Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 81, NWS Pittsburgh, PA

June 21, 2021Indiana County, Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Jun 21, 2021, 4:43 PM EDT for Indiana County, Westmoreland County, Pennsylvania. It was in force for 32 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: Jun 21, 2021, 4:43 PM EDT (20:43 UTC)
Expired: Jun 21, 2021, 5:15 PM EDT
In force: 32 min
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Indiana County, PA, Westmoreland County, PA

The radar

The Pittsburgh radar (KPBZ), 97 km from the middle of the area, began a volume at 20:46 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
Jun 21, 12:31 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 8.7 hours before the alert went out and 83 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: 931 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 988 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 260 m²/s²
0-3 km storm-relative helicity: 277 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 5.1

Open this sounding in Storm Lab

The text

As transmitted.

048 
WUUS51 KPBZ 212043
SVRPBZ
PAC063-129-212115-
/O.NEW.KPBZ.SV.W.0081.210621T2043Z-210621T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pittsburgh PA
443 PM EDT Mon Jun 21 2021

The National Weather Service in Pittsburgh has issued a

* Severe Thunderstorm Warning for...
  Southern Indiana County in west central Pennsylvania...
  Southeastern Westmoreland County in southwestern Pennsylvania...

* Until 515 PM EDT.

* At 443 PM EDT, a severe thunderstorm was located near Ligonier, or
  11 miles southeast of Latrobe, moving east at 45 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...
  Ligonier...                       New Florence...
  Laurel Mountain...                Loyalhanna Gorge...
  Laurel Mountain State Park...     Acme...

This includes Pennsylvania Turnpike between mile markers 86 and 87,
and between
  mile markers 94 and 99.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing widespread wind damage. Seek shelter inside a
sturdy structure and stay away from windows!

Wind damage with this storm will occur before any rain or lightning.
Do not wait for the sound of thunder before taking cover.

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

&&

LAT...LON 4028 7906 4023 7910 4020 7911 4020 7913
      4018 7913 4018 7914 4016 7914 4016 7916
      4014 7916 4011 7918 4012 7921 4010 7923
      4016 7949 4032 7922 4041 7913 4039 7898
TIME...MOT...LOC 2043Z 281DEG 41KT 4018 7923 

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

1 follow-up statement

513 
WWUS51 KPBZ 212112
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
512 PM EDT Mon Jun 21 2021

PAC063-129-212121-
/O.EXP.KPBZ.SV.W.0081.000000T0000Z-210621T2115Z/
Indiana PA-Westmoreland PA-
512 PM EDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN INDIANA AND
SOUTHEASTERN WESTMORELAND COUNTIES WILL EXPIRE AT 515 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
southwestern and west central Pennsylvania.

LAT...LON 4028 7906 4023 7910 4020 7911 4020 7913
      4018 7913 4018 7914 4016 7914 4016 7916
      4014 7916 4011 7918 4012 7921 4010 7923
      4016 7949 4032 7922 4041 7913 4039 7898
TIME...MOT...LOC 2111Z 281DEG 41KT 4012 7886 

$$

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 Jun 21, 12:53 PM EDT, 3 hours 50 minutes earlier.

Area forecast discussion, Jun 21, 12:53 PM EDT, 3 hours 50 minutes before

Area Forecast Discussion
National Weather Service Pittsburgh PA
1253 PM EDT Mon Jun 21 2021

.SYNOPSIS...
Thunderstorms, potentially strong to severe, are expected this
afternoon and early evening with a crossing cold front. Cooler and
dry conditions expected Tuesday followed by a warming trend through
the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Sfc low pressure across the Great Lakes will shift northeastward
into southern Ontario as a trailing cold front crosses the upper
Ohio Valley today. Convection ahead of the front is already underway
and with ML CAPE values in excess of 2000 J/kg, 35kts, effective
shear, and steep low level lapse rates, severe weather will be
possible with damaging winds the primary threat. Tornadoes will also
be possible with discreet storms as latest hodographs and expected
storm motion will be ideal for streamwise vorticity into storms.
Large hail isn't completely out of the question with discreet cells
ahead of the front but 50dbz cores would need to be at least 35kft or
so before that became a possibility. A Severe Thunderstorm Watch has
been issued for the entire forecast area and runs until 7PM this
evening.

Minor flooding is also possible given high PWATs, but quick storm
motion should prevent more widespread concerns.

Storms will end with FROPA this evening followed by post- frontal
showers overnight.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
Dry and seasonably cool conditions expected Tuesday in the wake of
the front with afternoon temperatures in the 60s for most of the
area, and lows dipping into the 40s Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Building sfc high pressure will promote continued dry weather through
the work week under relatively low amplitude ern CONUS troughing.
High temperatures will rapidly moderate back into the 80s by
Thursday.

The next rain chance will come with the progged approach of a weekend
long wave trough.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A shortwave trough and sfc cold front will approach and pass the
region through tonight and provide increased chances for showers and
thunderstorms. Timing for convection should peak during the aftn
just ahead of a prefrontal trough associated with a SW to W wind
wind shift, with any thunderstorms capable of producing erratic,
gusty wind and rapidly lower vsbys. Conditions will generally dry out
after the prefrontal trough passage, though iso/sct showers will
remain possible as the cold front passes shortly thereafter.

Showers will dissipate after cold fropa, but the lagging upper trough
may maintain light rain S/E of PIT into Tuesday morning. MVFR to
localized IFR cigs are likely overnight amid strong cold advection.
Diurnal heating/mixing of drier air with developing high pressure
will return most terminals to VFR by Tuesday aftn.

.Outlook...
VFR conditions are likely for much of the week under the influence of
high pressure.

&&

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

&&

Hazardous weather outlook, Jun 21, 4:32 PM EDT, 11 minutes before

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
432 PM EDT Mon Jun 21 2021

OHZ059-068-069-PAZ016-023-029-031-073>076-WVZ003-004-012-021-509>514-
222045-
Belmont-Noble-Monroe-Jefferson PA-Indiana-Washington-Greene-
Westmoreland-Higher Elevations of Westmoreland-Fayette-
Higher Elevations of Fayette-Ohio-Marshall-Wetzel-Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-Preston-
Eastern Preston-Western Tucker-Eastern Tucker-
432 PM EDT Mon Jun 21 2021

...SEVERE THUNDERSTORM WATCH 299 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

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...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...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

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

OHZ039>041-048>050-057-058-PAZ007>009-013>015-020>022-WVZ001-002-
222045-
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-
Muskingum-Guernsey-Mercer-Venango-Forest-Lawrence-Butler-Clarion-
Beaver-Allegheny-Armstrong-Hancock-Brooke-
432 PM EDT Mon Jun 21 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...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

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

In the hours before

Local storm report, Jun 21, 4:18 PM EDT, 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
418 PM EDT MON JUN 21 2021

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

0345 PM     TSTM WND DMG     LAWRENCEVILLE           40.47N  79.96W
06/21/2021                   ALLEGHENY          PA   PUBLIC

            LARGE TREE LIMBS DOWN

&&

EVENT NUMBER PBZ2101759

07

Local storm report, Jun 21, 4:21 PM EDT, 22 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
421 PM EDT MON JUN 21 2021

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

0246 PM     TSTM WND DMG     ECONOMY                 40.64N  80.19W
06/21/2021                   BEAVER             PA   SOCIAL MEDIA

            TREES AND LARGE LIMBS DOWN

&&

EVENT NUMBER PBZ2101760

07

Local storm report, Jun 21, 4:27 PM EDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
427 PM EDT MON JUN 21 2021

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

0400 PM     TSTM WND DMG     HOMER CITY              40.54N  79.16W
06/21/2021                   INDIANA            PA   911 CALL CENTER

            TREES DOWN ON RESIDENCE IN CENTER TOWNSHIP

&&

EVENT NUMBER PBZ2101761

AMILLER

Local storm report, Jun 21, 4:30 PM EDT, 13 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
430 PM EDT MON JUN 21 2021

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

0257 PM     TSTM WND DMG     TIONESTA                41.50N  79.45W
06/21/2021                   FOREST             PA   PUBLIC

            COUPLE OF TREES DOWN

&&

EVENT NUMBER PBZ2101762

07

Local storm report, Jun 21, 4:33 PM EDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
433 PM EDT MON JUN 21 2021

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

0355 PM     TSTM WND DMG     2 SSW SMATHERS          40.51N  79.23W
06/21/2021                   INDIANA            PA   911 CALL CENTER

            TREES DOWN ON BLACK LICK ROAD

&&

EVENT NUMBER PBZ2101763

AMILLER

Local storm report, Jun 21, 4:40 PM EDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
440 PM EDT MON JUN 21 2021

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

0438 PM     TSTM WND DMG     1 E JACKSONVILLE        40.54N  79.26W
06/21/2021                   INDIANA            PA   911 CALL CENTER

            TREES DOWN ON HUNTER SCHOOL ROAD

&&

EVENT NUMBER PBZ2101765

AMILLER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 8:55 PM EDT	Special Weather Statement	PBZ	Armstrong	20 min
Jun 21, 7:27 AM EDT	Special Weather Statement	PBZ	Lawrence, Mercer	33 min
Jun 21, 1:57 PM EDT	Severe Thunderstorm Warning	PBZ	Beaver, Lawrence	48 min
Jun 21, 2:08 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette	22 min
Jun 21, 2:15 PM EDT	Severe Thunderstorm Warning	PBZ	Mercer, Venango	30 min
Jun 21, 2:21 PM EDT	Severe Thunderstorm Warning	PBZ	Beaver, Lawrence	24 min
Jun 21, 2:37 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Butler, Lawrence, Washington	23 min
Jun 21, 2:45 PM EDT	Severe Thunderstorm Warning	PBZ	Forest, Venango	30 min
Jun 21, 2:51 PM EDT	Tornado Warning	PBZ	Allegheny, Beaver, Butler	9 min
Jun 21, 2:55 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Armstrong, Beaver, Butler, Westmoreland	35 min
Jun 21, 2:58 PM EDT	Tornado Warning	PBZ	Allegheny, Butler	17 min
Jun 21, 3:00 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Washington	30 min
Jun 21, 3:21 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Armstrong, Butler, Indiana, Westmoreland	24 min
Jun 21, 3:25 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Westmoreland	35 min
Jun 21, 3:29 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Washington	46 min
Jun 21, 3:37 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Armstrong, Indiana, Jefferson, Westmoreland	23 min
Jun 21, 3:45 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Armstrong, Indiana, Westmoreland	45 min
Jun 21, 3:47 PM EDT	Special Weather Statement	PBZ	Washington	28 min
Jun 21, 3:53 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Fayette, Greene, Washington, Westmoreland	37 min
Jun 21, 3:55 PM EDT	Areal Flood Advisory	PBZ	Allegheny, Westmoreland	111 min
Jun 21, 3:55 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Indiana, Westmoreland	35 min
Jun 21, 3:57 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Clarion, Jefferson	33 min
Jun 21, 4:05 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Fayette, Washington, Westmoreland	25 min
Jun 21, 4:13 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Westmoreland	32 min
Jun 21, 4:18 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette, Greene, Washington, Westmoreland	27 min
Jun 21, 4:19 PM EDT	Severe Thunderstorm Warning	PBZ	Greene, Washington	41 min
Jun 21, 4:27 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Westmoreland	33 min
Jun 21, 4:28 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette, Westmoreland	32 min
Jun 21, 4:41 PM EDT	Severe Thunderstorm Warning	PBZ	Fayette, Greene, Washington, Westmoreland	49 min
Jun 21, 4:57 PM EDT	Severe Thunderstorm Warning	PBZ	Greene	29 min
Jun 21, 5:03 PM EDT	Tornado Warning	PBZ	Greene	6 min
Jun 21, 5:08 PM EDT	Areal Flood Advisory	PBZ	Fayette, Greene, Washington, Westmoreland	3 hr
Jun 21, 6:39 PM EDT	Areal Flood Advisory	PBZ	Allegheny, Greene, Washington, Westmoreland	2 hr
Jun 21, 6:43 PM EDT	Special Weather Statement	PBZ	Fayette	32 min
Jun 21, 7:23 PM EDT	Flash Flood Warning	PBZ	Allegheny, Fayette, Washington, Westmoreland	3 hr
Jun 21, 7:46 PM EDT	Areal Flood Warning	PBZ	Fayette, Greene, Washington, Westmoreland	3 hr

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.