Alert archive / Delaware / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 13, NWS Philadelphia/Mount Holly

February 25, 2017Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Feb 25, 2017, 4:50 PM EST for Kent County, Sussex County, Delaware; Caroline County, Talbot County, Maryland. It was in force for 55 min. 2 reports 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: Feb 25, 2017, 4:50 PM EST (21:50 UTC)
Expired: Feb 25, 2017, 5:45 PM EST
In force: 55 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Kent County, DE, Sussex County, DE, Caroline County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 26 km from the middle of the area, began a volume at 21:54 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
Feb 25, 5:09 PM EST	HAIL 0.25	Dover Afb, DE
Feb 25, 5:09 PM EST	HAIL 0.25	Farmington, DE

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

The watch it was issued in

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

Issued	Product	Office	Lasted
Feb 25, 1:30 PM EST	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 9.8 hours before the alert went out and 97 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 960 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 68 m²/s²
0-3 km storm-relative helicity: 83 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

229 
WUUS51 KPHI 252150
SVRPHI
DEC001-005-MDC011-041-252245-
/O.NEW.KPHI.SV.W.0013.170225T2150Z-170225T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
450 PM EST SAT FEB 25 2017

The National Weather Service in Mount Holly NJ  has issued a

* Severe Thunderstorm Warning for...
  Northern Sussex County in southern Delaware...
  Southern Kent County in central Delaware...
  Southeastern Talbot County in eastern Maryland...
  Southern Caroline County in eastern Maryland...

* Until 545 PM EST

* At 448 PM EST, severe thunderstorms were located along a line
  extending from Camden to near Andrewsville to near Trappe, moving
  east at 40 mph.

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

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Severe thunderstorms will be near,
  Dover, Harrington, Camden, Woodside, Dover Base Housing, Rising 
  Sun-Lebanon, Rising Sun and Andrewsville around 455 PM EST. 
  Viola around 500 PM EST. 
  Harmony around 505 PM EST. 
  Milford around 510 PM EST. 
  Federalsburg, Bowers and Agner around 515 PM EST. 
  Smithville around 520 PM EST. 
  Seaford around 525 PM EST. 
  Bridgeville around 530 PM EST. 

Other locations impacted by these severe thunderstorms include
Highland Acres, Felton, Rodney Village, Woodside East, Frederica,
Greenwood, Wyoming, Farmington, Magnolia and Riverview.

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.

&&

LAT...LON 3860 7606 3863 7610 3891 7576 3910 7568
      3916 7537 3903 7536 3892 7528 3885 7518
      3872 7529 3864 7571 3869 7577 3868 7580
      3871 7584 3870 7590 3866 7596 3859 7599
      3858 7605
TIME...MOT...LOC 2148Z 253DEG 36KT 3912 7558 3893 7568 3862 7607 

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

Robertson

1 follow-up statement

559 
WWUS51 KPHI 252227
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
527 PM EST SAT FEB 25 2017

MDC041-252237-
/O.CAN.KPHI.SV.W.0013.000000T0000Z-170225T2245Z/
Talbot MD-
527 PM EST SAT FEB 25 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 800 PM EST for
central and southern Delaware...and eastern Maryland.

LAT...LON 3869 7577 3909 7539 3893 7529 3885 7518
      3872 7530 3864 7571
TIME...MOT...LOC 2227Z 261DEG 32KT 3903 7529 3872 7569 

$$

DEC001-005-MDC011-252245-
/O.CON.KPHI.SV.W.0013.000000T0000Z-170225T2245Z/
Sussex DE-Kent DE-Caroline MD-
527 PM EST SAT FEB 25 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EST
FOR NORTHERN SUSSEX...SOUTHEASTERN KENT AND SOUTHEASTERN CAROLINE
COUNTIES...

At 527 PM EST, severe thunderstorms were located along a line
extending from near Big Stone Beach to near Smithville, moving east
at 35 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 545 PM EST. 

Other locations impacted by these severe thunderstorms include
Farmington, Frederica, 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.

&&

LAT...LON 3869 7577 3909 7539 3893 7529 3885 7518
      3872 7530 3864 7571
TIME...MOT...LOC 2227Z 261DEG 32KT 3903 7529 3872 7569 

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

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 25, 4:04 PM EST	Severe Thunderstorm Warning	PHI	Kent, New Castle	41 min
Feb 25, 4:11 PM EST	Severe Thunderstorm Warning	PHI	Kent	49 min
Feb 25, 4:40 PM EST	Severe Thunderstorm Warning	PHI	Kent, New Castle	50 min
Feb 25, 5:42 PM EST	Special Weather Statement	PHI	New Castle	33 min
Feb 25, 5:45 PM EST	Special Weather Statement	PHI	Sussex	30 min
Feb 25, 5:46 PM EST	Special Weather Statement	PHI	Sussex	29 min
Feb 25, 3:05 PM EST	Special Weather Statement	PHI	Cecil, Kent, Queen Anne's, Talbot	55 min
Feb 25, 3:18 PM EST	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	57 min
Feb 25, 3:26 PM EST	Severe Thunderstorm Warning	PHI	Cecil	64 min
Feb 25, 5:07 PM EST	Special Weather Statement	PHI	Kent	38 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2017 Severe Thunderstorm Warnings in Maryland, 2017 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.