Alert archive / Delaware / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 268, NWS Philadelphia/Mount Holly

August 26, 2021Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 26, 2021, 2:36 PM EDT for Sussex County, Delaware. It was in force for 43 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: Aug 26, 2021, 2:36 PM EDT (18:36 UTC)
Expired: Aug 26, 2021, 3:19 PM EDT
In force: 43 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), 29 km from the middle of the area, began a volume at 18:39 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.

What was reported inside it

Time	Report	Where	Remark
Aug 26, 2:38 PM EDT	TSTM WND DMG	1 Ene Seaford, DE	TREES DOWN ONTO POWER LINES ON MIDDLEFORD ROAD IN SEAFORD. TIME ESTIMATED FROM RADAR.
Aug 26, 2:40 PM EDT	TSTM WND DMG	Laurel, DE	TREE LIMBS DOWN IN LAUREL DUE TO STRONG OUTFLOW WINDS FROM INCOMING THUNDERSTORM. TIME BASED ON THE REPORT AND RADAR.

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, 6.6 hours before the alert went out and 76 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: 84 J/kg
Mixed-layer CIN: -192 J/kg
Mixed-layer LCL: 1374 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

355 
WUUS51 KPHI 261836
SVRPHI
DEC005-261930-
/O.NEW.KPHI.SV.W.0268.210826T1836Z-210826T1930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
236 PM EDT Thu Aug 26 2021

The National Weather Service in Mount Holly NJ has issued a

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

* Until 330 PM EDT.

* At 236 PM EDT, a severe thunderstorm was located over Seaford, or
  11 miles east of Hurlock, moving southeast at 10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Seaford, Laurel, Bridgeville, Sycamore, Blades and
  Bethel.

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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3849 7570 3870 7571 3881 7554 3863 7528
      3846 7569
TIME...MOT...LOC 1836Z 323DEG 9KT 3864 7565 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Gorse

3 follow-up statements

192 
WWUS51 KPHI 261848
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
248 PM EDT Thu Aug 26 2021

DEC005-261930-
/O.CON.KPHI.SV.W.0268.000000T0000Z-210826T1930Z/
Sussex DE-
248 PM EDT Thu Aug 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR SOUTHWESTERN SUSSEX COUNTY...

At 248 PM EDT, a severe thunderstorm was located near Laurel, or 11
miles southwest of Georgetown, moving southeast at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Georgetown, Seaford, Laurel, Sycamore, Blades and Bethel. 

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 this storm. 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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3867 7571 3878 7550 3863 7528 3846 7569
      3849 7570
TIME...MOT...LOC 1848Z 308DEG 12KT 3861 7557 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Gorse

613 
WWUS51 KPHI 261907
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
307 PM EDT Thu Aug 26 2021

DEC005-261930-
/O.CON.KPHI.SV.W.0268.000000T0000Z-210826T1930Z/
Sussex DE-
307 PM EDT Thu Aug 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR SOUTHWESTERN SUSSEX COUNTY...

At 306 PM EDT, a severe thunderstorm was located over Laurel, or 12
miles north of Salisbury, moving south at 10 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Laurel, Sycamore and Bethel. 

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 this storm. 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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3860 7570 3866 7547 3860 7536 3846 7569
      3849 7570
TIME...MOT...LOC 1906Z 347DEG 9KT 3856 7557 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Gorse

977 
WWUS51 KPHI 261919
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
319 PM EDT Thu Aug 26 2021

DEC005-261929-
/O.CAN.KPHI.SV.W.0268.000000T0000Z-210826T1930Z/
Sussex DE-
319 PM EDT Thu Aug 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SUSSEX COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 3860 7570 3866 7547 3860 7536 3846 7569
      3849 7570
TIME...MOT...LOC 1918Z 323DEG 9KT 3853 7554 

$$

Gorse

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 26, 3:30 PM EDT	Flash Flood Watch	PHI	New Castle	48 hr

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.