Alert archive / Delaware / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 27, NWS Philadelphia/Mount Holly

May 4, 2021Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 4, 2021, 7:38 PM EDT for Kent County, Sussex County, Delaware. It was in force for 31 min. 2 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: May 4, 2021, 7:38 PM EDT (23:38 UTC)
Expired: May 4, 2021, 8:09 PM EDT
In force: 31 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 7 km from the middle of the area, began a volume at 23:40 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
May 4, 8:03 PM EDT	MARINE TSTM WIND 40	Lewes, DE
May 4, 8:08 PM EDT	MARINE TSTM WIND 43	Lewes, DE

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 11.6 hours before the alert went out and 100 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 60 J/kg
Mixed-layer CIN: -270 J/kg
Mixed-layer LCL: 1140 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 46 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

598 
WUUS51 KPHI 042338
SVRPHI
DEC001-005-050030-
/O.NEW.KPHI.SV.W.0027.210504T2338Z-210505T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
738 PM EDT Tue May 4 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Central Sussex County in southern Delaware...
  Southeastern Kent County in central Delaware...

* Until 830 PM EDT.

* At 737 PM EDT, severe thunderstorms were located along a line
  extending from near Andrewsville to near Sycamore, moving northeast
  at 30 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Georgetown, Milford, Lewes, Milton, Ellendale, Cape Henlopen State
  Park and Greenwood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of 
a building.

&&

LAT...LON 3898 7532 3878 7504 3859 7545 3881 7565
TIME...MOT...LOC 2337Z 231DEG 28KT 3881 7560 3863 7546 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...60MPH
 
$$

JEO

2 follow-up statements

888 
WWUS51 KPHI 042351
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
751 PM EDT Tue May 4 2021

DEC001-005-050030-
/O.CON.KPHI.SV.W.0027.000000T0000Z-210505T0030Z/
Sussex DE-Kent DE-
751 PM EDT Tue May 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM EDT
FOR NORTHEASTERN SUSSEX AND SOUTHEASTERN KENT COUNTIES...

At 750 PM EDT, severe thunderstorms were located along a line
extending from near Harrington to Georgetown, moving northeast at 30
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Georgetown, Milford, Lewes, Milton, Ellendale and Cape Henlopen State
Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3886 7555 3898 7532 3878 7504 3863 7537
TIME...MOT...LOC 2350Z 231DEG 28KT 3887 7551 3869 7537 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

JEO

356 
WWUS51 KPHI 050009
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
809 PM EDT Tue May 4 2021

DEC001-005-050016-
/O.CAN.KPHI.SV.W.0027.000000T0000Z-210505T0030Z/
Sussex DE-Kent DE-
809 PM EDT Tue May 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN SUSSEX AND
SOUTHEASTERN KENT COUNTIES IS CANCELLED...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning has
been cancelled.

LAT...LON 3886 7555 3898 7532 3878 7504 3863 7537
TIME...MOT...LOC 0005Z 231DEG 28KT 3894 7539 3876 7525 

$$

JEO

The office that day

Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 4, 7:04 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	41 min
May 4, 7:43 PM EDT	Special Weather Statement	PHI	Sussex	47 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2021 Every 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.