Alert archive / New Jersey / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 77, NWS Philadelphia/Mount Holly

July 1, 20174 counties in Pennsylvania; 5 counties in New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 1, 2017, 5:08 PM EDT for 4 counties in Pennsylvania; 5 counties in New Jersey. It was in force for 52 min. 1 report 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 1, 2017, 5:08 PM EDT (21:08 UTC)
Expired: Jul 1, 2017, 6:00 PM EDT
In force: 52 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 1.0 in
Wind: 60.0 mph

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

The radar

The Philadelphia radar (KDIX), 100 km from the middle of the area, began a volume at 21:10 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 1, 5:40 PM EDT	TSTM WND DMG	Delaware Twp, NJ	SEVERAL TREES AND WIRES BLOWN DOWN IN THE DELAWARE...EAST AMWELL...AND WEST AMWELL TOWNSHIPS. 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 1, 1:34 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 9.1 hours before the alert went out and 164 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: 361 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 752 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 104 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

As transmitted.

241 
WUUS51 KPHI 012108
SVRPHI
NJC019-021-027-035-041-PAC017-077-091-095-012200-
/O.NEW.KPHI.SV.W.0077.170701T2108Z-170701T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
508 PM EDT SAT JUL 1 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern Morris County in northern New Jersey...
  Hunterdon County in northwestern New Jersey...
  Southern Warren County in northwestern New Jersey...
  Northwestern Mercer County in central New Jersey...
  Western Somerset County in northern New Jersey...
  North central Montgomery County in southeastern Pennsylvania...
  Southeastern Lehigh County in eastern Pennsylvania...
  Bucks County in southeastern Pennsylvania...
  Central Northampton County in eastern Pennsylvania...

* Until 600 PM EDT

* At 507 PM EDT, severe thunderstorms were located along a line
  extending from near Belfast to near Perkasie, moving east at 40
  mph.

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

  SOURCE...Radar indicated. 

  IMPACT...Minor damage to vehicles is possible. Expect damage to 
           trees and power lines. 

* Locations impacted include...
  Easton, Bethlehem, Bridgewater, Ewing, Dover, Forks, Hackettstown,
  Quakertown, Perkasie, Doylestown, Byram, Wilson, Souderton,
  Bedminster, Wharton, Washington, Rockaway, Hellertown, Nazareth and
  Mount Arlington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4097 7448 4025 7481 4034 7552 4083 7532
      4092 7478 4092 7473 4090 7471 4092 7465
      4094 7464
TIME...MOT...LOC 2107Z 252DEG 36KT 4077 7522 4036 7538 

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

SFJ

1 follow-up statement

112 
WWUS51 KPHI 012132
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
532 PM EDT SAT JUL 1 2017

PAC077-091-012141-
/O.CAN.KPHI.SV.W.0077.000000T0000Z-170701T2200Z/
Montgomery PA-Lehigh PA-
532 PM EDT SAT JUL 1 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL MONTGOMERY AND
SOUTHEASTERN LEHIGH COUNTIES 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 900 PM EDT for
central, northern and northwestern New Jersey...and eastern and
southeastern Pennsylvania.

LAT...LON 4097 7448 4025 7481 4033 7534 4034 7535
      4085 7519 4092 7478 4092 7473 4090 7471
      4092 7465 4094 7464
TIME...MOT...LOC 2131Z 270DEG 30KT 4075 7498 4034 7514 

$$

NJC019-021-027-035-041-PAC017-095-012200-
/O.CON.KPHI.SV.W.0077.000000T0000Z-170701T2200Z/
Morris NJ-Hunterdon NJ-Warren NJ-Mercer NJ-Somerset NJ-Bucks PA-
Northampton PA-
532 PM EDT SAT JUL 1 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR SOUTHWESTERN MORRIS...HUNTERDON...SOUTHERN WARREN...NORTHWESTERN
MERCER...WESTERN SOMERSET...NORTHERN BUCKS AND SOUTHEASTERN
NORTHAMPTON COUNTIES...

At 531 PM EDT, severe thunderstorms were located along a line
extending from Washington to Robesonia, moving east at 35 mph.

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

SOURCE...Radar indicated. 

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

Locations impacted include...
Easton, Bridgewater, Ewing, Dover, Forks, Hackettstown, Perkasie,
Doylestown, Byram, Wilson, Bedminster, Wharton, Washington, Rockaway,
Mount Arlington, Mendham, Flemington, Tinicum, High Bridge and
Stanhope.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4097 7448 4025 7481 4033 7534 4034 7535
      4085 7519 4092 7478 4092 7473 4090 7471
      4092 7465 4094 7464
TIME...MOT...LOC 2131Z 270DEG 30KT 4075 7498 4034 7514 

HAIL...0.75IN
WIND...60MPH
 
$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 30, 8:09 PM EDT	Special Weather Statement	PHI	Montgomery	51 min
Jun 30, 8:32 PM EDT	Areal Flood Advisory	PHI	Berks, Bucks, Lehigh, Montgomery	118 min
Jun 30, 9:17 PM EDT	Special Weather Statement	PHI	Bucks	43 min
Jul 1, 2:38 PM EDT	Special Weather Statement	PHI	Berks	52 min
Jul 1, 3:22 PM EDT	Special Weather Statement	PHI	Berks, Carbon	23 min
Jul 1, 3:24 PM EDT	Areal Flood Advisory	PHI	Berks, Lehigh	3 hr
Jul 1, 3:41 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Lehigh, Northampton	49 min
Jul 1, 4:05 PM EDT	Special Weather Statement	PHI	Chester	40 min
Jul 1, 4:20 PM EDT	Flash Flood Warning	PHI	Berks, Lehigh	4 hr
Jul 1, 4:24 PM EDT	Severe Thunderstorm Warning	PHI	Berks, Bucks, Chester, Lehigh, Montgomery, Northampton	51 min
Jul 1, 5:00 PM EDT	Areal Flood Advisory	PHI	Bucks, Lehigh, Northampton	4 hr
Jul 1, 5:01 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	44 min
Jul 1, 5:30 PM EDT	Areal Flood Advisory	PHI	Bucks, Chester, Delaware, Montgomery, Philadelphia	4 hr
Jul 1, 5:35 PM EDT	Severe Thunderstorm Warning	PHI	Bucks, Delaware, Montgomery, Philadelphia	40 min
Jul 1, 5:50 PM EDT	Severe Thunderstorm Warning	PHI	Bucks	40 min
Jul 1, 6:17 PM EDT	Areal Flood Advisory	PHI	Monroe, Northampton	4 hr
Jun 30, 9:48 PM EDT	Special Weather Statement	PHI	Middlesex	42 min
Jun 30, 9:55 PM EDT	Special Weather Statement	PHI	Middlesex	20 min
Jun 30, 10:32 PM EDT	Special Weather Statement	PHI	Middlesex	28 min
Jul 1, 9:48 AM EDT	Marine Dense Fog Advisory	PHI		5 hr
Jul 1, 5:10 PM EDT	Special Marine Warning	PHI		95 min
Jul 1, 5:29 PM EDT	Special Weather Statement	PHI	Sussex	31 min
Jul 1, 5:41 PM EDT	Special Weather Statement	PHI	Atlantic, Cape May, Cumberland, Salem	34 min
Jul 1, 6:07 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Gloucester, Mercer	23 min
Jul 1, 6:22 PM EDT	Special Weather Statement	PHI	Middlesex, Monmouth, Morris	23 min
Jul 1, 6:33 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Cumberland, Gloucester	27 min
Jul 1, 6:59 PM EDT	Special Marine Warning	PHI		61 min
Jul 1, 7:01 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Ocean	29 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.