Alert archive / Delaware / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 258, NWS Philadelphia/Mount Holly

July 29, 2023Kent County, Sussex County, Delaware; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 29, 2023, 6:00 PM EDT for Kent County, Sussex County, Delaware; Caroline County, Maryland. It was in force for 75 min. 9 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: Jul 29, 2023, 6:00 PM EDT (22:00 UTC)
Expired: Jul 29, 2023, 7:15 PM EDT
In force: 75 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Damage threat: Considerable
Hail: 0.75 in
Wind: 70.0 mph

Counties Kent County, DE, Sussex County, DE, Caroline County, MD

The radar

The Dover AFB radar (KDOX), 23 km from the middle of the area, began a volume at 22:01 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
Jul 29, 6:03 PM EDT	TSTM WND DMG	2 N Smithville, MD	Several large branches blown down on Nobel and Breeding Road. Time estimated from radar.
Jul 29, 6:20 PM EDT	TSTM WND GST 48	2 Sse Greenwood, DE	Wunderground station KDEGREEN1.
Jul 29, 6:21 PM EDT	TSTM WND DMG	Seaford, DE	Several reports of trees and power lines down in the Seaford area. A few other similar reports from western Sussex County (US Route 13 corridor), which was the hardest hit area from the storm. Time estimated from radar.
Jul 29, 6:39 PM EDT	TSTM WND GST 41	1 Nne Milton, DE	Wunderground station KDEMILTO84.
Jul 29, 6:47 PM EDT	TSTM WND DMG	1 Ese Millsboro, DE	A few reports of trees and power lines down across Millsboro. Time estimated from radar.
Jul 29, 6:54 PM EDT	TSTM WND GST 45	1 Sw Delaware Coastal A, DE	ASOS station KGED Georgetown.
Jul 29, 6:54 PM EDT	TSTM WND GST 48	1 Ene Lewes, DE	USGS gauge at Lewes Ferry.
Jul 29, 6:54 PM EDT	TSTM WND GST 48	1 Ene Lewes, DE	USGS gauge at Lewes Ferry.
Jul 29, 6:55 PM EDT	TSTM WND GST 41	Dagsboro, DE	DEOS gauge at Dagsboro.

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
Jul 29, 2:48 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 10.0 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.

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: 245 J/kg
Mixed-layer CIN: -215 J/kg
Mixed-layer LCL: 1190 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 179 m²/s²
0-3 km storm-relative helicity: 159 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

314 
WUUS51 KPHI 292200
SVRPHI
DEC001-005-MDC011-292315-
/O.NEW.KPHI.SV.W.0258.230729T2200Z-230729T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
600 PM EDT Sat Jul 29 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Sussex County in southern Delaware...
  Kent County in central Delaware...
  Caroline County in eastern Maryland...

* Until 715 PM EDT.

* At 559 PM EDT, severe thunderstorms were located along a line
  extending from Goldsboro to near Denton to near Federalsburg, 
  moving east at 40 mph. This storm has a history of producing 
  measured wind gusts near 60 mph across the eastern shore of 
  Maryland.

  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...
  Dover, Georgetown, Milford, Seaford, Denton, Millsboro, Laurel,
  Harrington, Camden, Lewes, Federalsburg, Milton, Selbyville,
  Bridgeville, Greensboro, Delmar, Dagsboro, Preston, Millville and
  Ellendale.

People at the Delaware State Fair should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3846 7569 3865 7571 3869 7577 3868 7580
      3870 7580 3871 7584 3870 7590 3868 7594
      3871 7597 3891 7586 3905 7588 3916 7573
      3915 7535 3880 7507 3845 7503 3845 7537
TIME...MOT...LOC 2159Z 283DEG 34KT 3902 7576 3890 7575 3871 7583 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Staarmann

4 follow-up statements

001 
WWUS51 KPHI 292215
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
615 PM EDT Sat Jul 29 2023

DEC001-005-MDC011-292315-
/O.CON.KPHI.SV.W.0258.000000T0000Z-230729T2315Z/
Sussex DE-Kent DE-Caroline MD-
615 PM EDT Sat Jul 29 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR SUSSEX...KENT AND SOUTHERN CAROLINE COUNTIES...

At 615 PM EDT, severe thunderstorms were located along a line
extending from Viola to near Andrewsville to near Seaford, moving
east at 40 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...
Dover, Georgetown, Milford, Seaford, Denton, Millsboro, Laurel,
Harrington, Camden, Lewes, Federalsburg, Milton, Selbyville,
Bridgeville, Delmar, Dagsboro, Preston, Millville, Ellendale and
Bowers.

People at the Delaware State Fair should seek safe shelter
immediately!

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.

&&

LAT...LON 3846 7569 3865 7571 3871 7584 3868 7594
      3871 7597 3891 7586 3899 7574 3916 7573
      3915 7535 3880 7507 3845 7503
TIME...MOT...LOC 2215Z 282DEG 34KT 3903 7554 3887 7558 3868 7566 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Staarmann

223 
WWUS51 KPHI 292228
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
628 PM EDT Sat Jul 29 2023

MDC011-292238-
/O.CAN.KPHI.SV.W.0258.000000T0000Z-230729T2315Z/
Caroline MD-
628 PM EDT Sat Jul 29 2023

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CAROLINE 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 900 PM EDT for
central and southern Delaware...and eastern Maryland.

LAT...LON 3846 7569 3865 7571 3888 7560 3915 7554
      3915 7535 3880 7507 3845 7503
TIME...MOT...LOC 2228Z 284DEG 35KT 3899 7534 3883 7542 3860 7556 

$$

DEC001-005-292315-
/O.CON.KPHI.SV.W.0258.000000T0000Z-230729T2315Z/
Sussex DE-Kent DE-
628 PM EDT Sat Jul 29 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR SUSSEX AND SOUTHEASTERN KENT COUNTIES...

At 628 PM EDT, severe thunderstorms were located along a line
extending from Big Stone Beach to Ellendale to near Laurel, moving
east at 40 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...
Dover, Georgetown, Milford, Seaford, Millsboro, Laurel, Harrington,
Camden, Lewes, Milton, Selbyville, Bridgeville, Delmar, Dagsboro,
Millville, Ellendale, Bowers, Henlopen Acres, Gumboro and Rising
Sun-Lebanon.

People at the Delaware State Fair should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

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.

&&

LAT...LON 3846 7569 3865 7571 3888 7560 3915 7554
      3915 7535 3880 7507 3845 7503
TIME...MOT...LOC 2228Z 284DEG 35KT 3899 7534 3883 7542 3860 7556 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Staarmann

385 
WWUS51 KPHI 292241
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
641 PM EDT Sat Jul 29 2023

DEC001-005-292315-
/O.CON.KPHI.SV.W.0258.000000T0000Z-230729T2315Z/
Sussex DE-Kent DE-
641 PM EDT Sat Jul 29 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR SUSSEX AND SOUTHEASTERN KENT COUNTIES...

At 641 PM EDT, severe thunderstorms were located along a line
extending from 9 miles west of North Cape May to near Milton to near
Sycamore, moving east at 40 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, Milford, Seaford, Millsboro, Laurel, Lewes, Milton,
Dagsboro, Millville, Ellendale, Bowers, Henlopen Acres, Gumboro, Cape
Henlopen State Park, Sycamore, Big Stone Beach, Long Neck, Ocean
View, Blades and Frankford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

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, and
the storm will affect the beaches. For your safety, immediately move
off the beach and seek shelter indoors.

&&

LAT...LON 3859 7570 3882 7546 3905 7543 3912 7532
      3879 7506 3846 7503 3846 7569
TIME...MOT...LOC 2241Z 286DEG 36KT 3899 7513 3876 7526 3855 7546 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Staarmann

355 
WWUS51 KPHI 292301
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
701 PM EDT Sat Jul 29 2023

DEC001-292311-
/O.CAN.KPHI.SV.W.0258.000000T0000Z-230729T2315Z/
Kent DE-
701 PM EDT Sat Jul 29 2023

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN 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 900 PM EDT for
southern Delaware.

LAT...LON 3846 7569 3864 7539 3880 7537 3892 7516
      3879 7506 3846 7503
TIME...MOT...LOC 2301Z 290DEG 36KT 3882 7501 3864 7502 3846 7530 

$$

DEC005-292315-
/O.CON.KPHI.SV.W.0258.000000T0000Z-230729T2315Z/
Sussex DE-
701 PM EDT Sat Jul 29 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR EASTERN SUSSEX COUNTY...

At 701 PM EDT, severe thunderstorms were located along a line
extending from near Cape Henlopen State Park to 7 miles southeast of
Henlopen Acres to near Gumboro, moving east at 40 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, Millsboro, Lewes, Milton, Dagsboro, Millville, Henlopen
Acres, Gumboro, Cape Henlopen State Park, Long Neck, Ocean View,
Frankford, South Bethany and Dewey Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

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, and
the storm will affect the beaches. For your safety, immediately move
off the beach and seek shelter indoors.

&&

LAT...LON 3846 7569 3864 7539 3880 7537 3892 7516
      3879 7506 3846 7503
TIME...MOT...LOC 2301Z 290DEG 36KT 3882 7501 3864 7502 3846 7530 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 8:04 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	41 min
Jul 28, 8:33 PM EDT	Special Weather Statement	PHI	New Castle	42 min
Jul 28, 10:07 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	38 min
Jul 28, 10:44 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	31 min
Jul 28, 11:00 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	60 min
Jul 28, 11:33 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	27 min
Jul 28, 11:59 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	31 min
Jul 29, 12:12 AM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	36 min
Jul 29, 4:55 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	50 min
Jul 29, 5:00 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Kent, New Castle	60 min
Jul 29, 5:44 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Kent, New Castle	46 min
Jul 29, 6:18 PM EDT	Tornado Warning	PHI	Sussex	27 min
Jul 29, 6:26 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	49 min
Jul 28, 8:18 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Queen Anne's	42 min
Jul 28, 9:30 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	45 min
Jul 29, 5:02 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Caroline, Kent, Queen Anne's, Talbot	73 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2023 Severe Thunderstorm Warnings in Maryland, 2023 Every severe thunderstorm warning in 2023

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.