Alert archive / Delaware / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 40, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 31, 2009, 8:29 AM EDT for Sussex County, Delaware. It was in force for 17 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
- May 31, 2009, 8:29 AM EDT (12:29 UTC)
- Expired
- May 31, 2009, 8:46 AM EDT
- In force
- 17 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
County Sussex County, DE
The radar
The Dover AFB radar (KDOX), 28 km from the middle of the area, began a volume at 12:32 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 nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 12:00Z, 0.5 hours before the alert went out and 92 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.
- Mixed-layer CAPE
- 579 J/kg
- Mixed-layer CIN
- -69 J/kg
- Mixed-layer LCL
- 1296 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 100 m²/s²
- 0-3 km storm-relative helicity
- 102 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 0.5
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 311229
SVRPHI
DEC005-311300-
/O.NEW.KPHI.SV.W.0040.090531T1229Z-090531T1300Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
829 AM EDT SUN MAY 31 2009
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
EAST CENTRAL SUSSEX COUNTY IN SOUTHERN DELAWARE...
* UNTIL 900 AM EDT
* AT 828 AM 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
LEWES...OR 12 MILES EAST OF GEORGETOWN...AND MOVING EAST AT 35 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
REHOBOTH BEACH AROUND 835 AM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.
&&
LAT...LON 3879 7532 3882 7519 3879 7513 3879 7511
3881 7508 3878 7506 3874 7507 3865 7505
3864 7508 3868 7508 3868 7512 3864 7511
3861 7526
TIME...MOT...LOC 1229Z 255DEG 29KT 3873 7517
$$
RNS1 follow-up statement
000
WWUS51 KPHI 311246
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
846 AM EDT SUN MAY 31 2009
DEC005-311255-
/O.CAN.KPHI.SV.W.0040.000000T0000Z-090531T1300Z/
SUSSEX DE-
846 AM EDT SUN MAY 31 2009
...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL SUSSEX COUNTY IS
CANCELLED...
THE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS HAS MOVED OFF
TO THE EAST.
LAT...LON 3879 7532 3882 7519 3879 7513 3879 7511
3881 7508 3878 7506 3874 7507 3865 7505
3864 7508 3868 7508 3868 7512 3864 7511
3861 7526
TIME...MOT...LOC 1244Z 255DEG 29KT 1386 6979
$$
RNSNearby
Severe Thunderstorm Warnings in Delaware, 2009Every severe thunderstorm warning in 2009
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.