Alert archive / Pennsylvania / Tornado Warnings in 2009

Tornado Warning 4, NWS Philadelphia/Mount Holly

June 9, 2009Chester County, Pennsylvania; Cecil County, Maryland

NWS Philadelphia/Mount Holly issued this tornado warning at Jun 9, 2009, 3:14 PM EDT for Chester County, Pennsylvania; Cecil County, Maryland. It was in force for 46 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, 3:14 PM EDT (19:14 UTC)
Expired
Jun 9, 2009, 4:00 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Cecil County, MD, Chester County, PA

The radar

The Dover AFB radar (KDOX), 107 km from the middle of the area, began a volume at 19:14 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, 7.2 hours before the alert went out and 30 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, Phillips Aaf/Abe, MD at 12:00Z on 2009-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1272 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, Phillips Aaf/Abe, MD at 12:00Z on 2009-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.193958Sfc1 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
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 091914
TORPHI
MDC015-PAC029-092000-
/O.NEW.KPHI.TO.W.0004.090609T1914Z-090609T2000Z/

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

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  NORTH CENTRAL CECIL COUNTY IN NORTHEAST MARYLAND...
  SOUTHWESTERN CHESTER COUNTY IN SOUTHEAST PENNSYLVANIA...

* UNTIL 400 PM EDT

* AT 314 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR LOMBARD...
  OR 12 MILES WEST OF NEWARK...MOVING SOUTHEAST AT 15 MPH.

* THE TORNADO WILL BE NEAR...
  LOMBARD AND CALVERT BY 320 PM EDT...
  BLAKE AND ZION BY 325 PM EDT...
  BAY VIEW BY 330 PM EDT...
  PLEASANT HILL...FAIR HILL AND KEMBLESVILLE BY 335 PM EDT...
  ANDORA BY 340 PM EDT...

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 3976 7581 3961 7589 3964 7607 3978 7606
TIME...MOT...LOC 1914Z 308DEG 14KT 3974 7598

$$

NIERENBERG

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 9, 4:17 AM EDTDense Fog AdvisoryPHI5 hr
Jun 9, 5:38 AM EDTSevere Thunderstorm WarningPHIBerks67 min
Jun 9, 7:20 AM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia55 min
Jun 9, 8:00 AM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia60 min
Jun 9, 8:06 AM EDTSevere Thunderstorm WarningPHIPhiladelphia54 min
Jun 9, 8:20 AM EDTAreal Flood AdvisoryPHIDelaware, Montgomery, Philadelphia3 hr
Jun 9, 8:42 AM EDTAreal Flood AdvisoryPHIBucks3 hr
Jun 9, 9:56 AM EDTFlash Flood WarningPHIChester105 min
Jun 9, 1:49 PM EDTFlash Flood WatchPHIDelaware, Philadelphia5 hr
Jun 9, 2:20 PM EDTFlash Flood WarningPHIBerks, Chester3 hr
Jun 9, 2:24 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery66 min
Jun 9, 2:59 PM EDTTornado WarningPHIChester32 min
Jun 9, 3:08 PM EDTTornado WarningPHIChester28 min
Jun 9, 3:29 PM EDTSevere Thunderstorm WarningPHIChester61 min
Jun 9, 4:19 PM EDTSevere Thunderstorm WarningPHICecil, Kent, Queen Anne's56 min
Jun 9, 5:13 PM EDTSevere Thunderstorm WarningPHICaroline, Cecil, Kent, Queen Anne's, Talbot92 min
Jun 9, 5:19 PM EDTAreal Flood WarningPHICecil71 min

Nearby

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