Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 53, NWS Philadelphia/Mount Holly

June 4, 2021Bucks County, Montgomery County, Philadelphia County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 4, 2021, 3:14 PM EDT for Bucks County, Montgomery County, Philadelphia County, Pennsylvania. It was in force for 46 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
Jun 4, 2021, 3:14 PM EDT (19:14 UTC)
Expired
Jun 4, 2021, 4:00 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Bucks County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 68 km from the middle of the area, began a volume at 19:17 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
Jun 4, 3:19 PM EDTTSTM WND DMGNorristown, PAA COUPLE OF DOWNED TREE AND WIRE REPORTS IN NORRISTOWN. TIME ESTIMATED FROM RADAR.
Jun 4, 3:26 PM EDTTSTM WND DMG1 Sw Ambler, PADOWNED TREE NEAR THE INTERSECTION OF MORRIS ROAD AND BEECH ROAD. TIME ESTIMATED FROM RADAR.
Jun 4, 3:29 PM EDTTSTM WND DMG1 W Flourtown, PADOWNED TREE LIMB BLOCKING VALLEY VIEW ROAD NEAR PARKSIDE ROAD. TIME ESTIMATED FROM RADAR.
Jun 4, 3:30 PM EDTTSTM WND DMGWhitemarsh Twp, PAA COUPLE OF TREES DOWN IN WHITEMARSH TWP. TIME ESTIMATED FROM RADAR.
Jun 4, 3:31 PM EDTTSTM WND DMGFlourtown, PADOWNED TREE LIMBS AND WIRES NEAR HARSTON LANE. TIME ESTIMATED FROM RADAR.
Jun 4, 3:32 PM EDTTSTM WND DMGUpper Dublin Twp, PAA COUPLE OF CALLS FOR DOWNED TREES AND/OR WIRES IN UPPER DUBLIN TWP. TIME ESTIMATED FROM RADAR.
Jun 4, 3:56 PM EDTTSTM WND DMGAndalusia, PASOCIAL MEDIA REPORT OF DOWNED TREE LIMBS FROM STRONG WINDS AND PEA-SIZED HAIL. TIME ESTIMATED FROM RADAR.
Jun 4, 3:58 PM EDTHAIL 0.751 Wnw Eddington, PA

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
Jun 4, 3:09 PM EDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 7.2 hours before the alert went out and 214 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, Brookhaven, NY at 12:00Z on 2021-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 233 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, Brookhaven, NY at 12:00Z on 2021-06-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939587897Sfc1 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
233 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
526 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

503 
WUUS51 KPHI 041914
SVRPHI
PAC017-091-101-042000-
/O.NEW.KPHI.SV.W.0053.210604T1914Z-210604T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
314 PM EDT Fri Jun 4 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...
  Northern Philadelphia County in southeastern Pennsylvania...

* Until 400 PM EDT.

* At 314 PM EDT, a severe thunderstorm was located over Plymouth
  Meeting, or 11 miles northwest of Philadelphia, moving east 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...
  Philadelphia, Bensalem, Norristown, West Norriton, East Norriton,
  Conshohocken, Hatboro, Ambler, Jenkintown, Rockledge, Abington,
  Langhorne, Bryn Athyn, Feasterville-Trevose, Willow Grove,
  Northeast Philadelphia, Feasterville, Andalusia, Holmesburg and
  Plymouth Meeting.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 326 and 353.
 Northeast Extension between mile markers 21 and 26.
 Interstate 95 in Pennsylvania between mile markers 31 and 35.
 Interstate 76 in Pennsylvania between mile markers 327 and 329, and
between mile markers 333 and 334.
 Interstate 476 in Pennsylvania between mile markers 17 and 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4006 7495 4003 7501 4008 7540 4009 7542
      4009 7546 4020 7535 4019 7492
TIME...MOT...LOC 1914Z 280DEG 21KT 4014 7527 

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

JEO
2 follow-up statements
776 
WWUS51 KPHI 041932
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
332 PM EDT Fri Jun 4 2021

PAC017-091-101-042000-
/O.CON.KPHI.SV.W.0053.000000T0000Z-210604T2000Z/
Montgomery PA-Bucks PA-Philadelphia PA-
332 PM EDT Fri Jun 4 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM EDT
FOR SOUTHEASTERN MONTGOMERY...SOUTH CENTRAL BUCKS AND NORTHERN
PHILADELPHIA COUNTIES...

At 332 PM EDT, a severe thunderstorm was located over Abington, or 7
miles north of Philadelphia, moving east 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...
Philadelphia, Bensalem, Conshohocken, Hatboro, Ambler, Jenkintown,
Rockledge, Abington, Langhorne, Bryn Athyn, Feasterville-Trevose,
Willow Grove, Northeast Philadelphia, Feasterville, Andalusia,
Holmesburg, Plymouth Meeting, Chestnut Hill, Horsham and Langhorne
Manor.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 334 and 353.
 Interstate 95 in Pennsylvania between mile markers 31 and 35.
 Interstate 76 in Pennsylvania between mile markers 333 and 334.
 Interstate 476 in Pennsylvania near mile marker 19.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4006 7495 4003 7501 4007 7531 4020 7524
      4019 7492
TIME...MOT...LOC 1932Z 280DEG 21KT 4012 7513 

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

JEO
003 
WWUS51 KPHI 041953 RRA
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
353 PM EDT Fri Jun 4 2021

PAC017-091-101-042003-
/O.EXP.KPHI.SV.W.0053.000000T0000Z-210604T2000Z/
Montgomery PA-Bucks PA-Philadelphia PA-
353 PM EDT Fri Jun 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MONTGOMERY...
SOUTH CENTRAL BUCKS AND NORTHERN PHILADELPHIA COUNTIES WILL EXPIRE AT
400 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

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

LAT...LON 4006 7495 4003 7501 4007 7531 4020 7524
      4019 7492
TIME...MOT...LOC 1953Z 280DEG 21KT 4010 7493 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 3, 8:44 PM EDTSevere Thunderstorm WarningPHIBucks30 min
Jun 4, 1:02 PM EDTSpecial Weather StatementPHILehigh28 min
Jun 4, 1:07 PM EDTSpecial Weather StatementPHICarbon, Monroe38 min
Jun 4, 1:29 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh2 hr
Jun 4, 1:45 PM EDTAreal Flood AdvisoryPHIMonroe, Northampton97 min
Jun 4, 1:49 PM EDTSevere Thunderstorm WarningPHIMonroe, Northampton41 min
Jun 4, 2:21 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery21 min
Jun 4, 2:24 PM EDTSevere Thunderstorm WarningPHIBucks, Montgomery51 min
Jun 4, 2:27 PM EDTSevere Thunderstorm WarningPHIBerks48 min
Jun 4, 3:16 PM EDTAreal Flood AdvisoryPHIBucks, Chester, Delaware, Montgomery, Philadelphia98 min
Jun 4, 3:18 PM EDTSevere Thunderstorm WarningPHIBucks42 min
Jun 4, 3:23 PM EDTSevere Thunderstorm WarningPHIBucks67 min
Jun 4, 3:46 PM EDTSevere Thunderstorm WarningPHIBucks, Philadelphia44 min
Jun 4, 4:20 PM EDTSevere Thunderstorm WarningPHIPhiladelphia40 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 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.