Alert archive / Pennsylvania / Tornado Warnings in 2009

Tornado Warning 2, NWS Philadelphia/Mount Holly

June 9, 2009Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this tornado warning at Jun 9, 2009, 2:59 PM EDT for Chester County, Pennsylvania. It was in force for 32 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: Jun 9, 2009, 2:59 PM EDT (18:59 UTC)
Expired: Jun 9, 2009, 3:31 PM EDT
In force: 32 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Chester County, PA

The radar

The Dover AFB radar (KDOX), 124 km from the middle of the area, began a volume at 19:01 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.0 hours before the alert went out and 43 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: 1272 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 804 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

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

000 
WFUS51 KPHI 091859
TORPHI
PAC029-091945-
/O.NEW.KPHI.TO.W.0002.090609T1859Z-090609T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
259 PM EDT TUE JUN 9 2009

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  WEST CENTRAL CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 345 PM EDT

* AT 257 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR
  HOMEVILLE...OR 16 MILES NORTHWEST OF NEWARK...MOVING SOUTHEAST AT
  10 MPH.

* THE TORNADO WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE
  INDICATED COUNTY.

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...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.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
TUESDAY EVENING FOR NORTHEASTERN PENNSYLVANIA.

&&

LAT...LON 3984 7603 3985 7603 3987 7601 3991 7601
      3992 7599 3986 7591 3980 7601 3981 7605
      3983 7605
TIME...MOT...LOC 1858Z 325DEG 10KT 3983 7599

$$

NIERENBERG

1 follow-up statement

000 
WWUS51 KPHI 091931
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
331 PM EDT TUE JUN 9 2009

PAC029-091941-
/O.CAN.KPHI.TO.W.0002.000000T0000Z-090609T1945Z/
CHESTER PA-
331 PM EDT TUE JUN 9 2009

...THE TORNADO WARNING FOR WEST CENTRAL CHESTER COUNTY IS
CANCELLED...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM EDT
TUESDAY EVENING FOR NORTHEASTERN PENNSYLVANIA.

LAT...LON 3984 7603 3985 7603 3987 7601 3991 7601
      3992 7599 3986 7591 3980 7601 3981 7605
      3983 7605
TIME...MOT...LOC 1931Z 325DEG 10KT 3975 7592

$$

NIERENBERG

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 9, 4:17 AM EDT	Dense Fog Advisory	PHI		5 hr
Jun 9, 5:38 AM EDT	Severe Thunderstorm Warning	PHI	Berks	67 min
Jun 9, 7:20 AM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	55 min
Jun 9, 8:00 AM EDT	Severe Thunderstorm Warning	PHI	Delaware, Philadelphia	60 min
Jun 9, 8:06 AM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	54 min
Jun 9, 8:20 AM EDT	Areal Flood Advisory	PHI	Delaware, Montgomery, Philadelphia	3 hr
Jun 9, 8:42 AM EDT	Areal Flood Advisory	PHI	Bucks	3 hr
Jun 9, 9:56 AM EDT	Flash Flood Warning	PHI	Chester	105 min
Jun 9, 1:49 PM EDT	Flash Flood Watch	PHI	Delaware, Philadelphia	5 hr
Jun 9, 2:20 PM EDT	Flash Flood Warning	PHI	Berks, Chester	3 hr
Jun 9, 2:24 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	66 min
Jun 9, 3:08 PM EDT	Tornado Warning	PHI	Chester	28 min
Jun 9, 3:14 PM EDT	Tornado Warning	PHI	Chester	46 min
Jun 9, 3:29 PM EDT	Severe Thunderstorm Warning	PHI	Chester	61 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.