Alert archive / New Jersey / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 110, NWS Philadelphia/Mount Holly

July 20, 20174 counties in New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 20, 2017, 7:00 PM EDT for 4 counties in New Jersey; 4 counties in Pennsylvania. It was in force for 60 min. 6 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 20, 2017, 7:00 PM EDT (23:00 UTC)
Expired: Jul 20, 2017, 8:00 PM EDT
In force: 60 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Hunterdon County, NJ, Mercer County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA, Carbon County, PA, Lehigh County, PA, Northampton County, PA

The radar

The Philadelphia radar (KDIX), 120 km from the middle of the area, began a volume at 22:59 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 20, 7:07 PM EDT	TSTM WND DMG	Easton, PA	SEVERAL REPORTS OF TREES AND WIRES DOWN IN EASTON. TIME APPROXIMATED FROM RADAR.
Jul 20, 7:10 PM EDT	TSTM WND DMG	Bethlehem, PA	SEVERAL TREES AND WIRES REPORTED DOWN IN BETHLEHEM AND HELLERTOWN. TIME APPROXIMATED FROM RADAR.
Jul 20, 7:10 PM EDT	TSTM WND DMG	Phillipsburg, NJ	LARGE TREE LIMBS BLOCKING ROAD. TIME ESTIMATED FROM RADAR.
Jul 20, 7:40 PM EDT	TSTM WND DMG	3 S Ringoes, NJ	MULTIPLE REPORTS OF TREES AND POWERLINES DOWN.
Jul 20, 7:40 PM EDT	TSTM WND DMG	Stockton, NJ	REPORTS OF TREES DOWN. TIME ESTIMATED FROM RADAR.
Jul 20, 8:07 PM EDT	TSTM WND DMG	1 S Marshalls Corner, NJ	TREE DOWN ON STATE HIGHWAY 31 SOUTHBOUND BETWEEN TITUS MILL ROAD AND WOODVILLE ROAD...FORCING A ROAD CLOSURE AND DETOURS. 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 20, 5:03 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 11.0 hours before the alert went out and 221 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: 14 J/kg
Mixed-layer CIN: -148 J/kg
Mixed-layer LCL: 1647 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

250 
WUUS51 KPHI 202300
SVRPHI
NJC019-021-035-041-PAC017-025-077-095-210000-
/O.NEW.KPHI.SV.W.0110.170720T2300Z-170721T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
700 PM EDT THU JUL 20 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Hunterdon County in northwestern New Jersey...
  Southwestern Warren County in northwestern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Southwestern Somerset County in northern New Jersey...
  Lehigh County in eastern Pennsylvania...
  Southwestern Carbon County in northeastern Pennsylvania...
  Bucks County in southeastern Pennsylvania...
  Northampton County in eastern Pennsylvania...

* Until 800 PM EDT

* At 700 PM EDT, severe thunderstorms were located along a line
  extending from near Belfast to Bethlehem to New Mahoning, moving
  southeast at 35 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to trees and power lines. 

* Severe thunderstorms will be near,
  Bethlehem, Hellertown, Nazareth, Bangor, Pen Argyl, Wind Gap, 
  Belfast, Tatamy, East Bangor and Steuben around 705 PM EDT. 
  Easton, Forks, Wilson, Harmony, West Easton and Roxburg around 710 
  PM EDT. 
  Riegelsville, Glendon, Pleasant Valley, Springtown and Emerald 
  around 715 PM EDT. 
  Alpha, Ferndale and Pleasant Valley around 720 PM EDT. 
  Glen Gardner, Hampton, Bloomsbury, Claussville, Revere, 
  Schnecksville and Neffs around 725 PM EDT. 
  Bedminster, Milford, Ottsville, Coffeetown and Erwinna around 730 
  PM EDT. 
  Allentown, Tinicum, Clinton, Dublin, Frenchtown, Pipersville and 
  Annandale around 735 PM EDT. 
  Emmaus, Byram, Ancient Oaks, Gardenville and Lumberville around 
  740 PM EDT. 

Other locations impacted by these severe thunderstorms include
Churchville, Hulmeville, Hokendauqua, Stockertown, Eastlawn Gardens,
North Catasauqua, Village Shires, Freemansburg, New Britain and
Roseto.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is a DANGEROUS SITUATION. These storms have produced wind 
damage across Carbon Counry. SEEK SHELTER NOW inside a sturdy 
structure and stay away from windows! 

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

LAT...LON 4088 7596 4077 7544 4092 7521 4055 7457
      4011 7493 4045 7553 4067 7588 4074 7576
TIME...MOT...LOC 2300Z 320DEG 31KT 4081 7524 4065 7537 4079 7585 

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

Robertson

2 follow-up statements

561 
WWUS51 KPHI 202324
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
724 PM EDT THU JUL 20 2017

PAC025-202332-
/O.CAN.KPHI.SV.W.0110.000000T0000Z-170721T0000Z/
Carbon PA-
724 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CARBON COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has weakened.
Therefore, the warning has been cancelled. However gusty winds and 
heavy rain are still possible with these thunderstorms.

A severe thunderstorm watch remains in effect until 1000 PM EDT for
central, northern and northwestern New Jersey...and eastern and
southeastern Pennsylvania.

LAT...LON 4069 7543 4082 7503 4055 7457 4011 7493
      4034 7533
TIME...MOT...LOC 2322Z 312DEG 31KT 4054 7511 

$$

NJC019-021-035-041-PAC017-077-095-210000-
/O.CON.KPHI.SV.W.0110.000000T0000Z-170721T0000Z/
Hunterdon NJ-Warren NJ-Mercer NJ-Somerset NJ-Lehigh PA-Bucks PA-
Northampton PA-
724 PM EDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR HUNTERDON...SOUTHWESTERN WARREN...NORTHWESTERN MERCER...
SOUTHWESTERN SOMERSET...EAST CENTRAL LEHIGH...BUCKS AND SOUTHEASTERN
NORTHAMPTON COUNTIES...

At 722 PM EDT, a severe thunderstorm was located over Milford, or 11
miles southeast of Easton, moving southeast at 35 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

This severe storm will be near...
  Byram around 735 PM EDT. 
  Flemington, Stockton, Sergeantsville, Sand Brook and Lumberville 
  around 740 PM EDT. 
  New Hope around 750 PM EDT. 
  Ewing, Pennington, Yardley, Hopewell, Washington Crossing, 
  Washington Crossing, Woodside and Skillman around 800 PM EDT. 

Other locations impacted by this severe thunderstorm include
Churchville, Hulmeville, Sellersville, Raritan, Fountain Hill,
Richlandtown, Silverdale, Lambertville, Woodbourne and Village
Shires.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is a DANGEROUS SITUATION. These storms have produced wind 
damage across Carbon County. SEEK SHELTER NOW inside a sturdy 
structure and stay away from windows! 

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

&&

LAT...LON 4069 7543 4082 7503 4055 7457 4011 7493
      4034 7533
TIME...MOT...LOC 2322Z 312DEG 31KT 4054 7511 

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

Robertson

572 
WWUS51 KPHI 202345
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
745 PM EDT THU JUL 20 2017

NJC041-PAC077-095-202354-
/O.CAN.KPHI.SV.W.0110.000000T0000Z-170721T0000Z/
Warren NJ-Lehigh PA-Northampton PA-
745 PM EDT THU JUL 20 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN WARREN...EAST
CENTRAL LEHIGH AND SOUTHEASTERN NORTHAMPTON COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has weakened.
Therefore, the warning has been cancelled. However gusty winds and 
heavy rain are still possible with these thunderstorms.

A severe thunderstorm watch remains in effect until 1000 PM EDT for
central, northern and northwestern New Jersey...and southeastern
Pennsylvania.

LAT...LON 4041 7513 4057 7487 4050 7461 4011 7493
      4020 7508
TIME...MOT...LOC 2344Z 320DEG 31KT 4039 7495 

$$

NJC019-021-035-PAC017-210000-
/O.CON.KPHI.SV.W.0110.000000T0000Z-170721T0000Z/
Hunterdon NJ-Mercer NJ-Somerset NJ-Bucks PA-
745 PM EDT THU JUL 20 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR SOUTHEASTERN HUNTERDON...NORTHWESTERN MERCER...SOUTHWESTERN
SOMERSET AND CENTRAL BUCKS COUNTIES...

At 744 PM EDT, a severe thunderstorm was located over Stockton, or 15
miles northwest of Trenton, moving southeast at 35 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

This severe storm will be near...
  Hopewell around 755 PM EDT. 
  Ewing, Pennington, Yardley, Newtown, Washington Crossing, 
  Washington Crossing and Woodside around 800 PM EDT. 

Other locations impacted by this severe thunderstorm include Village
Shires, Churchville, Hulmeville, Langhorne Manor, Newtown Grant,
Penndel, Lambertville and Woodbourne.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 this storm. Move indoors
immediately. Remember...if you can hear thunder...you are close
enough to be struck by lightning.

&&

LAT...LON 4041 7513 4057 7487 4050 7461 4011 7493
      4020 7508
TIME...MOT...LOC 2344Z 320DEG 31KT 4039 7495 

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

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 3:43 AM EDT	Heat Advisory	PHI	Atlantic, Burlington, Cape May, Cumberland, Hunterdon, Middlesex and 4 more	15 hr
Jul 20, 6:22 PM EDT	Severe Thunderstorm Warning	PHI	Warren	53 min
Jul 20, 6:24 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Morris, Sussex, Warren	66 min
Jul 20, 7:31 PM EDT	Special Weather Statement	PHI	Morris	29 min
Jul 20, 7:52 PM EDT	Severe Thunderstorm Warning	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Ocean and 1 more	53 min
Jul 20, 7:56 PM EDT	Special Weather Statement	PHI	Middlesex, Monmouth, Somerset	49 min
Jul 20, 5:35 PM EDT	Severe Thunderstorm Warning	PHI	Carbon, Monroe	55 min
Jul 20, 5:37 PM EDT	Severe Thunderstorm Warning	PHI	Monroe	53 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2017 Severe Thunderstorm Warnings in Pennsylvania, 2017 Every severe thunderstorm warning in 2017

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.