Alert archive / Delaware / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 191, NWS Philadelphia/Mount Holly

August 16, 2007Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 16, 2007, 11:31 PM EDT for Sussex County, Delaware. It was in force for 25 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
Aug 16, 2007, 11:31 PM EDT (03:31 UTC)
Expired
Aug 16, 2007, 11:56 PM EDT
In force
25 min
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 30 km from the middle of the area, began a volume at 03:33 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
Aug 16, 11:07 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 3.5 hours before the alert went out and 85 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 2007-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4766 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 2007-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 175 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
4766 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
852 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
175 m²/s²
0-3 km storm-relative helicity
289 m²/s²
Significant tornado parameter
4.7
Supercell composite
26.2

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 170332
SVRPHI
DEC005-170415-
/O.NEW.KPHI.SV.W.0191.070817T0331Z-070817T0415Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1131 PM EDT THU AUG 16 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL SUSSEX COUNTY IN SOUTHERN DELAWARE...

* UNTIL 1215 AM EDT

* AT 1123 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  REHOBOTH BEACH...OR ABOUT 39 MILES SOUTHEAST OF DOVER...AND
  MOVING EAST AT 25 MPH. OTHER STRONG WINDS WERE INDICATED JUST
  SOUTHEAST OF GEORGETOWN.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  HENLOPEN ACRES AND DEWEY BEACH

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS. SEEK 
SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 AM EDT FRIDAY
MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND.

LAT...LON 3858 7516 3859 7516 3860 7516 3858 7518
      3861 7544 3881 7540 3881 7517 3879 7514
      3879 7511 3881 7508 3866 7505 3866 7506
      3859 7504 3857 7505
TIME...MOT...LOC 0331Z 269DEG 24KT 3869 7503

$$

JRP
1 follow-up statement
000 
WWUS51 KPHI 170356
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1154 PM EDT THU AUG 16 2007

DEC005-170404-
/O.CAN.KPHI.SV.W.0191.000000T0000Z-070817T0415Z/
SUSSEX DE-
1154 PM EDT THU AUG 16 2007

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL SUSSEX COUNTY IS
CANCELLED...

THUNDERSTORMS HAVE WEAKENED OVER EAST-CENTRAL SUSSEX COUNTY. ANOTHER 
STRONG THUNDERSTORM WAS OVER FAR NORTHWESTERN PORTIONS OF SUSSEX 
COUNTY HOWEVER...AND THIS WILL BE MONITORED. HEAVY RAIN, BRIEF GUSTY 
WINDS, AND FREQUENT LIGHTNING ARE POSSIBLE WITH THIS CELL AS IT 
MOVES TO THE EAST AT 20 MILES AN HOUR...REACHING GREENWOOD BETWEEN 
1210 AND 1220 AM.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 600 AM EDT FRIDAY
MORNING FOR DELAWARE AND NORTHEASTERN MARYLAND.

LAT...LON 3858 7516 3859 7516 3860 7516 3858 7518
      3861 7544 3881 7540 3881 7517 3879 7514
      3879 7511 3881 7508 3866 7505 3866 7506
      3859 7504 3857 7505
TIME...MOT...LOC 0354Z 269DEG 24KT 3869 7483

$$

JRP

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 10:16 PM EDTSevere Thunderstorm WarningPHISussex44 min
Aug 16, 10:20 PM EDTSevere Thunderstorm WarningPHISussex55 min
Aug 16, 10:54 PM EDTSevere Thunderstorm WarningPHISussex36 min
Aug 17, 12:26 AM EDTSevere Thunderstorm WarningPHISussex22 min
Aug 17, 2:36 PM EDTSevere Thunderstorm WarningPHINew Castle54 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2007Every severe thunderstorm warning in 2007

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.