Alert archive / Delaware / Special Weather Statements in 2015

Special Weather Statement, NWS Philadelphia/Mount Holly

August 20, 2015Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 20, 2015, 2:29 PM EDT for Kent County, Sussex County, Delaware. It was in force for 46 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 20, 2015, 2:29 PM EDT (18:29 UTC)
Expired
Aug 20, 2015, 3:15 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 14 km from the middle of the area, began a volume at 18:31 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, 6.5 hours before the alert went out and 85 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 2015-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 664 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 2015-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.1939Sfc1 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
664 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
705 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
46 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

330 
WWUS81 KPHI 201829
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
229 PM EDT THU AUG 20 2015
 
DEZ001>003-MDZ015-020-201915-
KENT-INLAND SUSSEX-NEW CASTLE-CAROLINE-QUEEN ANNE'S-
229 PM EDT THU AUG 20 2015

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTH CENTRAL NEW
CASTLE...KENT...CENTRAL SUSSEX...NORTHEASTERN QUEEN ANNE'S AND
NORTHEASTERN CAROLINE COUNTIES...

AT 228 PM EDT...A LINE OF STRONG THUNDERSTORMS WAS ALONG A LINE
EXTENDING FROM NEAR GOLDSBORO TO NEAR BRIDGEVILLE TO NEAR
PARSONSBURG...AND MOVING NORTHEAST AT 15 MPH.

TORRENTIAL RAINFALL IS OCCURRING WITH THESE STORMS...WILL LIKELY 
CAUSE PONDING OF WATER ON ROADWAYS AND POOR DRAINAGE AREAS. DO NOT 
DRIVE YOUR VEHICLE THROUGH AREAS OF HIGH WATER.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM. 
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE 
SHELTER INSIDE A BUILDING OR VEHICLE.

WIND GUSTS UP TO 30 MPH ARE POSSIBLE WITH THESE STORMS.

THESE STORMS WILL BE NEAR...
  GOLDSBORO AND SANDTOWN AROUND 235 PM EDT.
  HAZLETTVILLE AROUND 245 PM EDT.
  HARTLY AROUND 255 PM EDT.
  ANDREWSVILLE AROUND 300 PM EDT.
  ELLENDALE AROUND 305 PM EDT.
  DOVER...SMYRNA...MILFORD...MILLSBORO...HARRINGTON...CLAYTON...
CHESWOLD...DAGSBORO...GREEN SPRING AND DOVER SPEEDWAY AROUND 315 PM
EDT.

OTHER LOCATIONS IMPACTED BY THESE STORMS INCLUDE FREDERICA...
RIVERVIEW...MAGNOLIA...HOUSTON...FARMINGTON...KENTON...HENDERSON...
CHAMBERSVILLE...WYOMING AND MARYDEL.

LAT...LON 3846 7551 3908 7583 3941 7560 3859 7522
      3859 7523 3854 7519 3845 7531
TIME...MOT...LOC 1828Z 207DEG 13KT 3908 7575 3871 7557 3841 7543 
$$

ROBERTSON

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 2:46 PM EDTFlash Flood WatchPHIBurlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 5 more13 hr
Aug 20, 5:31 PM EDTAreal Flood AdvisoryPHIBerks6 hr
Aug 20, 5:43 PM EDTSpecial Weather StatementPHIBerks47 min
Aug 20, 7:14 PM EDTAreal Flood AdvisoryPHIChester4 hr
Aug 20, 1:53 PM EDTSpecial Weather StatementPHICaroline37 min
Aug 20, 3:26 PM EDTSpecial Weather StatementPHICecil49 min

Nearby

Special Weather Statements in Delaware, 2015Every special weather statement in 2015

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.