Alert archive / Delaware / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 159, NWS Philadelphia/Mount Holly

July 9, 2021New Castle County, Delaware; Salem County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 9, 2021, 6:19 PM EDT for New Castle County, Delaware; Salem County, New Jersey. It was in force for 41 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
Jul 9, 2021, 6:19 PM EDT (22:19 UTC)
Expired
Jul 9, 2021, 7:00 PM EDT
In force
41 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

Counties New Castle County, DE, Salem County, NJ

The radar

The Dover AFB radar (KDOX), 80 km from the middle of the area, began a volume at 22:21 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 9, 6:24 PM EDTTSTM WND DMG2 Ssw Newark, DETREE DOWN IN THE 400 BLOCK OF LARK DRIVE. TIME ESTIMATED FROM RADAR.
Jul 9, 6:55 PM EDTMARINE TSTM WIND 404 Ssw Elsinboro Twp, NJGUST MEASURED AT NJ WXNET SITE AT LOWER ALLOWAYS CREEK.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.3 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-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
862 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

029 
WUUS51 KPHI 092219
SVRPHI
DEC003-NJC033-092300-
/O.NEW.KPHI.SV.W.0159.210709T2219Z-210709T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
619 PM EDT Fri Jul 9 2021

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 700 PM EDT.

* At 618 PM EDT, a severe thunderstorm was located over Elkton,
  moving east at 30 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Minor damage to vehicles is possible. Wind damage to 
           roofs, siding, trees, and power lines is possible.

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

This includes the following highways...
 New Jersey Turnpike near exit 1.
 Interstate 95 in Delaware between mile markers 0 and 13.
 Interstate 295 in New Jersey between mile markers 0 and 8.

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.

&&

LAT...LON 3975 7538 3946 7539 3945 7541 3944 7541
      3943 7540 3943 7541 3942 7541 3952 7578
      3962 7579 3972 7579
TIME...MOT...LOC 2218Z 269DEG 27KT 3963 7582 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann
2 follow-up statements
300 
WWUS51 KPHI 092243
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
643 PM EDT Fri Jul 9 2021

DEC003-NJC033-092300-
/O.CON.KPHI.SV.W.0159.000000T0000Z-210709T2300Z/
New Castle DE-Salem NJ-
643 PM EDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHERN NEW CASTLE AND WESTERN SALEM COUNTIES...

At 643 PM EDT, a severe thunderstorm was located over Bear, or 7
miles southeast of Newark, moving east at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

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

This includes the following highways...
 New Jersey Turnpike near exit 1.
 Interstate 95 in Delaware between mile markers 0 and 13.
 Interstate 295 in New Jersey between mile markers 0 and 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3975 7538 3946 7539 3945 7541 3944 7541
      3943 7540 3943 7541 3942 7541 3952 7578
      3962 7579 3972 7579
TIME...MOT...LOC 2243Z 269DEG 25KT 3963 7563 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann
654 
WWUS51 KPHI 092253
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
653 PM EDT Fri Jul 9 2021

DEC003-NJC033-092300-
/O.CON.KPHI.SV.W.0159.000000T0000Z-210709T2300Z/
New Castle DE-Salem NJ-
653 PM EDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR CENTRAL NEW CASTLE AND WESTERN SALEM COUNTIES...

At 652 PM EDT, a severe thunderstorm was located near New Castle, or
8 miles south of Wilmington, moving east at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Wilmington, Pennsville, Carneys Point, Elsmere, New Castle, Penns
Grove, Salem, Alloway, Quinton, Delaware City, Newport, Saint
Georges, Mount Pleasant, Stanton, Delaware Memorial Bridge, Hancocks
Bridge, Port Penn, Wilmington Manor, Hope Creek and Newport Meadows.

This includes the following highways...
 New Jersey Turnpike near exit 1.
 Interstate 95 in Delaware between mile markers 7 and 13.
 Interstate 295 in New Jersey between mile markers 0 and 8.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3960 7566 3973 7567 3975 7538 3946 7539
      3945 7541 3944 7541 3943 7540 3943 7541
      3942 7541 3952 7578 3957 7578
TIME...MOT...LOC 2252Z 269DEG 26KT 3962 7557 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 10:19 PM EDTAreal Flood AdvisoryPHIKent, Sussex5 hr
Jul 8, 11:37 PM EDTTornado WarningPHISussex23 min
Jul 8, 11:59 PM EDTTornado WarningPHISussex12 min
Jul 9, 12:04 AM EDTTornado WarningPHISussex26 min
Jul 9, 12:11 AM EDTTornado WarningPHISussex35 min
Jul 9, 12:28 AM EDTTornado WarningPHISussex17 min
Jul 9, 4:54 PM EDTSpecial Weather StatementPHINew Castle66 min
Jul 9, 5:17 PM EDTSevere Thunderstorm WarningPHINew Castle43 min
Jul 9, 6:50 PM EDTAreal Flood AdvisoryPHINew Castle2 hr
Jul 9, 6:57 PM EDTSevere Thunderstorm WarningPHINew Castle63 min
Jul 8, 10:25 PM EDTAreal Flood AdvisoryPHICape May, Cumberland7 hr
Jul 8, 11:02 PM EDTSpecial Marine WarningPHI88 min
Jul 8, 11:59 PM EDTAreal Flood AdvisoryPHISalem5 hr
Jul 9, 12:07 AM EDTSpecial Marine WarningPHI53 min
Jul 9, 12:08 AM EDTAreal Flood AdvisoryPHIAtlantic, Camden, Gloucester6 hr
Jul 9, 12:25 AM EDTSpecial Marine WarningPHI95 min
Jul 9, 1:34 AM EDTSpecial Marine WarningPHI86 min
Jul 9, 1:49 AM EDTSpecial Marine WarningPHI26 min
Jul 9, 2:05 AM EDTAreal Flood AdvisoryPHIBurlington, Monmouth, Ocean8 hr
Jul 9, 2:50 AM EDTTornado WarningPHIAtlantic, Cape May, Cumberland25 min
Jul 9, 2:53 AM EDTSpecial Marine WarningPHI68 min
Jul 9, 3:38 AM EDTTornado WarningPHIAtlantic, Burlington, Ocean18 min
Jul 9, 3:51 AM EDTSpecial Marine WarningPHI84 min
Jul 9, 4:08 AM EDTGale WarningPHI3 hr
Jul 9, 4:41 AM EDTTornado WarningPHIMonmouth, Ocean34 min
Jul 9, 4:44 AM EDTAreal Flood AdvisoryPHIMercer, Middlesex5 hr
Jul 9, 4:54 AM EDTAreal Flood AdvisoryPHIMorris, Somerset5 hr
Jul 9, 4:58 AM EDTSpecial Marine WarningPHI39 min
Jul 9, 5:34 PM EDTAreal Flood AdvisoryPHISussex, Warren2 hr
Jul 9, 6:24 PM EDTSpecial Marine WarningPHI66 min
Jul 9, 7:17 PM EDTSevere Thunderstorm WarningPHICamden, Gloucester23 min
Jul 9, 7:39 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Sussex, Warren2 hr
Jul 9, 7:43 PM EDTSevere Thunderstorm WarningPHIAtlantic, Camden, Cape May, Cumberland, Gloucester, Salem62 min
Jul 9, 7:46 PM EDTAreal Flood AdvisoryPHIAtlantic, Camden, Cumberland, Gloucester, Salem108 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2021Severe Thunderstorm Warnings in New Jersey, 2021Every 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.