DOWN ON HOMER LANE AND COLT ROAD.

&&

EVENT NUMBER PBZ2101946

SKH

Local storm report, Jul 13, 4:21 PM EDT, 47 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
421 PM EDT TUE JUL 13 2021

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

0415 PM     TSTM WND DMG     ZELIENOPLE              40.79N  80.14W
07/13/2021                   BUTLER             PA   911 CALL CENTER

            TREES DOWN IN EAST BEAVER STREET.

&&

EVENT NUMBER PBZ2101947

SKH

Local storm report, Jul 13, 4:32 PM EDT, 36 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
432 PM EDT TUE JUL 13 2021

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

0412 PM     TSTM WND DMG     KARNS CITY              41.00N  79.73W
07/13/2021                   BUTLER             PA   911 CALL CENTER

            TREE DOWN ON HOOKER ROAD.

&&

EVENT NUMBER PBZ2101948

SKH

Local storm report, Jul 13, 4:41 PM EDT, 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
441 PM EDT TUE JUL 13 2021

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

0418 PM     TSTM WND DMG     1 NNE NICHOLA           40.89N  79.67W
07/13/2021                   ARMSTRONG          PA   911 CALL CENTER

            TREES DOWN ON ST. PATRICKS RD

&&

EVENT NUMBER PBZ2101949

SKH

Local storm report, Jul 13, 4:50 PM EDT, 18 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
450 PM EDT TUE JUL 13 2021

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

0423 PM     TSTM WND DMG     1 NW FORD CITY          40.78N  79.54W
07/13/2021                   ARMSTRONG          PA   911 CALL CENTER

            TREE DOWN ON BUNKER HILL RD.

&&

EVENT NUMBER PBZ2101950

SKH

The office that day

Everything else NWS Pittsburgh, PA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 12, 8:00 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Butler, Clarion, Venango	30 min
Jul 13, 3:23 AM EDT	Special Weather Statement	PBZ	Washington	37 min
Jul 13, 3:37 AM EDT	Severe Thunderstorm Warning	PBZ	Washington	22 min
Jul 13, 3:53 AM EDT	Special Weather Statement	PBZ	Allegheny	37 min
Jul 13, 4:06 AM EDT	Special Weather Statement	PBZ	Westmoreland	24 min
Jul 13, 4:10 AM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Westmoreland	35 min
Jul 13, 4:17 AM EDT	Special Weather Statement	PBZ	Armstrong	28 min
Jul 13, 4:41 AM EDT	Special Weather Statement	PBZ	Indiana	34 min
Jul 13, 5:24 AM EDT	Special Weather Statement	PBZ	Indiana	36 min
Jul 13, 3:04 PM EDT	Special Weather Statement	PBZ	Lawrence	26 min
Jul 13, 3:14 PM EDT	Severe Thunderstorm Warning	PBZ	Butler, Lawrence, Mercer	31 min
Jul 13, 3:25 PM EDT	Severe Thunderstorm Warning	PBZ	Mercer	35 min
Jul 13, 3:36 PM EDT	Severe Thunderstorm Warning	PBZ	Butler, Mercer, Venango	39 min
Jul 13, 3:39 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Armstrong, Butler	51 min
Jul 13, 4:05 PM EDT	Severe Thunderstorm Warning	PBZ	Forest, Mercer, Venango	40 min
Jul 13, 4:11 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Butler, Clarion, Venango	49 min
Jul 13, 4:14 PM EDT	Severe Thunderstorm Warning	PBZ	Beaver, Butler, Lawrence	31 min
Jul 13, 4:25 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Clarion, Indiana, Jefferson	50 min
Jul 13, 4:41 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Butler, Clarion, Venango	34 min
Jul 13, 4:47 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Clarion, Forest, Jefferson, Venango	43 min
Jul 13, 4:50 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Westmoreland	40 min
Jul 13, 5:00 PM EDT	Severe Thunderstorm Warning	PBZ	Clarion, Forest, Venango	45 min
Jul 13, 5:12 PM EDT	Severe Thunderstorm Warning	PBZ	Clarion, Forest, Jefferson, Venango	48 min
Jul 13, 5:25 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Jefferson, Westmoreland	50 min
Jul 13, 5:47 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Fayette, Greene, Washington, Westmoreland	28 min
Jul 13, 6:08 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Jefferson, Westmoreland	37 min
Jul 13, 6:14 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette, Westmoreland	31 min
Jul 13, 6:43 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Indiana, Westmoreland	32 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Every severe thunderstorm warning in 2021

Sources

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.