Alert archive / Delaware / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 255, NWS Philadelphia/Mount Holly

July 28, 2026New Castle County, Delaware; Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 28, 2026, 5:29 PM EDT for New Castle County, Delaware; Chester County, Pennsylvania. It was in force for 61 min. 4 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 28, 2026, 5:29 PM EDT (21:29 UTC)
Expired
Jul 28, 2026, 6:30 PM EDT
In force
61 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties New Castle County, DE, Chester County, PA

The radar

The Dover AFB radar (KDOX), 117 km from the middle of the area, began a volume at 21:33 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

TimeReportWhereRemark
Jul 28, 6:35 PM EDTTSTM WND DMG1 Nne Thorndale, PATwo trees down in roadway near 4200 Hazelwood Avenue. Time estimated from radar.
Jul 28, 6:35 PM EDTTSTM WND DMGNew Garden, PALarge Limb partially blocking lane near 236 Bucktoe Road. Time estimated from radar.
Jul 28, 6:35 PM EDTTSTM WND DMGValley Twp, PACorrects previous tstm wnd dmg time of report from Valley Twp. Tree down in roadway. Time estimated from radar.
Jul 28, 6:40 PM EDTTSTM WND DMGNewport, DEScattered reports of a few downed trees and wires around Newport. Time estimated by radar.

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.

IssuedProductOfficeLasted
Jul 28, 12:51 PM EDTSevere Thunderstorm WatchSPC8 hr
Jul 28, 4:20 PM EDTTornado WatchSPC5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.5 hours before the alert went out and 160 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2026-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 710 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2026-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
710 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
968 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
174 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

356 
WUUS51 KPHI 282129
SVRPHI
DEC003-PAC029-282230-
/O.NEW.KPHI.SV.W.0255.260728T2129Z-260728T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
529 PM EDT Tue Jul 28 2026

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern New Castle County in northern Delaware...
  Chester County in southeastern Pennsylvania...

* Until 630 PM EDT.

* At 529 PM EDT, severe thunderstorms were located along a line
  extending from Millersville to Bel Air North, moving east 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...
  Newark, Middletown, West Chester, Coatesville, Downingtown,
  Elsmere, Kennett Square, New Castle, Oxford, Parkesburg, West
  Grove, Delaware City, Newport, Glen Roy, Homeville, Cochranville,
  Stanton, North Star, Glasgow, and Bear.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 310 and 315.
 Interstate 95 in Delaware between mile markers 0 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM EDT for northern
Delaware...and southeastern Pennsylvania.

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

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

A Tornado Watch remains in effect until 1000 PM EDT for northern
Delaware...and southeastern Pennsylvania.

&&

LAT...LON 3976 7606 3981 7603 3983 7604 3983 7602
      3987 7599 3993 7600 3994 7598 3995 7600
      4004 7593 4010 7560 3986 7560 3944 7557
      3945 7578 3972 7579 3972 7613
TIME...MOT...LOC 2129Z 270DEG 28KT 4002 7637 3954 7635 

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

$$

MJL
1 follow-up statement
467 
WWUS51 KPHI 282154
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
554 PM EDT Tue Jul 28 2026

DEC003-PAC029-282230-
/O.CON.KPHI.SV.W.0255.000000T0000Z-260728T2230Z/
New Castle DE-Chester PA-
554 PM EDT Tue Jul 28 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR NORTHWESTERN NEW CASTLE AND CHESTER COUNTIES...

At 554 PM EDT, severe thunderstorms were located along a line
extending from Paradise to Havre De Grace, moving east 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...
Newark, Middletown, West Chester, Coatesville, Downingtown, Elsmere,
Kennett Square, New Castle, Oxford, Parkesburg, West Grove, Delaware
City, Newport, Glen Roy, Homeville, Cochranville, Stanton, North
Star, Glasgow, and Bear.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 310 and 315.
 Interstate 95 in Delaware between mile markers 0 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM EDT for northern
Delaware...and southeastern Pennsylvania.

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

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

&&

LAT...LON 3976 7606 3981 7603 3983 7604 3983 7602
      3987 7599 3993 7600 3994 7598 3995 7600
      4004 7593 4010 7560 3986 7560 3944 7557
      3945 7578 3972 7579 3972 7613
TIME...MOT...LOC 2154Z 270DEG 28KT 4002 7612 3954 7610 

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

$$

MJL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 5:53 PM EDTSevere Thunderstorm WarningPHIKent52 min
Jul 28, 6:08 PM EDTSevere Thunderstorm WarningPHIKent, New Castle52 min
Jul 28, 6:16 PM EDTTornado WarningPHINew Castle29 min
Jul 28, 6:23 PM EDTSevere Thunderstorm WarningPHINew Castle67 min
Jul 28, 6:38 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIKent, New Castle67 min
Jul 28, 6:46 PM EDTTornado WarningPHINew Castle29 min
Jul 28, 6:55 PM EDTSevere Thunderstorm WarningPHIKent50 min
Jul 28, 6:59 PM EDTSevere Thunderstorm WarningPHIKent, Sussex61 min
Jul 28, 7:11 PM EDTFlash Flood WarningPHINew Castle3 hr
Jul 28, 7:40 PM EDTSevere Thunderstorm WarningPHISussex50 min
Jul 27, 8:01 PM EDTSevere Thunderstorm WarningPHIChester23 min
Jul 28, 1:02 PM EDTFlash Flood WarningPHILehigh, Monroe, Northampton4 hr
Jul 28, 1:22 PM EDTSevere Thunderstorm WarningPHILehigh, Northampton38 min
Jul 28, 1:31 PM EDTSevere Thunderstorm WarningPHINorthampton44 min
Jul 28, 1:49 PM EDTTornado WarningPHIMonroe, Northampton26 min
Jul 28, 2:15 PM EDTSevere Thunderstorm WarningPHINorthampton45 min
Jul 28, 5:08 PM EDTSevere Thunderstorm WarningPHILehigh, Northampton15 min
Jul 28, 5:22 PM EDTSevere Thunderstorm WarningPHIBucks34 min
Jul 28, 5:47 PM EDTSevere Thunderstorm WarningPHIBucks, Northampton43 min
Jul 28, 5:55 PM EDTFlash Flood WarningPHIBerks3 hr
Jul 28, 6:17 PM EDTFlash Flood WarningPHIBucks, Lehigh, Northampton6 hr
Jul 28, 6:56 PM EDTFlash Flood WarningPHIBucks, Lehigh, Northampton5 hr
Jul 28, 7:06 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia54 min
Jul 28, 7:08 PM EDTSevere Thunderstorm WarningPHIBerks, Chester, Montgomery35 min
Jul 28, 7:24 PM EDTFlash Flood WarningPHIChester4 hr
Jul 28, 7:31 PM EDTSevere Thunderstorm WarningPHIBucks, Northampton44 min
Jul 28, 7:55 PM EDTFlash Flood WarningPHIBucks, Montgomery4 hr

Nearby

Severe Thunderstorm Warnings in Delaware, 2026Severe Thunderstorm Warnings in Pennsylvania, 2026Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.