Alert archive / Delaware / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 91, NWS Philadelphia/Mount Holly

August 31, 2018Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 31, 2018, 12:35 PM EDT for Kent County, Sussex County, Delaware. It was in force for 40 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: Aug 31, 2018, 12:35 PM EDT (16:35 UTC)
Expired: Aug 31, 2018, 1:15 PM EDT
In force: 40 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 3 km from the middle of the area, began a volume at 16:34 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
Aug 31, 12:36 PM EDT	TSTM WND DMG	1 Wnw Milford, DE	NUMEROUS TREES AND LIMBS DOWN AROUND THE AREA.

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 4.6 hours before the alert went out and 100 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: 72 J/kg
Mixed-layer CIN: -177 J/kg
Mixed-layer LCL: 1245 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

017 
WUUS51 KPHI 311635
SVRPHI
DEC001-005-311715-
/O.NEW.KPHI.SV.W.0091.180831T1635Z-180831T1715Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1235 PM EDT FRI AUG 31 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 115 PM EDT.

* At 1234 PM EDT, a severe thunderstorm was located over Milton, or 9
  miles northeast of Georgetown, moving southeast 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, Milford, Harrington, Lewes, Milton, Bridgeville,
  Ellendale, Greenwood, Houston and Farmington.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. 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 3894 7559 3895 7537 3878 7513 3867 7548
      3868 7568
TIME...MOT...LOC 1634Z 305DEG 39KT 3882 7530 

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

jjm

2 follow-up statements

593 
WWUS51 KPHI 311654
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1254 PM EDT FRI AUG 31 2018

DEC001-005-311715-
/O.CON.KPHI.SV.W.0091.000000T0000Z-180831T1715Z/
Sussex DE-Kent DE-
1254 PM EDT FRI AUG 31 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM EDT
FOR NORTHERN SUSSEX AND SOUTH CENTRAL KENT COUNTIES...

At 1253 PM EDT, a severe thunderstorm was located over Ellendale, or
10 miles northwest of Georgetown, moving southeast 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.

This severe storm will be near...
  Ellendale around 110 PM EDT.
  Georgetown and Milton around 115 PM EDT.

Other locations impacted by this severe thunderstorm include
Greenwood and Houston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. Remember, if you can hear thunder, you are close enough
to be struck by lightning.

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

&&

LAT...LON 3871 7567 3878 7565 3887 7557 3891 7555
      3894 7540 3890 7530 3878 7513 3877 7515
      3867 7547
TIME...MOT...LOC 1653Z 335DEG 9KT 3883 7547 

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

JRK

388 
WWUS51 KPHI 311704
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
104 PM EDT FRI AUG 31 2018

DEC001-311714-
/O.CAN.KPHI.SV.W.0091.000000T0000Z-180831T1715Z/
Kent DE-
104 PM EDT FRI AUG 31 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL KENT COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3871 7564 3884 7556 3891 7547 3891 7538
      3887 7526 3878 7513 3877 7515 3873 7529
      3872 7531 3867 7547
TIME...MOT...LOC 1704Z 335DEG 9KT 3881 7545 

$$

DEC005-311715-
/O.CON.KPHI.SV.W.0091.000000T0000Z-180831T1715Z/
Sussex DE-
104 PM EDT FRI AUG 31 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 PM EDT
FOR NORTHERN SUSSEX COUNTY...

At 104 PM EDT, a severe thunderstorm was located over Ellendale, or 8
miles north of Georgetown, moving southeast 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.

This severe storm will be near...
  Georgetown and Milton around 115 PM EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large hail and damaging winds, frequent cloud to
ground lightning is occurring with this storm. Move indoors
immediately. 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 3871 7564 3884 7556 3891 7547 3891 7538
      3887 7526 3878 7513 3877 7515 3873 7529
      3872 7531 3867 7547
TIME...MOT...LOC 1704Z 335DEG 9KT 3881 7545 

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

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 1:37 AM EDT	Special Weather Statement	PHI	Sussex	53 min
Aug 31, 10:57 AM EDT	Areal Flood Advisory	PHI	Kent	107 min
Aug 31, 11:31 AM EDT	Flash Flood Warning	PHI	Kent	11 hr
Aug 31, 11:53 AM EDT	Special Weather Statement	PHI	Kent	37 min
Aug 31, 12:00 PM EDT	Severe Thunderstorm Warning	PHI	Kent	15 min
Aug 31, 12:15 PM EDT	Flash Flood Warning	PHI	Kent, Sussex	7 hr
Aug 31, 12:28 PM EDT	Special Weather Statement	PHI	Kent	32 min
Aug 31, 12:54 PM EDT	Flash Flood Warning	PHI	Sussex	4 hr
Aug 31, 1:09 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	51 min
Aug 31, 1:58 PM EDT	Special Weather Statement	PHI	Sussex	32 min
Aug 31, 4:27 PM EDT	Special Weather Statement	PHI	Sussex	18 min
Aug 31, 4:32 PM EDT	Flash Flood Warning	PHI	Sussex	4 hr
Aug 31, 4:41 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle	4 hr
Aug 31, 4:42 PM EDT	Special Weather Statement	PHI	Sussex	33 min
Aug 31, 5:00 PM EDT	Flash Flood Warning	PHI	New Castle	4 hr
Aug 31, 5:14 PM EDT	Special Weather Statement	PHI	Sussex	46 min
Aug 31, 5:38 PM EDT	Areal Flood Advisory	PHI	Kent, New Castle, Sussex	4 hr
Aug 31, 5:48 PM EDT	Flash Flood Warning	PHI	Sussex	3 hr
Aug 31, 7:11 PM EDT	Areal Flood Warning	PHI	Kent, Sussex	4 hr
Aug 31, 7:37 PM EDT	Flash Flood Warning	PHI	Kent, New Castle	4 hr

Nearby

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.