Alert archive / Delaware / Tornado Warnings in 2011

Tornado Warning 15, NWS Philadelphia/Mount Holly

August 27, 2011Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this tornado warning at Aug 27, 2011, 6:22 PM EDT for Kent County, Sussex County, Delaware. 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: Aug 27, 2011, 6:22 PM EDT (22:22 UTC)
Expired: Aug 27, 2011, 6:45 PM EDT
In force: 23 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), 12 km from the middle of the area, began a volume at 22:25 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
Aug 27, 6:35 PM EDT	TORNADO	2 Sw Lewes, DE	AROUND 15 HOMES DAMAGED IN THE NASSAU STATION AND TRADEWINDS SUBDIVISIONS SW OF LEWES. ONE HOME DEMOLISHED.

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
Aug 27, 10:41 AM EDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 10.4 hours before the alert went out and 100 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: 330 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 691 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 221 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

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

680 
WFUS51 KPHI 272222
TORPHI
DEC001-005-272245-
/O.NEW.KPHI.TO.W.0015.110827T2222Z-110827T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
622 PM EDT SAT AUG 27 2011

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN KENT COUNTY IN CENTRAL DELAWARE...
  NORTHERN SUSSEX COUNTY IN SOUTHERN DELAWARE...

* UNTIL 645 PM EDT

* AT 620 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 6 MILES EAST OF
  REHOBOTH BEACH...OR 15 MILES SOUTH OF CAPE MAY...MOVING WEST AT 75
  MPH.

* THE TORNADO WILL BE NEAR...
  LEWES BY 630 PM EDT...
  MILTON AND 9 MILES SOUTH OF SLAUGHTER BEACH BY 635 PM EDT...
  ELLENDALE AND 8 MILES SOUTH OF MILFORD BY 640 PM EDT...
  6 MILES SOUTHEAST OF ANDREWSVILLE AND 8 MILES SOUTH OF HARRINGTON
  BY 645 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

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 3877 7568 3900 7567 3892 7529 3889 7525
      3883 7521 3880 7516 3879 7511 3881 7509
      3880 7507 3868 7506
TIME...MOT...LOC 2222Z 101DEG 64KT 3874 7502

$$

DRAG

1 follow-up statement

200 
WWUS51 KPHI 272233
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
633 PM EDT SAT AUG 27 2011

DEC001-005-272245-
/O.CON.KPHI.TO.W.0015.000000T0000Z-110827T2245Z/
KENT DE-SUSSEX DE-
633 PM EDT SAT AUG 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 645 PM EDT FOR NORTHERN
SUSSEX AND SOUTHERN KENT COUNTIES...

AT 629 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED NEAR HENLOPEN ACRES...
OR 14 MILES SOUTHWEST OF CAPE MAY...MOVING NORTHWEST AT 50 MPH.

THE TORNADO WILL BE NEAR...
  LEWES BY 640 PM EDT...
  6 MILES NORTHEAST OF MILTON AND 7 MILES SOUTHEAST OF SLAUGHTER
  BEACH BY 645 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

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 3868 7508 3878 7560 3900 7567 3892 7529
      3889 7525 3883 7521 3880 7516 3879 7511
      3881 7509 3880 7507
TIME...MOT...LOC 2233Z 116DEG 43KT 3877 7507

$$

DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 27, 12:12 PM EDT	Tornado Warning	PHI	Sussex	28 min
Aug 27, 1:28 PM EDT	Special Weather Statement	PHI	Kent, New Castle, Sussex	62 min
Aug 27, 2:14 PM EDT	Areal Flood Warning	PHI	Kent, New Castle, Sussex	6 hr
Aug 27, 2:36 PM EDT	Special Weather Statement	PHI	Kent, New Castle, Sussex	54 min
Aug 27, 3:47 PM EDT	Areal Flood Advisory	PHI	New Castle	118 min
Aug 27, 4:06 PM EDT	River Flood Warning	PHI	New Castle	37 hr
Aug 27, 5:37 PM EDT	River Flood Warning	PHI	New Castle	18 hr
Aug 27, 5:37 PM EDT	River Flood Warning	PHI	New Castle	19 hr
Aug 27, 5:37 PM EDT	River Flood Warning	PHI	New Castle	24 hr
Aug 27, 5:42 PM EDT	Areal Flood Warning	PHI	New Castle	6 hr
Aug 27, 6:14 PM EDT	Special Weather Statement	PHI	Sussex	31 min
Aug 27, 7:27 PM EDT	Flash Flood Warning	PHI	Kent, Sussex	12 hr

Nearby

Tornado Warnings in Delaware, 2011 Every tornado warning in 2011 Tornadoes 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.