Alert archive / Delaware / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 166, NWS Philadelphia/Mount Holly

July 29, 2007Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 29, 2007, 1:20 PM EDT for Sussex County, Delaware. It was in force for 40 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 29, 2007, 1:20 PM EDT (17:20 UTC)
Expired
Jul 29, 2007, 2:00 PM EDT
In force
40 min
Issued by
NWS Philadelphia/Mount Holly
Area
Counties, with a storm outline in the text

County Sussex County, DE

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.3 hours before the alert went out and 93 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 2007-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2108 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 2007-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
2108 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
627 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
15 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.

000 
WUUS51 KPHI 291720
SVRPHI
DEC005-291800-
/O.NEW.KPHI.SV.W.0166.070729T1720Z-070729T1800Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
120 PM EDT SUN JUL 29 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 200 PM EDT

* AT 116 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 MILTON...OR ABOUT 28 MILES
  SOUTH OF DOVER...AND MOVING SOUTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES SOUTHWEST OF LEWES BY 150 PM EDT...
  8 MILES NORTHEAST OF MILLSBORO BY 155 PM EDT...

THUNDERSTORMS ARE CAPABLE OF PRODUCING HEAVY RAINFALL WHICH MAY
RESULT IN LOCALIZED AREAS OF FLOODING. DO NOT DRIVE IN AREAS WHERE
WATER IS CROSSING THE ROAD.

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 NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

LAT...LON 3889 7537 3877 7549 3853 7530 3876 7508

$$

AMC
1 follow-up statement
000 
WWUS51 KPHI 291806
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
205 PM EDT SUN JUL 29 2007

DEC005-291815-
/O.EXP.KPHI.SV.W.0166.000000T0000Z-070729T1800Z/
SUSSEX DE-
205 PM EDT SUN JUL 29 2007

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL SUSSEX COUNTY EXPIRED
AT 200 PM EDT...

HOWEVER...STRONG THUNDERSTORMS CONTINUE TO DEVELOP OVER THE AREA... 
AND MAY PRODUCE INTENSE CLOUD-TO-GROUND LIGHTNING AND VERY HEAVY 
RAIN WITH LOCALIZED FLOODING.

LAT...LON 3870 7568 3849 7568 3848 7507 3881 7516

$$

AMC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 6:07 AM EDTSevere Thunderstorm WarningPHIKent53 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.