Alert archive / Delaware / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 85, NWS Philadelphia/Mount Holly

August 1, 2013Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 1, 2013, 12:50 PM EDT for Sussex County, Delaware. It was in force for 40 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, 12:50 PM EDT (16:50 UTC)
Expired
Aug 1, 2013, 1:30 PM EDT
In force
40 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 7 km from the middle of the area, began a volume at 16:53 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 4.8 hours before the alert went out and 87 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, Phillips Aaf/Abe, MD at 12:00Z on 2013-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 19 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phillips Aaf/Abe, MD at 12:00Z on 2013-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 141 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
19 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
551 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
226 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.

824 
WUUS51 KPHI 011650
SVRPHI
DEC005-011730-
/O.NEW.KPHI.SV.W.0085.130801T1650Z-130801T1730Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1250 PM EDT THU AUG 1 2013

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 130 PM EDT

* AT 1249 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM. THE STORM WAS NEAR GREENWOOD...MOVING EAST AT
  20 MPH. THIS STORM IS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ELLENDALE AROUND 100 PM EDT...
  MILFORD AROUND 105 PM EDT...
  MILTON AROUND 115 PM EDT...
  SLAUGHTER BEACH AROUND 125 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 3885 7554 3886 7552 3888 7551 3891 7548
      3892 7544 3892 7542 3894 7540 3895 7534
      3894 7531 3893 7532 3879 7515 3876 7552
TIME...MOT...LOC 1650Z 253DEG 18KT 3882 7550

$$

FORECASTER: HEAVENER
1 follow-up statement
134 
WWUS51 KPHI 011717
SVSPHI

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

DEC005-011730-
/O.CON.KPHI.SV.W.0085.000000T0000Z-130801T1730Z/
SUSSEX DE-
117 PM EDT THU AUG 1 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM EDT
FOR NORTH CENTRAL SUSSEX COUNTY...

AT 113 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH. THIS STORM WAS LOCATED 6 MILES NORTHWEST OF
MILTON...OR 11 MILES NORTH OF GEORGETOWN...MOVING EAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL AFFECT...
RURAL NORTHERN SUSSEX COUNTY...

LAT...LON 3878 7534 3888 7536 3890 7528 3879 7515
TIME...MOT...LOC 1717Z 253DEG 18KT 3886 7533

$$

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, 1:12 PM EDTSevere Thunderstorm WarningPHISussex48 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.