Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 268, NWS Philadelphia/Mount Holly

August 7, 2023Berks County, Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 7, 2023, 5:33 PM EDT for Berks County, Chester County, Pennsylvania. It was in force for 57 min. 8 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, 5:33 PM EDT (21:33 UTC)
Expired
Aug 7, 2023, 6:30 PM EDT
In force
57 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Damage threat
Considerable
Hail
0.88 in
Wind
70.0 mph

Counties Berks County, PA, Chester County, PA

The radar

The Philadelphia radar (KDIX), 118 km from the middle of the area, began a volume at 21:35 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
Aug 7, 5:57 PM EDTTSTM WND DMGOxford, PAReport of multiple large trees down in Oxford, PA on social media. Time estimated via radar.
Aug 7, 6:04 PM EDTTSTM WND DMGCochranville, PAReport on social media of trees down and power outages in Cochranville. Time estimated via radar.
Aug 7, 6:11 PM EDTTSTM WND DMGKennett Square, PA911 Call Center received multiple reports of down trees in Kennet Square and New Garden Township. Time estimated from radar.
Aug 7, 6:12 PM EDTHAIL 0.25Kemblesville, PATrained Spotter reports pea size hail 1 mile east of Kimblesville, PA at 6:12 PM.
Aug 7, 6:15 PM EDTFUNNEL CLOUDCoatesville, PAEM reported funnel cloud near Coatesville.
Aug 7, 6:32 PM EDTTSTM WND GST 681 Nnw Uwchlan Twp, PA68 MPH gust measured by trained spotter. Time given in report.
Aug 7, 6:32 PM EDTTSTM WND GST 681 Nnw Uwchlan Twp, PA68 MPH gust measured by trained spotter. Time given in report.
Aug 7, 6:36 PM EDTTSTM WND DMGSpring Twp, PATree Down into house. Time estimated from 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
Aug 7, 3:13 PM EDTTornado WatchSPC8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.6 hours before the alert went out and 182 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 2023-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 285 joules per kilogram.LCLLFCEL10008507005003002001001 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 2023-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
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.

854 
WUUS51 KPHI 072133
SVRPHI
PAC011-029-072230-
/O.NEW.KPHI.SV.W.0268.230807T2133Z-230807T2230Z/

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

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Berks County in eastern Pennsylvania...
  Chester County in southeastern Pennsylvania...

* Until 630 PM EDT.

* At 533 PM EDT, a severe thunderstorm was located near Sunnyburn, or
  10 miles southeast of Red Lion, moving northeast 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...
  Reading, West Chester, Pottstown, Phoenixville, Coatesville,
  Westtown, Wyomissing, Downingtown, Kennett Square, Birdsboro,
  Oxford, Sinking Spring, Laureldale, Parkesburg, West Grove,
  Wernersville, Honey Brook, Elverson, New Morgan and Glen Roy.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 296 and 324.
 Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM EDT for northern
Delaware...and eastern 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 northern
Delaware...and eastern and southeastern Pennsylvania.

&&

LAT...LON 3976 7606 3987 7599 3995 7600 4004 7593
      4011 7594 4014 7588 4031 7613 4045 7583
      4029 7566 4024 7569 4024 7560 4015 7553
      4005 7539 3998 7544 3988 7559 3984 7559
      3981 7570 3972 7577 3972 7613
TIME...MOT...LOC 2133Z 240DEG 49KT 3982 7643 

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
247 
WWUS51 KPHI 072159
SVSPHI

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

PAC011-029-072230-
/O.CON.KPHI.SV.W.0268.000000T0000Z-230807T2230Z/
Berks PA-Chester PA-
559 PM EDT Mon Aug 7 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM EDT
FOR SOUTHEASTERN BERKS AND CHESTER COUNTIES...

At 558 PM EDT, severe thunderstorms were located along a line
extending from near East Petersburg to near Blake, moving northeast
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...
Reading, West Chester, Pottstown, Phoenixville, Coatesville,
Westtown, Wyomissing, Downingtown, Kennett Square, Birdsboro, Oxford,
Sinking Spring, Laureldale, Parkesburg, West Grove, Wernersville,
Honey Brook, Elverson, New Morgan and Glen Roy.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 296 and 324.
 Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1100 PM EDT for northern
Delaware...and eastern and southeastern Pennsylvania.

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

&&

LAT...LON 3976 7606 3987 7599 3995 7600 4004 7593
      4011 7594 4014 7588 4031 7613 4045 7583
      4029 7566 4024 7569 4024 7560 4015 7553
      4005 7539 3998 7544 3988 7559 3984 7559
      3981 7570 3972 7577 3972 7613
TIME...MOT...LOC 2158Z 239DEG 47KT 4013 7633 3975 7590 

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.

IssuedProductOfficeCountiesLasted
Aug 7, 5:37 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIDelaware53 min
Aug 7, 5:57 PM EDTAreal Flood AdvisoryPHIChester, Delaware79 min
Aug 7, 6:08 PM EDTTornado WarningPHIChester19 min
Aug 7, 6:21 PM EDTSevere Thunderstorm Warning Considerable damage threatPHIBerks, Bucks, Chester, Delaware, Montgomery, Philadelphia69 min
Aug 7, 6:29 PM EDTAreal Flood AdvisoryPHIChester, Delaware, Montgomery, Philadelphia63 min
Aug 7, 6:35 PM EDTTornado WarningPHIChester, Delaware, Montgomery, Philadelphia25 min
Aug 7, 6:45 PM EDTSevere Thunderstorm WarningPHICarbon, Monroe45 min
Aug 7, 6:53 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Carbon, Lehigh, Monroe, Montgomery and 1 more52 min
Aug 7, 7:00 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh, Montgomery, Northampton66 min
Aug 7, 7:20 PM EDTSevere Thunderstorm WarningPHIBucks58 min
Aug 7, 7:27 PM EDTSevere Thunderstorm WarningPHICarbon, Lehigh, Monroe, Northampton48 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2023Every 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.