Alert archive / Delaware / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 86, NWS Philadelphia/Mount Holly

August 1, 2013Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 1, 2013, 1:12 PM EDT for Sussex County, Delaware. It was in force for 48 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 1, 2013, 1:12 PM EDT (17:12 UTC)
Expired
Aug 1, 2013, 2:00 PM EDT
In force
48 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 26 km from the middle of the area, began a volume at 17:13 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, 5.2 hours before the alert went out and 92 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 2013-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 23 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 2013-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 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
23 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
972 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

722 
WUUS51 KPHI 011712
SVRPHI
DEC005-011800-
/O.NEW.KPHI.SV.W.0086.130801T1712Z-130801T1800Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
112 PM EDT THU AUG 1 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL SUSSEX COUNTY IN SOUTHERN DELAWARE...

* UNTIL 200 PM EDT

* AT 109 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS. THESE SEVERE STORMS EXTENDED FROM
  MILTON TO MILTON TO GEORGETOWN...MOVING EAST AT 20 MPH. THESE
  STORMS ARE CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  LEWES AROUND 130 PM EDT...
  CAPE HENLOPEN STATE PARK AROUND 140 PM EDT...
  REHOBOTH BEACH AROUND 145 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE WINDS OF MORE THAN 57 MPH...OR HAIL ONE
INCH OR LARGER.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM...AND
THE STORM WILL AFFECT THE BEACHES. FOR YOUR SAFETY...IMMEDIATELY MOVE
OFF THE BEACH AND SEEK SHELTER INDOORS.

&&

LAT...LON 3867 7549 3881 7529 3882 7518 3879 7515
      3879 7511 3881 7510 3881 7509 3877 7507
      3867 7506 3866 7505 3866 7506 3860 7505
TIME...MOT...LOC 1712Z 277DEG 19KT 3881 7528 3874 7529
          3868 7541

$$

FORECASTER: HEAVENER
2 follow-up statements
546 
WWUS51 KPHI 011742
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
142 PM EDT THU AUG 1 2013

DEC005-011800-
/O.CON.KPHI.SV.W.0086.000000T0000Z-130801T1800Z/
SUSSEX DE-
142 PM EDT THU AUG 1 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM EDT
FOR EAST CENTRAL SUSSEX COUNTY...

AT 137 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM CAPE HENLOPEN STATE PARK TO REHOBOTH BEACH TO 9 MILES
WEST OF DEWEY BEACH...MOVING EAST AT 20 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
DEWEY BEACH AROUND 150 PM EDT...

LAT...LON 3867 7514 3879 7515 3879 7511 3881 7510
      3881 7509 3877 7507 3867 7506
TIME...MOT...LOC 1742Z 277DEG 19KT 3879 7508 3872 7509
          3866 7521

$$

FORECASTER: HEAVENER
826 
WWUS51 KPHI 011750
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
150 PM EDT THU AUG 1 2013

DEC005-011800-
/O.EXP.KPHI.SV.W.0086.000000T0000Z-130801T1800Z/
SUSSEX DE-
150 PM EDT THU AUG 1 2013

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL SUSSEX COUNTY
WILL EXPIRE AT 200 PM EDT...

THE SEVERE THUNDERSTORM WARNING WILL BE ALLOWED TO EXPIRE.

LAT...LON 3867 7514 3879 7515 3879 7511 3881 7510
      3881 7509 3877 7507 3867 7506
TIME...MOT...LOC 1750Z 277DEG 19KT 3878 7503 3871 7504
          3865 7516

$$

FORECASTER: HEAVENER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 3:42 AM EDTFlash Flood WatchPHINew Castle14 hr
Aug 1, 10:50 AM EDTAreal Flood AdvisoryPHINew Castle3 hr
Aug 1, 11:57 AM EDTRiver Flood WarningPHINew Castle3 hr
Aug 1, 12:17 PM EDTSpecial Weather StatementPHIKent43 min
Aug 1, 12:48 PM EDTAreal Flood AdvisoryPHIKent, Sussex3 hr
Aug 1, 12:50 PM EDTSevere Thunderstorm WarningPHISussex40 min
Aug 1, 2:35 PM EDTAreal Flood AdvisoryPHISussex3 hr
Aug 1, 2:57 PM EDTFlash Flood WarningPHISussex3 hr
Aug 1, 5:58 PM EDTFlash Flood WarningPHISussex4 hr

Nearby

Severe Thunderstorm Warnings in Delaware, 2013Every severe thunderstorm warning in 2013

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.