Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 252, NWS Pittsburgh, PA

August 17, 2019Allegheny County, Armstrong County, Westmoreland County, Pennsylvania

NWS Pittsburgh, PA issued this severe thunderstorm warning at Aug 17, 2019, 7:15 PM EDT for Allegheny County, Armstrong County, Westmoreland County, Pennsylvania. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 17, 2019, 7:15 PM EDT (23:15 UTC)
Expired
Aug 17, 2019, 7:45 PM EDT
In force
30 min
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Allegheny County, PA, Armstrong County, PA, Westmoreland County, PA

The radar

The Pittsburgh radar (KPBZ), 49 km from the middle of the area, began a volume at 23:19 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.

The watch it was issued in

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

IssuedProductOfficeLasted
Aug 17, 4:03 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 11.3 hours before the alert went out and 41 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-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2019-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 37 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 12:00Z on 2019-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
37 J/kg
Mixed-layer CIN
-100 J/kg
Mixed-layer LCL
1297 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
155 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

441 
WUUS51 KPBZ 172315
SVRPBZ
PAC003-005-129-172345-
/O.NEW.KPBZ.SV.W.0252.190817T2315Z-190817T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pittsburgh PA
715 PM EDT Sat Aug 17 2019

The National Weather Service in Pittsburgh has issued a

* Severe Thunderstorm Warning for...
  Northeastern Allegheny County in southwestern Pennsylvania...
  Northwestern Westmoreland County in southwestern Pennsylvania...
  Southwestern Armstrong County in west central Pennsylvania...

* Until 745 PM EDT.

* At 715 PM EDT, a severe thunderstorm was located over Fox Chapel,
  or over Penn Hills, moving northeast at 30 mph.

  HAZARD...Wind gusts to 60 mph and quarter-size hail.

  SOURCE...Radar.

  IMPACT...Minor hail damage to vehicles is possible. Expect wind 
           damage to trees and power lines, resulting in some power 
           outages.

* Locations impacted include...
  Pittsburgh...                     Penn Hills...
  Monroeville...                    Vandergrift...
  Apollo...                         Shaler Township...
  Plum...                           Murrysville...
  Hampton Township...               Wilkinsburg...
  New Kensington...                 Lower Burrell...

This includes the following highways...
  Pennsylvania Turnpike between mile markers 43 and 55.
  Interstate 376 in Pennsylvania between mile markers 75 and 83.

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 4053 7945 4040 7992 4053 7999 4067 7977
      4067 7969 4072 7969 4077 7961
TIME...MOT...LOC 2315Z 243DEG 24KT 4052 7989 

HAIL...1.00IN
WIND...60MPH
 
$$
2 follow-up statements
578 
WWUS51 KPBZ 172322
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
722 PM EDT Sat Aug 17 2019

PAC003-005-129-172345-
/O.CON.KPBZ.SV.W.0252.000000T0000Z-190817T2345Z/
Allegheny PA-Westmoreland PA-Armstrong PA-
722 PM EDT Sat Aug 17 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR NORTHEASTERN ALLEGHENY...NORTHWESTERN WESTMORELAND AND
SOUTHWESTERN ARMSTRONG COUNTIES...

At 722 PM EDT, a severe thunderstorm was located over Penn Hills,
moving east at 25 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...
Pittsburgh...                     Penn Hills...
Monroeville...                    Vandergrift...
Apollo...                         Shaler Township...
Plum...                           Murrysville...
Hampton Township...               Wilkinsburg...
New Kensington...                 Lower Burrell...

This includes the following highways...
  Pennsylvania Turnpike between mile markers 43 and 55.
  Interstate 376 in Pennsylvania between mile markers 75 and 83.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter indoors 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 4053 7945 4040 7992 4053 7999 4067 7977
      4067 7969 4072 7969 4077 7961
TIME...MOT...LOC 2322Z 259DEG 21KT 4049 7984 

HAIL...<.75IN
WIND...60MPH
 
$$
925 
WWUS51 KPBZ 172337
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
737 PM EDT Sat Aug 17 2019

PAC003-005-129-172346-
/O.EXP.KPBZ.SV.W.0252.000000T0000Z-190817T2345Z/
Allegheny PA-Westmoreland PA-Armstrong PA-
737 PM EDT Sat Aug 17 2019

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ALLEGHENY...
NORTHWESTERN WESTMORELAND AND SOUTHWESTERN ARMSTRONG COUNTIES WILL
EXPIRE AT 745 PM EDT...
                
The storm that prompted the warning has weakened and the warning 
will be allowed to expire.


LAT...LON 4053 7945 4040 7992 4053 7999 4067 7977
      4067 7969 4072 7969 4077 7961
TIME...MOT...LOC 2336Z 243DEG 24KT 4052 7975 

$$

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 Aug 17, 6:34 PM EDT, 41 minutes earlier.

Area forecast discussion, Aug 17, 6:34 PM EDT, 41 minutes before
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Hazardous weather outlook, Aug 17, 6:28 PM EDT, 47 minutes before
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In the hours before

Local storm report, Aug 17, 4:29 PM EDT, 2 hours 46 minutes before
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Local storm report, Aug 17, 4:50 PM EDT, 2 hours 25 minutes before
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Local storm report, Aug 17, 4:58 PM EDT, 2 hours 17 minutes before
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Local storm report, Aug 17, 6:55 PM EDT, 20 minutes before
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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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Special weather statement, Aug 17, 7:05 PM EDT, 10 minutes before
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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 3:27 PM EDTSevere Thunderstorm WarningPBZVenango48 min
Aug 17, 3:31 PM EDTSevere Thunderstorm WarningPBZMercer44 min
Aug 17, 4:11 PM EDTSevere Thunderstorm WarningPBZClarion, Forest, Venango49 min
Aug 17, 4:13 PM EDTSevere Thunderstorm WarningPBZMercer47 min
Aug 17, 4:57 PM EDTSevere Thunderstorm WarningPBZClarion, Forest, Jefferson48 min
Aug 17, 5:01 PM EDTSevere Thunderstorm WarningPBZArmstrong, Butler, Clarion, Venango44 min
Aug 17, 7:05 PM EDTSpecial Weather StatementPBZAllegheny25 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2019Every severe thunderstorm warning in 2019

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.