Alert archive / Delaware / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 72, NWS Philadelphia/Mount Holly

August 11, 2018Kent County, New Castle County, Delaware; Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2018, 6:08 PM EDT for Kent County, New Castle County, Delaware; Kent County, Queen Anne's County, Maryland. It was in force for 52 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 11, 2018, 6:08 PM EDT (22:08 UTC)
Expired
Aug 11, 2018, 7:00 PM EDT
In force
52 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Kent County, DE, New Castle County, DE, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 62 km from the middle of the area, began a volume at 22:12 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.1 hours before the alert went out and 122 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, Washington/Dulle, VA at 12:00Z on 2018-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 963 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, Washington/Dulle, VA at 12:00Z on 2018-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 square meters per square second.193958Sfc1 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
963 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1021 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

As transmitted.

703 
WUUS51 KPHI 112208
SVRPHI
DEC001-003-MDC029-035-112300-
/O.NEW.KPHI.SV.W.0072.180811T2208Z-180811T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
608 PM EDT SAT AUG 11 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern New Castle County in northern Delaware...
  Northern Kent County in central Delaware...
  Central Queen Anne's County in northeastern Maryland...
  Kent County in northeastern Maryland...

* Until 700 PM EDT.

* At 607 PM EDT, severe thunderstorms were located along a line
  extending from near Hope Creek to Green Spring to near Millington
  to near Bodkin Point, moving east at 15 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.

* Severe thunderstorms will be near...
  Clayton, Green Spring, Massey and Crumpton around 615 PM EDT.
  Millington around 620 PM EDT.
  Smyrna and Sudlersville around 625 PM EDT.
  Delaney Corner around 635 PM EDT.
  Dover and Woodland Beach around 650 PM EDT.
  Langford around 655 PM EDT.
  Centreville, Cheswold, Hartly, Overton and Old Town around 700 PM 
  EDT.

Other locations impacted by these severe thunderstorms include
Templeville, Kenton, Townsend, Barclay, Leipsic, Chambersville,
Kingstown and Odessa.

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 these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3904 7631 3903 7630 3903 7625 3905 7623
      3909 7623 3915 7628 3922 7625 3937 7573
      3943 7572 3948 7557 3927 7537 3924 7537
      3914 7573 3901 7622 3902 7632
TIME...MOT...LOC 2207Z 292DEG 11KT 3942 7559 3934 7565 3928 7588 3914
7637

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

JRK
3 follow-up statements
197 
WWUS51 KPHI 112231
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
631 PM EDT SAT AUG 11 2018

DEC001-003-MDC029-035-112300-
/O.CON.KPHI.SV.W.0072.000000T0000Z-180811T2300Z/
New Castle DE-Kent DE-Queen Anne's MD-Kent MD-
631 PM EDT SAT AUG 11 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR SOUTH CENTRAL NEW CASTLE...NORTHERN KENT...NORTHEASTERN QUEEN
ANNE'S AND CENTRAL KENT COUNTIES...

At 630 PM EDT, severe thunderstorms were located along a line
extending from 6 miles south of Hope Creek to near Woodland Beach to
near Clayton to Langford, moving southeast at 10 mph.

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

SOURCE...Radar indicated.

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

These severe storms will be near...
  Smyrna, Clayton and Green Spring around 635 PM EDT.
  Woodland Beach around 650 PM EDT.
  Dover, Centreville, Cheswold, Church Hill, Hartly, Starkey Corner 
  and Overton around 700 PM EDT.

Other locations impacted by these severe thunderstorms include
Templeville, Kenton, Barclay, Leipsic, Chambersville and Kingstown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to 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 also occurring with these storms, and may 
lead to flash flooding. Do not drive your vehicle through flooded 
roadways.

&&

LAT...LON 3921 7624 3932 7575 3941 7558 3945 7555
      3927 7537 3924 7537 3901 7620 3902 7621
      3909 7623 3916 7627
TIME...MOT...LOC 2230Z 328DEG 11KT 3938 7552 3935 7554 3928 7568 3917
7616

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

JRK
398 
WWUS51 KPHI 112244
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
644 PM EDT SAT AUG 11 2018

DEC003-112254-
/O.CAN.KPHI.SV.W.0072.000000T0000Z-180811T2300Z/
New Castle DE-
644 PM EDT SAT AUG 11 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL NEW CASTLE
COUNTY IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3921 7617 3928 7582 3927 7569 3931 7562
      3931 7558 3935 7556 3939 7549 3927 7537
      3924 7537 3913 7579 3911 7582 3901 7618
      3902 7621 3915 7626
TIME...MOT...LOC 2244Z 312DEG 11KT 3930 7551 3922 7567 3922 7582 3914
7610

$$

DEC001-MDC029-035-112300-
/O.CON.KPHI.SV.W.0072.000000T0000Z-180811T2300Z/
Kent DE-Queen Anne's MD-Kent MD-
644 PM EDT SAT AUG 11 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM EDT
FOR NORTHERN KENT...NORTHEASTERN QUEEN ANNE'S AND SOUTHERN KENT
COUNTIES...

At 644 PM EDT, severe thunderstorms were located along a line
extending from near Woodland Beach to near Hartly to near Millington
to Old Town, 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.

These severe storms will be near...
  Smyrna, Clayton, Hartly and Woodland Beach around 650 PM EDT.
  Dover and Cheswold around 700 PM EDT.

Other locations impacted by these severe thunderstorms include
Kenton, Barclay, Leipsic, Kingstown and Templeville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to 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 also occurring with these storms, and may 
lead to flash flooding. Do not drive your vehicle through flooded 
roadways.

&&

LAT...LON 3921 7617 3928 7582 3927 7569 3931 7562
      3931 7558 3935 7556 3939 7549 3927 7537
      3924 7537 3913 7579 3911 7582 3901 7618
      3902 7621 3915 7626
TIME...MOT...LOC 2244Z 312DEG 11KT 3930 7551 3922 7567 3922 7582 3914
7610

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

JRK
634 
WWUS51 KPHI 112257
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
657 PM EDT SAT AUG 11 2018

DEC001-MDC029-035-112306-
/O.EXP.KPHI.SV.W.0072.000000T0000Z-180811T2300Z/
Kent DE-Queen Anne's MD-Kent MD-
657 PM EDT SAT AUG 11 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN KENT...NORTHEASTERN
QUEEN ANNE'S AND SOUTHERN KENT COUNTIES WILL EXPIRE AT 700 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

Remember, a Severe Thunderstorm Warning still remains in effect 
farther south and east for portions of Queen Anne's County in 
Maryland and Kent County in Delaware until 745 PM.

LAT...LON 3921 7617 3928 7582 3927 7569 3931 7562
      3931 7558 3935 7556 3939 7549 3927 7537
      3924 7537 3913 7579 3911 7582 3901 7618
      3902 7621 3915 7626
TIME...MOT...LOC 2256Z 292DEG 11KT 3929 7547 3921 7563 3921 7578 3913
7606

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 3:24 AM EDTFlash Flood WatchPHIKent, New Castle20 hr
Aug 11, 4:26 AM EDTCoastal Flood AdvisoryPHIKent, New Castle, Sussex24 hr
Aug 11, 1:23 PM EDTSevere Thunderstorm WarningPHISussex37 min
Aug 11, 4:19 PM EDTAreal Flood AdvisoryPHINew Castle3 hr
Aug 11, 4:19 PM EDTSevere Thunderstorm WarningPHINew Castle29 min
Aug 11, 5:20 PM EDTAreal Flood AdvisoryPHIKent, New Castle4 hr
Aug 11, 6:12 PM EDTFlash Flood WarningPHIKent, New Castle3 hr
Aug 11, 6:45 PM EDTFlash Flood WarningPHIKent5 hr
Aug 11, 6:55 PM EDTSevere Thunderstorm WarningPHIKent50 min
Aug 11, 7:42 PM EDTSpecial Weather StatementPHIKent48 min
Aug 11, 5:24 PM EDTSpecial Weather StatementPHICecil36 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2018Severe Thunderstorm Warnings in Maryland, 2018Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.