Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 162, NWS Philadelphia/Mount Holly

July 22, 20207 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 22, 2020, 5:09 PM EDT for 7 counties in Pennsylvania. It was in force for 66 min. 10 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 22, 2020, 5:09 PM EDT (21:09 UTC)
Expired: Jul 22, 2020, 6:15 PM EDT
In force: 66 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 70.0 mph

Counties Berks County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lehigh County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 97 km from the middle of the area, began a volume at 21:08 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
Jul 22, 5:11 PM EDT	TSTM WND DMG	1 Wsw Emmaus, PA	DOWNED WIRES NEAR WALNUT STREET IN EMMAUS. TIME ESTIMATED FROM RADAR.
Jul 22, 5:21 PM EDT	TSTM WND DMG	1 Sw East Whiteland Twp, PA	DOWNED UTILITY ON U.S. HIGHWAY 30 NEAR PLANEBROOK ROAD. TIME ESTIMATED FROM RADAR.
Jul 22, 5:22 PM EDT	TSTM WND DMG	1 Ese Trappe, PA	TREE AND/OR WIRES DOWN ON COLLEGE AVE AT 3RD AVE. TIME ESTIMATED FROM RADAR.
Jul 22, 5:25 PM EDT	TSTM WND DMG	1 Ssw Hatfield, PA	DOWNED WIRES NEAR LEON DRIVE IN HATFIELD. TIME ESTIMATED FROM RADAR.
Jul 22, 5:25 PM EDT	TSTM WND DMG	2 Nnw West Rockhill Twp, PA	DOWNED TREES AND WIRES NEAR SCHUKRAFT ROAD IN WEST ROCKHILL TWP. TIME ESTIMATED FROM RADAR.
Jul 22, 5:28 PM EDT	TSTM WND DMG	1 W Perkasie, PA	SEVERAL REPORTS OF WIRES DOWN BETWEEN WHITE HORSE AND PERKASIE. TIME ESTIMATED FROM RADAR.
Jul 22, 5:32 PM EDT	TSTM WND DMG	Chalfont, PA	8 INCH DIAMETER MAPLE BRANCH SNAPPED OFF TREE IN CHALFONT.
Jul 22, 5:34 PM EDT	TSTM WND DMG	3 Nne East Rockhill Twp, PA	DOWNED TREE LIMBS AND WIRES NEAR MOUNTAIN VIEW ROAD NEAR QUAKERTOWN. TIME ESTIMATED FROM RADAR.
Jul 22, 5:37 PM EDT	TSTM WND DMG	Montgomeryville, PA	TREE AND/OR WIRES DOWN ON MCLAUGHLIN RD AT COUNTRY CLUB DR NEAR THE PINECREST GOLF CLUB. TIME ESTIMATED FROM RADAR.
Jul 22, 5:54 PM EDT	TSTM WND DMG	Oreland, PA	TREE AND/OR WIRES DOWN ON W PENNSYLVANIA AVE. 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
Jul 22, 2:57 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.2 hours before the alert went out and 225 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: 15 J/kg
Mixed-layer CIN: -173 J/kg
Mixed-layer LCL: 1410 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 111 m²/s²
0-3 km storm-relative helicity: 183 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

090 
WUUS51 KPHI 222109
SVRPHI
PAC011-017-029-045-077-091-101-222215-
/O.NEW.KPHI.SV.W.0162.200722T2109Z-200722T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
509 PM EDT Wed Jul 22 2020

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  East central Berks County in eastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  Montgomery County in southeastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Northeastern Chester County in southeastern Pennsylvania...
  Northwestern Philadelphia County in southeastern Pennsylvania...
  Northern Delaware County in southeastern Pennsylvania...

* Until 615 PM EDT.

* At 508 PM EDT, severe thunderstorms were located along a line
  extending from Zionsville to near Chester Springs, moving east at
  25 mph.

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

  SOURCE...Law enforcement. These storms have produced wind damage 
           in Lehigh and Berks Counties.

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

* Locations impacted include...
  Philadelphia, Norristown, Pottstown, Phoenixville, Lansdale, West
  Norriton, East Norriton, Emmaus, Quakertown, Perkasie, Doylestown,
  Downingtown, Conshohocken, Souderton, Bedminster, Ambler,
  Collegeville, Royersford, Narberth and Chalfont.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 308 and 339.
 Northeast Extension between mile markers 21 and 53.
 Interstate 76 in Pennsylvania between mile markers 327 and 339.
 Interstate 476 in Pennsylvania between mile markers 12 and 19.

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.

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with these storms. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

&&

LAT...LON 4054 7555 4054 7507 4001 7520 4002 7578
TIME...MOT...LOC 2108Z 257DEG 20KT 4047 7550 4011 7567 

HAIL...0.75IN
WIND...70MPH
 
$$

CMS

3 follow-up statements

364 
WWUS51 KPHI 222129
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
529 PM EDT Wed Jul 22 2020

PAC011-222138-
/O.CAN.KPHI.SV.W.0162.000000T0000Z-200722T2215Z/
Berks PA-
529 PM EDT Wed Jul 22 2020

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL BERKS COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
eastern and southeastern Pennsylvania.

LAT...LON 4054 7546 4054 7507 4001 7520 4002 7569
TIME...MOT...LOC 2128Z 251DEG 26KT 4052 7531 4016 7548 

$$

PAC017-029-045-077-091-101-222215-
/O.CON.KPHI.SV.W.0162.000000T0000Z-200722T2215Z/
Lehigh PA-Montgomery PA-Bucks PA-Chester PA-Philadelphia PA-
Delaware PA-
529 PM EDT Wed Jul 22 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR SOUTHEASTERN LEHIGH...MONTGOMERY...NORTHWESTERN BUCKS...
NORTHEASTERN CHESTER...NORTHWESTERN PHILADELPHIA AND NORTHERN
DELAWARE COUNTIES...

At 528 PM EDT, severe thunderstorms were located along a line
extending from Pleasant Valley to near Collegeville, moving east at
30 mph.

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

SOURCE...Law enforcement.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Norristown, Phoenixville, Lansdale, West Norriton, East
Norriton, Quakertown, Perkasie, Doylestown, Conshohocken, Souderton,
Bedminster, Ambler, Collegeville, Royersford, Narberth, Chalfont,
Tinicum, Trappe and Hatfield.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 312 and 339.
 Northeast Extension between mile markers 21 and 48.
 Interstate 76 in Pennsylvania between mile markers 327 and 339.
 Interstate 476 in Pennsylvania between mile markers 12 and 19.

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.

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4054 7546 4054 7507 4001 7520 4002 7569
TIME...MOT...LOC 2128Z 251DEG 26KT 4052 7531 4016 7548 

HAIL...0.75IN
WIND...60MPH
 
$$

CMS

077 
WWUS51 KPHI 222156
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
556 PM EDT Wed Jul 22 2020

PAC029-077-222205-
/O.CAN.KPHI.SV.W.0162.000000T0000Z-200722T2215Z/
Lehigh PA-Chester PA-
556 PM EDT Wed Jul 22 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LEHIGH AND
NORTHEASTERN CHESTER COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
southeastern Pennsylvania.

LAT...LON 4003 7540 4004 7541 4007 7536 4006 7539
      4009 7541 4054 7523 4054 7507 4001 7520
      4002 7541
TIME...MOT...LOC 2155Z 257DEG 20KT 4055 7512 4019 7529 

$$

PAC017-045-091-101-222215-
/O.CON.KPHI.SV.W.0162.000000T0000Z-200722T2215Z/
Montgomery PA-Bucks PA-Philadelphia PA-Delaware PA-
556 PM EDT Wed Jul 22 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR CENTRAL MONTGOMERY...CENTRAL BUCKS...NORTHWESTERN PHILADELPHIA
AND NORTHERN DELAWARE COUNTIES...

At 555 PM EDT, severe thunderstorms were located along a line
extending from Milford to near Lansdale, moving east at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Law enforcement. Several reports of trees and wires down 
         have been received from Bucks and Montgomery Counties.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Philadelphia, Norristown, Lansdale, West Norriton, East Norriton,
Perkasie, Doylestown, Conshohocken, Souderton, Bedminster, Ambler,
Chalfont, Tinicum, Hatfield, Dublin, Ferndale, Fricks, Revere, Bryn
Mawr and Radnor Township.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 327 and 339.
 Northeast Extension between mile markers 21 and 30.
 Interstate 76 in Pennsylvania between mile markers 327 and 339.
 Interstate 476 in Pennsylvania between mile markers 12 and 19.

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.

Frequent cloud to ground lightning is occurring with these storms.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4003 7540 4004 7541 4007 7536 4006 7539
      4009 7541 4054 7523 4054 7507 4001 7520
      4002 7541
TIME...MOT...LOC 2155Z 257DEG 20KT 4055 7512 4019 7529 

HAIL...<.75IN
WIND...60MPH
 
$$

CMS

238 
WWUS51 KPHI 222205
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
605 PM EDT Wed Jul 22 2020

PAC017-045-091-101-222215-
/O.EXP.KPHI.SV.W.0162.000000T0000Z-200722T2215Z/
Montgomery PA-Bucks PA-Philadelphia PA-Delaware PA-
605 PM EDT Wed Jul 22 2020

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY...CENTRAL
BUCKS...NORTHWESTERN PHILADELPHIA AND NORTHERN DELAWARE COUNTIES WILL
EXPIRE AT 615 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However, gusty 
winds and heavy rain are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 1000 PM EDT for
southeastern Pennsylvania.

LAT...LON 4003 7540 4004 7541 4007 7536 4006 7539
      4009 7541 4054 7523 4054 7507 4001 7520
      4002 7541
TIME...MOT...LOC 2205Z 257DEG 20KT 4056 7507 4020 7524 

$$

CMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 8:45 PM EDT	Special Weather Statement	PHI	Berks	30 min
Jul 21, 9:20 PM EDT	Special Weather Statement	PHI	Montgomery	25 min
Jul 22, 1:36 PM EDT	Special Weather Statement	PHI	Carbon	24 min
Jul 22, 1:58 PM EDT	Special Weather Statement	PHI	Monroe	32 min
Jul 22, 2:10 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	50 min
Jul 22, 3:29 PM EDT	Special Weather Statement	PHI	Lebanon	46 min
Jul 22, 3:39 PM EDT	Severe Thunderstorm Warning	PHI	Berks	51 min
Jul 22, 4:01 PM EDT	Severe Thunderstorm Warning	PHI	Chester	22 min
Jul 22, 4:10 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Northampton	65 min
Jul 22, 4:25 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery	50 min
Jul 22, 4:38 PM EDT	Severe Thunderstorm Warning	PHI	Chester	52 min
Jul 22, 4:49 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Carbon, Lehigh, Monroe, Northampton	56 min
Jul 22, 5:16 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Monroe, Northampton	59 min
Jul 22, 5:23 PM EDT	Areal Flood Advisory	PHI	Northampton	3 hr
Jul 22, 5:33 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	57 min
Jul 22, 5:40 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	65 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.