Alert archive / Delaware / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 65, NWS Philadelphia/Mount Holly

May 23, 2011Kent County, Sussex County, Delaware; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 23, 2011, 8:04 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Maryland. It was in force for 56 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
May 23, 2011, 8:04 PM EDT (00:04 UTC)
Expired
May 23, 2011, 9:00 PM EDT
In force
56 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), 31 km from the middle of the area, began a volume at 00:04 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

TimeReportWhereRemark
May 23, 8:10 PM EDTHAIL 1.75Greensboro, MD

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.1 hours before the alert went out and 127 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, Wallops Is Stn, VA at 00:00Z on 2011-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1685 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, Wallops Is Stn, VA at 00:00Z on 2011-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
1685 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
831 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
179 m²/s²
Significant tornado parameter
0.9
Supercell composite
6.0

Open this sounding in Storm Lab

The text

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

498 
WUUS51 KPHI 240004
SVRPHI
DEC001-005-MDC011-240100-
/O.NEW.KPHI.SV.W.0065.110524T0004Z-110524T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
804 PM EDT MON MAY 23 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 900 PM EDT

* AT 755 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
  JUMPTOWN...OR 11 MILES SOUTHEAST OF CENTERVILLE...AND MOVING
  NORTHEAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GOLDSBORO AROUND 815 PM EDT...
  SANDTOWN AROUND 820 PM EDT...
  HAZLETTVILLE...WOODSIDE AND VIOLA AROUND 830 PM EDT...
  CAMDEN AROUND 835 PM EDT...
  DOVER...DOVER SPEEDWAY...RISING SUN AND CHESWOLD AROUND 840 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 3880 7587 3896 7595 3900 7593 3907 7586
      3909 7586 3914 7578 3914 7576 3915 7575
      3934 7545 3924 7538 3916 7540 3907 7539
      3903 7533 3898 7529 3895 7530
TIME...MOT...LOC 0004Z 234DEG 30KT 3897 7584

$$

TFG
1 follow-up statement
819 
WWUS51 KPHI 240026
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
826 PM EDT MON MAY 23 2011

DEC005-MDC011-240035-
/O.CAN.KPHI.SV.W.0065.000000T0000Z-110524T0100Z/
CAROLINE MD-SUSSEX DE-
826 PM EDT MON MAY 23 2011

...THE SEVERE THUNDERSTORM WARNING FOR EXTREME NORTH CENTRAL SUSSEX
AND NORTHERN CAROLINE COUNTIES IS CANCELLED...

THE SEVERE THUNDERSTORM IS IN KENT COUNTY DELAWARE.

LAT...LON 3889 7570 3909 7574 3931 7543 3924 7538
      3916 7540 3907 7539 3903 7533 3898 7529
TIME...MOT...LOC 0025Z 242DEG 30KT 3902 7564

$$

DEC001-240100-
/O.CON.KPHI.SV.W.0065.000000T0000Z-110524T0100Z/
KENT DE-
826 PM EDT MON MAY 23 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM EDT
FOR KENT COUNTY...

AT 822 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER TO GOLF
BALL SIZE HAIL...AND DAMAGING WINDS TO 60 MPH.  THIS STORM WAS 
LOCATED NEAR SANDTOWN...OR 13 MILES SOUTHWEST OF DOVER...MOVING 
NORTHEAST AT 35 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  VIOLA AND FELTON BY 830 PM EDT...
  WOODSIDE EAST...WOODSIDE...RIVERVIEW AND WYOMING BY 835 PM EDT...
  MAGNOLIA...RISING SUN...HIGHLAND ACRES AND CAMDEN BY 840 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 7570 3909 7574 3931 7543 3924 7538
      3916 7540 3907 7539 3903 7533 3898 7529
TIME...MOT...LOC 0025Z 242DEG 30KT 3902 7564

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
May 24, 2:15 PM EDTSpecial Weather StatementPHITalbot60 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2011Severe Thunderstorm Warnings in Maryland, 2011Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.