Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 154, NWS Philadelphia/Mount Holly

July 8, 2021Hunterdon County, New Jersey; Bucks County, Montgomery County, Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 8, 2021, 6:06 PM EDT for Hunterdon County, New Jersey; Bucks County, Montgomery County, Pennsylvania. It was in force for 39 min. 4 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 8, 2021, 6:06 PM EDT (22:06 UTC)
Expired
Jul 8, 2021, 6:45 PM EDT
In force
39 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Hunterdon County, NJ, Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 67 km from the middle of the area, began a volume at 22:09 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
Jul 8, 6:07 PM EDTTSTM WND DMG1 E North Wales, PADOWNED TREE BLOCKING E PROSPECT AVE AT 10TH ST. TIME ESTIMATED FROM RADAR.
Jul 8, 6:10 PM EDTTSTM WND DMGDoylestown, PALARGE TREE BRANCHES AND WIRES DOWN IN DOYLESTOWN.
Jul 8, 6:10 PM EDTTSTM WND DMGDoylestown, PATREE BRANCHES AND WIRES DOWN IN DOYLESTOWN.
Jul 8, 6:12 PM EDTTSTM WND DMG1 Se New Britain, PAVIDEO OF MULTIPLE LARGE TREES DOWN ON POWERLINES ALONG ALMSHOUSE ROAD IN DOYLESTOWN PA. 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
Jul 8, 2:09 PM EDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 10.1 hours before the alert went out and 191 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 2021-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 973 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 2021-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
973 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
751 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
93 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted.

356 
WUUS51 KPHI 082206
SVRPHI
NJC019-PAC017-091-082245-
/O.NEW.KPHI.SV.W.0154.210708T2206Z-210708T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
606 PM EDT Thu Jul 8 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southern Hunterdon County in northwestern New Jersey...
  East central Montgomery County in southeastern Pennsylvania...
  Central Bucks County in southeastern Pennsylvania...

* Until 645 PM EDT.

* At 606 PM EDT, a severe thunderstorm was located near Ambler, or 15
  miles north of Philadelphia, moving northeast at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Lansdale, Doylestown, Byram, Hatboro, Bedminster, Ambler,
  Jenkintown, Chalfont, Tinicum, Hatfield, New Hope, Dublin,
  Abington, Ferndale, Bryn Athyn, Frenchtown, Milford, Ivyland,
  Riegelsville and Stockton.

This includes the following highways...
 Pennsylvania Turnpike between mile markers 338 and 346.
 Northeast Extension between mile markers 24 and 27.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4034 7491 4034 7494 4032 7492 4009 7511
      4018 7534 4059 7520 4048 7479
TIME...MOT...LOC 2206Z 202DEG 34KT 4022 7520 

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

JEO
2 follow-up statements
575 
WWUS51 KPHI 082219
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
619 PM EDT Thu Jul 8 2021

PAC091-082228-
/O.CAN.KPHI.SV.W.0154.000000T0000Z-210708T2245Z/
Montgomery PA-
619 PM EDT Thu Jul 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MONTGOMERY 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
central and northwestern New Jersey...and southeastern Pennsylvania.

LAT...LON 4034 7491 4034 7494 4032 7492 4018 7506
      4031 7530 4059 7520 4048 7479
TIME...MOT...LOC 2218Z 202DEG 34KT 4033 7514 

$$

NJC019-PAC017-082245-
/O.CON.KPHI.SV.W.0154.000000T0000Z-210708T2245Z/
Hunterdon NJ-Bucks PA-
619 PM EDT Thu Jul 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM EDT
FOR SOUTHERN HUNTERDON AND CENTRAL BUCKS COUNTIES...

At 618 PM EDT, a severe thunderstorm was located over Doylestown, or
21 miles west of Trenton, moving north at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Law enforcement. There have been numerous reports of downed 
         trees and wires with these storms.

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

Locations impacted include...
Perkasie, Doylestown, Byram, Bedminster, Chalfont, Tinicum, New Hope,
Dublin, Ferndale, Frenchtown, Milford, Ivyland, Riegelsville,
Stockton, Fricks, Revere, Lumberville, Ottsville, Sergeantsville and
Pipersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4034 7491 4034 7494 4032 7492 4018 7506
      4031 7530 4059 7520 4048 7479
TIME...MOT...LOC 2218Z 202DEG 34KT 4033 7514 

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

JEO
715 
WWUS51 KPHI 082240
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
640 PM EDT Thu Jul 8 2021

NJC019-PAC017-082250-
/O.EXP.KPHI.SV.W.0154.000000T0000Z-210708T2245Z/
Hunterdon NJ-Bucks PA-
640 PM EDT Thu Jul 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN HUNTERDON AND CENTRAL
BUCKS COUNTIES WILL EXPIRE AT 645 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty 
winds are still possible with this thunderstorm.

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

LAT...LON 4034 7491 4034 7494 4032 7492 4018 7506
      4031 7530 4059 7520 4048 7479
TIME...MOT...LOC 2240Z 202DEG 34KT 4034 7514 

$$

JEO

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 11:06 PM EDTTropical Storm WarningPHIAtlantic, Burlington, Cape May, Monmouth, Ocean32 hr
Jul 7, 11:37 PM EDTSpecial Weather StatementPHISussex38 min
Jul 8, 5:27 AM EDTSmall Craft AdvisoryPHI34 hr
Jul 8, 1:49 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset41 min
Jul 8, 2:09 PM EDTSpecial Marine WarningPHI81 min
Jul 8, 2:26 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean21 min
Jul 8, 2:29 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Warren46 min
Jul 8, 2:43 PM EDTRip Current StatementPHIAtlantic, Cape May, Monmouth, Ocean27 hr
Jul 8, 3:03 PM EDTSevere Thunderstorm WarningPHIHunterdon, Middlesex, Morris, Somerset42 min
Jul 8, 4:02 PM EDTSpecial Marine WarningPHI33 min
Jul 8, 4:02 PM EDTSevere Thunderstorm WarningPHIMonmouth31 min
Jul 8, 4:43 PM EDTSevere Thunderstorm WarningPHIMiddlesex, Somerset16 min
Jul 8, 5:29 PM EDTSpecial Weather StatementPHIMorris, Warren46 min
Jul 8, 5:34 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Sussex, Warren41 min
Jul 8, 6:09 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Sussex51 min
Jul 8, 6:16 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Sussex, Warren44 min
Jul 7, 11:11 PM EDTSpecial Weather StatementPHIMonroe49 min
Jul 8, 8:53 AM EDTSpecial Weather StatementPHIMonroe52 min
Jul 8, 9:31 AM EDTAreal Flood AdvisoryPHICarbon, Monroe119 min
Jul 8, 9:46 AM EDTSpecial Weather StatementPHIMonroe44 min
Jul 8, 3:50 PM EDTSpecial Weather StatementPHIBerks25 min
Jul 8, 4:06 PM EDTSevere Thunderstorm WarningPHIBerks, Montgomery39 min
Jul 8, 4:25 PM EDTSevere Thunderstorm WarningPHIBerks50 min
Jul 8, 4:45 PM EDTSevere Thunderstorm WarningPHIBerks, Bucks, Lehigh, Montgomery, Northampton45 min
Jul 8, 4:51 PM EDTSevere Thunderstorm WarningPHIBerks54 min
Jul 8, 5:11 PM EDTSpecial Weather StatementPHILehigh34 min
Jul 8, 5:21 PM EDTSevere Thunderstorm WarningPHIChester, Delaware, Montgomery, Philadelphia39 min
Jul 8, 5:52 PM EDTSpecial Weather StatementPHIBerks23 min

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021Severe Thunderstorm Warnings in New Jersey, 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.