Alert archive / Delaware / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 23, NWS Philadelphia/Mount Holly

April 6, 2017Kent County, New Castle County, Sussex County, Delaware; Caroline County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Apr 6, 2017, 1:08 PM EDT for Kent County, New Castle County, Sussex County, Delaware; Caroline County, Talbot County, Maryland. It was in force for 40 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
Apr 6, 2017, 1:08 PM EDT (17:08 UTC)
Expired
Apr 6, 2017, 1:48 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, New Castle County, DE, Sussex County, DE, Caroline County, MD, Talbot County, MD

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 6, 12:45 PM EDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 5.1 hours before the alert went out and 92 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 2017-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 61 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 2017-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 square meters per square second.1939587897117Sfc1 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
61 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
1205 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

381 
WUUS51 KPHI 061708
SVRPHI
DEC001-003-005-MDC011-041-061800-
/O.NEW.KPHI.SV.W.0023.170406T1708Z-170406T1800Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
108 PM EDT THU APR 6 2017

The National Weather Service in Mount Holly NJ  has issued a

* Severe Thunderstorm Warning for...
  Sussex County in southern Delaware...
  South central New Castle County in northern Delaware...
  Kent County in central Delaware...
  Southeastern Talbot County in eastern Maryland...
  Caroline County in eastern Maryland...

* Until 200 PM EDT

* At 108 PM EDT, severe thunderstorms were located along a line
  extending from 6 miles south of Secretary to near Vienna to 11
  miles southwest of Hebron to near Deal Island to Tylerton, moving
  northeast at 60 mph.

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

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Severe thunderstorms will be near,
  Choptank and Windyhill around 115 PM EDT. 
  Federalsburg and Preston around 120 PM EDT. 
  Agner, Smithville and Harmony around 125 PM EDT. 
  Seaford, Denton, Bridgeville and Delmar around 130 PM EDT. 
  Laurel and Andrewsville around 135 PM EDT. 
  Harrington and Ellendale around 140 PM EDT. 
  Georgetown, Milford, Woodside, Viola and Hazlettville around 145 
  PM EDT. 
  Dover, Camden, Bowers, Sycamore, Dover Base Housing, Rising 
  Sun-Lebanon, Rising Sun and Dover Speedway around 150 PM EDT. 

Other locations impacted by these severe thunderstorms include
Kenton, Leipsic, Chambersville, Rodney Village, Blades, Greenwood,
Wyoming, Kent Acres, Magnolia and Riverview.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Seek shelter in an interior room on the lowest floor of a well-built 
structure. Abandon vehicles in search of a more substantial 
permanent structure. Stay away from windows.

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

&&

LAT...LON 3846 7569 3864 7571 3869 7577 3868 7580
      3870 7580 3871 7584 3868 7593 3860 7599
      3857 7604 3858 7604 3941 7560 3926 7537
      3905 7537 3890 7526 3847 7528 3845 7531
TIME...MOT...LOC 1708Z 212DEG 63KT 3851 7597 3846 7590 3833 7586 3815
7588 3797 7600

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

33
2 follow-up statements
421 
WWUS51 KPHI 061737
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
137 PM EDT THU APR 6 2017

MDC041-061746-
/O.CAN.KPHI.SV.W.0023.000000T0000Z-170406T1800Z/
Talbot MD-
137 PM EDT THU APR 6 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN TALBOT COUNTY IS
CANCELLED...

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

A severe thunderstorm watch remains in effect until 500 PM EDT for
central, northern and southern Delaware...and eastern Maryland.

LAT...LON 3846 7569 3875 7572 3890 7585 3941 7560
      3926 7537 3905 7537 3890 7526 3847 7528
      3845 7531
TIME...MOT...LOC 1736Z 270DEG 63KT 3888 7563 3883 7556 3870 7552 3852
7554 3834 7566

$$

DEC001-003-005-MDC011-061800-
/O.CON.KPHI.SV.W.0023.000000T0000Z-170406T1800Z/
Sussex DE-New Castle DE-Kent DE-Caroline MD-
137 PM EDT THU APR 6 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR SUSSEX...SOUTH CENTRAL NEW CASTLE...KENT AND NORTHEASTERN
CAROLINE COUNTIES...

At 136 PM EDT, severe thunderstorms were located along a line
extending from Andrewsville to 6 miles south of Harrington to near 
Bridgeville to near Laurel to near Fruitland, moving northeast at 60 
mph.

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

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

These severe storms will be near...
  Georgetown and Ellendale around 140 PM EDT. 
  Milford, Millsboro, Milton and Gumboro around 145 PM EDT. 

Other locations impacted by these severe thunderstorms include
Kenton, Leipsic, Chambersville, Rodney Village, Blades, Greenwood,
Wyoming, Kent Acres, Magnolia and Riverview.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3846 7569 3875 7572 3890 7585 3941 7560
      3926 7537 3905 7537 3890 7526 3847 7528
      3845 7531
TIME...MOT...LOC 1736Z 270DEG 63KT 3888 7563 3883 7556 3870 7552 3852
7554 3834 7566

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

33
301 
WWUS51 KPHI 061748
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
148 PM EDT THU APR 6 2017

DEC001-003-005-MDC011-061757-
/O.CAN.KPHI.SV.W.0023.000000T0000Z-170406T1800Z/
Sussex DE-New Castle DE-Kent DE-Caroline MD-
148 PM EDT THU APR 6 2017

...THE SEVERE THUNDERSTORM WARNING FOR SUSSEX...SOUTH CENTRAL NEW
CASTLE...KENT AND NORTHEASTERN CAROLINE COUNTIES IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning has been cancelled.  However gusty winds and
heavy rain are still possible with these thunderstorms.

A severe thunderstorm watch remains in effect until 500 PM EDT for
central, northern and southern Delaware...and eastern Maryland.

LAT...LON 3846 7569 3875 7572 3890 7585 3941 7560
      3926 7537 3905 7537 3890 7526 3847 7528
      3845 7531
TIME...MOT...LOC 1743Z 212DEG 63KT 3899 7554 3894 7547 3881 7543 3863
7545 3845 7557

$$

33

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 6, 12:17 PM EDTSevere Thunderstorm WarningPHIKent, New Castle24 min
Apr 6, 1:00 PM EDTSpecial Weather StatementPHIKent, Sussex60 min
Apr 6, 2:07 PM EDTSpecial Weather StatementPHIKent, Sussex53 min
Apr 6, 2:56 PM EDTSpecial Weather StatementPHIKent, New Castle64 min
Apr 6, 11:58 AM EDTAreal Flood AdvisoryPHICecil, Kent4 hr
Apr 6, 11:59 AM EDTSpecial Weather StatementPHICaroline31 min
Apr 6, 2:13 PM EDTSpecial Weather StatementPHIKent, Queen Anne's, Talbot47 min
Apr 6, 4:02 PM EDTAreal Flood AdvisoryPHICecil, Kent6 hr
Apr 6, 4:41 PM EDTSpecial Weather StatementPHITalbot34 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.