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, 1:37 PM EDT for Sussex County, Delaware. It was in force for 38 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
Jul 29, 2021, 1:37 PM EDT (17:37 UTC)
Expired
Jul 29, 2021, 2:15 PM EDT
In force
38 min
Issued by
NWS Philadelphia/Mount Holly

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 24 km from the middle of the area, began a volume at 17:41 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, 5.6 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 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.

303 
WWUS81 KPHI 291737
SPSPHI

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

DEZ003-291815-
Inland Sussex-
137 PM EDT Thu Jul 29 2021

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

At 137 PM EDT, a strong thunderstorm was located near Seaford, or 11
miles east of Hurlock, moving east at 20 mph.

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

Locations impacted include...
Seaford, Bridgeville and Blades. 

If outdoors, consider seeking shelter inside a building.

LAT...LON 3862 7570 3863 7571 3870 7571 3884 7553
      3862 7542
TIME...MOT...LOC 1737Z 250DEG 17KT 3868 7566 

$$

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, 2:38 PM EDTSpecial Weather StatementPHISussex37 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.