Alert archive / Delaware / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 190, NWS Philadelphia/Mount Holly

August 16, 2007Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 16, 2007, 10:54 PM EDT for Sussex County, Delaware. It was in force for 36 min. 3 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: Aug 16, 2007, 10:54 PM EDT (02:54 UTC)
Expired: Aug 16, 2007, 11:30 PM EDT
In force: 36 min
Issued by: NWS Philadelphia/Mount Holly
Area: Counties, with a storm outline in the text

County Sussex County, DE

The radar

The Dover AFB radar (KDOX), 29 km from the middle of the area, began a volume at 02:54 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 16, 10:55 PM EDT	TSTM WND DMG	Dewey Beach, DE	THREE UTILITY POLES DOWN.
Aug 16, 11:04 PM EDT	TSTM WND DMG	Lewes, DE	TREES DOWN.
Aug 16, 11:13 PM EDT	TSTM WND DMG	Rehoboth Beach, DE	TREES DOWN.

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

The nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 00:00Z, 2.9 hours before the alert went out and 86 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: 4766 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 852 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 175 m²/s²
0-3 km storm-relative helicity: 289 m²/s²
Significant tornado parameter: 4.7
Supercell composite: 26.2

Open this sounding in Storm Lab

The text

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

000 
WUUS51 KPHI 170254
SVRPHI
DEC005-170330-
/O.NEW.KPHI.SV.W.0190.070817T0254Z-070817T0330Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1054 PM EDT THU AUG 16 2007

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN AND EAST-CENTRAL SUSSEX COUNTY IN SOUTHERN DELAWARE...

* UNTIL 1130 PM EDT

* AT 1049 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  MILTON...OR ABOUT 30 MILES SOUTH OF DOVER...AND MOVING EAST AT
  20 TO 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  LEWES AND 8 MILES NORTH OF LONG NECK BY 1115 PM EDT...
  REHOBOTH BEACH BY 1125 PM EDT...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...FREQUENT 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.

LAT...LON 3859 7509 3862 7509 3861 7512 3859 7511
      3859 7514 3861 7512 3860 7516 3863 7544
      3884 7541 3881 7517 3879 7514 3881 7508
      3866 7505 3858 7505
TIME...MOT...LOC 0254Z 273DEG 20KT 3874 7529

$$

JRP

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 16, 10:16 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	44 min
Aug 16, 10:20 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	55 min
Aug 16, 11:31 PM EDT	Severe Thunderstorm Warning	PHI	Sussex	25 min
Aug 17, 12:26 AM EDT	Severe Thunderstorm Warning	PHI	Sussex	22 min
Aug 17, 2:36 PM EDT	Severe Thunderstorm Warning	PHI	New Castle	54 min

Nearby

Severe Thunderstorm Warnings in Delaware, 2007 Every severe thunderstorm warning in 2007

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.