Alert archive / Delaware / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 294, NWS Philadelphia/Mount Holly

July 31, 2019Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 31, 2019, 4:33 PM EDT for Sussex County, Delaware. It was in force for 9 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 31, 2019, 4:33 PM EDT (20:33 UTC)
Expired: Jul 31, 2019, 4:42 PM EDT
In force: 9 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 35 km from the middle of the area, began a volume at 20:36 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 31, 1:17 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.6 hours before the alert went out and 79 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: 80 J/kg
Mixed-layer CIN: -82 J/kg
Mixed-layer LCL: 1478 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 41 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted.

520 
WUUS51 KPHI 312033
SVRPHI
DEC005-312115-
/O.NEW.KPHI.SV.W.0294.190731T2033Z-190731T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
433 PM EDT Wed Jul 31 2019

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southeastern Sussex County in southern Delaware...

* Until 515 PM EDT.

* At 433 PM EDT, a severe thunderstorm was located near Millsboro, or
  near Georgetown, moving east at 10 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Millsboro, Dagsboro, Millville, Henlopen Acres, Long
  Neck, Ocean View, Frankford, South Bethany and Dewey Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3854 7537 3872 7538 3877 7508 3867 7507
      3869 7514 3864 7513 3862 7508 3866 7507
      3861 7506 3859 7521 3857 7518 3858 7507
      3860 7509 3860 7506 3852 7505 3851 7505
TIME...MOT...LOC 2033Z 267DEG 8KT 3864 7529 

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

MPS

1 follow-up statement

890 
WWUS51 KPHI 312042
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
442 PM EDT Wed Jul 31 2019

DEC005-312051-
/O.CAN.KPHI.SV.W.0294.000000T0000Z-190731T2115Z/
Sussex DE-
442 PM EDT Wed Jul 31 2019

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SUSSEX COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until 900 PM EDT for
southern Delaware.

LAT...LON 3854 7537 3872 7538 3877 7508 3867 7507
      3869 7514 3864 7513 3862 7508 3866 7507
      3861 7506 3859 7521 3857 7518 3858 7507
      3860 7509 3860 7506 3852 7505 3851 7505
TIME...MOT...LOC 2040Z 267DEG 8KT 3864 7527 

$$

MPS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 3:28 AM EDT	Flash Flood Watch	PHI	New Castle	17 hr
Jul 31, 2:46 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	44 min
Jul 31, 4:00 PM EDT	Special Weather Statement	PHI	Sussex	30 min
Jul 31, 6:05 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	26 min

Nearby

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