Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 273, NWS Philadelphia/Mount Holly

August 28, 2020Berks County, Chester County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 28, 2020, 3:36 PM EDT for Berks County, Chester County, Pennsylvania. It was in force for 54 min. 15 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 28, 2020, 3:36 PM EDT (19:36 UTC)
Expired: Aug 28, 2020, 4:30 PM EDT
In force: 54 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Berks County, PA, Chester County, PA

The radar

The Philadelphia radar (KDIX), 125 km from the middle of the area, began a volume at 19:39 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 28, 3:36 PM EDT	TSTM WND DMG	2 Ne Mount Penn, PA	DOWNED TREE NEAR THE INTERSECTION OF WOODLAND AVENUE AND CARSONIA AVENUE IN LOWER ALSACE TWP. TIME ESTIMATED FROM RADAR.
Aug 28, 3:36 PM EDT	TSTM WND DMG	2 Nnw Exeter Twp, PA	DOWNED TREES AND WIRES NEAR DAUTRICH ROAD. TIME ESTIMATED FROM RADAR.
Aug 28, 3:39 PM EDT	TSTM WND DMG	1 Wsw Lorane, PA	DOWNED POWER LINES IN THE VICINITY OF OLD GIBRALTAR ROAD. TIME ESTIMATED FROM RADAR.
Aug 28, 3:48 PM EDT	TSTM WND DMG	1 W Douglassville, PA	DOWNED POWER LINES IN THE VICINITY OF MAIN STREET EAST OF MONOCACY. TIME ESTIMATED FROM RADAR.
Aug 28, 3:55 PM EDT	TSTM WND DMG	3 Ne Warwick Twp, PA	DOWNED POWER LINES REPORTED IN THE HARMONYVILLE AREA. TIME ESTIMATED FROM RADAR.
Aug 28, 4:11 PM EDT	TSTM WND DMG	1 Se West Brandywine Tw, PA	DOWNED TREE BLOCKING MANOR ROAD NEAR RED OAK DRIVE. TIME ESTIMATED FROM RADAR.
Aug 28, 4:11 PM EDT	TSTM WND DMG	1 W Chester Springs, PA	DOWNED TREE LIMBS AND POWER LINES NEAR MESSNER ROAD. TIME ESTIMATED FROM RADAR.
Aug 28, 4:13 PM EDT	TSTM WND DMG	1 Sw East Brandywine Tw, PA	DOWNED TREE ON HADFIELD ROAD. TIME ESTIMATED FROM RADAR.
Aug 28, 4:16 PM EDT	TSTM WND DMG	2 Wnw East Whiteland Tw, PA	DOWNED TREE LIMBS AND WIRES NEAR SHAMROCK HILL LANE. TIME ESTIMATED FROM RADAR.
Aug 28, 4:18 PM EDT	TSTM WND DMG	1 Nw Caln Twp, PA	DOWNED TREE BLOCKING WESTBOUND ROUTE 30 BYPASS NEAR BAILEY ROAD. TIME ESTIMATED FROM RADAR.
Aug 28, 4:21 PM EDT	TSTM WND DMG	2 Ssw East Whiteland Tw, PA	DOWNED TREE BLOCKING KING ROAD NEAR RAVINE ROAD. TIME ESTIMATED FROM RADAR.
Aug 28, 4:21 PM EDT	TSTM WND DMG	2 Sw East Whiteland Twp, PA	DOWNED TREE ON LANCASTER AVENUE NEAR LOCKWOOD LANE. TIME ESTIMATED FROM RADAR.
Aug 28, 4:23 PM EDT	TSTM WND DMG	2 N East Goshen Twp., PA	DOWNED TREE ON FOREST LANE NEAR CHESTER ROAD. TIME ESTIMATED FROM RADAR.
Aug 28, 4:26 PM EDT	TSTM WND DMG	1 Nw East Goshen Twp., PA	DOWNED TREE ON CORNWALLIS DRIVE. TIME ESTIMATED FROM RADAR.
Aug 28, 4:26 PM EDT	TSTM WND DMG	1 Sw West Chester, PA	DOWNED TREE BLOCKING WOLLERTON ALLEY NEAR DARLINGTON STREET. 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.

Issued	Product	Office	Lasted
Aug 28, 1:37 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.6 hours before the alert went out and 190 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: 511 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 1109 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 102 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

409 
WUUS51 KPHI 281936
SVRPHI
PAC011-029-282030-
/O.NEW.KPHI.SV.W.0273.200828T1936Z-200828T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
336 PM EDT Fri Aug 28 2020

The National Weather Service in Mount Holly NJ has issued a

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

* Until 430 PM EDT.

* At 336 PM EDT, a severe thunderstorm was located near Reading,
  moving southeast at 25 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...
  Reading, West Chester, Phoenixville, Coatesville, Wyomissing,
  Downingtown, Birdsboro, Laureldale, Honey Brook, Elverson, New
  Morgan, Pughtown, Marshallton, Lionville-Marchwood, Glenmoore,
  Chester Springs, Lionville, Cedarville, West Goshen and Stowe.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 296 and 322.
 Interstate 176 in Pennsylvania between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 4040 7590 4008 7548 3986 7568 4009 7594
      4012 7593 4014 7588 4026 7607
TIME...MOT...LOC 1936Z 303DEG 23KT 4029 7592 

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

Iovino

1 follow-up statement

832 
WWUS51 KPHI 282004
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
404 PM EDT Fri Aug 28 2020

PAC011-282013-
/O.CAN.KPHI.SV.W.0273.000000T0000Z-200828T2030Z/
Berks PA-
404 PM EDT Fri Aug 28 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BERKS COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
Berks County. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
eastern and southeastern Pennsylvania.

LAT...LON 4012 7593 4014 7587 4021 7575 4024 7569
      4008 7548 3986 7568 4009 7594
TIME...MOT...LOC 2003Z 303DEG 23KT 4019 7573 

$$

PAC029-282030-
/O.CON.KPHI.SV.W.0273.000000T0000Z-200828T2030Z/
Chester PA-
404 PM EDT Fri Aug 28 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR NORTHEASTERN CHESTER COUNTY...

At 403 PM EDT, a severe thunderstorm was located near Pughtown, or 14
miles southeast of Reading, moving southeast at 25 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...
West Chester, Phoenixville, Coatesville, Downingtown, Honey Brook,
Elverson, Glenmoore, Chester Springs, Pughtown, Lionville,
Marshallton, Lionville-Marchwood, Cedarville, West Goshen, Stowe,
Malvern, South Coatesville, Modena, Exton and Thorndale.

This includes Pennsylvania Turnpike between mile markers 301 and 322.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Protecting yourself from immediate threats to life and safety shall
take priority.  Whenever possible, as long as it does not cause
greater harm, all COVID-19 protective action guidance should be
followed.

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

&&

LAT...LON 4012 7593 4014 7587 4021 7575 4024 7569
      4008 7548 3986 7568 4009 7594
TIME...MOT...LOC 2003Z 303DEG 23KT 4019 7573 

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

Iovino

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 27, 8:13 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Lehigh, Northampton	47 min
Aug 27, 8:26 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	26 min
Aug 27, 8:29 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	46 min
Aug 28, 3:22 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	53 min
Aug 28, 3:33 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	101 min
Aug 28, 3:52 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	53 min
Aug 28, 3:56 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	49 min
Aug 28, 4:01 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware	44 min
Aug 28, 4:39 PM EDT	Severe Thunderstorm Warning	PHI	Delaware, Montgomery, Philadelphia	66 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2020 Every severe thunderstorm warning in 2020

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.