Alert archive / Delaware / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 177, NWS Philadelphia/Mount Holly

July 19, 2011Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 19, 2011, 2:43 PM EDT for Kent County, Sussex County, Delaware. It was in force for 92 min. 2 reports 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 19, 2011, 2:43 PM EDT (18:43 UTC)
Expired: Jul 19, 2011, 4:15 PM EDT
In force: 92 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

Counties Kent County, DE, Sussex County, DE

The radar

The Dover AFB radar (KDOX), 15 km from the middle of the area, began a volume at 18:45 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 19, 3:25 PM EDT	TSTM WND DMG	Lewes, DE	TREE DOWN NEAR LEWES
Jul 19, 3:30 PM EDT	TSTM WND DMG	Ese Viola, DE	TREE DOWN AT INTERSECTION OF CANTERBERRY RD AND ANDREWS LAKE RD

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

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.7 hours before the alert went out and 96 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: 1090 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 1062 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 68 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.6

Open this sounding in Storm Lab

The text

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

224 
WUUS51 KPHI 191843
SVRPHI
DEC001-005-192015-
/O.NEW.KPHI.SV.W.0177.110719T1843Z-110719T2015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
243 PM EDT TUE JUL 19 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 415 PM EDT

* AT 239 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  VIOLA...OR 9 MILES SOUTH OF DOVER...AND MOVING SOUTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES SOUTHWEST OF BOWERS AROUND 300 PM EDT...
  MILFORD AND 7 MILES SOUTHWEST OF BIG STONE BEACH AROUND 320 PM
  EDT...
  SLAUGHTER BEACH AROUND 340 PM EDT...
  MILTON AROUND 405 PM EDT...
  LEWES...8 MILES WEST OF CAPE HENLOPEN STATE PARK AND 9 MILES
  NORTHWEST OF REHOBOTH BEACH AROUND 415 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE 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...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES GREATEST KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

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.

&&

LAT...LON 3903 7568 3916 7555 3903 7532 3898 7529
      3893 7530 3889 7525 3886 7523 3881 7518
      3879 7513 3879 7511 3881 7509 3880 7507
      3849 7504
TIME...MOT...LOC 1844Z 317DEG 14KT 3903 7555

$$

NIERENBERG

1 follow-up statement

409 
WWUS51 KPHI 191938
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
338 PM EDT TUE JUL 19 2011

DEC001-005-192015-
/O.CON.KPHI.SV.W.0177.000000T0000Z-110719T2015Z/
KENT DE-SUSSEX DE-
338 PM EDT TUE JUL 19 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM EDT
FOR NORTHEASTERN SUSSEX AND SOUTHERN KENT COUNTIES...

AT 335 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE 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 FELTON TO OCEAN VIEW...OR
ALONG A LINE EXTENDING FROM 13 MILES SOUTH OF DOVER TO 17 MILES
SOUTHEAST OF GEORGETOWN...MOVING SOUTH AT 10 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  OCEAN VIEW BY 345 PM EDT...
  BETHANY BEACH BY 350 PM EDT...
  SOUTH BETHANY BY 355 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

VERY HEAVY RAIN IS ALSO FALLING AND WILL CAUSE PONDING OF WATER IN
POOR DRAINAGE AREAS.

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.

&&

LAT...LON 3880 7508 3850 7505 3903 7568 3916 7555
      3898 7539 3895 7535 3893 7531 3889 7526
      3886 7524 3881 7519 3879 7513 3879 7511
      3881 7509
TIME...MOT...LOC 1938Z 359DEG 10KT 3897 7559 3856 7512

$$
 
TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 6:02 AM EDT	Heat Advisory	PHI	New Castle	13 hr
Jul 19, 2:13 PM EDT	Special Weather Statement	PHI	Kent, New Castle, Sussex	92 min
Jul 19, 2:29 PM EDT	Excessive Heat Warning	PHI	Kent, New Castle, Sussex	5 days
Jul 19, 3:45 PM EDT	Areal Flood Advisory	PHI	Kent, Sussex	3 hr
Jul 19, 4:12 PM EDT	Flash Flood Warning	PHI	Kent	3 hr
Jul 19, 4:25 PM EDT	Special Weather Statement	PHI	Kent, Sussex	80 min
Jul 19, 4:40 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	32 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2011 Every severe thunderstorm warning in 2011

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.