Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 178, NWS Pittsburgh, PA

July 17, 2021Fayette County, Westmoreland County, Pennsylvania; Monongalia County, West Virginia

NWS Pittsburgh, PA issued this severe thunderstorm warning at Jul 17, 2021, 4:30 PM EDT for Fayette County, Westmoreland County, Pennsylvania; Monongalia County, West Virginia. It was in force for 45 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 17, 2021, 4:30 PM EDT (20:30 UTC)
Expired: Jul 17, 2021, 5:15 PM EDT
In force: 45 min
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Fayette County, PA, Westmoreland County, PA, Monongalia County, WV

The radar

The Pittsburgh radar (KPBZ), 103 km from the middle of the area, began a volume at 20:30 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.

What was reported inside it

Time	Report	Where	Remark
Jul 17, 4:35 PM EDT	TSTM WND DMG	1 Se Woodbridgetown, PA	A FEW TREES DOWN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 8.5 hours before the alert went out and 86 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: 70 J/kg
Mixed-layer CIN: -81 J/kg
Mixed-layer LCL: 882 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 80 m²/s²
0-3 km storm-relative helicity: 128 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

209 
WUUS51 KPBZ 172030
SVRPBZ
PAC051-129-WVC061-172115-
/O.NEW.KPBZ.SV.W.0178.210717T2030Z-210717T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pittsburgh PA
430 PM EDT Sat Jul 17 2021

The National Weather Service in Pittsburgh has issued a

* Severe Thunderstorm Warning for...
  South central Westmoreland County in southwestern Pennsylvania...
  Southeastern Fayette County in southwestern Pennsylvania...
  Northeastern Monongalia County in northern West Virginia...

* Until 515 PM EDT.

* At 429 PM EDT, a severe thunderstorm was located near Farmington,
  or 7 miles southeast of Uniontown, moving east at 55 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...
  Uniontown...                      Farmington...
  Seven Springs...                  Fairchance...
  Markleysburg...                   Chalkhill...
  Ohiopyle...                       Mill Run...
  Normalville...                    

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 3991 7939 3985 7942 3982 7937 3980 7937
      3979 7935 3979 7938 3978 7939 3977 7938
      3976 7940 3974 7940 3972 7981 3987 7979
      4006 7928
TIME...MOT...LOC 2029Z 247DEG 49KT 3983 7961 

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

2 follow-up statements

362 
WWUS51 KPBZ 172050
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
450 PM EDT Sat Jul 17 2021

WVC061-172059-
/O.CAN.KPBZ.SV.W.0178.000000T0000Z-210717T2115Z/
Monongalia WV-
450 PM EDT Sat Jul 17 2021

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

LAT...LON 3991 7939 3985 7942 3982 7937 3980 7937
      3979 7935 3979 7938 3978 7939 3977 7938
      3976 7940 3974 7940 3973 7967 3992 7965
      4006 7928
TIME...MOT...LOC 2049Z 247DEG 49KT 3994 7927 

$$

PAC051-129-172115-
/O.CON.KPBZ.SV.W.0178.000000T0000Z-210717T2115Z/
Westmoreland PA-Fayette PA-
450 PM EDT Sat Jul 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM EDT
FOR SOUTH CENTRAL WESTMORELAND AND SOUTHEASTERN FAYETTE COUNTIES...

At 449 PM EDT, a severe thunderstorm was located near New
Centerville, or 11 miles southwest of Somerset, moving northeast at
55 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...
Farmington...                     Seven Springs...
Markleysburg...                   Chalkhill...
Ohiopyle...                       Mill Run...
Normalville...                    

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 3991 7939 3985 7942 3982 7937 3980 7937
      3979 7935 3979 7938 3978 7939 3977 7938
      3976 7940 3974 7940 3973 7967 3992 7965
      4006 7928
TIME...MOT...LOC 2049Z 247DEG 49KT 3994 7927 

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

268 
WWUS51 KPBZ 172105
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
505 PM EDT Sat Jul 17 2021

PAC051-129-172115-
/O.EXP.KPBZ.SV.W.0178.000000T0000Z-210717T2115Z/
Westmoreland PA-Fayette PA-
505 PM EDT Sat Jul 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL WESTMORELAND AND
SOUTHEASTERN FAYETTE COUNTIES WILL EXPIRE AT 515 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 3991 7939 3985 7942 3982 7937 3980 7937
      3979 7935 3979 7938 3978 7939 3977 7938
      3976 7940 3974 7940 3973 7967 3992 7965
      4006 7928
TIME...MOT...LOC 2105Z 247DEG 49KT 4000 7908 

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 16, 10:28 PM EDT	Areal Flood Advisory	PBZ	Mercer, Venango	3 hr
Jul 17, 2:46 AM EDT	Flash Flood Watch	PBZ	Armstrong, Beaver, Butler, Clarion, Forest, Jefferson and 3 more	15 hr
Jul 17, 11:21 AM EDT	Areal Flood Advisory	PBZ	Forest, Mercer, Venango	4 hr
Jul 17, 12:34 PM EDT	Flash Flood Warning	PBZ	Mercer, Venango	3 hr
Jul 17, 1:39 PM EDT	Areal Flood Advisory	PBZ	Allegheny, Washington	3 hr
Jul 17, 2:30 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Indiana, Westmoreland	45 min
Jul 17, 2:51 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana	39 min
Jul 17, 4:01 PM EDT	Areal Flood Advisory	PBZ	Allegheny, Fayette, Greene, Washington, Westmoreland	92 min
Jul 17, 12:43 PM EDT	Areal Flood Advisory	PBZ	Brooke, Hancock, Ohio	3 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Severe Thunderstorm Warnings in West Virginia, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.