Alert archive / New Jersey / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 231, NWS Philadelphia/Mount Holly

July 17, 20197 counties in New Jersey; 4 counties in Pennsylvania

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2019, 8:15 PM EDT for 7 counties in New Jersey; 4 counties in Pennsylvania. It was in force for 45 min. 5 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 17, 2019, 8:15 PM EDT (00:15 UTC)
Expired: Jul 17, 2019, 9:00 PM EDT
In force: 45 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Salem County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 61 km from the middle of the area, began a volume at 00:18 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 17, 8:16 PM EDT	TSTM WND DMG	Collingswood, NJ	TREE DOWN ON A CAR ON HADDON AVE AT ZANE AVE. TIME ESTIMATED FROM RADAR.
Jul 17, 8:25 PM EDT	TSTM WND DMG	1 Nw Rancocas, NJ	SEVERAL VERY LARGE TREE BRANCHES DOWN IN WILLINGBORO.
Jul 17, 8:35 PM EDT	TSTM WND DMG	3 S Roebling, NJ	DELAYED REPORT. MULTIPLE DOWNED TREES AND POLES INCLUDING A 60 FOOT SYCAMORE SNAPPED. TIME ESTIMATED FROM RADAR.
Jul 17, 8:40 PM EDT	TSTM WND DMG	1 Ene Ewing, NJ	TREE DOWN AND BLOCKING A LANE OF NJ-31 NORTHBOUND NEAR CR-636. TIME ESTIMATED FROM RADAR.
Jul 17, 8:41 PM EDT	TSTM WND DMG	1 Nnw Morrisville, PA	DOWNED TREE ON PA-32. 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 17, 1:58 PM EDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 17, 4:51 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.3 hours before the alert went out and 216 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: 1810 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 1434 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 169 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.5

Open this sounding in Storm Lab

The text

As transmitted.

870 
WUUS51 KPHI 180015
SVRPHI
NJC001-005-007-015-019-021-033-PAC017-045-091-101-180100-
/O.NEW.KPHI.SV.W.0231.190718T0015Z-190718T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
815 PM EDT Wed Jul 17 2019

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northwestern Atlantic County in southern New Jersey...
  East central Salem County in southern New Jersey...
  South central Hunterdon County in northwestern New Jersey...
  Camden County in southern New Jersey...
  Western Mercer County in central New Jersey...
  Gloucester County in southern New Jersey...
  Burlington County in southern New Jersey...
  Central Montgomery County in southeastern Pennsylvania...
  Bucks County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Eastern Delaware County in southeastern Pennsylvania...

* Until 900 PM EDT.

* At 814 PM EDT, severe thunderstorms were located along a line
  extending from Dublin to near Buena, moving northeast at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Philadelphia, Trenton, Camden, Gloucester City, Cherry Hill,
  Bensalem, Evesham, Mount Laurel, Ewing, Norristown, Willingboro,
  Deptford, Voorhees, Medford, West Deptford, Glassboro, Lindenwold,
  Lansdale, West Norriton and Hammonton.

People attending Burlington County Farm Fair should seek safe shelter
immediately!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3956 7504 3956 7506 3955 7507 3952 7518
      4006 7538 4007 7536 4007 7538 4030 7546
      4051 7486 3968 7451
TIME...MOT...LOC 0014Z 243DEG 28KT 4037 7520 3959 7494 

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

Fitzsimmons

2 follow-up statements

909 
WWUS51 KPHI 180035
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
835 PM EDT Wed Jul 17 2019

NJC033-PAC045-180045-
/O.CAN.KPHI.SV.W.0231.000000T0000Z-190718T0100Z/
Salem NJ-Delaware PA-
835 PM EDT Wed Jul 17 2019

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL SALEM AND EASTERN
DELAWARE 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 1000 PM EDT for
southern, central and northwestern New Jersey...and southeastern
Pennsylvania.

LAT...LON 3958 7496 4032 7514 4051 7486 3968 7451
TIME...MOT...LOC 0035Z 251DEG 30KT 4027 7492 3968 7472 

$$

NJC001-005-007-015-019-021-PAC017-091-101-180100-
/O.CON.KPHI.SV.W.0231.000000T0000Z-190718T0100Z/
Atlantic NJ-Hunterdon NJ-Camden NJ-Mercer NJ-Gloucester NJ-
Burlington NJ-Montgomery PA-Bucks PA-Philadelphia PA-
835 PM EDT Wed Jul 17 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM EDT
FOR NORTHWESTERN ATLANTIC...SOUTH CENTRAL HUNTERDON...CAMDEN...
WESTERN MERCER...EAST CENTRAL GLOUCESTER...BURLINGTON...EAST CENTRAL
MONTGOMERY...SOUTHEASTERN BUCKS AND NORTHEASTERN PHILADELPHIA
COUNTIES...

At 835 PM EDT, severe thunderstorms were located along a line
extending from near Washington Crossing to near Atsion, moving east
at 35 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Philadelphia, Trenton, Cherry Hill, Bensalem, Evesham, Mount Laurel,
Ewing, Willingboro, Voorhees, Medford, Lindenwold, Hammonton,
Lumberton, Florence, Burlington, Bristol, Mount Holly, Doylestown,
Riverside and Berlin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3958 7496 4032 7514 4051 7486 3968 7451
TIME...MOT...LOC 0035Z 251DEG 30KT 4027 7492 3968 7472 

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

Staarmann

680 
WWUS51 KPHI 180051
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
851 PM EDT Wed Jul 17 2019

NJC001-005-007-015-019-021-PAC017-091-101-180100-
/O.EXP.KPHI.SV.W.0231.000000T0000Z-190718T0100Z/
Atlantic NJ-Hunterdon NJ-Camden NJ-Mercer NJ-Gloucester NJ-
Burlington NJ-Montgomery PA-Bucks PA-Philadelphia PA-
851 PM EDT Wed Jul 17 2019

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ATLANTIC...SOUTH
CENTRAL HUNTERDON...CAMDEN...WESTERN MERCER...EAST CENTRAL
GLOUCESTER...BURLINGTON...EAST CENTRAL MONTGOMERY...SOUTHEASTERN
BUCKS AND NORTHEASTERN PHILADELPHIA COUNTIES WILL EXPIRE AT 900 PM
EDT...
    
The storms which prompted the warning have weakened and are moving 
out of the area. Therefore, the warning will be allowed to expire. 
However gusty winds are still possible with these thunderstorms.

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

LAT...LON 3958 7496 4032 7514 4051 7486 3968 7451
TIME...MOT...LOC 0050Z 243DEG 28KT 4032 7480 3973 7460 

$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:01 PM EDT	Areal Flood Advisory	PHI	Warren	88 min
Jul 17, 8:10 PM EDT	Special Marine Warning	PHI		95 min
Jul 17, 8:39 PM EDT	Areal Flood Advisory	PHI	Morris, Sussex	3 hr
Jul 17, 8:40 PM EDT	Special Weather Statement	PHI	Atlantic, Burlington, Mercer, Middlesex, Monmouth, Ocean	65 min
Jul 17, 8:43 PM EDT	Special Marine Warning	PHI		92 min
Jul 17, 8:50 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth, Somerset	40 min
Jul 17, 8:55 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Somerset	49 min
Jul 17, 9:02 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Somerset	3 hr
Jul 17, 9:19 PM EDT	Severe Thunderstorm Warning	PHI	Middlesex, Monmouth, Ocean	41 min
Jul 17, 9:44 PM EDT	Special Marine Warning	PHI		61 min
Jul 17, 10:41 PM EDT	Special Marine Warning	PHI		49 min
Jul 17, 11:12 PM EDT	Areal Flood Warning	PHI	Somerset	3 hr
Jul 18, 1:30 PM EDT	Areal Flood Advisory	PHI	Gloucester	4 hr
Jul 18, 2:13 PM EDT	Areal Flood Advisory	PHI	Burlington, Camden, Gloucester, Ocean	4 hr
Jul 18, 2:24 PM EDT	Areal Flood Advisory	PHI	Salem	3 hr
Jul 18, 2:47 PM EDT	Flash Flood Warning	PHI	Burlington, Ocean	4 hr
Jul 18, 3:48 PM EDT	Areal Flood Advisory	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	4 hr
Jul 18, 3:59 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Camden, Gloucester, Ocean, Salem	3 hr
Jul 18, 4:19 PM EDT	Flash Flood Warning	PHI	Atlantic, Burlington, Ocean	3 hr
Jul 18, 4:30 PM EDT	Areal Flood Advisory	PHI	Hunterdon	4 hr
Jul 18, 4:52 PM EDT	Special Marine Warning	PHI		53 min
Jul 18, 4:53 PM EDT	Areal Flood Advisory	PHI	Mercer, Middlesex, Monmouth, Somerset	4 hr
Jul 18, 4:56 PM EDT	Areal Flood Advisory	PHI	Cumberland, Gloucester, Salem	3 hr
Jul 18, 5:13 PM EDT	Flash Flood Warning	PHI	Mercer, Middlesex, Monmouth, Somerset	3 hr
Jul 18, 5:57 PM EDT	Areal Flood Advisory	PHI	Cumberland, Salem	2 hr
Jul 18, 6:01 PM EDT	Flash Flood Warning	PHI	Hunterdon, Middlesex, Somerset	4 hr
Jul 18, 2:55 PM EDT	Flash Flood Warning	PHI	Chester	4 hr
Jul 18, 3:33 PM EDT	Flash Flood Warning	PHI	Chester, Delaware	4 hr
Jul 18, 7:44 PM EDT	Special Weather Statement	PHI	Berks	46 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2019 Severe Thunderstorm Warnings in Pennsylvania, 2019 Every severe thunderstorm warning in 2019

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.