Alert archive / Pennsylvania / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 134, NWS Philadelphia/Mount Holly

July 6, 2021Bucks County, Lehigh County, Northampton County, Pennsylvania; Hunterdon County, Warren County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 6, 2021, 8:29 PM EDT for Bucks County, Lehigh County, Northampton County, Pennsylvania; Hunterdon County, Warren County, New Jersey. It was in force for 46 min. 2 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 6, 2021, 8:29 PM EDT (00:29 UTC)
Expired: Jul 6, 2021, 9:15 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 Hunterdon County, NJ, Warren County, NJ, Bucks County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 101 km from the middle of the area, began a volume at 00:29 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 6, 8:56 PM EDT	TSTM WND DMG	2 N Erwinna, PA	MULTIPLE LARGE TREES DOWN ON UHLERSTOWN HILL ROAD, NEAR TINICUM TOWNSHIP IN BUCKS COUNTY.
Jul 6, 8:56 PM EDT	TSTM WND DMG	Upper Black Eddy, PA	A LARGE TREE FELL AND OTHER BRANCHES AND LIMBS ARE DOWN IN THE AREA FROM WHAT APPEARS TO HAVE BEEN A DOWNBURST. 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 6, 1:32 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 0.5 hours before the alert went out and 211 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: 1647 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 876 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 85 m²/s²
0-3 km storm-relative helicity: 93 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

As transmitted.

245 
WUUS51 KPHI 070029
SVRPHI
NJC019-041-PAC017-077-095-070115-
/O.NEW.KPHI.SV.W.0134.210707T0029Z-210707T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
829 PM EDT Tue Jul 6 2021

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Hunterdon County in northwestern New Jersey...
  Southwestern Warren County in northwestern New Jersey...
  Southeastern Lehigh County in eastern Pennsylvania...
  Northwestern Bucks County in southeastern Pennsylvania...
  Southwestern Northampton County in eastern Pennsylvania...

* Until 915 PM EDT.

* At 829 PM EDT, a severe thunderstorm was located over Allentown,
  moving southeast at 35 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...
  Allentown, Easton, Bethlehem, Emmaus, Northampton, Quakertown,
  Perkasie, Doylestown, Byram, Bedminster, Hellertown, Chalfont,
  Tinicum, Dublin, Ferndale, Frenchtown, Milford, Riegelsville,
  Pleasant Valley and Revere.

This includes the following highways...
 Northeast Extension between mile markers 45 and 54.
 Interstate 78 in Pennsylvania between mile markers 56 and 73.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4054 7556 4069 7547 4057 7488 4026 7518
TIME...MOT...LOC 0029Z 297DEG 31KT 4059 7543 

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

Staarmann

2 follow-up statements

800 
WWUS51 KPHI 070045
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
845 PM EDT Tue Jul 6 2021

PAC077-070054-
/O.CAN.KPHI.SV.W.0134.000000T0000Z-210707T0115Z/
Lehigh PA-
845 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LEHIGH 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 1000 PM EDT for
northwestern New Jersey...and eastern and southeastern Pennsylvania.

LAT...LON 4026 7518 4035 7529 4054 7534 4055 7534
      4056 7535 4066 7530 4057 7488
TIME...MOT...LOC 0044Z 294DEG 31KT 4055 7523 

$$

NJC019-041-PAC017-095-070115-
/O.CON.KPHI.SV.W.0134.000000T0000Z-210707T0115Z/
Hunterdon NJ-Warren NJ-Bucks PA-Northampton PA-
845 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM EDT
FOR SOUTHWESTERN HUNTERDON...SOUTHWESTERN WARREN...NORTHWESTERN BUCKS
AND SOUTH CENTRAL NORTHAMPTON COUNTIES...

At 844 PM EDT, a severe thunderstorm was located over Ferndale, or 9 
miles south of Easton, moving southeast at 35 mph. This storm has a 
history of producing 60 mph wind gusts.

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

SOURCE...Trained weather spotters.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Easton, Bethlehem, Perkasie, Doylestown, Byram, Bedminster,
Hellertown, Chalfont, Tinicum, Dublin, Ferndale, Frenchtown, Milford,
Riegelsville, Pleasant Valley, Revere, Ottsville, Pipersville,
Springtown and Erwinna.

This includes Interstate 78 in Pennsylvania between mile markers 68
and 73.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

&&

LAT...LON 4026 7518 4035 7529 4054 7534 4055 7534
      4056 7535 4066 7530 4057 7488
TIME...MOT...LOC 0044Z 294DEG 31KT 4055 7523 

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

Staarmann

160 
WWUS51 KPHI 070059
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
859 PM EDT Tue Jul 6 2021

NJC041-PAC095-070109-
/O.CAN.KPHI.SV.W.0134.000000T0000Z-210707T0115Z/
Warren NJ-Northampton PA-
859 PM EDT Tue Jul 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WARREN AND SOUTH
CENTRAL NORTHAMPTON COUNTIES 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 1000 PM EDT for
northwestern New Jersey...and southeastern Pennsylvania.

LAT...LON 4043 7501 4053 7523 4060 7518 4063 7515
      4057 7488
TIME...MOT...LOC 0059Z 294DEG 31KT 4052 7504 

$$

NJC019-PAC017-070115-
/O.CON.KPHI.SV.W.0134.000000T0000Z-210707T0115Z/
Hunterdon NJ-Bucks PA-
859 PM EDT Tue Jul 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM EDT
FOR SOUTHWESTERN HUNTERDON AND NORTH CENTRAL BUCKS COUNTIES...

At 859 PM EDT, a severe thunderstorm was located over Frenchtown, or
14 miles southeast of Easton, moving southeast at 35 mph.

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

SOURCE...Trained weather spotters.

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...
Ferndale, Frenchtown, Milford, Erwinna and Revere. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should seek shelter inside a well-built structure and away from
windows.

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

&&

LAT...LON 4043 7501 4053 7523 4060 7518 4063 7515
      4057 7488
TIME...MOT...LOC 0059Z 294DEG 31KT 4052 7504 

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
Jul 6, 8:16 PM EDT	Special Weather Statement	PHI	Lehigh	29 min
Jul 6, 8:50 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	40 min
Jul 6, 9:04 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	41 min
Jul 6, 9:10 PM EDT	Areal Flood Advisory	PHI	Bucks	2 hr
Jul 6, 9:29 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	61 min
Jul 6, 9:48 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	57 min
Jul 6, 10:08 PM EDT	Special Weather Statement	PHI	Philadelphia	37 min
Jul 6, 10:21 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery, Philadelphia	39 min
Jul 7, 3:32 PM EDT	Flash Flood Watch	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	42 hr
Jul 6, 8:03 PM EDT	Special Weather Statement	PHI	Burlington, Ocean	42 min
Jul 6, 8:11 PM EDT	Special Marine Warning	PHI		82 min
Jul 6, 8:24 PM EDT	Special Marine Warning	PHI		2 hr
Jul 6, 8:37 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Middlesex, Monmouth, Morris, Somerset	53 min
Jul 6, 9:37 PM EDT	Special Marine Warning	PHI		113 min
Jul 6, 10:50 PM EDT	Areal Flood Advisory	PHI	Monmouth, Ocean	2 hr
Jul 6, 10:54 PM EDT	Special Weather Statement	PHI	Burlington	51 min
Jul 6, 11:11 PM EDT	Special Weather Statement	PHI	Burlington	19 min
Jul 6, 11:30 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Camden, Ocean	45 min
Jul 6, 11:39 PM EDT	Special Marine Warning	PHI		66 min
Jul 6, 11:55 PM EDT	Special Weather Statement	PHI	Monmouth	50 min
Jul 7, 12:01 AM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth	71 min
Jul 7, 12:10 AM EDT	Special Marine Warning	PHI		95 min
Jul 7, 11:19 AM EDT	Tropical Storm Watch	PHI	Atlantic, Burlington, Cape May, Monmouth, Ocean	18 hr

Nearby

Severe Thunderstorm Warnings in Pennsylvania, 2021 Severe Thunderstorm Warnings in New Jersey, 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; radar from the NEXRAD Level II archive.