Alert archive / Delaware / Special Weather Statements in 2011

Special Weather Statement, NWS Philadelphia/Mount Holly

August 21, 2011Kent County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Aug 21, 2011, 9:19 AM EDT for Kent County, Delaware. It was in force for 56 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 21, 2011, 9:19 AM EDT (13:19 UTC)
Expired
Aug 21, 2011, 10:15 AM EDT
In force
56 min
Issued by
NWS Philadelphia/Mount Holly

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 56 km from the middle of the area, began a volume at 13:20 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 1.3 hours before the alert went out and 144 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, Washington/Dulle, VA at 12:00Z on 2011-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1589 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, Washington/Dulle, VA at 12:00Z on 2011-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
1589 J/kg
Mixed-layer CIN
-99 J/kg
Mixed-layer LCL
969 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.6
Supercell composite
4.9

Open this sounding in Storm Lab

The text

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

880 
WWUS81 KPHI 211319
SPSPHI

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
919 AM EDT SUN AUG 21 2011

DEZ002-MDZ015-211415-
KENT DE-QUEEN ANNE'S MD-
919 AM EDT SUN AUG 21 2011

...STRONG THUNDERSTORMS WILL AFFECT KENT AND QUEEN ANNE'S COUNTIES...

AT 916 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 11 MILES SOUTHWEST
OF MIDDLETOWN TO 11 MILES NORTH OF CENTERVILLE...MOVING EAST AT 20
MPH. THE THUNDERSTORMS WILL BE NEAR CRUMPTON AROUND 930 AM...
MILLINGTON AROUND 935 AM...DELANEY CORNER AROUND 940 AM...
SUDLERSVILLE...BARCLAY AROUND 955 AM...CLAYTON...SMYRNA AROUND 1000
AM AND KENTON AROUND 1010 AM.

WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE STORMS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS. 
DO NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE 
INDOORS WHEN A THUNDERSTORM APPROACHES.

LAT...LON 3925 7598 3925 7591 3927 7585 3925 7581
      3925 7577 3930 7575 3929 7565 3931 7559
      3934 7556 3934 7545 3932 7544 3913 7577
      3916 7604 3920 7606

$$

ROBERTSON

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 3:24 AM EDTSmall Craft AdvisoryPHI30 hr
Aug 21, 3:28 AM EDTFlash Flood WatchPHIBurlington, Camden, Cumberland, Gloucester, Hunterdon, Mercer and 6 more17 hr
Aug 21, 8:41 AM EDTSpecial Weather StatementPHISalem64 min
Aug 21, 10:33 AM EDTSpecial Marine WarningPHI57 min
Aug 21, 11:07 AM EDTSpecial Marine WarningPHI83 min
Aug 21, 12:20 PM EDTSpecial Weather StatementPHIMorris55 min
Aug 21, 12:33 PM EDTSevere Thunderstorm WarningPHIMorris33 min
Aug 21, 12:39 PM EDTSpecial Weather StatementPHIBurlington, Camden66 min
Aug 21, 1:47 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Mercer58 min
Aug 21, 2:33 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Mercer117 min
Aug 21, 2:43 PM EDTSevere Thunderstorm WarningPHIBurlington, Camden, Gloucester, Mercer62 min
Aug 21, 3:08 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean67 min
Aug 21, 3:21 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean54 min
Aug 21, 3:22 PM EDTSpecial Marine WarningPHI83 min
Aug 21, 3:46 PM EDTFlash Flood WarningPHIBurlington2 hr
Aug 21, 4:14 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean46 min
Aug 21, 4:26 PM EDTSpecial Marine WarningPHI57 min
Aug 21, 4:35 PM EDTAreal Flood AdvisoryPHIBurlington, Camden, Mercer, Middlesex, Monmouth, Ocean3 hr
Aug 21, 5:44 PM EDTSpecial Weather StatementPHIMercer61 min
Aug 21, 6:05 PM EDTFlash Flood WarningPHIBurlington6 hr
Aug 21, 6:12 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean63 min
Aug 21, 6:20 PM EDTSpecial Weather StatementPHIHunterdon55 min
Aug 21, 6:54 PM EDTAreal Flood AdvisoryPHIHunterdon, Middlesex, Morris, Somerset, Sussex, Warren111 min
Aug 21, 7:08 PM EDTSpecial Weather StatementPHIHunterdon, Middlesex, Somerset52 min
Aug 21, 7:18 PM EDTSevere Thunderstorm WarningPHIMonmouth, Ocean42 min
Aug 21, 7:21 PM EDTSpecial Marine WarningPHI84 min
Aug 21, 7:24 PM EDTFlash Flood WarningPHIMercer, Monmouth, Ocean5 hr
Aug 21, 7:35 PM EDTAreal Flood AdvisoryPHIBurlington, Mercer, Middlesex, Monmouth, Ocean115 min
Aug 21, 1:11 PM EDTSpecial Weather StatementPHIMontgomery64 min
Aug 21, 1:25 PM EDTAreal Flood AdvisoryPHIBucks, Chester, Montgomery110 min
Aug 21, 3:31 PM EDTFlash Flood WarningPHIPhiladelphia8 hr
Aug 21, 4:11 PM EDTSpecial Weather StatementPHICarbon, Monroe64 min
Aug 21, 4:19 PM EDTAreal Flood AdvisoryPHICarbon, Monroe3 hr
Aug 21, 4:53 PM EDTSpecial Weather StatementPHILehigh, Northampton67 min
Aug 21, 6:41 PM EDTSpecial Weather StatementPHIBerks64 min
Aug 21, 8:01 AM EDTSpecial Weather StatementPHICecil, Kent59 min
Aug 21, 9:08 AM EDTSpecial Weather StatementPHICecil, Kent52 min
Aug 21, 9:36 AM EDTAreal Flood AdvisoryPHICecil, Kent, Queen Anne's2 hr
Aug 21, 2:01 PM EDTSevere Thunderstorm WarningPHICecil, Kent, Queen Anne's59 min
Aug 21, 2:43 PM EDTAreal Flood AdvisoryPHICecil, Kent, Queen Anne's3 hr
Aug 21, 2:55 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's, Talbot65 min
Aug 21, 3:11 PM EDTAreal Flood AdvisoryPHIKent, Queen Anne's2 hr
Aug 21, 4:03 PM EDTSpecial Weather StatementPHICaroline, Kent, Queen Anne's, Talbot57 min
Aug 21, 4:45 PM EDTFlash Flood WarningPHIKent3 hr
Aug 21, 5:09 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot37 min
Aug 21, 5:20 PM EDTAreal Flood AdvisoryPHICaroline, Queen Anne's, Talbot115 min
Aug 21, 7:17 PM EDTAreal Flood AdvisoryPHICaroline118 min
Aug 21, 10:15 AM EDTSpecial Weather StatementPHIKent60 min
Aug 21, 10:33 AM EDTSevere Thunderstorm WarningPHIKent57 min
Aug 21, 6:29 PM EDTSpecial Weather StatementPHISussex61 min
Aug 21, 7:03 PM EDTSevere Thunderstorm WarningPHIKent, Sussex42 min

Nearby

Special Weather Statements in Delaware, 2011Every special weather statement in 2011

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.