Alert archive / Delaware / Special Weather Statements in 2021

Special Weather Statement, NWS Philadelphia/Mount Holly

July 29, 2021Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 29, 2021, 2:38 PM EDT for Sussex County, Delaware. It was in force for 37 min. 3 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
Jul 29, 2021, 2:38 PM EDT (18:38 UTC)
Expired
Jul 29, 2021, 3:15 PM EDT
In force
37 min
Issued by
NWS Philadelphia/Mount Holly

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 25 km from the middle of the area, began a volume at 18:42 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

TimeReportWhereRemark
Jul 29, 2:48 PM EDTTSTM WND DMG4 Se Harbeson, DEA SUPERCELL THUNDERSTORM IMPACTED THE EASTERN PORTIONS OF SUSSEX COUNTY, DE IN THE EARLY AFTERNOON HOURS OF JULY 29. THE NATIONAL WEATHER SERVICE INVESTIGATED REPORTS OF DAMAGE IN THIS AREA. A SURVEY WAS CONDUCTED ALONG A PATH OF RADAR-INDICATED ROTATION FROM
Jul 29, 2:48 PM EDTTSTM WND DMG4 Se Harbeson, DETREES DOWN NEAR HOLLYMOUNT, DE.
Jul 29, 2:59 PM EDTHAIL 13 Nw Long Neck, DEONE INCH HAIL REPORTED NORTH OF LONG NECK, DE.

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 6.6 hours before the alert went out and 84 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 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 581 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.19395878Sfc1 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
581 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
863 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
112 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted.

274 
WWUS81 KPHI 291838
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
238 PM EDT Thu Jul 29 2021

DEZ003-291915-
Inland Sussex-
238 PM EDT Thu Jul 29 2021

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL SUSSEX COUNTY...

At 237 PM EDT, a strong thunderstorm was located near Georgetown,
moving east at 15 mph.

Wind gusts up to 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Georgetown, Lewes, Milton and Long Neck. 

If outdoors, consider seeking shelter inside a building.

LAT...LON 3865 7538 3875 7540 3885 7518 3864 7512
      3863 7513 3862 7511 3861 7513
TIME...MOT...LOC 1837Z 263DEG 11KT 3871 7532 

$$

Staarmann

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 3:33 AM EDTSmall Craft AdvisoryPHI20 hr
Jul 29, 1:33 PM EDTSpecial Marine WarningPHI42 min
Jul 29, 2:53 PM EDTSpecial Marine WarningPHI100 min
Jul 29, 4:26 PM EDTSpecial Weather StatementPHIMorris34 min
Jul 29, 4:30 PM EDTSevere Thunderstorm WarningPHIHunterdon, Warren45 min
Jul 29, 4:57 PM EDTAreal Flood AdvisoryPHIHunterdon, Morris, Sussex, Warren3 hr
Jul 29, 5:01 PM EDTSpecial Weather StatementPHIMorris29 min
Jul 29, 5:03 PM EDTSevere Thunderstorm WarningPHIHunterdon, Morris, Somerset, Sussex, Warren42 min
Jul 29, 5:08 PM EDTTornado WarningPHIHunterdon37 min
Jul 29, 5:27 PM EDTAreal Flood AdvisoryPHIHunterdon, Mercer, Morris, Somerset3 hr
Jul 29, 5:32 PM EDTFlash Flood WarningPHIWarren2 hr
Jul 29, 5:32 PM EDTTornado WarningPHIHunterdon28 min
Jul 29, 5:51 PM EDTTornado Warning Tornado observedConsiderable damage threatPHIHunterdon, Mercer24 min
Jul 29, 5:58 PM EDTFlash Flood WarningPHIHunterdon, Mercer, Somerset3 hr
Jul 29, 6:06 PM EDTTornado Warning Considerable damage threatPHIBurlington, Hunterdon, Mercer, Middlesex, Monmouth39 min
Jul 29, 6:44 PM EDTTornado WarningPHIMercer, Monmouth, Ocean46 min
Jul 29, 6:45 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer45 min
Jul 29, 6:56 PM EDTFlash Flood WarningPHIMercer, Middlesex, Monmouth, Ocean, Somerset4 hr
Jul 29, 7:07 PM EDTTornado WarningPHIBurlington23 min
Jul 29, 7:12 PM EDTFlash Flood WarningPHIBurlington4 hr
Jul 29, 7:18 PM EDTTornado WarningPHIMercer, Middlesex, Monmouth, Ocean27 min
Jul 29, 7:25 PM EDTSevere Thunderstorm WarningPHIBurlington, Monmouth, Ocean50 min
Jul 29, 7:28 PM EDTSevere Thunderstorm WarningPHIBurlington, Mercer, Middlesex, Monmouth, Ocean47 min
Jul 29, 7:52 PM EDTSpecial Marine WarningPHI113 min
Jul 29, 3:48 PM EDTSevere Thunderstorm WarningPHIBerks, Lehigh, Northampton42 min
Jul 29, 4:03 PM EDTTornado WarningPHIBerks, Lehigh, Northampton27 min
Jul 29, 4:27 PM EDTTornado WarningPHILehigh, Northampton16 min
Jul 29, 4:46 PM EDTAreal Flood AdvisoryPHIBerks, Lehigh, Northampton3 hr
Jul 29, 4:56 PM EDTTornado WarningPHIBucks, Lehigh, Northampton34 min
Jul 29, 6:21 PM EDTSpecial Weather StatementPHIBucks24 min
Jul 29, 1:37 PM EDTSpecial Weather StatementPHISussex38 min
Jul 29, 2:43 PM EDTSevere Thunderstorm WarningPHISussex62 min
Jul 29, 3:02 PM EDTTornado WarningPHISussex43 min
Jul 29, 11:35 AM EDTSpecial Weather StatementPHITalbot55 min
Jul 29, 11:48 AM EDTSevere Thunderstorm WarningPHICaroline, Talbot45 min
Jul 29, 12:12 PM EDTAreal Flood AdvisoryPHICaroline, Talbot84 min
Jul 29, 5:59 PM EDTSpecial Weather StatementPHIQueen Anne's31 min

Nearby

Special Weather Statements in Delaware, 2021Every special weather statement in 2021

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.