Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 315, NWS Philadelphia/Mount Holly

October 25, 2021New Castle County, Delaware; Chester County, Delaware County, Pennsylvania; Salem County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Oct 25, 2021, 6:33 PM EDT for New Castle County, Delaware; Chester County, Delaware County, Pennsylvania; Salem County, New Jersey. It was in force for 42 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
Oct 25, 2021, 6:33 PM EDT (22:33 UTC)
Expired
Oct 25, 2021, 7:15 PM EDT
In force
42 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, Chester County, PA, Delaware County, PA

The radar

The Dover AFB radar (KDOX), 99 km from the middle of the area, began a volume at 22:35 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
Oct 25, 7:05 PM EDTHAIL 0.25Newark, DE
Oct 25, 7:13 PM EDTTSTM WND DMG1 Sw Winterthur, DEDOWNED TREE ON WALNUT GREEN ROAD. TIME ESTIMATED FROM RADAR.
Oct 25, 7:13 PM EDTTSTM WND DMG3 Wsw Brookfield, PATREE AND WIRES DOWN ON CENTER MILL RD. TIME ESTIMATED FROM RADAR.
Oct 25, 7:22 PM EDTTSTM WND DMG2 Ene Kennett Square, PADOWNED TREES AND WIRES NEAR SILLS MILL ROAD. TIME ESTIMATED FROM RADAR.

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, 10.6 hours before the alert went out and 179 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 2021-10-25Temperature 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 2021-10-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 213 square meters per square second.19395878Sfc1 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
1230 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
213 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

063 
WUUS51 KPHI 252233
SVRPHI
DEC003-NJC033-PAC029-045-252315-
/O.NEW.KPHI.SV.W.0315.211025T2233Z-211025T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
633 PM EDT Mon Oct 25 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  New Castle County in northern Delaware...
  Northwestern Salem County in southern New Jersey...
  South central Chester County in southeastern Pennsylvania...
  Southwestern Delaware County in southeastern Pennsylvania...

* Until 715 PM EDT.

* At 633 PM EDT, a severe thunderstorm was located over Warwick, or
  near Middletown, moving north at 40 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, Middletown, Chester, Pennsville, Carneys Point,
  Elsmere, Kennett Square, New Castle, Penns Grove, Salem, Delaware
  City, Newport, Arden, Stanton, North Star, Glasgow, Bear,
  Talleyville and Port Penn.

This includes the following highways...
 Interstate 95 in Pennsylvania between mile markers 0 and 1.
 Interstate 95 in Delaware between mile markers 0 and 23.
 Interstate 295 in New Jersey between mile markers 0 and 6.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3987 7577 3983 7538 3979 7541 3978 7544
      3978 7541 3976 7540 3936 7552 3937 7577
      3968 7579
TIME...MOT...LOC 2233Z 199DEG 35KT 3942 7575 

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

$$

JEO
2 follow-up statements
618 
WWUS51 KPHI 252247
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
647 PM EDT Mon Oct 25 2021

DEC003-NJC033-PAC029-045-252315-
/O.CON.KPHI.SV.W.0315.000000T0000Z-211025T2315Z/
New Castle DE-Salem NJ-Chester PA-Delaware PA-
647 PM EDT Mon Oct 25 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM EDT
FOR NEW CASTLE...NORTHWESTERN SALEM...SOUTH CENTRAL CHESTER AND
SOUTHWESTERN DELAWARE COUNTIES...

At 647 PM EDT, a severe thunderstorm was located over Saint Georges,
or 7 miles north of Middletown, moving north at 40 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, Chester, Pennsville, Carneys Point, Elsmere,
Kennett Square, New Castle, Penns Grove, Salem, Delaware City,
Newport, Arden, Stanton, North Star, Glasgow, Bear, Talleyville, Port
Penn and Wilmington Manor.

This includes the following highways...
 Interstate 95 in Pennsylvania between mile markers 0 and 1.
 Interstate 95 in Delaware between mile markers 0 and 23.
 Interstate 295 in New Jersey between mile markers 0 and 6.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3987 7577 3983 7538 3980 7541 3979 7541
      3978 7544 3978 7541 3976 7540 3946 7549
      3948 7578 3968 7579
TIME...MOT...LOC 2247Z 199DEG 35KT 3955 7569 

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

$$

JEO
759 
WWUS51 KPHI 252312
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
712 PM EDT Mon Oct 25 2021

DEC003-NJC033-PAC029-045-252322-
/O.EXP.KPHI.SV.W.0315.000000T0000Z-211025T2315Z/
New Castle DE-Salem NJ-Chester PA-Delaware PA-
712 PM EDT Mon Oct 25 2021

...THE SEVERE THUNDERSTORM WARNING FOR NEW CASTLE...NORTHWESTERN
SALEM...SOUTH CENTRAL CHESTER AND SOUTHWESTERN DELAWARE COUNTIES WILL
EXPIRE AT 715 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 3987 7577 3983 7538 3980 7541 3979 7541
      3978 7544 3978 7541 3976 7540 3946 7549
      3948 7578 3968 7579
TIME...MOT...LOC 2312Z 199DEG 35KT 3976 7560 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 25, 4:15 PM EDTSpecial Weather StatementPHISussex30 min
Oct 25, 5:27 PM EDTSpecial Weather StatementPHIKent33 min
Oct 25, 6:27 PM EDTSpecial Weather StatementPHINew Castle33 min
Oct 25, 6:57 PM EDTSevere Thunderstorm WarningPHINew Castle48 min
Oct 25, 7:34 PM EDTSevere Thunderstorm WarningPHIDelaware, Philadelphia26 min
Oct 25, 7:43 PM EDTSpecial Weather StatementPHIBucks, Montgomery47 min
Oct 25, 3:12 AM EDTGale WatchPHI13 hr
Oct 25, 4:15 PM EDTGale WarningPHI46 hr
Oct 25, 6:03 PM EDTSpecial Marine WarningPHI57 min
Oct 25, 7:02 PM EDTSpecial Weather StatementPHICamden, Gloucester, Salem43 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021Severe 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.