Alert archive / Delaware / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 11, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 5, 2011, 5:28 AM EDT for Kent County, New Castle County, Sussex County, Delaware; Caroline County, Queen Anne's County, Talbot County, Maryland. It was in force for 62 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Apr 5, 2011, 5:28 AM EDT (09:28 UTC)
- Expired
- Apr 5, 2011, 6:30 AM EDT
- In force
- 62 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
Counties Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Queen Anne's County, MD, Talbot County, MD
The radar
The Dover AFB radar (KDOX), 40 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 5, 6:13 AM EDT | TSTM WND DMG | Bridgeville, DE | 10 UTILITY POLES SNAPPED AND LAYING IN SAME DIRECTION. RESULT OF T-STORM WIND GUST. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 5, 2:18 AM EDT | Tornado Watch | SPC | 8 hr |
The nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 00:00Z, 9.5 hours before the alert went out and 99 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1729 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 229 m²/s²
- 0-3 km storm-relative helicity
- 317 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
058
WUUS51 KPHI 050928
SVRPHI
DEC001-003-005-MDC011-035-041-051030-
/O.NEW.KPHI.SV.W.0011.110405T0928Z-110405T1030Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
528 AM EDT TUE APR 5 2011
THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
KENT COUNTY IN CENTRAL DELAWARE...
THIS INCLUDES THE CITY OF DOVER...
SOUTHERN CAROLINE COUNTY IN EASTERN MARYLAND...
TALBOT COUNTY IN EASTERN MARYLAND...
THIS INCLUDES THE CITY OF EASTON...
SOUTH CENTRAL QUEEN ANNE'S COUNTY IN NORTHEAST MARYLAND...
SOUTH CENTRAL NEW CASTLE COUNTY IN NORTHERN DELAWARE...
SUSSEX COUNTY IN SOUTHERN DELAWARE...
THIS INCLUDES THE CITY OF GEORGETOWN...
* UNTIL 630 AM EDT
* AT 526 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM 19 MILES NORTHWEST OF CENTERVILLE TO 8 MILES WEST OF
CENTERVILLE TO 11 MILES WEST OF EASTON TO 21 MILES SOUTHWEST OF
EASTON...AND MOVING NORTHEAST AT 45 MPH.
* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
COPPERVILLE...HAMBLETON...TRAPPE...CORDOVA...QUEEN ANNE...
TANYARD...WINDYHILL...MATTHEWS...GRIFFIN...CHOPTANK...PRESTON...
HARMONY...DENTON...FEDERALSBURG...AGNER...LAUREL...SEAFORD...
SMYRNA...SMITHVILLE...HAZLETTVILLE...CHESWOLD...BRIDGEVILLE...
SYCAMORE...ANDREWSVILLE...WOODSIDE...VIOLA...CAMDEN...GUMBORO...
DOVER SPEEDWAY...HARRINGTON...RISING SUN...MILLSBORO...ELLENDALE...
DAGSBORO...BOWERS...MILFORD...MILTON...MILLVILLE AND BETHANY BEACH
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.
THIS SEVERE THUNDERSTORM MAY CONTAIN LITTLE OR NO LIGHTNING. DO NOT
WAIT FOR THUNDER BEFORE TAKING COVER. SEEK SHELTER IMMEDIATELY INSIDE
A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.
A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT TUESDAY MORNING
FOR DELAWARE AND NORTHEASTERN MARYLAND.
&&
LAT...LON 3846 7570 3865 7572 3867 7576 3869 7590
3856 7604 3867 7622 3873 7625 3866 7634
3867 7634 3887 7625 3882 7621 3883 7620
3891 7625 3894 7622 3894 7573 3942 7559
3861 7512 3860 7514 3847 7504
TIME...MOT...LOC 0928Z 243DEG 60KT 3930 7617 3905 7617
3873 7622 3854 7624
$$
HAYES1 follow-up statement
747
WWUS51 KPHI 051017
SVSPHI
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
617 AM EDT TUE APR 5 2011
DEC003-MDC035-041-051027-
/O.CAN.KPHI.SV.W.0011.000000T0000Z-110405T1030Z/
QUEEN ANNE'S MD-TALBOT MD-NEW CASTLE DE-
617 AM EDT TUE APR 5 2011
...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL NEW CASTLE...
TALBOT AND SOUTH CENTRAL QUEEN ANNE'S COUNTIES IS CANCELLED...
A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT TUESDAY MORNING
FOR DELAWARE AND NORTHEASTERN MARYLAND. A SEVERE THUNDERSTORM WATCH
ALSO REMAINS IN EFFECT UNTIL 1000 AM EDT TUESDAY MORNING FOR
NORTHEAST MARYLAND AND NEW JERSEY AND EASTERN PENNSYLVANIA.
LAT...LON 3846 7570 3865 7572 3867 7576 3869 7589
3894 7573 3905 7563 3906 7539 3861 7512
3860 7514 3847 7504
TIME...MOT...LOC 1017Z 243DEG 60KT 3965 7521 3940 7522
3908 7527 3889 7530
$$
DEC001-005-MDC011-051030-
/O.CON.KPHI.SV.W.0011.000000T0000Z-110405T1030Z/
KENT DE-CAROLINE MD-SUSSEX DE-
617 AM EDT TUE APR 5 2011
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 AM EDT
FOR SUSSEX...SOUTHEASTERN CAROLINE AND SOUTHERN KENT COUNTIES...
AT 612 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM 42 MILES NORTH OF VIOLA TO 26 MILES NORTHEAST OF
RIVERVIEW TO 6 MILES NORTHEAST OF FREDERICA TO ELLENDALE...OR ALONG A
LINE EXTENDING FROM 14 MILES SOUTHEAST OF WILMINGTON TO 14 MILES WEST
OF MILLVILLE TO 11 MILES SOUTHEAST OF DOVER TO 11 MILES NORTH OF
GEORGETOWN...MOVING NORTHEAST AT 450 MPH.
OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
SLAUGHTER BEACH
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A TORNADO WATCH REMAINS IN EFFECT UNTIL 1000 AM EDT TUESDAY MORNING
FOR DELAWARE AND NORTHEASTERN MARYLAND.
&&
LAT...LON 3846 7570 3865 7572 3867 7576 3869 7589
3894 7573 3905 7563 3906 7539 3861 7512
3860 7514 3847 7504
TIME...MOT...LOC 1017Z 243DEG 60KT 3965 7521 3940 7522
3908 7527 3889 7530
$$
HAYESThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 5, 5:01 AM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 74 min |
| Apr 5, 8:55 AM EDT | Special Weather Statement | PHI | Kent, New Castle | 65 min |
| Apr 5, 9:37 AM EDT | Special Weather Statement | PHI | Kent, New Castle | 53 min |
| Apr 5, 10:16 AM EDT | Severe Thunderstorm Warning | PHI | New Castle | 44 min |
| Apr 5, 10:20 AM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 40 min |
| Apr 5, 3:05 PM EDT | Frost Advisory | PHI | Kent, Sussex | 13 hr |
Nearby
Severe Thunderstorm Warnings in Delaware, 2011Severe Thunderstorm Warnings in Maryland, 2011Every severe thunderstorm warning in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.