Alert archive / Delaware / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 264, NWS Philadelphia/Mount Holly

September 9, 2008Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 9, 2008, 1:09 PM EDT for Kent County, Sussex County, Delaware. It was in force for 36 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
Sep 9, 2008, 1:09 PM EDT (17:09 UTC)
Expired
Sep 9, 2008, 1:45 PM EDT
In force
36 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), 18 km from the middle of the area, began a volume at 17:08 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
Sep 9, 9:33 AM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 5.2 hours before the alert went out and 84 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, Phillips Aaf/Abe, MD at 12:00Z on 2008-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1988 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phillips Aaf/Abe, MD at 12:00Z on 2008-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 118 square meters per square second.19395878Sfc1 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
1988 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
557 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.3

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 091709
SVRPHI
DEC001-005-091745-
/O.NEW.KPHI.SV.W.0264.080909T1709Z-080909T1745Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
109 PM EDT TUE SEP 9 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 145 PM EDT

* AT 105 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
  MILFORD...OR ABOUT 16 MILES SOUTH OF DOVER...AND MOVING EAST AT 32
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BIG STONE BEACH AND SLAUGHTER BEACH BY 115 PM...

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 PM TUESDAY
AFTERNOON FOR SOUTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
SOUTHERN NEW JERSEY.

LAT...LON 3904 7555 3909 7540 3908 7539 3903 7533
      3900 7531 3898 7529 3892 7530 3889 7525
      3883 7521 3882 7540
TIME...MOT...LOC 1709Z 249DEG 28KT 3896 7537

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 9:21 AM EDTSevere Thunderstorm WarningPHINew Castle39 min
Sep 9, 9:59 AM EDTFlash Flood WarningPHINew Castle3 hr
Sep 9, 1:58 PM EDTSevere Thunderstorm WarningPHISussex92 min
Sep 9, 2:42 PM EDTAreal Flood AdvisoryPHISussex3 hr

Nearby

Severe Thunderstorm Warnings in Delaware, 2008Every severe thunderstorm warning in 2008

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.