Alert archive / Delaware / Special Weather Statements in 2010

Special Weather Statement, NWS Philadelphia/Mount Holly

August 17, 2010Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 17, 2010, 3:21 PM EDT for Sussex County, Delaware. It was in force for 54 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 17, 2010, 3:21 PM EDT (19:21 UTC)
Expired
Aug 17, 2010, 4:15 PM EDT
In force
54 min
Issued by
NWS Philadelphia/Mount Holly

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 22 km from the middle of the area, began a volume at 19:23 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 91 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 2010-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 494 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 2010-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
494 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
1086 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
36 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.

785 
WWUS81 KPHI 171921
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
321 PM EDT TUE AUG 17 2010

DEZ002>004-172015-
DELAWARE BEACHES DE-INLAND SUSSEX DE-KENT DE-
321 PM EDT TUE AUG 17 2010

...STRONG THUNDERSTORMS WILL AFFECT KENT AND SUSSEX COUNTIES...

AT 313 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
STRONG THUNDERSTORMS CONTINUE TO FORM AS A SEA BREEZE FRONT MOVES TO 
THE WEST. THE LATEST WESTERN EXTENT OF THE STORMS EXTEND ALONG A 
LINE FROM 15 MILES NORTHEAST OF GEORGETOWN TO 4 MILES SOUTH OF 
GEORGETOWN...MOVING SOUTHEAST AT 15 MPH. THE THUNDERSTORMS WILL BE 
NEAR LEWES AROUND 345 PM...DEWEY BEACH...HENLOPEN ACRES AROUND 400 
PM...FRANKFORD AND LONG NECK AROUND 415 PM.

HEAVY RAIN WILL FALL FROM THESE STORMS...AND WILL CAUSE WATER TO 
POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS.
A FLASH FLOOD WARNING REMAINS IN EFFECT FOR THE EXTREME SOUTHEASTERN 
PART OF SUSSEX COUNTY.

LAT...LON 3845 7530 3863 7551 3902 7533 3898 7529
      3893 7530 3889 7525 3883 7521 3879 7513
      3879 7511 3881 7509 3880 7507 3847 7503
      3844 7505

$$

TFG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 12:19 AM EDTSpecial Weather StatementPHIMonmouth41 min
Aug 17, 1:29 PM EDTSpecial Weather StatementPHIAtlantic61 min
Aug 17, 1:32 PM EDTSpecial Marine WarningPHI88 min
Aug 17, 2:42 PM EDTSpecial Weather StatementPHIAtlantic63 min
Aug 17, 2:58 PM EDTSpecial Marine WarningPHI2 hr
Aug 17, 3:27 PM EDTAreal Flood AdvisoryPHIAtlantic2 hr
Aug 17, 3:40 PM EDTSpecial Marine WarningPHI95 min
Aug 17, 3:58 PM EDTFlash Flood WarningPHIAtlantic3 hr
Aug 16, 9:52 PM EDTSpecial Weather StatementPHIChester113 min
Aug 16, 11:28 PM EDTSpecial Weather StatementPHIBucks, Montgomery62 min
Aug 17, 1:23 PM EDTSpecial Weather StatementPHISussex82 min
Aug 17, 2:21 PM EDTAreal Flood AdvisoryPHISussex114 min
Aug 17, 2:36 PM EDTFlash Flood WarningPHISussex2 hr
Aug 17, 4:23 PM EDTSpecial Weather StatementPHISussex112 min

Nearby

Special Weather Statements in Delaware, 2010Every special weather statement in 2010

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.