Alert archive / New Jersey / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 186, NWS Philadelphia/Mount Holly

August 22, 2017Bucks County, Montgomery County, Pennsylvania; 6 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 22, 2017, 9:42 PM EDT for Bucks County, Montgomery County, Pennsylvania; 6 counties in New Jersey. It was in force for 48 min. 3 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: Aug 22, 2017, 9:42 PM EDT (01:42 UTC)
Expired: Aug 22, 2017, 10:30 PM EDT
In force: 48 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 70.0 mph

Counties Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Somerset County, NJ, Warren County, NJ, Bucks County, PA, Montgomery County, PA

The radar

The Philadelphia radar (KDIX), 72 km from the middle of the area, began a volume at 01:44 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
Aug 22, 9:47 PM EDT	TSTM WND DMG	Long Valley, NJ	TREES AND POWER POLES REPORTED DOWN IN LONG VALLEY. TIME ESTIMATED FROM RADAR.
Aug 22, 9:53 PM EDT	TSTM WND DMG	Flemington, NJ	TREE DOWN ONTO A CAR. NO INJURIES REPORTED. TIME ESTIMATED FROM RADAR.
Aug 22, 10:10 PM EDT	TSTM WND DMG	1 S Morristown, NJ	TREE BLOWN DOWN ON 287. 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
Aug 22, 4:19 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 00:00Z, 1.7 hours before the alert went out and 140 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: 1278 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 845 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 171 m²/s²
0-3 km storm-relative helicity: 220 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 4.6

Open this sounding in Storm Lab

The text

As transmitted.

312 
WUUS51 KPHI 230142
SVRPHI
NJC019-021-023-027-035-041-PAC017-091-230230-
/O.NEW.KPHI.SV.W.0186.170823T0142Z-170823T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
942 PM EDT TUE AUG 22 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southern Morris County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  Southeastern Warren County in northwestern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Somerset County in northern New Jersey...
  Middlesex County in northern New Jersey...
  Northwestern Montgomery County in southeastern Pennsylvania...
  Central Bucks County in southeastern Pennsylvania...

* Until 1030 PM EDT

* At 941 PM EDT, severe thunderstorms were located along a line
  extending from Beatyestown to near Erwinna to near Green Lane, 
  moving east at 40 mph. This line of storms has a history of 
  producing wind damage in much of eastern Pennsylvania.

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

  SOURCE...Radar indicated. 

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings. 

* Locations impacted include...
  New Brunswick, Perth Amboy, Morristown, Somerville, Somerset,
  Edison, Old Bridge, East Brunswick, Bridgewater, South Brunswick,
  Sayreville, North Brunswick, Ewing, Carteret, Dover, Madison,
  Middlesex, Princeton, Florham Park and East Hanover.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4056 7421 4055 7425 4050 7426 4050 7428
      4046 7425 4041 7428 4026 7487 4033 7562
      4049 7520 4087 7490 4088 7434 4086 7432
      4079 7437 4074 7437 4067 7446 4065 7440
      4060 7446 4059 7420
TIME...MOT...LOC 0141Z 274DEG 36KT 4080 7485 4047 7504 4036 7544 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...70MPH
 
$$

CMS

2 follow-up statements

397 
WWUS51 KPHI 230201
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1001 PM EDT TUE AUG 22 2017

NJC041-230210-
/O.CAN.KPHI.SV.W.0186.000000T0000Z-170823T0230Z/
Warren NJ-
1001 PM EDT TUE AUG 22 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WARREN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until midnight EDT for
northern and northwestern New Jersey...and southeastern Pennsylvania.

LAT...LON 4031 7544 4034 7560 4042 7539 4057 7492
      4087 7473 4088 7434 4086 7432 4079 7437
      4074 7437 4067 7446 4065 7440 4060 7446
      4059 7420 4056 7421 4055 7425 4050 7426
      4050 7428 4046 7425 4041 7428 4026 7487
TIME...MOT...LOC 0200Z 266DEG 39KT 4079 7461 4051 7476 4040 7525 

$$

NJC019-021-023-027-035-PAC017-091-230230-
/O.CON.KPHI.SV.W.0186.000000T0000Z-170823T0230Z/
Morris NJ-Hunterdon NJ-Mercer NJ-Somerset NJ-Middlesex NJ-
Montgomery PA-Bucks PA-
1001 PM EDT TUE AUG 22 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR SOUTHERN MORRIS...HUNTERDON...NORTHWESTERN MERCER...SOMERSET...
MIDDLESEX...NORTHWESTERN MONTGOMERY AND CENTRAL BUCKS COUNTIES...

At 1000 PM EDT, severe thunderstorms were located along a line
extending from Mendham to Cloverhill to near Perkasie, moving east at
45 mph.

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

SOURCE...Law enforcement. Wind damage has been reported in Hunterdon 
         County as the line has moved through.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. 

Locations impacted include...
New Brunswick, Perth Amboy, Morristown, Somerville, Somerset, Edison,
Old Bridge, East Brunswick, Bridgewater, South Brunswick, Sayreville,
North Brunswick, Ewing, Carteret, Dover, Madison, Middlesex,
Princeton, Florham Park and East Hanover.

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.

&&

LAT...LON 4031 7544 4034 7560 4042 7539 4057 7492
      4087 7473 4088 7434 4086 7432 4079 7437
      4074 7437 4067 7446 4065 7440 4060 7446
      4059 7420 4056 7421 4055 7425 4050 7426
      4050 7428 4046 7425 4041 7428 4026 7487
TIME...MOT...LOC 0200Z 266DEG 39KT 4079 7461 4051 7476 4040 7525 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...70MPH
 
$$

CMS

213 
WWUS51 KPHI 230223
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1023 PM EDT TUE AUG 22 2017

NJC027-230232-
/O.CAN.KPHI.SV.W.0186.000000T0000Z-170823T0230Z/
Morris NJ-
1023 PM EDT TUE AUG 22 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MORRIS COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 4056 7421 4055 7425 4050 7426 4050 7428
      4046 7425 4041 7428 4026 7487 4031 7544
      4034 7560 4057 7492 4058 7460 4066 7453
      4067 7448 4065 7441 4060 7446 4059 7421
TIME...MOT...LOC 0222Z 273DEG 36KT 4078 7434 4050 7449 4041 7510 

$$

NJC019-021-023-035-PAC017-091-230230-
/O.CON.KPHI.SV.W.0186.000000T0000Z-170823T0230Z/
Hunterdon NJ-Mercer NJ-Somerset NJ-Middlesex NJ-Montgomery PA-
Bucks PA-
1023 PM EDT TUE AUG 22 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR SOUTHEASTERN HUNTERDON...NORTHWESTERN MERCER...SOMERSET...
MIDDLESEX...NORTHWESTERN MONTGOMERY AND CENTRAL BUCKS COUNTIES...

At 1022 PM EDT, severe thunderstorms were located along a line
extending from near Florham Park to Somerset to near Byram, moving 
east at 40 mph. Wind damage has been reported in Somerset and 
Hunterdon Counties with these storms.

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

SOURCE...Public. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. 

Locations impacted include...
New Brunswick, Perth Amboy, Somerville, Somerset, Edison, Old Bridge,
East Brunswick, South Brunswick, Sayreville, North Brunswick, Ewing,
Carteret, Middlesex, Princeton, Bound Brook, Manville, Perkasie,
Doylestown, Byram and Souderton.

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 4056 7421 4055 7425 4050 7426 4050 7428
      4046 7425 4041 7428 4026 7487 4031 7544
      4034 7560 4057 7492 4058 7460 4066 7453
      4067 7448 4065 7441 4060 7446 4059 7421
TIME...MOT...LOC 0222Z 273DEG 36KT 4078 7434 4050 7449 4041 7510 

TORNADO...POSSIBLE
HAIL...0.75IN
WIND...70MPH
 
$$

CMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 8:12 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	48 min
Aug 22, 8:15 PM EDT	Tornado Warning	PHI	Monroe, Northampton	30 min
Aug 22, 8:45 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Carbon, Chester, Lehigh, Monroe and 2 more	60 min
Aug 22, 8:58 PM EDT	Severe Thunderstorm Warning	PHI	Monroe, Northampton	24 min
Aug 22, 9:18 PM EDT	Areal Flood Advisory	PHI	Berks, Montgomery	4 hr
Aug 22, 9:23 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Chester, Montgomery	52 min
Aug 22, 9:40 PM EDT	Tornado Warning	PHI	Berks, Chester, Montgomery	20 min
Aug 22, 10:07 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Delaware, Montgomery, Philadelphia	53 min
Aug 22, 10:27 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Montgomery	48 min
Aug 22, 10:37 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery, Northampton	4 hr
Aug 22, 10:40 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Aug 22, 10:58 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	62 min
Aug 22, 11:46 PM EDT	Severe Thunderstorm Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	44 min
Aug 23, 12:06 AM EDT	Flash Flood Warning	PHI	Chester, Delaware, Montgomery, Philadelphia	4 hr
Aug 23, 12:29 AM EDT	Severe Thunderstorm Warning	PHI	Philadelphia	46 min
Aug 23, 4:02 AM EDT	Areal Flood Warning	PHI	Chester, Delaware, Philadelphia	4 hr
Aug 22, 8:20 PM EDT	Special Weather Statement	PHI	Sussex	40 min
Aug 22, 10:13 PM EDT	Special Marine Warning	PHI		92 min
Aug 22, 11:39 PM EDT	Special Marine Warning	PHI		66 min
Aug 22, 11:42 PM EDT	Flash Flood Warning	PHI	Hunterdon, Middlesex, Somerset	4 hr
Aug 23, 12:37 AM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Mercer, Middlesex, Monmouth and 1 more	4 hr
Aug 23, 1:56 AM EDT	Areal Flood Advisory	PHI	Salem	4 hr
Aug 23, 2:43 AM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Cumberland, Gloucester, Ocean and 1 more	4 hr
Aug 23, 3:37 AM EDT	Areal Flood Warning	PHI	Hunterdon, Middlesex, Somerset	4 hr

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.