Alert archive / Delaware / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 71, NWS Philadelphia/Mount Holly

June 9, 2021Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 2021, 3:11 PM EDT for Sussex County, Delaware. It was in force for 64 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: Jun 9, 2021, 3:11 PM EDT (19:11 UTC)
Expired: Jun 9, 2021, 4:15 PM EDT
In force: 64 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 26 km from the middle of the area, began a volume at 19:14 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
Jun 9, 3:43 PM EDT	TSTM WND DMG	1 Se Stockley, DE	TREE DOWN ACROSS GRAVEL HILL RD AND DOC FRAME RD.

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, 7.2 hours before the alert went out and 77 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: 795 J/kg
Mixed-layer CIN: -87 J/kg
Mixed-layer LCL: 967 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

992 
WUUS51 KPHI 091911
SVRPHI
DEC005-092015-
/O.NEW.KPHI.SV.W.0071.210609T1911Z-210609T2015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
311 PM EDT Wed Jun 9 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 415 PM EDT.

* At 309 PM EDT, a severe thunderstorm was located near Millsboro, or
  9 miles southeast of Georgetown, moving south at 10 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, Millsboro, Dagsboro, Millville, Long Neck, Ocean View,
  Frankford and South Bethany.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to damaging winds, frequent cloud to ground lightning is 
occurring with this storm. Move indoors immediately. Remember, if 
you can hear thunder, you are close enough to be struck by lightning.
The storm will affect the beaches, and for your safety immediately 
move off the beach and seek shelter indoors.

&&

LAT...LON 3854 7544 3875 7550 3878 7539 3863 7505
      3845 7504
TIME...MOT...LOC 1909Z 352DEG 7KT 3862 7523 

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

Gorse

3 follow-up statements

124 
WWUS51 KPHI 091936
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
336 PM EDT Wed Jun 9 2021

DEC005-092015-
/O.CON.KPHI.SV.W.0071.000000T0000Z-210609T2015Z/
Sussex DE-
336 PM EDT Wed Jun 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR SOUTHEASTERN SUSSEX COUNTY...

At 335 PM EDT, severe thunderstorms were located along a line
extending from near Millville to near Sycamore to near Seaford to
near Bridgeville, moving west at 20 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, Millsboro, Dagsboro, Millville, Long Neck, Ocean View,
Frankford and South Bethany.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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. For your safety, remain off the beaches and 
seek shelter indoors.

&&

LAT...LON 3854 7544 3875 7550 3878 7539 3863 7505
      3845 7504
TIME...MOT...LOC 1935Z 092DEG 18KT 3852 7507 3862 7542 3867 7555 3872
7556

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

Gorse

892 
WWUS51 KPHI 091953
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
353 PM EDT Wed Jun 9 2021

DEC005-092015-
/O.CON.KPHI.SV.W.0071.000000T0000Z-210609T2015Z/
Sussex DE-
353 PM EDT Wed Jun 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR SOUTHEASTERN SUSSEX COUNTY...

At 352 PM EDT, severe thunderstorms were located along a line
extending from near Millville to near Sycamore to near Seaford to
near Bridgeville, moving south at 10 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, Millsboro, Dagsboro, Millville, Long Neck, Ocean View,
Frankford and South Bethany.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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. For your safety, remain off the beaches and 
seek shelter indoors.

&&

LAT...LON 3854 7544 3875 7550 3863 7505 3845 7504
TIME...MOT...LOC 1952Z 352DEG 7KT 3849 7506 3859 7541 3864 7554 3869
7555

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

Gorse

696 
WWUS51 KPHI 092007
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
407 PM EDT Wed Jun 9 2021

DEC005-092017-
/O.EXP.KPHI.SV.W.0071.000000T0000Z-210609T2015Z/
Sussex DE-
407 PM EDT Wed Jun 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SUSSEX COUNTY
WILL EXPIRE AT 415 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty 
winds are possible and heavy rain is occurring with these 
thunderstorms.

LAT...LON 3854 7544 3875 7550 3863 7505 3845 7504
TIME...MOT...LOC 2007Z 352DEG 7KT 3846 7506 3856 7540 3861 7553 3866
7554

$$

Gorse

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 8, 8:15 PM EDT	Special Weather Statement	PHI	Sussex	45 min
Jun 9, 7:54 AM EDT	River Flood Warning	PHI	New Castle	5 hr
Jun 9, 1:35 PM EDT	Special Weather Statement	PHI	New Castle	25 min
Jun 9, 2:07 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	23 min
Jun 9, 2:21 PM EDT	Flash Flood Warning	PHI	New Castle	73 min
Jun 9, 2:26 PM EDT	Severe Thunderstorm Warning	PHI	Kent	64 min
Jun 9, 2:28 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	62 min
Jun 9, 3:24 PM EDT	Areal Flood Advisory	PHI	Sussex	3 hr
Jun 9, 4:32 PM EDT	Areal Flood Advisory	PHI	Sussex	108 min
Jun 9, 4:37 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	27 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.