Alert archive / Pennsylvania / Tornado Warnings in 2009

Tornado Warning 13, NWS State College, PA

August 20, 2009Lancaster County, Pennsylvania

NWS State College, PA issued this tornado warning at Aug 20, 2009, 4:57 PM EDT for Lancaster County, Pennsylvania. It was in force for 63 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: Aug 20, 2009, 4:57 PM EDT (20:57 UTC)
Expired: Aug 20, 2009, 6:00 PM EDT
In force: 63 min
Issued by: NWS State College, PA
Area: Storm-based polygon

County Lancaster County, PA

The radar

The Dover AFB radar (KDOX), 143 km from the middle of the area, began a volume at 20:57 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
Aug 20, 5:00 PM EDT	TSTM WND DMG	Lancaster, PA	TV METEOROLOGIST REPORTED THAT POWER COMPANY HAD 5200 REPORTS OF OUTAGES ACROSS LANCASTER COUNTY.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.0 hours before the alert went out and 161 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: 975 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 749 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.5

Open this sounding in Storm Lab

The text

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

000 
WFUS51 KCTP 202057
TORCTP
PAC071-202200-
/O.NEW.KCTP.TO.W.0013.090820T2057Z-090820T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE STATE COLLEGE PA
457 PM EDT THU AUG 20 2009

THE NATIONAL WEATHER SERVICE IN STATE COLLEGE PA HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL LANCASTER COUNTY IN SOUTH CENTRAL PENNSYLVANIA...

* UNTIL 600 PM EDT

* AT 455 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR WILLOW   
  STREET...MOVING EAST AT 15 MPH.  THIS STORM HAS A HISTORY OF
  PRODUCING WIND DAMAGE.

* THE TORNADO WILL BE NEAR...
  STRASBURG AND LEOLA AROUND 510 PM EDT...
  QUARRYVILLE AROUND 515 PM EDT...
  PARADISE AROUND 525 PM EDT...
  NEW HOLLAND AROUND 530 PM EDT...
  GAP AROUND 550 PM EDT...

THIS WILL IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 30...ROUTE 222...
ROUTE 322...STATE ROAD 41.

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.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...TAKE SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN A MOBILE HOME OR VEHICLE...LEAVE IT AND GET INSIDE A STRONG
BUILDING. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST DITCH
OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 4005 7594 4001 7596 3992 7600 3987 7599
      3985 7602 3990 7625 3994 7632 4001 7633
      4007 7630 4010 7625 4013 7614 4012 7593
TIME...MOT...LOC 2056Z 272DEG 12KT 4001 7626

$$

FORECASTER: RXR

2 follow-up statements

000 
WWUS51 KCTP 202128
SVSCTP

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
528 PM EDT THU AUG 20 2009

PAC071-202200-
/O.CON.KCTP.TO.W.0013.000000T0000Z-090820T2200Z/
LANCASTER PA-
528 PM EDT THU AUG 20 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 600 PM EDT FOR EAST
CENTRAL LANCASTER COUNTY...

AT 525 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A POTENTIAL TORNADO.  THIS TORNADO WAS LOCATED NEAR 
GAP...OR 9 MILES SOUTH OF NEW HOLLAND...MOVING EAST AT 15 MPH.

THIS WILL IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 30...STATE ROAD
41.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING DAMAGING WINDS AS IT HAS 
TRACKED ACROSS LANCASTER COUNTY.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

&&

LAT...LON 3991 7600 3993 7613 3998 7615 4005 7613
      4007 7594 4005 7594 4001 7596 3992 7600
TIME...MOT...LOC 2126Z 274DEG 14KT 3998 7606

$$

FORECASTER: RXR

000 
WWUS51 KCTP 202201
SVSCTP

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
601 PM EDT THU AUG 20 2009

PAC071-202209-
/O.EXP.KCTP.TO.W.0013.000000T0000Z-090820T2200Z/
LANCASTER PA-
601 PM EDT THU AUG 20 2009

...THE TORNADO WARNING FOR EAST CENTRAL LANCASTER COUNTY WILL EXPIRE
AT 600 PM EDT...

THE THUNDERSTORM THAT PROMPTED THE WARNING IS WEAKENING AND MOVING 
OUT OF LANCASTER COUNTY.  THEREFORE...THE TORNADO WARNING WILL BE 
ALLOWED TO EXPIRE AT 6 PM.

PLEASE REPORT HAIL...STRONG WINDS OR WIND DAMAGE TO THE NATIONAL
WEATHER SERVICE BY CALLING TOLL FREE...1 8 7 7 6 3 3 6 7 7 2.

LAT...LON 3991 7600 3993 7613 3998 7615 4005 7613
      4007 7594 4005 7594 4001 7596 3992 7600
TIME...MOT...LOC 2159Z 274DEG 14KT 3997 7589

$$

FORECASTER: RXR

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 19, 8:13 PM EDT	Areal Flood Advisory	CTP	Lancaster, Lebanon, York	3 hr
Aug 19, 10:12 PM EDT	Areal Flood Warning	CTP	Cumberland	108 min
Aug 20, 1:43 PM EDT	Special Weather Statement	CTP	Dauphin	62 min
Aug 20, 1:48 PM EDT	Special Weather Statement	CTP	Juniata, Perry	57 min
Aug 20, 2:06 PM EDT	Special Weather Statement	CTP	Cambria	69 min
Aug 20, 2:32 PM EDT	Areal Flood Advisory	CTP	Juniata, Perry	118 min
Aug 20, 2:40 PM EDT	Severe Thunderstorm Warning	CTP	Dauphin, Juniata, Northumberland, Perry, Snyder	50 min
Aug 20, 3:04 PM EDT	Tornado Warning	CTP	Dauphin, Northumberland, Perry	26 min
Aug 20, 3:10 PM EDT	Special Weather Statement	CTP	Lebanon	50 min
Aug 20, 3:15 PM EDT	Severe Thunderstorm Warning	CTP	Dauphin, Lebanon, Northumberland, Perry, Schuylkill	60 min
Aug 20, 3:16 PM EDT	Special Weather Statement	CTP	Dauphin	59 min
Aug 20, 3:20 PM EDT	Special Weather Statement	CTP	Lancaster	25 min
Aug 20, 3:52 PM EDT	Severe Thunderstorm Warning	CTP	Lancaster, York	53 min
Aug 20, 4:22 PM EDT	Special Weather Statement	CTP	Lancaster	53 min
Aug 20, 4:29 PM EDT	Tornado Warning	CTP	Lancaster	31 min
Aug 20, 5:15 PM EDT	Special Weather Statement	CTP	Mifflin	60 min
Aug 20, 5:17 PM EDT	Special Weather Statement	CTP	Franklin	58 min
Aug 20, 7:57 PM EDT	Special Weather Statement	CTP	McKean	33 min

Nearby

Tornado Warnings in Pennsylvania, 2009 Every tornado warning in 2009 Tornadoes in 2009

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.