Alert archive / New Jersey / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 1, NWS Philadelphia/Mount Holly

April 4, 20184 counties in Pennsylvania; 8 counties in New Jersey; New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 4, 2018, 12:39 PM EDT for 4 counties in Pennsylvania; 8 counties in New Jersey; New Castle County, Delaware. It was in force for 51 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: Apr 4, 2018, 12:39 PM EDT (16:39 UTC)
Expired: Apr 4, 2018, 1:30 PM EDT
In force: 51 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties New Castle County, DE, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Bucks County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 41 km from the middle of the area, began a volume at 16:40 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
Apr 4, 12:56 PM EDT	TSTM WND GST 54	Larchmont, PA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Brookhaven, NY (KOKX), launched 12:00Z, 4.7 hours before the alert went out and 186 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 473 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 355 m²/s²
0-3 km storm-relative helicity: 388 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

269 
WUUS51 KPHI 041639
SVRPHI
DEC003-NJC005-007-015-021-023-025-029-033-PAC017-045-091-101-041730-
/O.NEW.KPHI.SV.W.0001.180404T1639Z-180404T1730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1239 PM EDT WED APR 4 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northeastern New Castle County in northern Delaware...
  Northwestern Ocean County in southern New Jersey...
  Camden County in southern New Jersey...
  Mercer County in central New Jersey...
  Northwestern Salem County in southern New Jersey...
  Gloucester County in southern New Jersey...
  Northern Burlington County in southern New Jersey...
  Southern Middlesex County in northern New Jersey...
  Central Monmouth County in central New Jersey...
  Southeastern Montgomery County in southeastern Pennsylvania...
  Southeastern Bucks County in southeastern Pennsylvania...
  Philadelphia County in southeastern Pennsylvania...
  Delaware County in southeastern Pennsylvania...

* Until 130 PM EDT

* At 1239 PM EDT, severe thunderstorms were located along a line
  extending from near Richboro to Chestnut Hill to near Wilmington,
  moving east at 50 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Philadelphia, Trenton, Camden, Wilmington, Gloucester City, Cherry
  Hill, Old Bridge, Bensalem, East Brunswick, Evesham, Mount Laurel,
  Marlboro, Manalapan, Ewing, Chester, Willingboro, Deptford,
  Voorhees, Medford and West Deptford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 4020 7428 3961 7489 3972 7561 3990 7550
      4035 7508 4034 7489 4036 7486 4040 7417
TIME...MOT...LOC 1639Z 260DEG 45KT 4027 7504 4008 7518 3977 7552 

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

JRK

3 follow-up statements

945 
WWUS51 KPHI 041658
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1258 PM EDT WED APR 4 2018

DEC003-041707-
/O.CAN.KPHI.SV.W.0001.000000T0000Z-180404T1730Z/
New Castle DE-
1258 PM EDT WED APR 4 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN NEW CASTLE COUNTY
IS CANCELLED...

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

LAT...LON 3969 7542 3993 7534 4006 7513 4024 7500
      4036 7484 4040 7417 4020 7428 3961 7489
TIME...MOT...LOC 1657Z 259DEG 45KT 4031 7475 4012 7489 3973 7528 

$$

NJC005-007-015-021-023-025-029-033-PAC017-045-091-101-041730-
/O.CON.KPHI.SV.W.0001.000000T0000Z-180404T1730Z/
Salem NJ-Ocean NJ-Camden NJ-Mercer NJ-Gloucester NJ-Burlington NJ-
Middlesex NJ-Monmouth NJ-Montgomery PA-Bucks PA-Philadelphia PA-
Delaware PA-
1258 PM EDT WED APR 4 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR NORTH CENTRAL SALEM...NORTHWESTERN OCEAN...CAMDEN...MERCER...
GLOUCESTER...NORTHERN BURLINGTON...SOUTHERN MIDDLESEX...CENTRAL
MONMOUTH...EAST CENTRAL MONTGOMERY...SOUTHEASTERN BUCKS...
PHILADELPHIA AND SOUTHEASTERN DELAWARE COUNTIES...

At 1257 PM EDT, severe thunderstorms were located along a line
extending from Lawrenceville to near Bristol to near Swedesboro,
moving east at 50 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

These severe storms will be near...
  Trenton, Princeton, Florence, Burlington, Bristol, Tullytown, 
  Florence-Roebling, Levittown, Edinburg and Columbus around 105 PM 
  EDT. 
  Ewing, Hightstown, Bordentown, Cranbury, Princeton Meadows, 
  Plainsboro Center, Kingston, White Horse, Georgetown and Jobstown 
  around 110 PM EDT. 
  Lindenwold, Jamesburg, Magnolia, Allentown, Whittingham, 
  Crosswicks, Clearbrook Park, Sicklerville, Dayton and Williamstown 
  around 115 PM EDT. 
  Evesham, Voorhees, Berlin, Imlaystown, Atco, Marlton Lakes, Cream 
  Ridge, Yorketown and Windsor around 120 PM EDT. 
  Old Bridge, Chesilhurst, Roosevelt, Morganville, Clarksburg, 
  Robertsville and Six Flags Theme Park around 125 PM EDT. 
  Marlboro, Manalapan, Medford, Matawan, Tabernacle, Vista Center, 
  West Freehold, Cassville and East Freehold around 130 PM EDT. 

Other locations impacted by these severe thunderstorms include Oak
Valley, Cornwells Heights-Eddington, Clifton Heights, Collingdale,
Churchville, Hulmeville, Moorestown-Lenola, Merchantville, Eddystone
and Tavistock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 3969 7542 3993 7534 4006 7513 4024 7500
      4036 7484 4040 7417 4020 7428 3961 7489
TIME...MOT...LOC 1657Z 259DEG 45KT 4031 7475 4012 7489 3973 7528 

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

JRK

476 
WWUS51 KPHI 041714
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
114 PM EDT WED APR 4 2018

NJC033-PAC045-091-101-041723-
/O.CAN.KPHI.SV.W.0001.000000T0000Z-180404T1730Z/
Salem NJ-Montgomery PA-Philadelphia PA-Delaware PA-
114 PM EDT WED APR 4 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL SALEM...EAST
CENTRAL MONTGOMERY...PHILADELPHIA AND SOUTHEASTERN DELAWARE COUNTIES
IS CANCELLED...

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

LAT...LON 4019 7429 3961 7489 3967 7520 3967 7521
      3982 7516 3995 7508 4005 7490 4038 7462
      4040 7417
TIME...MOT...LOC 1713Z 267DEG 37KT 4031 7454 4007 7473 3983 7506 3964
7514

$$

NJC005-007-015-021-023-025-029-PAC017-041730-
/O.CON.KPHI.SV.W.0001.000000T0000Z-180404T1730Z/
Ocean NJ-Camden NJ-Mercer NJ-Gloucester NJ-Burlington NJ-
Middlesex NJ-Monmouth NJ-Bucks PA-
114 PM EDT WED APR 4 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR NORTHWESTERN OCEAN...CAMDEN...EASTERN MERCER...NORTHEASTERN
GLOUCESTER...NORTHERN BURLINGTON...SOUTHERN MIDDLESEX...CENTRAL
MONMOUTH AND SOUTHEASTERN BUCKS COUNTIES...

At 113 PM EDT, severe thunderstorms were located along a line
extending from Cranbury to Columbus to near Magnolia to near Clayton,
moving east at 45 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

These severe storms will be near...
  Jamesburg, Hightstown, Bordentown, Cranbury, Pemberton, Roosevelt, 
  Wrightstown, Georgetown, Clearbrook Park and Whittingham around 
  120 PM EDT. 
  Manalapan, Allentown, Chesilhurst, Victory Lakes and Browns Mills 
  around 125 PM EDT. 
  Old Bridge, Marlboro, Medford, Tabernacle, Yorketown, 
  Robertsville, Woodruff, Morganville, Cream Ridge and West Freehold 
  around 130 PM EDT. 

Other locations impacted by these severe thunderstorms include Oak
Valley, Runnemede, Glendora, Barrington, Moorestown-Lenola,
Merchantville, Princeton Junction, Tavistock, Woodlynne and
Gibbsboro.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This severe thunderstorm may contain little or no lightning. Do not
wait until you hear thunder before taking cover.

&&

LAT...LON 4019 7429 3961 7489 3967 7520 3967 7521
      3982 7516 3995 7508 4005 7490 4038 7462
      4040 7417
TIME...MOT...LOC 1713Z 267DEG 37KT 4031 7454 4007 7473 3983 7506 3964
7514

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

JRK

328 
WWUS51 KPHI 041728
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
128 PM EDT WED APR 4 2018

NJC005-007-015-021-023-025-029-PAC017-041737-
/O.EXP.KPHI.SV.W.0001.000000T0000Z-180404T1730Z/
Ocean NJ-Camden NJ-Mercer NJ-Gloucester NJ-Burlington NJ-
Middlesex NJ-Monmouth NJ-Bucks PA-
128 PM EDT WED APR 4 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN OCEAN...CAMDEN...
EASTERN MERCER...NORTHEASTERN GLOUCESTER...NORTHERN BURLINGTON...
SOUTHERN MIDDLESEX...CENTRAL MONMOUTH AND SOUTHEASTERN BUCKS COUNTIES
WILL EXPIRE AT 130 PM EDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore the warning will
be allowed to expire.  However gusty winds are still possible with
these thunderstorms.

LAT...LON 4019 7429 3961 7489 3967 7520 3967 7521
      3982 7516 3995 7508 4005 7490 4038 7462
      4040 7417
TIME...MOT...LOC 1727Z 260DEG 45KT 4034 7431 4010 7450 3986 7483 3967
7491

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 4, 12:01 AM EDT	Dense Fog Advisory	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	10 hr
Apr 4, 3:44 AM EDT	High Wind Warning	PHI	Berks, Bucks, Carbon, Chester, Delaware, Lehigh and 4 more	16 hr
Apr 4, 12:29 PM EDT	Special Weather Statement	PHI	Delaware, Philadelphia	31 min
Apr 3, 9:42 PM EDT	Marine Dense Fog Advisory	PHI		14 hr
Apr 4, 2:56 AM EDT	Special Weather Statement	PHI	Sussex	34 min
Apr 4, 12:54 PM EDT	Special Marine Warning	PHI		96 min
Apr 4, 1:07 PM EDT	Special Marine Warning	PHI		113 min
Apr 4, 1:13 PM EDT	Special Weather Statement	PHI	Atlantic, Cape May, Cumberland	62 min
Apr 4, 1:26 PM EDT	Special Weather Statement	PHI	Burlington, Camden, Middlesex, Monmouth, Ocean	49 min
Apr 4, 1:46 PM EDT	Areal Flood Advisory	PHI	Atlantic, Burlington, Cumberland	4 hr
Apr 4, 1:46 PM EDT	Special Marine Warning	PHI		59 min
Apr 4, 2:15 PM EDT	Special Weather Statement	PHI	Cape May, Ocean	30 min
Apr 4, 2:45 PM EDT	Special Marine Warning	PHI		90 min
Apr 4, 2:58 PM EDT	Special Marine Warning	PHI		92 min
Apr 4, 12:49 PM EDT	Special Weather Statement	PHI	Kent	26 min
Apr 4, 2:17 PM EDT	Special Weather Statement	PHI	Sussex	43 min

Nearby

Severe Thunderstorm Warnings in New Jersey, 2018 Severe Thunderstorm Warnings in Pennsylvania, 2018 Severe Thunderstorm Warnings in Delaware, 2018 Every severe thunderstorm warning in 2018

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.