Alert archive / Pennsylvania / Tornado Warnings in 2021

Tornado Warning 4, NWS Pittsburgh, PA

May 4, 2021Jefferson County, Pennsylvania

NWS Pittsburgh, PA issued this tornado warning at May 4, 2021, 2:56 PM EDT for Jefferson County, Pennsylvania. It was in force for 19 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 4, 2021, 2:56 PM EDT (18:56 UTC)
Expired: May 4, 2021, 3:15 PM EDT
In force: 19 min
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Jefferson County, PA

The radar

The State College radar (KCCX), 77 km from the middle of the area, began a volume at 18:56 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 nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 6.9 hours before the alert went out and 142 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 662 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 157 m²/s²
0-3 km storm-relative helicity: 163 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

856 
WFUS51 KPBZ 041856
TORPBZ
PAC065-041930-
/O.NEW.KPBZ.TO.W.0004.210504T1856Z-210504T1930Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Pittsburgh PA
256 PM EDT Tue May 4 2021

The National Weather Service in Pittsburgh has issued a

* Tornado Warning for...
  Northeastern Jefferson County in west central Pennsylvania...

* Until 330 PM EDT.
    
* At 256 PM EDT, a severe thunderstorm capable of producing a tornado
  was located 7 miles northeast of Brookville, moving east at 25 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Brockway around 320 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

LAT...LON 4121 7890 4123 7893 4126 7894 4131 7884
      4126 7874 4123 7874 4123 7871 4122 7871
TIME...MOT...LOC 1856Z 254DEG 23KT 4124 7897 

TORNADO...RADAR INDICATED
HAIL...0.00IN

$$

Brown

2 follow-up statements

592 
WWUS51 KPBZ 041908
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
308 PM EDT Tue May 4 2021

PAC065-041930-
/O.CON.KPBZ.TO.W.0004.000000T0000Z-210504T1930Z/
Jefferson PA-
308 PM EDT Tue May 4 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM EDT FOR
NORTHEASTERN JEFFERSON COUNTY...
    
At 308 PM EDT, a severe thunderstorm capable of producing a tornado
was located near Brockway, or 11 miles northwest of DuBois, moving
east at 25 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This dangerous storm will be near...
  Brockway around 320 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4123 7880 4125 7884 4128 7883 4129 7881
      4126 7874 4123 7874
TIME...MOT...LOC 1908Z 254DEG 23KT 4126 7889 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

Brown

291 
WWUS51 KPBZ 041915
SVSPBZ

Severe Weather Statement
National Weather Service Pittsburgh PA
315 PM EDT Tue May 4 2021

PAC065-041925-
/O.CAN.KPBZ.TO.W.0004.000000T0000Z-210504T1930Z/
Jefferson PA-
315 PM EDT Tue May 4 2021

...THE TORNADO WARNING FOR NORTHEASTERN JEFFERSON COUNTY IS
CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

LAT...LON 4123 7880 4125 7884 4128 7883 4129 7881
      4126 7874 4123 7874
TIME...MOT...LOC 1913Z 254DEG 23KT 4127 7883 

$$

Brown

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 8:54 PM EDT	Tornado Warning	PBZ	Lawrence	36 min
May 3, 9:29 PM EDT	Tornado Warning	PBZ	Butler, Lawrence	31 min
May 4, 6:00 PM EDT	Flash Flood Watch	PBZ	Fayette, Greene	11 hr

Nearby

Tornado Warnings in Pennsylvania, 2021 Every tornado warning in 2021 Tornadoes 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.