Alert archive / Delaware / Severe Thunderstorm Warnings in 2020
Severe Thunderstorm Warning 291, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 3, 2020, 7:40 PM EDT for Sussex County, Delaware. It was in force for 65 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 3, 2020, 7:40 PM EDT (23:40 UTC)
- Expired
- Sep 3, 2020, 8:45 PM EDT
- In force
- 65 min
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 0.75 in
- Wind
- 70.0 mph
County Sussex County, DE
The radar
The Dover AFB radar (KDOX), 8 km from the middle of the area, began a volume at 23:39 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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Sep 3, 3:42 PM EDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.7 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
- 72 J/kg
- Mixed-layer CIN
- -137 J/kg
- Mixed-layer LCL
- 1124 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -21 m²/s²
- 0-3 km storm-relative helicity
- 55 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.9
The text
As transmitted.
045
WUUS51 KPHI 032340
SVRPHI
DEC005-040045-
/O.NEW.KPHI.SV.W.0291.200903T2340Z-200904T0045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
740 PM EDT Thu Sep 3 2020
The National Weather Service in Mount Holly NJ has issued a
* Severe Thunderstorm Warning for...
Central Sussex County in southern Delaware...
* Until 845 PM EDT.
* At 739 PM EDT, severe thunderstorms were located along a line
extending from near Ellendale to near Bridgeville to Seaford,
moving east at 45 mph.
HAZARD...70 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect considerable tree damage. Damage is likely to
mobile homes, roofs, and outbuildings.
* Locations impacted include...
Georgetown, Seaford, Millsboro, Lewes, Milton, Bridgeville,
Millville, Ellendale, Henlopen Acres, Cape Henlopen State Park,
Long Neck, Ocean View, Greenwood and Dewey Beach.
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.
Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure. A Tornado
Watch remains in effect until 1000 PM EDT for central and southern
Delaware.
In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with these storms. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.
&&
LAT...LON 3866 7568 3884 7560 3884 7555 3885 7554
3888 7521 3881 7508 3852 7503
TIME...MOT...LOC 2339Z 276DEG 37KT 3882 7550 3873 7551 3866 7558
TORNADO...POSSIBLE
HAIL...0.75IN
WIND...70MPH
$$
Staarmann4 follow-up statements
036
WWUS51 KPHI 040006
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
806 PM EDT Thu Sep 3 2020
DEC005-040045-
/O.CON.KPHI.SV.W.0291.000000T0000Z-200904T0045Z/
Sussex DE-
806 PM EDT Thu Sep 3 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR SOUTHEASTERN SUSSEX COUNTY...
At 805 PM EDT, severe thunderstorms were located along a line
extending from near Lewes to 7 miles southeast of Milton to near
Millsboro, moving east at 40 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Wind damage to roofs,
siding, trees, and power lines is possible.
Locations impacted include...
Millsboro, Lewes, Milton, Millville, Henlopen Acres, Cape Henlopen
State Park, Long Neck, Ocean View and Dewey Beach.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Protecting yourself from immediate threats to life and safety shall
take priority. Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.
Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure. A Tornado
Watch remains in effect until 1000 PM EDT for southern Delaware.
Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 3860 7539 3870 7536 3881 7530 3882 7508
3859 7504 3855 7503 3852 7504
TIME...MOT...LOC 0005Z 276DEG 35KT 3876 7522 3869 7523 3862 7528
TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
$$
Staarmann954
WWUS51 KPHI 040022
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
822 PM EDT Thu Sep 3 2020
DEC005-040045-
/O.CON.KPHI.SV.W.0291.000000T0000Z-200904T0045Z/
Sussex DE-
822 PM EDT Thu Sep 3 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR SOUTHEASTERN SUSSEX COUNTY...
At 822 PM EDT, severe thunderstorms were located along a line
extending from near Henlopen Acres to near Millville to near
Dagsboro, moving east at 35 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...
Millville, Henlopen Acres, Long Neck, Ocean View, South Bethany and
Dewey Beach.
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.
Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure. A Tornado
Watch remains in effect until 1000 PM EDT for southern Delaware.
Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 3857 7525 3862 7519 3873 7522 3875 7507
3874 7506 3857 7503 3853 7503 3852 7504
3852 7506
TIME...MOT...LOC 0022Z 280DEG 30KT 3868 7504 3863 7511 3857 7518
TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
$$
Staarmann446
WWUS51 KPHI 040031
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
831 PM EDT Thu Sep 3 2020
DEC005-040045-
/O.CON.KPHI.SV.W.0291.000000T0000Z-200904T0045Z/
Sussex DE-
831 PM EDT Thu Sep 3 2020
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR EAST CENTRAL SUSSEX COUNTY...
At 831 PM EDT, severe thunderstorms were located along a line
extending from near Henlopen Acres to Millville, moving east at 30
mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Minor damage to vehicles is possible. Wind damage to roofs,
siding, trees, and power lines is possible.
Locations impacted include...
Millville, Long Neck, Ocean View and Dewey Beach.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Protecting yourself from immediate threats to life and safety shall
take priority. Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.
Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure. A Tornado
Watch remains in effect until 1000 PM EDT for southern Delaware.
Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 3853 7509 3856 7515 3871 7511 3871 7506
3863 7504 3853 7503 3852 7504
TIME...MOT...LOC 0031Z 282DEG 26KT 3866 7505 3857 7510
TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
$$
Staarmann216
WWUS51 KPHI 040038
SVSPHI
Severe Weather Statement
National Weather Service Mount Holly NJ
838 PM EDT Thu Sep 3 2020
DEC005-040046-
/O.EXP.KPHI.SV.W.0291.000000T0000Z-200904T0045Z/
Sussex DE-
838 PM EDT Thu Sep 3 2020
...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL SUSSEX COUNTY
WILL EXPIRE AT 845 PM EDT...
The storms which prompted the warning have weakened below severe
limits and have moved offshore. Therefore, the warning will be
allowed to expire. However gusty winds and heavy rain are still
possible over the next half hour or so.
A Tornado Watch remains in effect until 1000 PM EDT for southern
Delaware.
LAT...LON 3853 7509 3856 7515 3871 7511 3871 7506
3863 7504 3853 7503 3852 7504
TIME...MOT...LOC 0036Z 276DEG 37KT 3865 7499 3856 7504
$$
StaarmannThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 2, 10:35 PM EDT | Special Weather Statement | PHI | Sussex | 55 min |
| Sep 3, 6:48 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 57 min |
Nearby
Severe Thunderstorm Warnings in Delaware, 2020Every severe thunderstorm warning in 2020
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.