Alert archive / Delaware / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 147, NWS Philadelphia/Mount Holly

July 28, 2012Sussex County, Delaware; Cape May County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 28, 2012, 9:21 PM EDT for Sussex County, Delaware; Cape May County, New Jersey. It was in force for 23 min. 1 report 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 28, 2012, 9:21 PM EDT (01:21 UTC)
Expired: Jul 28, 2012, 9:44 PM EDT
In force: 23 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Sussex County, DE, Cape May County, NJ

The radar

The Dover AFB radar (KDOX), 31 km from the middle of the area, began a volume at 01:24 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

Time	Report	Where	Remark
Jul 28, 9:23 PM EDT	MARINE TSTM WIND 43	Dewey Beach, DE

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

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 28, 1:36 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 1.4 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-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: 1078 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 1476 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: -7 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.6

Open this sounding in Storm Lab

The text

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

657 
WUUS51 KPHI 290121
SVRPHI
DEC005-NJC009-290200-
/O.NEW.KPHI.SV.W.0147.120729T0121Z-120729T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
921 PM EDT SAT JUL 28 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN SUSSEX COUNTY IN CENTRAL DELAWARE...
  SOUTHWESTERN CAPE MAY COUNTY IN SOUTHERN NEW JERSEY...
  THIS INCLUDES THE CITY OF CAPE MAY...

* UNTIL 1000 PM EDT

* AT 916 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM NORTH CAPE MAY TO REHOBOTH
  BEACH TO SELBYVILLE...OR ALONG A LINE EXTENDING FROM CAPE MAY TO 17
  MILES EAST OF GEORGETOWN TO 17 MILES SOUTHEAST OF GEORGETOWN...AND
  MOVING EAST AT 20 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  CAPE MAY AROUND 930 PM EDT...
  BETHANY BEACH AROUND 935 PM EDT...
  WILDWOOD CREST AND WILDWOOD AROUND 940 PM EDT...
  FENWICK ISLAND AND 6 MILES SOUTH OF NORTH WILDWOOD AROUND 945 PM
  EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. 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.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SATURDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 3847 7534 3870 7516 3879 7513 3880 7510
      3893 7497 3894 7498 3900 7496 3901 7478
      3900 7478 3893 7487 3892 7497 3881 7509
      3867 7505 3845 7504 3844 7534
TIME...MOT...LOC 0121Z 273DEG 18KT 3893 7496 3870 7505
          3846 7522

$$

HAYES

1 follow-up statement

430 
WWUS51 KPHI 290144
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
944 PM EDT SAT JUL 28 2012

DEC005-NJC009-290154-
/O.CAN.KPHI.SV.W.0147.000000T0000Z-120729T0200Z/
SUSSEX DE-CAPE MAY NJ-
944 PM EDT SAT JUL 28 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CAPE MAY AND
SOUTHEASTERN SUSSEX COUNTIES IS CANCELLED...

THE STORMS THAT PROMPTED THE WARNING HAVE MOVED OFFSHORE.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1000 PM EDT
SATURDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

LAT...LON 3847 7534 3870 7516 3879 7513 3880 7510
      3893 7497 3894 7498 3900 7496 3901 7478
      3900 7478 3893 7487 3892 7497 3881 7509
      3867 7505 3845 7504 3844 7534
TIME...MOT...LOC 0144Z 273DEG 18KT 3892 7481 3869 7490
          3845 7507

$$

HAYES

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 8:09 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	66 min
Jul 28, 8:41 PM EDT	Special Weather Statement	PHI	New Castle	64 min
Jul 28, 8:51 PM EDT	Special Weather Statement	PHI	Sussex	54 min
Jul 28, 9:28 PM EDT	Special Weather Statement	PHI	Sussex	62 min
Jul 28, 10:15 PM EDT	Areal Flood Advisory	PHI	Sussex	69 min
Jul 29, 2:23 PM EDT	Special Weather Statement	PHI	Sussex	52 min
Jul 29, 3:45 PM EDT	Special Weather Statement	PHI	Sussex	60 min
Jul 28, 8:02 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer	2 hr
Jul 28, 8:05 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon	55 min
Jul 28, 8:11 PM EDT	Special Marine Warning	PHI		64 min
Jul 28, 8:26 PM EDT	Areal Flood Advisory	PHI	Mercer	101 min
Jul 28, 8:38 PM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Somerset	67 min
Jul 28, 8:43 PM EDT	Special Marine Warning	PHI		62 min
Jul 28, 9:14 PM EDT	Special Marine Warning	PHI		61 min
Jul 28, 9:24 PM EDT	Severe Thunderstorm Warning	PHI	Mercer, Middlesex, Monmouth	66 min
Jul 28, 9:42 PM EDT	Special Marine Warning	PHI		63 min
Jul 28, 9:46 PM EDT	Special Weather Statement	PHI	Burlington, Ocean	59 min
Jul 28, 9:52 PM EDT	Areal Flood Advisory	PHI	Middlesex, Monmouth	118 min
Jul 28, 9:52 PM EDT	Special Weather Statement	PHI	Camden	53 min
Jul 28, 10:09 PM EDT	Special Marine Warning	PHI		66 min
Jul 28, 10:23 PM EDT	Severe Thunderstorm Warning	PHI	Monmouth	32 min
Jul 28, 10:31 PM EDT	Special Marine Warning	PHI		59 min
Jul 28, 10:39 PM EDT	Special Weather Statement	PHI	Ocean	66 min
Jul 29, 12:22 AM EDT	Special Marine Warning	PHI		23 min
Jul 29, 1:20 PM EDT	Special Weather Statement	PHI	Atlantic	55 min
Jul 29, 1:42 PM EDT	Areal Flood Advisory	PHI	Cape May	2 hr
Jul 29, 2:59 PM EDT	Special Weather Statement	PHI	Cape May	61 min
Jul 29, 3:35 PM EDT	Special Weather Statement	PHI	Atlantic	55 min
Jul 29, 4:41 PM EDT	Special Weather Statement	PHI	Hunterdon, Morris, Somerset	64 min
Jul 29, 5:53 PM EDT	Special Weather Statement	PHI	Middlesex	52 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2012 Severe Thunderstorm Warnings in New Jersey, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.