Alert archive / Delaware / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 90, NWS Philadelphia/Mount Holly

August 31, 2018Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 31, 2018, 12:00 PM EDT for Kent County, Delaware. It was in force for 15 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, 12:00 PM EDT (16:00 UTC)
Expired: Aug 31, 2018, 12:15 PM EDT
In force: 15 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 22 km from the middle of the area, began a volume at 15:59 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, 12:05 PM EDT	TSTM WND DMG	2 S Viola, DE	TREE FELL ON A HOUSE IN FELTON, DE. NUMEROUS TREES DOWN THROUGHOUT THE AREA. TIME ESTIMATED BY RADAR.

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, 4.0 hours before the alert went out and 121 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.

745 
WUUS51 KPHI 311600
SVRPHI
DEC001-311615-
/O.NEW.KPHI.SV.W.0090.180831T1600Z-180831T1615Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
1200 PM EDT FRI AUG 31 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 1215 PM EDT.

* At 1159 AM EDT, a severe thunderstorm was located near 
  Andrewsville, or 13 miles northwest of Georgetown, and nearly 
  stationary. 

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Woodside, Viola, Felton, Frederica, Riverview and Woodside East. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3907 7557 3905 7540 3896 7533 3894 7561
TIME...MOT...LOC 1559Z 018DEG 48KT 3883 7556 

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

jjm

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, 12:15 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, 12:35 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	40 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.