Alert archive / Delaware / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 110, NWS Philadelphia/Mount Holly

July 18, 2012Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 18, 2012, 6:57 PM EDT for Kent County, Delaware. It was in force for 17 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 18, 2012, 6:57 PM EDT (22:57 UTC)
Expired: Jul 18, 2012, 7:14 PM EDT
In force: 17 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

County Kent County, DE

The radar

The Dover AFB radar (KDOX), 21 km from the middle of the area, began a volume at 22:58 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 18, 12:41 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.0 hours before the alert went out and 74 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 884 J/kg
Mixed-layer CIN: -169 J/kg
Mixed-layer LCL: 1666 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

386 
WUUS51 KPHI 182257
SVRPHI
DEC001-182330-
/O.NEW.KPHI.SV.W.0110.120718T2257Z-120718T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
657 PM EDT WED JUL 18 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL KENT COUNTY IN CENTRAL DELAWARE...
  THIS INCLUDES THE CITY OF DOVER...

* UNTIL 730 PM EDT

* AT 656 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM HAZLETTVILLE TO CAMDEN TO RISING SUN TO VIOLA...OR ALONG A
  LINE EXTENDING FROM DOVER TO 6 MILES SOUTH OF DOVER TO 12 MILES
  SOUTH OF DOVER...AND MOVING EAST AT 35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  DOVER AND BOWERS AROUND 705 PM EDT...
  BIG STONE BEACH AROUND 715 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS STILL A DANGEROUS LINE OF STORMS. IF YOU ARE IN ITS 
PATH...PREPARE IMMEDIATELY FOR DAMAGING WINDS...LARGE HAIL...AND 
DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A 
SHELTER...PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE
ENOUGH TO BE STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 3894 7569 3907 7563 3910 7567 3920 7572
      3922 7539 3907 7539 3900 7532 3894 7530
      3893 7531 3895 7532 3895 7539 3893 7540
      3892 7542
TIME...MOT...LOC 2257Z 269DEG 32KT 3915 7559 3911 7553
          3907 7550 3899 7555

$$

DRAG

1 follow-up statement

409 
WWUS51 KPHI 182314
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
714 PM EDT WED JUL 18 2012

DEC001-182324-
/O.CAN.KPHI.SV.W.0110.000000T0000Z-120718T2330Z/
KENT DE-
714 PM EDT WED JUL 18 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL KENT COUNTY IS
CANCELLED...

OUTFLOW WINDS WERE DIMINISHING AS THE PRIMARY LINE OF THUNDERSTORMS 
HAS WEAKENED.  

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND SOUTHEASTERN PENNSYLVANIA.

LAT...LON 3894 7569 3907 7563 3910 7567 3920 7572
      3922 7539 3907 7539 3900 7532 3894 7530
      3893 7531 3895 7532 3895 7539 3893 7540
      3892 7542
TIME...MOT...LOC 2314Z 269DEG 32KT 3915 7539 3911 7533
          3907 7530 3899 7536

$$

DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 5:47 PM EDT	Special Weather Statement	PHI	Kent, New Castle	58 min
Jul 18, 6:01 PM EDT	Severe Thunderstorm Warning	PHI	Kent, New Castle	17 min
Jul 18, 6:23 PM EDT	Severe Thunderstorm Warning	PHI	Kent	37 min
Jul 18, 6:48 PM EDT	Special Weather Statement	PHI	Kent	12 min
Jul 18, 6:57 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	82 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2012 Every severe thunderstorm warning in 2012

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.