Alert archive / Delaware / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 265, NWS Philadelphia/Mount Holly

September 9, 2008Sussex County, Delaware; Cape May County, New Jersey

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 9, 2008, 1:58 PM EDT for Sussex County, Delaware; Cape May County, New Jersey. It was in force for 92 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: Sep 9, 2008, 1:58 PM EDT (17:58 UTC)
Expired: Sep 9, 2008, 3:30 PM EDT
In force: 92 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), 28 km from the middle of the area, began a volume at 18:00 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
Sep 9, 2:30 PM EDT	TSTM WND DMG	5 Wnw Millsboro, DE	TREES AND WIRES DOWN ON THE SOUTH SIDE OF GEORGETOWN.

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
Sep 9, 9:33 AM EDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 6.0 hours before the alert went out and 104 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: 2180 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 500 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 89 m²/s²
0-3 km storm-relative helicity: 77 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 4.8

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 091758
SVRPHI
DEC005-NJC009-091930-
/O.NEW.KPHI.SV.W.0265.080909T1758Z-080909T1930Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
158 PM EDT TUE SEP 9 2008

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SUSSEX COUNTY IN SOUTHERN DELAWARE...
  SOUTHERN CAPE MAY COUNTY IN SOUTHERN NEW JERSEY...

* UNTIL 330 PM EDT

* AT 156 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING NICKEL SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM GREEN CREEK TO ELLENDALE TO 7
  MILES WEST OF BRIDGEVILLE TO 17 MILES SOUTHWEST OF LAUREL...OR
  ALONG A LINE EXTENDING FROM 11 MILES NORTH OF CAPE MAY TO 11 MILES
  NORTHWEST OF GEORGETOWN TO 18 MILES EAST OF EASTON TO 14 MILES WEST
  OF SALISBURY...AND MOVING SOUTHEAST AT 24 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  CAPE MAY COURT HOUSE...GREEN CREEK...ELLENDALE AND BRIDGEVILLE BY
  205 PM...
  SCOTCH BONNET...RIO GRANDE AND NORTH CAPE MAY BY 210 PM...
  STONE HARBOR...AVALON AND SEAFORD BY 215 PM...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 PM TUESDAY
AFTERNOON FOR SOUTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
SOUTHERN NEW JERSEY.

IF YOU SEE THREATENING WEATHER PLEASE SEEK SHELTER IMMEDIATELY.

LAT...LON 3846 7571 3875 7572 3894 7530 3882 7519
      3879 7511 3892 7498 3899 7498 3913 7490
      3916 7484 3913 7470 3900 7478 3893 7488
      3892 7497 3881 7508 3860 7504 3845 7505
TIME...MOT...LOC 1758Z 308DEG 21KT 3909 7489 3881 7549
          3873 7573 3842 7582

$$
 
TFG

2 follow-up statements

000 
WWUS51 KPHI 091831
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
231 PM EDT TUE SEP 9 2008

NJC009-091840-
/O.CAN.KPHI.SV.W.0265.000000T0000Z-080909T1930Z/
CAPE MAY NJ-
230 PM EDT TUE SEP 9 2008

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CAPE MAY COUNTY IS
CANCELLED...

THE SEVERE THUNDERSTORM HAS MOVED EAST OF THE REGION.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 PM EDT
TUESDAY AFTERNOON FOR SOUTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
SOUTHERN NEW JERSEY.

LAT...LON 3849 7571 3851 7571 3865 7560 3890 7526
      3885 7523 3880 7515 3879 7511 3881 7508
      3866 7505 3864 7506 3860 7504 3860 7505
      3859 7504 3845 7505
TIME...MOT...LOC 1830Z 308DEG 21KT 3890 7466 3882 7527
          3860 7549 3831 7558

$$

DEC005-091930-
/O.CON.KPHI.SV.W.0265.000000T0000Z-080909T1930Z/
SUSSEX DE-
230 PM EDT TUE SEP 9 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR SUSSEX COUNTY...

AT 225 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING NICKEL
SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS
WERE LOCATED ALONG A LINE EXTENDING FROM 25 MILES NORTHEAST OF
HENLOPEN ACRES TO MILTON TO SYCAMORE TO 16 MILES SOUTH OF LAUREL...OR
ALONG A LINE EXTENDING FROM 12 MILES EAST OF CAPE MAY TO 12 MILES
NORTHEAST OF GEORGETOWN TO 9 MILES SOUTHWEST OF GEORGETOWN TO
SALISBURY...MOVING SOUTHEAST AT 24 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  LEWES BY 245 PM EDT...
  GUMBORO AND MILLSBORO BY 255 PM EDT...
  REHOBOTH BEACH...HENLOPEN ACRES AND DAGSBORO BY 300 PM EDT...
  LONG NECK...FRANKFORD AND DEWEY BEACH BY 305 PM EDT...
  SELBYVILLE BY 315 PM EDT...

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS LINE
SOUTH OF GEORGETOWN. WHILE NOT IMMEDIATELY LIKELY...A TORNADO 
MAY STILL DEVELOP. IF A TORNADO IS SPOTTED...ACT QUICKLY AND 
MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE...SUCH AS A 
BASEMENT OR SMALL INTERIOR ROOM.

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.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 PM EDT
TUESDAY AFTERNOON FOR SOUTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
SOUTHERN NEW JERSEY.

LAT...LON 3849 7571 3851 7571 3865 7560 3890 7526
      3885 7523 3880 7515 3879 7511 3881 7508
      3866 7505 3864 7506 3860 7504 3860 7505
      3859 7504 3845 7505
TIME...MOT...LOC 1830Z 308DEG 21KT 3890 7466 3882 7527
          3860 7549 3831 7558

$$

TFG

000 
WWUS51 KPHI 091900
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
300 PM EDT TUE SEP 9 2008

DEC005-091930-
/O.CON.KPHI.SV.W.0265.000000T0000Z-080909T1930Z/
SUSSEX DE-
259 PM EDT TUE SEP 9 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM EDT
FOR SOUTHEASTERN SUSSEX COUNTY...

AT 256 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING NICKEL
SIZE HAIL...AND DAMAGING WINDS TO 60 MPH. DOPPLER RADAR FROM DOVER
WAS SHOWING A WIDE AREA OF WINDS IN EXCESS OF 45 MPH ACROSS MUCH
OF EASTERN SUSSEX COUNTY. 

THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM 15 MILES NORTHEAST OF
HENLOPEN ACRES TO HENLOPEN ACRES TO GUMBORO TO 18 MILES SOUTH OF
GUMBORO...OR ALONG A LINE EXTENDING FROM 9 MILES SOUTHEAST OF CAPE
MAY TO 15 MILES EAST OF GEORGETOWN TO 13 MILES SOUTH OF GEORGETOWN TO
14 MILES SOUTHEAST OF SALISBURY...MOVING SOUTHEAST AT 25 MPH. 

SEVERE THUNDERSTORMS WILL BE NEAR...
  LONG NECK...FRANKFORD AND DEWEY BEACH BY 305 PM EDT...
  MILLVILLE BY 315 PM EDT...
  OCEAN VIEW AND BETHANY BEACH BY 320 PM EDT...
  SOUTH BETHANY BY 325 PM EDT...
  FENWICK ISLAND BY 330 PM EDT...

THUNDERSTORMS ARE CAPABLE OF PRODUCING HEAVY RAINFALL WHICH MAY
RESULT IN LOCALIZED AREAS OF FLOODING. DO NOT DRIVE IN AREAS WHERE
WATER IS COVERING THE ROAD.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 400 PM EDT
TUESDAY AFTERNOON FOR SOUTHERN DELAWARE AND NEW JERSEY.

LAT...LON 3846 7513 3847 7543 3850 7543 3860 7537
      3881 7518 3879 7519 3880 7515 3879 7511
      3881 7508 3866 7505 3864 7506 3860 7504
      3845 7505 3845 7513
TIME...MOT...LOC 1859Z 308DEG 21KT 3881 7481 3872 7510
          3850 7532 3821 7541

$$

TFG

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 9, 9:21 AM EDT	Severe Thunderstorm Warning	PHI	New Castle	39 min
Sep 9, 9:59 AM EDT	Flash Flood Warning	PHI	New Castle	3 hr
Sep 9, 1:09 PM EDT	Severe Thunderstorm Warning	PHI	Kent, Sussex	36 min
Sep 9, 2:42 PM EDT	Areal Flood Advisory	PHI	Sussex	3 hr
Sep 9, 3:36 AM EDT	Small Craft Advisory	PHI		36 hr
Sep 9, 9:09 AM EDT	Areal Flood Advisory	PHI	Sussex, Warren	3 hr
Sep 9, 9:41 AM EDT	Flash Flood Warning	PHI	Hunterdon, Morris, Somerset	3 hr
Sep 9, 10:04 AM EDT	Flash Flood Warning	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	3 hr
Sep 9, 10:57 AM EDT	Severe Thunderstorm Warning	PHI	Burlington, Mercer, Middlesex, Monmouth, Ocean	48 min
Sep 9, 11:07 AM EDT	Severe Thunderstorm Warning	PHI	Burlington, Camden, Gloucester, Salem	38 min
Sep 9, 11:50 AM EDT	Special Marine Warning	PHI		55 min
Sep 9, 12:11 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Burlington, Ocean	49 min
Sep 9, 12:44 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Cape May, Cumberland	46 min
Sep 9, 1:05 PM EDT	Special Marine Warning	PHI		55 min
Sep 9, 1:07 PM EDT	Severe Thunderstorm Warning	PHI	Atlantic, Cape May, Cumberland	53 min
Sep 9, 1:55 PM EDT	Special Marine Warning	PHI		65 min
Sep 9, 2:53 PM EDT	Special Marine Warning	PHI		86 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2008 Severe Thunderstorm Warnings in New Jersey, 2008 Every severe thunderstorm warning in 2008

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.