Alert archive / Delaware / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 232, NWS Philadelphia/Mount Holly

July 17, 2019Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 17, 2019, 8:30 PM EDT for Sussex County, Delaware. It was in force for 45 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: Jul 17, 2019, 8:30 PM EDT (00:30 UTC)
Expired: Jul 17, 2019, 9:15 PM EDT
In force: 45 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), 33 km from the middle of the area, began a volume at 00:31 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.

What was reported inside it

Time	Report	Where	Remark
Jul 17, 8:55 PM EDT	TSTM WND DMG	3 Wnw Harbeson, DE	NUMEROUS TREES DOWN IN A LONG CORRIDOR BETWEEN GEORGETOWN AND LEWES. RADAR INDICATED STRONG DOWNBURST OR MICROBURST SIGNATURE. 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, 4:51 PM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.5 hours before the alert went out and 68 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.

738 
WUUS51 KPHI 180030
SVRPHI
DEC005-180115-
/O.NEW.KPHI.SV.W.0232.190718T0030Z-190718T0115Z/

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

The National Weather Service in Mount Holly NJ has issued a

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

* Until 915 PM EDT.

* At 829 PM EDT, a severe thunderstorm was located near Sharptown, or
  10 miles northwest of Salisbury, moving northeast at 25 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Georgetown, Seaford, Millsboro, Laurel, Delmar, Sycamore, Gumboro,
  Blades and Bethel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3846 7569 3849 7570 3864 7570 3876 7533
      3850 7528 3845 7529
TIME...MOT...LOC 0029Z 246DEG 22KT 3851 7568 

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

Fitzsimmons

2 follow-up statements

824 
WWUS51 KPHI 180053
SVSPHI

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

DEC005-180115-
/O.CON.KPHI.SV.W.0232.000000T0000Z-190718T0115Z/
Sussex DE-
853 PM EDT Wed Jul 17 2019

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM EDT
FOR SOUTH CENTRAL SUSSEX COUNTY...

At 853 PM EDT, a severe thunderstorm was located near Georgetown,
moving northeast at 30 mph.

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

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Georgetown, Millsboro, Delmar, Sycamore and Gumboro. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 3846 7558 3864 7553 3876 7533 3850 7528
      3845 7529
TIME...MOT...LOC 0053Z 245DEG 28KT 3863 7536 

HAIL...1.00IN
WIND...60MPH
 
$$

Staarmann

610 
WWUS51 KPHI 180112
SVSPHI

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

DEC005-180120-
/O.EXP.KPHI.SV.W.0232.000000T0000Z-190718T0115Z/
Sussex DE-
912 PM EDT Wed Jul 17 2019

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL SUSSEX COUNTY
WILL EXPIRE AT 915 PM EDT...
        
The storm which prompted the warning is moving out of the area.
Therefore, the warning will be allowed to expire. However gusty 
winds are still possible with this thunderstorm as it's moving out. 

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

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Mount Holly NJ.

LAT...LON 3846 7558 3864 7553 3876 7533 3850 7528
      3845 7529
TIME...MOT...LOC 0110Z 246DEG 22KT 3867 7525 

$$

Fitzsimmons

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 8:54 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	36 min
Jul 17, 9:09 PM EDT	Areal Flood Advisory	PHI	Sussex	2 hr
Jul 17, 11:34 PM EDT	Areal Flood Advisory	PHI	Sussex	2 hr
Jul 18, 1:30 PM EDT	Areal Flood Advisory	PHI	New Castle	4 hr
Jul 18, 2:24 PM EDT	Areal Flood Advisory	PHI	New Castle	3 hr
Jul 18, 2:55 PM EDT	Flash Flood Warning	PHI	New Castle	4 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.