Alert archive / New Jersey / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 121, NWS Philadelphia/Mount Holly

July 23, 2017Cape May County, Cumberland County, New Jersey; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 23, 2017, 4:29 PM EDT for Cape May County, Cumberland County, New Jersey; Kent County, Delaware. It was in force for 26 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 23, 2017, 4:29 PM EDT (20:29 UTC)
Expired: Jul 23, 2017, 4:55 PM EDT
In force: 26 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Kent County, DE, Cape May County, NJ, Cumberland County, NJ

The radar

The Dover AFB radar (KDOX), 49 km from the middle of the area, began a volume at 20:31 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.

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.5 hours before the alert went out and 146 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: 651 J/kg
Mixed-layer CIN: -99 J/kg
Mixed-layer LCL: 853 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 65 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

607 
WUUS51 KPHI 232029
SVRPHI
DEC001-NJC009-011-232115-
/O.NEW.KPHI.SV.W.0121.170723T2029Z-170723T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
429 PM EDT SUN JUL 23 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Northeastern Kent County in central Delaware...
  Southern Cumberland County in southern New Jersey...
  West central Cape May County in southern New Jersey...

* Until 515 PM EDT

* At 427 PM EDT, severe thunderstorms were located along a line
  extending from Bivalve to near Dover, moving southeast at 5 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar and public indicated. A waterspout was reported in 
           far southeastern Cumberland County along the Maurice 
           River just after 400 PM. 

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

* Locations impacted include...
  Dover, Newport, Leesburg, Woodland Beach, Port Norris, Dividing
  Creek, Dennisville, Goshen, Cedarville, Bivalve, Fortesque, Eldora,
  Little Creek and Leipsic.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Intense thunderstorm can produce brief tornadoes and 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 3913 7472 3910 7494 3915 7493 3919 7508
      3916 7515 3930 7537 3928 7539 3927 7537
      3912 7537 3912 7547 3925 7558 3934 7551
      3934 7545 3929 7539 3931 7537 3934 7541
      3935 7526 3927 7494
TIME...MOT...LOC 2027Z 310DEG 5KT 3923 7502 3919 7544 

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

JRK

1 follow-up statement

368 
WWUS51 KPHI 232055
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
455 PM EDT SUN JUL 23 2017

DEC001-NJC009-011-232105-
/O.CAN.KPHI.SV.W.0121.000000T0000Z-170723T2115Z/
Kent DE-Cumberland NJ-Cape May NJ-
455 PM EDT SUN JUL 23 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN KENT...SOUTHERN
CUMBERLAND AND WEST CENTRAL CAPE MAY COUNTIES IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning has been cancelled.  However gusty winds and
heavy rain are still possible with these thunderstorms.

LAT...LON 3913 7472 3910 7494 3915 7493 3919 7508
      3916 7515 3930 7537 3928 7539 3927 7537
      3912 7537 3912 7547 3925 7558 3934 7551
      3934 7545 3929 7539 3931 7537 3934 7541
      3935 7526 3927 7494
TIME...MOT...LOC 2052Z 310DEG 5KT 3921 7498 3917 7540 

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 8:05 PM EDT	Special Weather Statement	PHI	Ocean	25 min
Jul 22, 10:52 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	4 hr
Jul 23, 12:01 AM EDT	Coastal Flood Advisory	PHI	Atlantic, Burlington, Cape May, Cumberland, Middlesex, Monmouth and 1 more	25 hr
Jul 23, 3:16 PM EDT	Flash Flood Watch	PHI	Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 6 more	15 hr
Jul 23, 3:43 PM EDT	Special Marine Warning	PHI		92 min
Jul 23, 4:39 PM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland, Salem	4 hr
Jul 23, 4:40 PM EDT	Special Marine Warning	PHI		65 min
Jul 22, 11:11 PM EDT	Special Weather Statement	PHI	Sussex	64 min
Jul 22, 11:26 PM EDT	Areal Flood Advisory	PHI	Sussex	4 hr
Jul 23, 3:53 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	4 hr
Jul 23, 4:15 PM EDT	Special Weather Statement	PHI	New Castle	30 min
Jul 23, 4:21 PM EDT	Areal Flood Advisory	PHI	Kent	3 hr
Jul 23, 4:26 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Jul 23, 4:44 PM EDT	Special Weather Statement	PHI	New Castle	16 min
Jul 23, 4:48 PM EDT	Areal Flood Advisory	PHI	New Castle	4 hr
Jul 23, 6:53 PM EDT	Flash Flood Warning	PHI	New Castle	14 hr

Nearby

Severe Thunderstorm Warnings in New Jersey, 2017 Severe Thunderstorm Warnings in Delaware, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.