Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 269, NWS Philadelphia/Mount Holly

August 7, 20234 states

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 7, 2023, 5:37 PM EDT for 4 states. It was in force for 53 min. 14 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 7, 2023, 5:37 PM EDT (21:37 UTC)
Expired: Aug 7, 2023, 6:30 PM EDT
In force: 53 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Damage threat: Considerable
Hail: 0.88 in
Wind: 70.0 mph

Counties New Castle County, DE, Kent County, MD, Salem County, NJ, Delaware County, PA

The radar

The Dover AFB radar (KDOX), 90 km from the middle of the area, began a volume at 21:37 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 7, 6:08 PM EDT	TSTM WND DMG	1 Nw Nottingham Manor, DE	Report of trees down in Newark, DE near the DE/MD border. Time estimated from radar.
Aug 7, 6:10 PM EDT	TSTM WND DMG	Hockessin, DE	A structure collapsed.
Aug 7, 6:12 PM EDT	TSTM WND DMG	1 Wnw Hyde Park, DE	Tree and wire damage along Mill Creek Road. Time estimated from radar.
Aug 7, 6:14 PM EDT	TSTM WND DMG	Brookside, DE	Report of multiple trees down with power outages in Brookside on social media. Time estimated via radar.
Aug 7, 6:14 PM EDT	TSTM WND DMG	Hockessin, DE	Report of multiple trees down across Meetinghouse and Benge Roads in Hockessin. Time estimated via radar.
Aug 7, 6:14 PM EDT	TSTM WND DMG	Newark, DE	Public report of large tree down in backyard on social media. Photo provided. Time estimated via radar.
Aug 7, 6:20 PM EDT	TSTM WND DMG	1 Ne Cleland Heights, DE	Picture of an uprooted tree at the corner of Linden and Franklin St. Time estimated from radar.
Aug 7, 6:20 PM EDT	TSTM WND DMG	Hockessin, DE	Path of significant tree damage reported between Yorktowne and Highland Meadows neighborhoods. Some minor siding damage to houses. Photos via social media.
Aug 7, 6:23 PM EDT	TSTM WND DMG	1 Ne Concordville, PA	Report of trees and wires down around Governor Markham Drive in Concord Township. Time estimated from radar.
Aug 7, 6:26 PM EDT	TSTM WND DMG	Wilmington, DE	Report of tree down in North Wilmington on social media. Time estimated via radar.
Aug 7, 6:27 PM EDT	TSTM WND GST 42	2 E Simonds Gardens, DE	DEDOT station DEL01.
Aug 7, 6:28 PM EDT	TSTM WND DMG	Glen Mills, PA	Report of multiple trees snapped in Glen Mills on social media. Times estimated via radar.
Aug 7, 6:30 PM EDT	TSTM WND DMG	1 Ne Newtown Twp, PA	Tree limbs down on Hansell Road.
Aug 7, 6:35 PM EDT	TSTM WND GST 54	Lower Alloways Creek, NJ

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
Aug 7, 3:13 PM EDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.6 hours before the alert went out and 169 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: 285 J/kg
Mixed-layer CIN: -147 J/kg
Mixed-layer LCL: 738 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 28 m²/s²
0-3 km storm-relative helicity: 86 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

959 
WUUS51 KPHI 072137
SVRPHI
DEC003-MDC029-NJC033-PAC045-072230-
/O.NEW.KPHI.SV.W.0269.230807T2137Z-230807T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
537 PM EDT Mon Aug 7 2023

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  Northern Kent County in northeastern Maryland...
  Western Salem County in southern New Jersey...
  Delaware County in southeastern Pennsylvania...

* Until 630 PM EDT.

* At 537 PM EDT, severe thunderstorms were located along a line
  extending from near Delta to Essex, moving east at 55 mph.

  HAZARD...70 mph wind gusts and nickel size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Wilmington, Newark, Middletown, Chester, Pennsville, Yeadon,
  Carneys Point, Folcroft, Swarthmore, Elsmere, New Castle, Penns
  Grove, Salem, Alloway, Quinton, Delaware City, Newport, Arden,
  Betterton and Stanton.

This includes the following highways...
 New Jersey Turnpike near exit 1.
 Interstate 95 in Pennsylvania between mile markers 0 and 9.
 Interstate 95 in Delaware between mile markers 1 and 23.
 Interstate 295 in New Jersey between mile markers 0 and 8.
 Interstate 476 in Pennsylvania between mile markers 0 and 14.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM EDT for central and
northern Delaware...northeastern Maryland...southern New Jersey...and
southeastern Pennsylvania.

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

This is a DANGEROUS SITUATION. SEEK SHELTER NOW inside a sturdy 
structure and stay away from windows! 

A Tornado Watch remains in effect until 1100 PM EDT for central and 
northern Delaware...northeastern Maryland...southern New 
Jersey...and southeastern Pennsylvania.

&&

LAT...LON 3937 7611 3936 7588 3938 7577 3972 7579
      3981 7570 3984 7560 3993 7554 3998 7544
      4004 7541 4006 7535 3997 7526 3985 7529
      3978 7544 3970 7534 3933 7545 3933 7550
      3936 7551 3931 7558 3929 7617 3931 7618
TIME...MOT...LOC 2137Z 264DEG 47KT 3974 7627 3929 7646 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

RCM

1 follow-up statement

202 
WWUS51 KPHI 072159 RRA
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
559 PM EDT Mon Aug 7 2023

DEC003-MDC029-NJC033-PAC045-072230-
/O.CON.KPHI.SV.W.0269.000000T0000Z-230807T2230Z/
New Castle DE-Kent MD-Salem NJ-Delaware PA-
559 PM EDT Mon Aug 7 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR NEW CASTLE...NORTHERN KENT...WESTERN SALEM AND DELAWARE
COUNTIES...

At 559 PM EDT, severe thunderstorms were located along a line
extending from near Oxford to near Newtown, moving east at 55 mph.

HAZARD...70 mph wind gusts and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Wilmington, Newark, Middletown, Chester, Pennsville, Yeadon, Carneys
Point, Folcroft, Swarthmore, Elsmere, New Castle, Penns Grove, Salem,
Alloway, Quinton, Delaware City, Newport, Arden, Betterton and
Stanton.

This includes the following highways...
 New Jersey Turnpike near exit 1.
 Interstate 95 in Pennsylvania between mile markers 0 and 9.
 Interstate 95 in Delaware between mile markers 1 and 23.
 Interstate 295 in New Jersey between mile markers 0 and 8.
 Interstate 476 in Pennsylvania between mile markers 0 and 14.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM EDT for central and
northern Delaware...northeastern Maryland...southern New Jersey...and
southeastern Pennsylvania.

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

&&

LAT...LON 3937 7611 3936 7588 3938 7577 3972 7579
      3981 7570 3984 7560 3993 7554 3998 7544
      4004 7541 4006 7535 3997 7526 3985 7529
      3978 7544 3970 7534 3933 7545 3933 7550
      3936 7551 3931 7558 3929 7617 3931 7618
TIME...MOT...LOC 2159Z 264DEG 47KT 3977 7592 3932 7611 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

RCM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 7, 5:33 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Berks, Chester	57 min
Aug 7, 5:57 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	79 min
Aug 7, 6:08 PM EDT	Tornado Warning	PHI	Chester	19 min
Aug 7, 6:21 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Berks, Bucks, Chester, Delaware, Montgomery, Philadelphia	69 min
Aug 7, 6:29 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware, Montgomery, Philadelphia	63 min
Aug 7, 6:35 PM EDT	Tornado Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	25 min
Aug 7, 6:45 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	45 min
Aug 7, 6:53 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Carbon, Lehigh, Monroe, Montgomery and 1 more	52 min
Aug 7, 7:00 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh, Montgomery, Northampton	66 min
Aug 7, 7:20 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	58 min
Aug 7, 7:27 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Lehigh, Monroe, Northampton	48 min
Aug 7, 5:57 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	63 min
Aug 7, 6:52 PM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	95 min
Aug 7, 6:58 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	Caroline, Kent, Queen Anne's, Talbot	62 min
Aug 7, 7:56 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Talbot	49 min
Aug 7, 5:39 PM EDT	Special Marine Warning	PHI		66 min
Aug 7, 6:49 PM EDT	Special Marine Warning	PHI		86 min
Aug 7, 7:21 PM EDT	Special Marine Warning	PHI		92 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2023 Severe Thunderstorm Warnings in Maryland, 2023 Severe Thunderstorm Warnings in New Jersey, 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.