Alert archive / Pennsylvania / Tornado Warnings in 2011

Tornado Warning 6, NWS Pittsburgh, PA

May 23, 2011Mercer County, Pennsylvania

NWS Pittsburgh, PA issued this tornado warning at May 23, 2011, 9:07 PM EDT for Mercer County, Pennsylvania. It was in force for 38 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
May 23, 2011, 9:07 PM EDT (01:07 UTC)
Expired
May 23, 2011, 9:45 PM EDT
In force
38 min
Issued by
NWS Pittsburgh, PA
Area
Storm-based polygon

County Mercer County, PA

The radar

The Pittsburgh radar (KPBZ), 81 km from the middle of the area, began a volume at 01:10 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
May 23, 8:31 PM EDTSevere Thunderstorm WatchSPC3 hr

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 00:00Z, 1.1 hours before the alert went out and 96 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 00:00Z on 2011-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 369 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 00:00Z on 2011-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 191 square meters per square second.19395878Sfc1 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
369 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
1384 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
191 m²/s²
0-3 km storm-relative helicity
340 m²/s²
Significant tornado parameter
0.2
Supercell composite
4.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

749 
WFUS51 KPBZ 240107
TORPBZ
PAC085-240145-
/O.NEW.KPBZ.TO.W.0006.110524T0107Z-110524T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE PITTSBURGH PA
907 PM EDT MON MAY 23 2011

THE NATIONAL WEATHER SERVICE IN PITTSBURGH HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN MERCER COUNTY IN NORTHWEST PENNSYLVANIA...

* UNTIL 945 PM EDT

* AT 906 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR SHARON...
  MOVING EAST AT 35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO  
  FARRELL...            SHARON...             HERMITAGE...
  FREDONIA...           MERCER...             STONEBORO...
  GROVE CITY...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

PLEASE REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE. 1-877-633-6772. WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 4136 8006 4111 8008 4118 8052 4131 8052
TIME...MOT...LOC 0107Z 268DEG 32KT 4126 8053

$$


15
2 follow-up statements
850 
WWUS51 KPBZ 240115
SVSPBZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
915 PM EDT MON MAY 23 2011

PAC085-240145-
/O.CON.KPBZ.TO.W.0006.000000T0000Z-110524T0145Z/
MERCER PA-
915 PM EDT MON MAY 23 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 945 PM EDT FOR MERCER
COUNTY...

AT 910 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED NEAR PRITCHARDS
CORNER...MOVING EAST AT 35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO  
  SHARON...             HERMITAGE...          FARRELL...
  FREDONIA...           MERCER...             GROVE CITY...
  STONEBORO...

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING 
LARGE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.  TAKE COVER IN AN 
INTERIOR ROOM OF THE LOWEST FLOOR WHEN THIS STORM APPROACHES.

PLEASE REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE. 1-877-633-6772. WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 200 AM EDT
TUESDAY MORNING FOR EAST CENTRAL OHIO AND WESTERN PENNSYLVANIA AND
NORTHERN WEST VIRGINIA.

LAT...LON 4136 8006 4111 8008 4118 8052 4131 8052
TIME...MOT...LOC 0114Z 265DEG 32KT 4127 8045

$$


15
623 
WWUS51 KPBZ 240139
SVSPBZ

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
939 PM EDT MON MAY 23 2011

PAC085-240149-
/O.EXP.KPBZ.TO.W.0006.000000T0000Z-110524T0145Z/
MERCER PA-
939 PM EDT MON MAY 23 2011

...THE TORNADO WARNING FOR MERCER COUNTY EXPIRES AT 945 PM EDT...

THE STORM THAT PROMPTED THE WARNING HAS WEAKENED.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 200 AM EDT
TUESDAY MORNING FOR EAST CENTRAL OHIO AND WESTERN PENNSYLVANIA AND
NORTHERN WEST VIRGINIA.

LAT...LON 4136 8006 4111 8008 4118 8052 4131 8052
TIME...MOT...LOC 0139Z 265DEG 32KT 4129 8015

$$


15

The office that day

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

IssuedProductOfficeCountiesLasted
May 23, 8:15 PM EDTSpecial Weather StatementPBZLawrence, Mercer30 min
May 23, 8:51 PM EDTSevere Thunderstorm WarningPBZMercer39 min
May 23, 9:38 PM EDTSpecial Weather StatementPBZVenango37 min
May 23, 11:15 PM EDTSpecial Weather StatementPBZVenango60 min
May 24, 12:10 AM EDTSpecial Weather StatementPBZArmstrong, Clarion, Indiana, Jefferson, Westmoreland35 min
May 24, 7:11 PM EDTSpecial Weather StatementPBZBeaver49 min

Nearby

Tornado Warnings in Pennsylvania, 2011Every tornado warning in 2011Tornadoes in 2011

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.