Alert archive / Delaware / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 139, NWS Philadelphia/Mount Holly

July 3, 2011Kent County, Sussex County, Delaware; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 3, 2011, 8:34 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Maryland. It was in force for 20 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: Jul 3, 2011, 8:34 PM EDT (00:34 UTC)
Expired: Jul 3, 2011, 8:54 PM EDT
In force: 20 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Kent County, DE, Sussex County, DE, Caroline County, MD

The radar

The Dover AFB radar (KDOX), 10 km from the middle of the area, began a volume at 00:38 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.6 hours before the alert went out and 108 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: 462 J/kg
Mixed-layer CIN: -121 J/kg
Mixed-layer LCL: 1523 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 42 m²/s²
0-3 km storm-relative helicity: 67 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

789 
WUUS51 KPHI 040034
SVRPHI
DEC001-005-MDC011-040130-
/O.NEW.KPHI.SV.W.0139.110704T0034Z-110704T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
834 PM EDT SUN JUL 3 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN KENT COUNTY IN CENTRAL DELAWARE...
  NORTHERN CAROLINE COUNTY IN EASTERN MARYLAND...
  NORTHWESTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...
  THIS INCLUDES THE CITY OF GEORGETOWN...

* UNTIL 930 PM EDT

* AT 832 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  GREENSBORO...OR 16 MILES SOUTHEAST OF CENTERVILLE...AND MOVING EAST
  AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  HARRINGTON AND ANDREWSVILLE AROUND 855 PM EDT...
  MILFORD AROUND 915 PM EDT...
  ELLENDALE AROUND 920 PM EDT...
  7 MILES SOUTH OF SLAUGHTER BEACH AROUND 925 PM EDT...
  9 MILES NORTH OF GEORGETOWN AROUND 930 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 3889 7594 3907 7577 3897 7530 3896 7529
      3893 7530 3889 7525 3888 7525 3863 7541
TIME...MOT...LOC 0034Z 291DEG 24KT 3894 7577

$$

HEAVENER

1 follow-up statement

191 
WWUS51 KPHI 040054
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
854 PM EDT SUN JUL 3 2011

DEC001-005-MDC011-040104-
/O.CAN.KPHI.SV.W.0139.000000T0000Z-110704T0130Z/
KENT DE-CAROLINE MD-SUSSEX DE-
854 PM EDT SUN JUL 3 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SUSSEX...NORTHERN
CAROLINE AND SOUTHERN KENT COUNTIES IS CANCELLED...

LAT...LON 3889 7594 3907 7577 3897 7530 3896 7529
      3893 7530 3889 7525 3888 7525 3863 7541
TIME...MOT...LOC 0054Z 291DEG 24KT 3889 7561

$$

HEAVENER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 4, 5:26 PM EDT	Special Weather Statement	PHI	Sussex	64 min
Jul 4, 5:48 PM EDT	Special Weather Statement	PHI	Sussex	57 min
Jul 3, 9:41 PM EDT	Special Weather Statement	PHI	Talbot	64 min
Jul 3, 10:08 PM EDT	Special Weather Statement	PHI	Queen Anne's, Talbot	52 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2011 Severe Thunderstorm Warnings in Maryland, 2011 Every severe thunderstorm warning 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.