Alert archive / Delaware / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 174, NWS Philadelphia/Mount Holly

July 11, 2011Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 11, 2011, 10:28 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland. It was in force for 33 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 11, 2011, 10:28 PM EDT (02:28 UTC)
Expired
Jul 11, 2011, 11:01 PM EDT
In force
33 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 34 km from the middle of the area, began a volume at 02:29 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 11, 9:01 PM EDTSevere Thunderstorm WatchSPC3 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.5 hours before the alert went out and 87 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 2011-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 107 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1437 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
107 m²/s²
0-3 km storm-relative helicity
172 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

781 
WUUS51 KPHI 120228
SVRPHI
DEC001-005-MDC011-041-120315-
/O.NEW.KPHI.SV.W.0174.110712T0228Z-110712T0315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1028 PM EDT MON JUL 11 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN KENT COUNTY IN CENTRAL DELAWARE...
  SOUTHERN CAROLINE COUNTY IN EASTERN MARYLAND...
  EAST CENTRAL TALBOT COUNTY IN EASTERN MARYLAND...
  THIS INCLUDES THE CITY OF EASTON...
  WESTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...
  THIS INCLUDES THE CITY OF GEORGETOWN...

* UNTIL 1115 PM EDT

* AT 1025 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 MATTHEWS...OR 7 MILES EAST
  OF EASTON...AND MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  SMITHVILLE...AGNER AND FEDERALSBURG AROUND 1040 PM EDT...
  BRIDGEVILLE AROUND 1050 PM EDT...
  BRIDGEVILLE AROUND 1055 PM EDT...
  6 MILES SOUTH OF ELLENDALE AROUND 1105 PM EDT...
  GEORGETOWN AROUND 1110 PM EDT...
  MILTON AROUND 1115 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO 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.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT
TUESDAY MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

&&

LAT...LON 3846 7570 3865 7572 3869 7586 3867 7595
      3863 7598 3874 7612 3893 7591 3886 7529
      3845 7540
TIME...MOT...LOC 0228Z 281DEG 36KT 3879 7591

$$

MPD
2 follow-up statements
355 
WWUS51 KPHI 120244
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1044 PM EDT MON JUL 11 2011

MDC041-120254-
/O.CAN.KPHI.SV.W.0174.000000T0000Z-110712T0315Z/
TALBOT MD-
1044 PM EDT MON JUL 11 2011

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL TALBOT COUNTY IS
CANCELLED...

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT
TUESDAY MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

LAT...LON 3846 7570 3865 7572 3869 7586 3871 7588
      3872 7592 3883 7589 3890 7567 3886 7529
      3845 7540
TIME...MOT...LOC 0244Z 281DEG 36KT 3876 7571

$$

DEC001-005-MDC011-120315-
/O.CON.KPHI.SV.W.0174.000000T0000Z-110712T0315Z/
KENT DE-CAROLINE MD-SUSSEX DE-
1044 PM EDT MON JUL 11 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1115 PM EDT
FOR WESTERN SUSSEX...SOUTHERN CAROLINE AND SOUTH CENTRAL KENT
COUNTIES...

AT 1039 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 AGNER...OR 16 MILES
EAST OF EASTON...MOVING EAST AT 40 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  BRIDGEVILLE...GREENWOOD AND 9 MILES SOUTH OF FARMINGTON BY 1050 PM
  EDT...
  BRIDGEVILLE...6 MILES NORTH OF SEAFORD AND 7 MILES NORTH OF BLADES
  BY 1055 PM EDT...
  6 MILES SOUTH OF ELLENDALE AND 9 MILES NORTH OF SYCAMORE BY 1105 PM
  EDT...
  GEORGETOWN BY 1110 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO DAMAGING WINDS...CONTINUOUS CLOUD TO GROUND LIGHTNING 
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.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT
TUESDAY MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

&&

LAT...LON 3846 7570 3865 7572 3869 7586 3871 7588
      3872 7592 3883 7589 3890 7567 3886 7529
      3845 7540
TIME...MOT...LOC 0244Z 281DEG 36KT 3876 7571

$$

MPD
558 
WWUS51 KPHI 120301
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1101 PM EDT MON JUL 11 2011

DEC001-005-MDC011-120310-
/O.CAN.KPHI.SV.W.0174.000000T0000Z-110712T0315Z/
KENT DE-CAROLINE MD-SUSSEX DE-
1101 PM EDT MON JUL 11 2011

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN SUSSEX...SOUTHERN
CAROLINE AND SOUTH CENTRAL KENT COUNTIES IS CANCELLED...

THE THUNDERSTORM WAS WEAKENING AS IT MOVED ACROSS SUSSEX COUNTY. 

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT EDT
TUESDAY MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND AND SOUTHERN
NEW JERSEY.

LAT...LON 3846 7570 3865 7572 3869 7586 3871 7588
      3872 7592 3883 7589 3890 7567 3886 7529
      3845 7540
TIME...MOT...LOC 0300Z 281DEG 36KT 3873 7551

$$

MPD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 9:11 PM EDTSevere Thunderstorm WarningPHINew Castle64 min
Jul 11, 9:33 PM EDTSevere Thunderstorm WarningPHIKent57 min
Jul 11, 9:25 PM EDTSpecial Weather StatementPHIQueen Anne's, Talbot65 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.