Alert archive / Delaware / Severe Thunderstorm Warnings in 2009
Severe Thunderstorm Warning 221, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 24, 2009, 5:31 AM EDT for Sussex County, Delaware. It was in force for 30 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 24, 2009, 5:31 AM EDT (09:31 UTC)
- Expired
- Aug 24, 2009, 6:01 AM EDT
- In force
- 30 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
County Sussex County, DE
The radar
The Dover AFB radar (KDOX), 42 km from the middle of the area, began a volume at 09:30 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 00:00Z, 9.5 hours before the alert went out and 70 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
- 265 J/kg
- Mixed-layer CIN
- -40 J/kg
- Mixed-layer LCL
- 985 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- -28 m²/s²
- 0-3 km storm-relative helicity
- 32 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WUUS51 KPHI 240931
SVRPHI
DEC005-241015-
/O.NEW.KPHI.SV.W.0221.090824T0931Z-090824T1015Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
531 AM EDT MON AUG 24 2009
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHEASTERN SUSSEX COUNTY IN SOUTHERN DELAWARE...
* UNTIL 615 AM EDT
* AT 530 AM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR
SELBYVILLE...OR 19 MILES SOUTHEAST OF GEORGETOWN...AND MOVING
EAST AT 15 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
SELBYVILLE AND 7 MILES SOUTH OF DAGSBORO AROUND 535 AM EDT...
MILLVILLE AROUND 600 AM EDT...
MILLVILLE AROUND 605 AM EDT...
FENWICK ISLAND AND BETHANY BEACH AROUND 610 AM EDT...
BETHANY BEACH AROUND 615 AM EDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT 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.
IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...HEAVY RAIN WILL OCCUR
WITH THIS STORM AND CAUSE LOW-LYING AND POOR DRAINAGE FLOODING.
&&
LAT...LON 3845 7531 3852 7533 3859 7511 3859 7509
3861 7505 3860 7504 3846 7503 3844 7505
TIME...MOT...LOC 0930Z 254DEG 13KT 3844 7524
$$1 follow-up statement
000
WWUS51 KPHI 241001
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
601 AM EDT MON AUG 24 2009
DEC005-241010-
/O.CAN.KPHI.SV.W.0221.000000T0000Z-090824T1015Z/
SUSSEX DE-
601 AM EDT MON AUG 24 2009
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SUSSEX COUNTY IS
CANCELLED...
THE SEVERE THUNDERSTORM WARNING IS CANCELLED AS THE THUNDERSTORM HAS
WEAKENED AS IT MOVED OFF THE COAST OF EXTREME SOUTHEASTERN DELAWARE.
LAT...LON 3845 7531 3852 7533 3859 7511 3859 7509
3861 7505 3860 7504 3846 7503 3844 7505
TIME...MOT...LOC 1000Z 254DEG 13KT 3847 7511
$$Nearby
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.