Alert archive / Delaware / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 17, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 21, 2021, 2:18 PM EDT for Kent County, Sussex County, Delaware. It was in force for 42 min. 4 reports 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 21, 2021, 2:18 PM EDT (18:18 UTC)
- Expired
- Apr 21, 2021, 3:00 PM EDT
- In force
- 42 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
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 18:17 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 21, 2:20 PM EDT | HAIL 0.25 | 2 N Georgetown, DE | |
| Apr 21, 2:25 PM EDT | TSTM WND GST 44 | Milton, DE | |
| Apr 21, 2:35 PM EDT | TSTM WND GST 58 | 1 Wnw Lewes, DE | |
| Apr 21, 2:35 PM EDT | MARINE TSTM WIND 58 | 1 Wnw Lewes, DE |
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 21, 12:28 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 12:00Z, 6.3 hours before the alert went out and 81 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
- 12 J/kg
- Mixed-layer CIN
- -142 J/kg
- Mixed-layer LCL
- 1437 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 136 m²/s²
- 0-3 km storm-relative helicity
- 126 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
541
WUUS51 KPHI 211818
SVRPHI
DEC001-005-211900-
/O.NEW.KPHI.SV.W.0017.210421T1818Z-210421T1900Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
218 PM EDT Wed Apr 21 2021
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Sussex County in southern Delaware...
South central Kent County in central Delaware...
* Until 300 PM EDT.
* At 218 PM EDT, severe thunderstorms were located along a line
extending from near Milford to Seaford, moving east at 40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Wind damage to
roofs, siding, trees, and power lines is possible.
* Locations impacted include...
Georgetown, Milford, Seaford, Millsboro, Laurel, Lewes, Milton,
Bridgeville, Dagsboro, Millville, Ellendale, Henlopen Acres, Cape
Henlopen State Park, Sycamore, Long Neck, Ocean View, Blades,
Greenwood, Frankford and South Bethany.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Protecting yourself from immediate threats to life and safety shall
take priority. Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3851 7570 3864 7571 3894 7551 3888 7505
3849 7503
TIME...MOT...LOC 1818Z 249DEG 34KT 3889 7533 3863 7559
HAIL...1.00IN
WIND...60MPH
$$
JEO3 follow-up statements
086
WWUS51 KPHI 211827
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
227 PM EDT Wed Apr 21 2021
DEC001-211836-
/O.CAN.KPHI.SV.W.0017.000000T0000Z-210421T1900Z/
Kent DE-
227 PM EDT Wed Apr 21 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL KENT COUNTY IS
CANCELLED...
The storms which prompted the warning have moved out of the warned
area. Therefore, the warning has been cancelled.
A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
southern Delaware.
LAT...LON 3851 7558 3863 7557 3892 7534 3888 7505
3849 7503
TIME...MOT...LOC 1826Z 249DEG 34KT 3892 7524 3866 7550
$$
DEC005-211900-
/O.CON.KPHI.SV.W.0017.000000T0000Z-210421T1900Z/
Sussex DE-
227 PM EDT Wed Apr 21 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR CENTRAL SUSSEX COUNTY...
At 226 PM EDT, severe thunderstorms were located along a line
extending from 7 miles southeast of Big Stone Beach to near Sycamore,
moving east at 40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Wind damage to roofs,
siding, trees, and power lines is possible.
Locations impacted include...
Georgetown, Millsboro, Laurel, Lewes, Milton, Dagsboro, Millville,
Ellendale, Henlopen Acres, Cape Henlopen State Park, Sycamore, Long
Neck, Ocean View, Frankford, South Bethany and Dewey Beach.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3851 7558 3863 7557 3892 7534 3888 7505
3849 7503
TIME...MOT...LOC 1826Z 249DEG 34KT 3892 7524 3866 7550
HAIL...1.00IN
WIND...60MPH
$$
JEO846
WWUS51 KPHI 211833
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
233 PM EDT Wed Apr 21 2021
DEC005-211900-
/O.CON.KPHI.SV.W.0017.000000T0000Z-210421T1900Z/
Sussex DE-
233 PM EDT Wed Apr 21 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM EDT
FOR EASTERN SUSSEX COUNTY...
At 233 PM EDT, severe thunderstorms were located along a line
extending from 9 miles southeast of Big Stone Beach to near
Georgetown, moving east at 40 mph.
HAZARD...70 mph wind gusts and quarter size hail.
SOURCE...Radar indicated. Radar strongly indicates that severe wind
is occurring with this storm.
IMPACT...Minor damage to vehicles is possible. Expect considerable
tree damage. Wind damage is also likely to mobile homes,
roofs, and outbuildings.
Locations impacted include...
Georgetown, Millsboro, Lewes, Milton, Dagsboro, Millville, Henlopen
Acres, Cape Henlopen State Park, Long Neck, Ocean View, Frankford,
South Bethany and Dewey Beach.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3850 7545 3851 7546 3892 7531 3888 7505
3849 7503
TIME...MOT...LOC 1833Z 270DEG 34KT 3894 7518 3868 7544
HAIL...1.00IN
WIND...70MPH
$$
JEO206
WWUS51 KPHI 211852
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
252 PM EDT Wed Apr 21 2021
DEC005-211901-
/O.EXP.KPHI.SV.W.0017.000000T0000Z-210421T1900Z/
Sussex DE-
252 PM EDT Wed Apr 21 2021
...THE SEVERE THUNDERSTORM WARNING FOR EASTERN SUSSEX COUNTY WILL
EXPIRE AT 300 PM EDT...
The storms which prompted the warning have moved out of the area and
offshore. Therefore, the warning will be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 600 PM EDT for
southern Delaware.
LAT...LON 3850 7545 3851 7546 3892 7531 3888 7505
3849 7503
TIME...MOT...LOC 1851Z 249DEG 34KT 3900 7498 3874 7524
$$
JEOThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 1:10 PM EDT | Severe Thunderstorm Warning | PHI | New Castle | 50 min |
| Apr 21, 1:23 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 37 min |
| Apr 21, 2:09 PM EDT | Special Weather Statement | PHI | Sussex | 36 min |
| Apr 21, 2:47 PM EDT | Severe Thunderstorm Warning | PHI | Sussex | 16 min |
Nearby
Severe Thunderstorm Warnings in Delaware, 2021Every severe thunderstorm warning in 2021
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.