Alert archive / Delaware / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 148, NWS Philadelphia/Mount Holly

August 2, 2017Kent County, Delaware; Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 2, 2017, 7:58 PM EDT for Kent County, Delaware; Caroline County, Maryland. It was in force for 47 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
Aug 2, 2017, 7:58 PM EDT (23:58 UTC)
Expired
Aug 2, 2017, 8:45 PM EDT
In force
47 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Kent County, DE, Caroline County, MD

The radar

The Dover AFB radar (KDOX), 24 km from the middle of the area, began a volume at 00:03 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, 12.0 hours before the alert went out and 119 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-pSkew-T log-p diagram, Wallops Is Stn, VA at 12:00Z on 2017-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 161 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 12:00Z on 2017-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
161 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
1466 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

497 
WUUS51 KPHI 022358
SVRPHI
DEC001-MDC011-030045-
/O.NEW.KPHI.SV.W.0148.170802T2358Z-170803T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
758 PM EDT WED AUG 2 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southern Kent County in central Delaware...
  Northeastern Caroline County in eastern Maryland...

* Until 845 PM EDT

* At 757 PM EDT, a severe thunderstorm was located over Sandtown, or
  13 miles southwest of Dover, moving east at 25 mph.

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

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to trees and power lines. 

* Locations impacted include...
  Milford, Harrington, Camden, Greensboro, Bowers, Goldsboro,
  Woodside, Viola, Rising Sun-Lebanon, Rising Sun, Hazlettville,
  Sandtown, Andrewsville, Wyoming, Felton, Frederica, Houston,
  Magnolia, Henderson and Marydel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3900 7587 3916 7572 3907 7537 3903 7536
      3884 7555 3883 7562
TIME...MOT...LOC 2357Z 282DEG 21KT 3905 7573 

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

po
1 follow-up statement
549 
WWUS51 KPHI 030025
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
825 PM EDT WED AUG 2 2017

MDC011-030035-
/O.CAN.KPHI.SV.W.0148.000000T0000Z-170803T0045Z/
Caroline MD-
825 PM EDT WED AUG 2 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CAROLINE COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. 

LAT...LON 3896 7569 3912 7564 3907 7537 3903 7536
      3886 7553 3885 7555 3885 7560
TIME...MOT...LOC 0025Z 270DEG 19KT 3903 7553 

$$

DEC001-030045-
/O.CON.KPHI.SV.W.0148.000000T0000Z-170803T0045Z/
Kent DE-
825 PM EDT WED AUG 2 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM EDT
FOR SOUTHERN KENT COUNTY...

At 825 PM EDT, a severe thunderstorm was located over Viola, or 9
miles south of Dover, moving east at 20 mph.

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

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

Locations impacted include...
Milford, Harrington, Camden, Bowers, Woodside, Viola, Rising
Sun-Lebanon, Felton, Frederica, Houston, Magnolia, Farmington,
Riverview and Woodside East.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3896 7569 3912 7564 3907 7537 3903 7536
      3886 7553 3885 7555 3885 7560
TIME...MOT...LOC 0025Z 270DEG 19KT 3903 7553 

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

po

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 12:28 PM EDTAreal Flood AdvisoryPHINew Castle4 hr
Aug 2, 1:44 PM EDTFlash Flood WarningPHINew Castle4 hr
Aug 2, 3:16 PM EDTAreal Flood AdvisoryPHIKent7 hr
Aug 2, 6:27 PM EDTSpecial Weather StatementPHIKent33 min
Aug 2, 6:00 PM EDTSpecial Weather StatementPHIKent30 min
Aug 2, 6:21 PM EDTSpecial Weather StatementPHIQueen Anne's39 min
Aug 2, 6:28 PM EDTAreal Flood AdvisoryPHIKent, Queen Anne's4 hr
Aug 2, 6:55 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's35 min
Aug 2, 7:30 PM EDTSpecial Weather StatementPHICaroline, Queen Anne's45 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2017Severe Thunderstorm Warnings in Maryland, 2017Every severe thunderstorm warning in 2017

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.