Alert archive / Delaware / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

August 15, 2017Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 15, 2017, 3:25 PM EDT for Sussex County, Delaware. It was in force for 50 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 15, 2017, 3:25 PM EDT (19:25 UTC)
Expired: Aug 15, 2017, 4:15 PM EDT
In force: 50 min
Issued by: NWS Philadelphia/Mount Holly

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 45 km from the middle of the area, began a volume at 19:25 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, 7.4 hours before the alert went out and 71 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: 499 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 656 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

788 
WWUS81 KPHI 151925
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
325 PM EDT TUE AUG 15 2017

DEZ003-004-152015-
Inland Sussex-Delaware Beaches-
325 PM EDT TUE AUG 15 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTHEASTERN SUSSEX
COUNTY...

At 325 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Millville to near Selbyville to near
Berlin. Movement was east at 15 mph.

Wind gusts up to 30 mph and are possible with this storm.

Heavy rainfall is also occurring with this storm...and may cause 
ponding on roadways and poor drainage areas. Do not drive your 
vehicle through flooded roadways.

Occasional lightning is occurring with this storm. Lightning can 
strike 15 miles away from a thunderstorm. If you see lightning or 
hear thunder seek a safe shelter inside a building or vehicle.

Locations impacted include...
Millville, Ocean View and South Bethany. 

LAT...LON 3856 7510 3858 7506 3854 7506 3854 7505
      3845 7505 3845 7523
TIME...MOT...LOC 1925Z 273DEG 14KT 3853 7508 3844 7520 3834 7530 

$$

Robertson

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 14, 9:44 PM EDT	Small Craft Advisory for Hazardous Seas	PHI		41 hr
Aug 15, 6:06 PM EDT	Areal Flood Advisory	PHI	Cumberland	4 hr
Aug 15, 6:54 PM EDT	Rip Current Statement	PHI	Atlantic, Cape May, Monmouth, Ocean	26 hr
Aug 15, 1:06 PM EDT	Areal Flood Advisory	PHI	Chester	4 hr
Aug 15, 1:39 PM EDT	Special Weather Statement	PHI	Kent	66 min
Aug 15, 2:54 PM EDT	Special Weather Statement	PHI	Queen Anne's	51 min
Aug 15, 3:21 PM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	4 hr

Nearby

Special Weather Statements in Delaware, 2017 Every special weather statement 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.