Alert archive / Delaware / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 73, NWS Philadelphia/Mount Holly

May 28, 2011Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 28, 2011, 2:12 PM EDT for Kent County, Sussex County, Delaware. It was in force for 48 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 28, 2011, 2:12 PM EDT (18:12 UTC)
Expired
May 28, 2011, 3:00 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 14 km from the middle of the area, began a volume at 18:15 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 28, 2:45 PM EDTTSTM WND DMGEllendale, DETREE REPORTED DOWN IN ELLENDALE

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 12:00Z, 6.2 hours before the alert went out and 88 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 12:00Z on 2011-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 117 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 12:00Z on 2011-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 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
117 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
1048 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
33 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.

183 
WUUS51 KPHI 281812
SVRPHI
DEC001-005-281900-
/O.NEW.KPHI.SV.W.0073.110528T1812Z-110528T1900Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
212 PM EDT SAT MAY 28 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTH CENTRAL KENT COUNTY IN CENTRAL DELAWARE...
  WESTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...
  THIS INCLUDES THE CITY OF GEORGETOWN...

* UNTIL 300 PM EDT

* AT 207 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR SYCAMORE...OR 9 MILES
  SOUTHWEST OF GEORGETOWN...AND MOVING NORTH AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  6 MILES EAST OF SEAFORD AROUND 220 PM EDT...
  6 MILES WEST OF GEORGETOWN AROUND 240 PM EDT...
  6 MILES EAST OF BRIDGEVILLE AROUND 245 PM EDT...
  ELLENDALE AROUND 300 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES GREATEST KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...HEAVY RAIN WILL OCCUR
WITH THESE STORMS AND CAUSE LOW-LYING AND POOR DRAINAGE FLOODING.

&&

LAT...LON 3858 7563 3896 7559 3891 7528 3855 7541
TIME...MOT...LOC 1812Z 190DEG 13KT 3861 7551

$$
DRAG
2 follow-up statements
306 
WWUS51 KPHI 281833
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
233 PM EDT SAT MAY 28 2011

DEC001-005-281900-
/O.CON.KPHI.SV.W.0073.000000T0000Z-110528T1900Z/
KENT DE-SUSSEX DE-
233 PM EDT SAT MAY 28 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR WESTERN SUSSEX AND SOUTH CENTRAL KENT COUNTIES...

AT 229 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR ELLENDALE...OR 6 MILES
NORTHWEST OF GEORGETOWN...MOVING NORTHEAST AT 40 MPH.

SO FAR THERE HAVE BEEN NO REPORTS OF DAMAGING WIND OR LARGE HAIL.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES SOUTHEAST OF HOUSTON BY 240 PM EDT...
  MILFORD BY 245 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO 
GROUND LIGHTNING AND VERY HEAVY RAIN IS OCCURRING WITH THIS STORM. 
MOVE INDOORS IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE 
KILLERS. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH 
TO BE STRUCK BY LIGHTNING.

&&

LAT...LON 3858 7563 3896 7559 3891 7528 3855 7541
TIME...MOT...LOC 1832Z 204DEG 36KT 3879 7544

$$

DRAG
349 
WWUS51 KPHI 281859
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
259 PM EDT SAT MAY 28 2011

DEC001-005-281908-
/O.EXP.KPHI.SV.W.0073.000000T0000Z-110528T1900Z/
KENT DE-SUSSEX DE-
259 PM EDT SAT MAY 28 2011

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN SUSSEX AND SOUTH
CENTRAL KENT COUNTIES WILL EXPIRE AT 300 PM EDT...

NO REPORTS OF SEVERE WEATHER WERE RECEIVED.  THE STORMS HAVE 
WEAKENED SINCE 245 PM.  HOWEVER SHOWERS AND THUNDERSTORMS WILL 
CONTINUE THROUGH 4 PM IN MUCH OF SOUTHERN AND CENTRAL DELAWARE. 

LAT...LON 3858 7563 3896 7559 3891 7528 3855 7541
TIME...MOT...LOC 1858Z 204DEG 36KT 3903 7530

$$
DRAG

The office that day

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

IssuedProductOfficeCountiesLasted
May 28, 2:06 PM EDTSpecial Weather StatementPHISussex54 min
May 28, 2:51 PM EDTAreal Flood AdvisoryPHIKent, Sussex99 min
May 28, 3:52 PM EDTSpecial Weather StatementPHISussex38 min

Nearby

Severe Thunderstorm Warnings in Delaware, 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.