Alert archive / Delaware / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 43, NWS Philadelphia/Mount Holly

May 20, 2026New Castle County, Delaware; Salem County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 20, 2026, 5:35 PM EDT for New Castle County, Delaware; Salem County, New Jersey. It was in force for 40 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: May 20, 2026, 5:35 PM EDT (21:35 UTC)
Expired: May 20, 2026, 6:15 PM EDT
In force: 40 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties New Castle County, DE, Salem County, NJ

The radar

The Dover AFB radar (KDOX), 88 km from the middle of the area, began a volume at 21:34 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
May 20, 2:10 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.6 hours before the alert went out and 176 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: 47 J/kg
Mixed-layer CIN: -204 J/kg
Mixed-layer LCL: 1752 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: -79 m²/s²
0-3 km storm-relative helicity: -47 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

523 
WUUS51 KPHI 202135
SVRPHI
DEC003-NJC033-202215-
/O.NEW.KPHI.SV.W.0043.260520T2135Z-260520T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
535 PM EDT Wed May 20 2026

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northern New Castle County in northern Delaware...
  Western Salem County in southern New Jersey...

* Until 615 PM EDT.

* At 534 PM EDT, a severe thunderstorm was located over near Elkton, 
  moving east at 25 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Wilmington, Newark, Pennsville, Carneys Point, New Castle, Penns
  Grove, Salem, Woodstown, Alloway, Quinton, Delaware City, Newport,
  Saint Georges, Mount Pleasant, Stanton, Glasgow, Bear, Delaware
  Memorial Bridge, Hancocks Bridge, and Port Penn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3973 7577 3973 7538 3970 7533 3949 7534
      3947 7535 3946 7537 3952 7578 3972 7579
TIME...MOT...LOC 2134Z 272DEG 24KT 3964 7587 

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

$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 4:50 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	40 min
May 20, 5:18 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	42 min
May 20, 5:29 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	46 min
May 20, 2:25 PM EDT	Small Craft Advisory	PHI		3 days
May 20, 4:43 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Warren	47 min
May 20, 5:01 PM EDT	Special Marine Warning	PHI		86 min
May 20, 5:10 PM EDT	Severe Thunderstorm Warning	PHI	Camden, Gloucester	50 min
May 20, 5:15 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Hunterdon, Mercer, Somerset	45 min
May 20, 5:24 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Morris, Somerset, Warren	51 min
May 20, 5:40 PM EDT	Flash Flood Warning	PHI	Burlington, Camden, Gloucester	3 hr
May 20, 5:41 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Monmouth, Ocean	49 min
May 20, 5:52 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Ocean and 1 more	38 min
May 20, 6:01 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester	44 min
May 20, 6:04 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Hunterdon, Middlesex, Monmouth, Morris, Somerset	56 min
May 20, 6:07 PM EDT	Special Marine Warning	PHI		53 min
May 20, 6:09 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Gloucester, Ocean	46 min
May 20, 6:12 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	33 min
May 20, 6:17 PM EDT	Special Marine Warning	PHI		118 min
May 20, 6:23 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean, Somerset	56 min
May 20, 6:58 PM EDT	Severe Thunderstorm Warning	PHI	Ocean	32 min
May 20, 7:30 PM EDT	Special Marine Warning	PHI		90 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2026 Severe Thunderstorm Warnings in New Jersey, 2026 Every severe thunderstorm warning in 2026

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.