Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 80, NWS Philadelphia/Mount Holly

June 14, 20215 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 14, 2021, 7:55 PM EDT for 5 counties in Pennsylvania. It was in force for 50 min. 14 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: Jun 14, 2021, 7:55 PM EDT (23:55 UTC)
Expired: Jun 14, 2021, 8:45 PM EDT
In force: 50 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

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

What was reported inside it

Time	Report	Where	Remark
Jun 14, 7:55 PM EDT	TSTM WND DMG	East Caln Twp, PA	DOWNED TREE ON OLD KINGS HIGHWAY. TIME ESTIMATED FROM RADAR.
Jun 14, 8:00 PM EDT	TSTM WND DMG	1 N Marshallton, PA	DOWNED TREE ON SUGARSBRIDGE ROAD NEAR ALTON PA. TIME ESTIMATED FROM RADAR.
Jun 14, 8:12 PM EDT	TSTM WND DMG	1 Nw Malvern, PA	TREES AND WIRES DOWN NEAR ROUTE 202 IN MALVERN, TIME ESTIMATED FROM RADAR.
Jun 14, 8:16 PM EDT	TSTM WND DMG	Bridgeport, PA	DOWNED TREE LIMBS NEAR DEPOT STREET. TIME ESTIMATED FROM RADAR.
Jun 14, 8:25 PM EDT	TSTM WND DMG	1 Nw Wyndmoor, PA	TREES AND WIRES DOWN ON MONTGOMERY AVE, TIME ESTIMATED FROM RADAR.
Jun 14, 8:25 PM EDT	TSTM WND DMG	1 Sse Newtown Square, PA	TREES DOWN CAUSING A POWER OUTAGE. TIME ESTIMATED FROM RADAR.
Jun 14, 8:30 PM EDT	HAIL 0.25	Newtown Square, PA
Jun 14, 8:37 PM EDT	HAIL 0.75	Lawrence Park, PA	REPORT FROM MPING: DIME (0.75 IN.).
Jun 14, 8:38 PM EDT	HAIL 0.75	1 Nw Broomall, PA	REPORT FROM MPING: DIME (0.75 IN.).
Jun 14, 8:39 PM EDT	TSTM WND DMG	Penn Wynne, PA	DOWNED TREE LIMBS BLOCKING HAVERFORD ROAD NEAR REMINGTON ROAD. TIME ESTIMATED FROM RADAR.
Jun 14, 8:46 PM EDT	HAIL 0.7	2 Wsw Penn Wynne, PA
Jun 14, 8:50 PM EDT	HAIL 0.5	1 Nw Belmont, PA	REPORT FROM MPING: HALF-INCH (0.50 IN.).
Jun 14, 8:54 PM EDT	HAIL 0.25	Glen Mills, PA
Jun 14, 8:55 PM EDT	TSTM WND DMG	2 Ne Lower Moreland Twp, PA	DOWNED TREE ON BYBERRY ROAD. 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
Jun 14, 2:06 PM EDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.9 hours before the alert went out and 213 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: 2 J/kg
Mixed-layer CIN: -447 J/kg
Mixed-layer LCL: 1007 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 87 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

651 
WUUS51 KPHI 142355 RRA
SVRPHI
PAC017-029-045-091-101-150045-
/O.NEW.KPHI.SV.W.0080.210614T2355Z-210615T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
755 PM EDT Mon Jun 14 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Montgomery County in southeastern Pennsylvania...
  South central Bucks County in southeastern Pennsylvania...
  Central Chester County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Central Delaware County in southeastern Pennsylvania...

* Until 845 PM EDT.

* At 754 PM EDT, a severe thunderstorm was located over Downingtown, 
  or near West Chester, moving east at 20 mph. Other storms were 
  developing northeast into lower Montgomery County and may also 
  become severe.

  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...
  Philadelphia, West Chester, Norristown, Phoenixville, West
  Norriton, East Norriton, Coatesville, Yeadon, Westtown,
  Downingtown, Conshohocken, Hatboro, Ambler, Jenkintown, Narberth,
  Parkesburg, East Lansdowne, Rockledge, Abington and Bryn Athyn.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 309 and 350.
 Northeast Extension between mile markers 21 and 26.
 Interstate 95 in Pennsylvania between mile markers 22 and 33.
 Interstate 76 in Pennsylvania between mile markers 327 and 345.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 476 in Pennsylvania between mile markers 5 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4005 7590 4027 7501 4004 7498 4002 7504
      3998 7507 3996 7513 3995 7514 3987 7594
TIME...MOT...LOC 2354Z 276DEG 18KT 4001 7565 

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

CMS

3 follow-up statements

226 
WWUS51 KPHI 150000
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
800 PM EDT Mon Jun 14 2021

PAC017-029-045-091-101-150045-
/O.CON.KPHI.SV.W.0080.000000T0000Z-210615T0045Z/
Montgomery PA-Bucks PA-Chester PA-Philadelphia PA-Delaware PA-
800 PM EDT Mon Jun 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR SOUTHEASTERN MONTGOMERY...SOUTH CENTRAL BUCKS...CENTRAL
CHESTER...PHILADELPHIA AND CENTRAL DELAWARE COUNTIES...

At 759 PM EDT, a severe thunderstorm was located near West Chester,
moving east at 20 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Philadelphia, West Chester, Norristown, Phoenixville, West Norriton,
East Norriton, Coatesville, Yeadon, Westtown, Downingtown,
Conshohocken, Hatboro, Ambler, Jenkintown, Narberth, Parkesburg, East
Lansdowne, Rockledge, Abington and Bryn Athyn.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 309 and 350.
 Northeast Extension between mile markers 21 and 26.
 Interstate 95 in Pennsylvania between mile markers 22 and 33.
 Interstate 76 in Pennsylvania between mile markers 327 and 345.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 476 in Pennsylvania between mile markers 5 and 19.

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 4005 7590 4027 7501 4004 7498 4002 7504
      3998 7507 3996 7513 3995 7514 3987 7594
TIME...MOT...LOC 2359Z 276DEG 18KT 4001 7561 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

CMS

668 
WWUS51 KPHI 150016
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
816 PM EDT Mon Jun 14 2021

PAC017-029-045-091-101-150045-
/O.CON.KPHI.SV.W.0080.000000T0000Z-210615T0045Z/
Montgomery PA-Bucks PA-Chester PA-Philadelphia PA-Delaware PA-
816 PM EDT Mon Jun 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR SOUTHEASTERN MONTGOMERY...SOUTH CENTRAL BUCKS...EAST CENTRAL
CHESTER...PHILADELPHIA AND CENTRAL DELAWARE COUNTIES...

At 815 PM EDT, a severe thunderstorm was located near Gradyville, or
near West Chester, moving east at 20 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Philadelphia, West Chester, Norristown, West Norriton, East Norriton,
Yeadon, Westtown, Conshohocken, Hatboro, Ambler, Jenkintown,
Narberth, East Lansdowne, Rockledge, Abington, Bryn Athyn, Ivyland,
Wissinoming, Cheyney and Morris Park.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 320 and 350.
 Northeast Extension between mile markers 21 and 23.
 Interstate 95 in Pennsylvania between mile markers 22 and 33.
 Interstate 76 in Pennsylvania between mile markers 327 and 345.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 476 in Pennsylvania between mile markers 5 and 19.

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 3990 7561 4006 7559 4027 7501 4004 7498
      4002 7504 3998 7507 3996 7513 3995 7514
TIME...MOT...LOC 0015Z 278DEG 19KT 3998 7549 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann

724 
WWUS51 KPHI 150033
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
833 PM EDT Mon Jun 14 2021

PAC029-150042-
/O.CAN.KPHI.SV.W.0080.000000T0000Z-210615T0045Z/
Chester PA-
833 PM EDT Mon Jun 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CHESTER COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 900 PM EDT for
southern New Jersey...and southeastern Pennsylvania.

LAT...LON 3998 7544 3999 7544 4012 7532 4024 7501
      4009 7498 4004 7499 4002 7504 3998 7507
      3997 7511 3995 7515 3992 7546 3997 7546
TIME...MOT...LOC 0032Z 276DEG 18KT 3997 7537 

$$

PAC017-045-091-101-150045-
/O.CON.KPHI.SV.W.0080.000000T0000Z-210615T0045Z/
Montgomery PA-Bucks PA-Philadelphia PA-Delaware PA-
833 PM EDT Mon Jun 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR SOUTHEASTERN MONTGOMERY...SOUTH CENTRAL BUCKS...PHILADELPHIA AND
NORTHEASTERN DELAWARE COUNTIES...

At 832 PM EDT, a severe thunderstorm was located over Broomall, or 12
miles east of West Chester, moving east at 20 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Philadelphia, Norristown, Yeadon, Conshohocken, Hatboro, Ambler,
Jenkintown, Narberth, East Lansdowne, Rockledge, Abington, Bryn
Athyn, Ivyland, Wissinoming, Morris Park, Bryn Mawr, Trout Lake,
Tacony, Radnor Township and Broomall.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 331 and 350.
 Northeast Extension near mile marker 21.
 Interstate 95 in Pennsylvania between mile markers 22 and 32.
 Interstate 76 in Pennsylvania between mile markers 330 and 344.
 Interstate 676 in Pennsylvania between mile markers 0 and 1.
 Interstate 476 in Pennsylvania between mile markers 5 and 19.

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.

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

&&

LAT...LON 3998 7544 3999 7544 4012 7532 4024 7501
      4009 7498 4004 7499 4002 7504 3998 7507
      3997 7511 3995 7515 3992 7546 3997 7546
TIME...MOT...LOC 0032Z 276DEG 18KT 3997 7537 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

Staarmann

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 14, 4:15 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Carbon, Lehigh, Monroe, Northampton	60 min
Jun 14, 5:29 PM EDT	Special Weather Statement	PHI	Monroe	31 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Every 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.