Alert archive / Pennsylvania / Tornado Warnings in 2011

Tornado Warning 38, NWS State College, PA

August 21, 20114 counties in Pennsylvania

NWS State College, PA issued this tornado warning at Aug 21, 2011, 2:15 PM EDT for 4 counties in Pennsylvania. It was in force for 21 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: Aug 21, 2011, 2:15 PM EDT (18:15 UTC)
Expired: Aug 21, 2011, 2:36 PM EDT
In force: 21 min
Issued by: NWS State College, PA
Area: Storm-based polygon

Counties Centre County, PA, Mifflin County, PA, Snyder County, PA, Union County, PA

The radar

The State College radar (KCCX), 36 km from the middle of the area, began a volume at 18:17 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.

Issued	Product	Office	Lasted
Aug 21, 12:52 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.3 hours before the alert went out and 202 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: 1589 J/kg
Mixed-layer CIN: -99 J/kg
Mixed-layer LCL: 969 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 131 m²/s²
0-3 km storm-relative helicity: 125 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 4.9

Open this sounding in Storm Lab

The text

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

061 
WFUS51 KCTP 211815
TORCTP
PAC027-087-109-119-211845-
/O.NEW.KCTP.TO.W.0038.110821T1815Z-110821T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
215 PM EDT SUN AUG 21 2011

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN MIFFLIN COUNTY IN CENTRAL PENNSYLVANIA...
  WEST CENTRAL SNYDER COUNTY IN CENTRAL PENNSYLVANIA...
  SOUTHWESTERN UNION COUNTY IN CENTRAL PENNSYLVANIA...
  SOUTHEASTERN CENTRE COUNTY IN CENTRAL PENNSYLVANIA...

* UNTIL 245 PM EDT

* AT 212 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THE STORM
  CONTAINING THE POSSIBLE TORNADO WAS NEAR CENTRE HALL...MOVING EAST
  AT 30 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  SEVEN MOUNTAINS AND MILROY...
  POE VALLEY STATE PARK AND REEDS GAP STATE PARK...
  SNYDER-MIDDLESWARTH STATE PARK AND WEIKERT...

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.

THIS WILL IMPACT I-99 BETWEEN MILE MARKERS 77 AND 81.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER INSIDE NOW. DO NOT WAIT TO SEE OR HEAR THE TORNADO. MOVE
TO AN INTERIOR ROOM ON THE LOWEST LEVEL OF A STURDY BUILDING. PUT AS
MANY WALLS BETWEEN YOU AND THE OUTSIDE AS YOU CAN. AVOID WINDOWS.
PROTECT YOURSELF FROM FLYING DEBRIS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT SUNDAY
EVENING FOR CENTRAL PENNSYLVANIA.

&&

LAT...LON 4072 7768 4073 7768 4072 7771 4073 7772
      4072 7778 4073 7779 4088 7781 4094 7725
      4071 7723 4070 7770
TIME...MOT...LOC 1815Z 265DEG 26KT 4080 7767

$$

FORECASTER: LA CORTE

1 follow-up statement

033 
WWUS51 KCTP 211836
SVSCTP

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
236 PM EDT SUN AUG 21 2011

PAC027-087-109-119-211846-
/O.CAN.KCTP.TO.W.0038.000000T0000Z-110821T1845Z/
MIFFLIN PA-SNYDER PA-UNION PA-CENTRE PA-
236 PM EDT SUN AUG 21 2011

...THE TORNADO WARNING FOR SOUTHEASTERN CENTRE...SOUTHWESTERN
UNION...WEST CENTRAL SNYDER AND NORTHEASTERN MIFFLIN COUNTIES IS
CANCELLED...

THE STORM HAS WEAKENED TO BELOW SEVERE LIMITS...THEREFORE THE TORNADO
WARNING HAS BEEN CANCELLED.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT SUNDAY
EVENING FOR CENTRAL PENNSYLVANIA.

LAT...LON 4072 7768 4073 7768 4072 7771 4073 7772
      4072 7778 4073 7779 4088 7781 4094 7725
      4071 7723 4070 7770
TIME...MOT...LOC 1836Z 265DEG 26KT 4081 7747

$$

FORECASTER:

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 7:07 AM EDT	Special Weather Statement	CTP	Cameron, Clearfield	23 min
Aug 21, 8:00 AM EDT	Special Weather Statement	CTP	Clinton	30 min
Aug 21, 8:36 AM EDT	Special Weather Statement	CTP	Lycoming	39 min
Aug 21, 9:10 AM EDT	Special Weather Statement	CTP	Elk	50 min
Aug 21, 12:38 PM EDT	Special Weather Statement	CTP	Clearfield	52 min
Aug 21, 1:18 PM EDT	Special Weather Statement	CTP	Centre	57 min
Aug 21, 2:01 PM EDT	Severe Thunderstorm Warning	CTP	Centre, Mifflin, Snyder, Union	59 min
Aug 21, 2:27 PM EDT	Special Weather Statement	CTP	Juniata, Mifflin, Perry	63 min
Aug 21, 2:35 PM EDT	Special Weather Statement	CTP	Lancaster	70 min
Aug 21, 2:52 PM EDT	Severe Thunderstorm Warning	CTP	Juniata, Mifflin, Perry, Snyder	53 min
Aug 21, 3:13 PM EDT	Special Weather Statement	CTP	York	62 min
Aug 21, 3:25 PM EDT	Special Weather Statement	CTP	Lancaster	50 min
Aug 21, 3:28 PM EDT	Severe Thunderstorm Warning	CTP	Cumberland, Dauphin, Juniata, Lancaster, Lebanon, Northumberland and 4 more	62 min
Aug 21, 3:40 PM EDT	Special Weather Statement	CTP	Schuylkill	80 min
Aug 21, 4:29 PM EDT	Severe Thunderstorm Warning	CTP	Dauphin, Lancaster, Lebanon	44 min
Aug 21, 4:34 PM EDT	Special Weather Statement	CTP	Potter	56 min
Aug 21, 5:06 PM EDT	Special Weather Statement	CTP	Cambria	39 min
Aug 21, 5:56 PM EDT	Special Weather Statement	CTP	Adams	49 min
Aug 21, 7:10 PM EDT	Special Weather Statement	CTP	Adams	65 min

Nearby

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