Alert archive / Delaware / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 41, NWS Philadelphia/Mount Holly

May 20, 2019Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 20, 2019, 5:57 PM EDT for Sussex County, Delaware. It was in force for 20 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: May 20, 2019, 5:57 PM EDT (21:57 UTC)
Expired: May 20, 2019, 6:17 PM EDT
In force: 20 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 32 km from the middle of the area, began a volume at 22:00 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, 10.0 hours before the alert went out and 78 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: 307 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 1193 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 118 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

762 
WUUS51 KPHI 202157
SVRPHI
DEC005-202245-
/O.NEW.KPHI.SV.W.0041.190520T2157Z-190520T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
557 PM EDT Mon May 20 2019

The National Weather Service in Mount Holly NJ has issued a

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

* Until 645 PM EDT.

* At 556 PM EDT, a severe thunderstorm was located over Sharptown, or
  11 miles northwest of Salisbury, moving east at 40 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Seaford, Millsboro, Laurel, Lewes, Selbyville, Delmar,
  Dagsboro, Millville, Henlopen Acres, Gumboro, Sycamore, Long Neck,
  Ocean View, Blades, Frankford, South Bethany, Dewey Beach and
  Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3846 7569 3865 7571 3879 7509 3867 7507
      3869 7508 3869 7514 3864 7513 3862 7508
      3866 7507 3861 7506 3862 7511 3859 7521
      3857 7518 3860 7509 3858 7509 3860 7507
      3860 7506 3845 7505
TIME...MOT...LOC 2156Z 257DEG 33KT 3852 7570 

HAIL...0.88IN
WIND...60MPH
 
$$

Fitzsimmons

1 follow-up statement

175 
WWUS51 KPHI 202217
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
617 PM EDT Mon May 20 2019

DEC005-202226-
/O.CAN.KPHI.SV.W.0041.000000T0000Z-190520T2245Z/
Sussex DE-
617 PM EDT Mon May 20 2019

...THE SEVERE THUNDERSTORM WARNING FOR 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.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 3846 7569 3865 7571 3879 7509 3867 7507
      3869 7508 3869 7514 3864 7513 3862 7508
      3866 7507 3861 7506 3862 7511 3859 7521
      3857 7518 3860 7509 3858 7509 3860 7507
      3860 7506 3845 7505
TIME...MOT...LOC 2215Z 257DEG 33KT 3856 7546 

$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 6:50 PM EDT	Areal Flood Advisory	PHI	Sussex	3 hr

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.