Alert archive / Delaware / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

July 23, 2017New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at Jul 23, 2017, 4:15 PM EDT for New Castle County, Delaware. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 23, 2017, 4:15 PM EDT (20:15 UTC)
Expired: Jul 23, 2017, 4:45 PM EDT
In force: 30 min
Issued by: NWS Philadelphia/Mount Holly

County New Castle County, DE

The radar

The Dover AFB radar (KDOX), 76 km from the middle of the area, began a volume at 20:18 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.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 8.3 hours before the alert went out and 170 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: 186 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 983 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

950 
WWUS81 KPHI 232015
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
415 PM EDT SUN JUL 23 2017

DEZ001-002-MDZ008-012-NJZ016-021-PAZ102-232045-
Kent-New Castle-Cecil-Kent-Salem-Cumberland-Eastern Chester-
415 PM EDT SUN JUL 23 2017

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NEW CASTLE...NORTHERN
KENT...NORTHEASTERN KENT...EASTERN CECIL...WEST CENTRAL CUMBERLAND...
SOUTHWESTERN SALEM AND SOUTHERN CHESTER COUNTIES...

At 413 PM EDT, radar indicated strong thunderstorms were located
along a line extending from near Glasgow to near Smyrna to near 
Dover Base Housing. Movement was variable with each storm but 
generally drifting to the east at 10 mph.

Locations impacted include...
Wilmington, Dover, Newark, Middletown, Elkton, Pennsville, Smyrna,
Elsmere, New Castle, Salem, Clayton, Delaware City, Cheswold,
Newport, Stanton, Glasgow, Bohemias Mills, Newport Meadows, Dover
Speedway and Saint Georges.

These storms will contain gusty winds up to 45 mph, torrential 
downpours and occasional cloud to ground lightning.  

Locally heavy rainfall will lead to ponding of water on roadways and 
poor visibility. Poor drainage flooding may occur with localized 
rainfall amounts of one to three inches. 

Lightning can strike 10 miles away from a thunderstorm. Seek a safe 
shelter inside a building or vehicle.

These storms may intensify, so be certain to monitor local radio 
stations and available television stations for additional 
information and possible warnings from the National Weather Service.

LAT...LON 3969 7585 3981 7559 3970 7553 3964 7560
      3960 7561 3959 7560 3960 7558 3957 7557
      3959 7554 3962 7557 3967 7551 3930 7530
      3935 7534 3930 7543 3921 7540 3907 7540
      3907 7546 3942 7586
TIME...MOT...LOC 2013Z 240DEG 12KT 3963 7577 3935 7558 3917 7543 

$$

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 8:05 PM EDT	Special Weather Statement	PHI	Ocean	25 min
Jul 22, 10:52 PM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Somerset	4 hr
Jul 23, 12:01 AM EDT	Coastal Flood Advisory	PHI	Atlantic, Burlington, Cape May, Cumberland, Middlesex, Monmouth and 1 more	25 hr
Jul 23, 3:16 PM EDT	Flash Flood Watch	PHI	Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex and 6 more	15 hr
Jul 23, 3:43 PM EDT	Special Marine Warning	PHI		92 min
Jul 23, 4:29 PM EDT	Severe Thunderstorm Warning	PHI	Cape May, Cumberland	26 min
Jul 23, 4:39 PM EDT	Areal Flood Advisory	PHI	Cape May, Cumberland, Salem	4 hr
Jul 23, 4:40 PM EDT	Special Marine Warning	PHI		65 min
Jul 23, 4:26 PM EDT	Areal Flood Advisory	PHI	Chester	3 hr
Jul 23, 4:48 PM EDT	Areal Flood Advisory	PHI	Chester, Delaware	4 hr
Jul 23, 5:22 PM EDT	Special Weather Statement	PHI	Delaware	23 min
Jul 23, 6:08 PM EDT	Special Weather Statement	PHI	Delaware	37 min
Jul 23, 6:53 PM EDT	Flash Flood Warning	PHI	Chester, Delaware	14 hr
Jul 23, 7:20 PM EDT	Flash Flood Warning	PHI	Berks, Chester, Montgomery	6 hr
Jul 23, 7:41 PM EDT	Flash Flood Warning	PHI	Bucks, Delaware, Montgomery, Philadelphia	6 hr
Jul 22, 10:18 PM EDT	Special Weather Statement	PHI	Caroline, Talbot	72 min
Jul 22, 11:26 PM EDT	Areal Flood Advisory	PHI	Caroline, Queen Anne's, Talbot	4 hr
Jul 23, 2:38 PM EDT	Special Weather Statement	PHI	Caroline, Kent, Queen Anne's, Talbot	67 min
Jul 23, 2:47 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	43 min
Jul 23, 2:53 PM EDT	Special Weather Statement	PHI	Cecil	52 min
Jul 23, 3:27 PM EDT	Special Weather Statement	PHI	Cecil	33 min
Jul 23, 3:31 PM EDT	Special Weather Statement	PHI	Dorchester	44 min
Jul 23, 3:53 PM EDT	Areal Flood Advisory	PHI	Cecil, Kent	4 hr
Jul 23, 5:40 PM EDT	Areal Flood Advisory	PHI	Cecil	4 hr
Jul 23, 5:47 PM EDT	Special Weather Statement	PHI	Cecil	28 min
Jul 23, 6:22 PM EDT	Special Weather Statement	PHI	Cecil	38 min
Jul 23, 6:26 PM EDT	Flash Flood Warning	PHI	Cecil	4 hr
Jul 22, 11:11 PM EDT	Special Weather Statement	PHI	Sussex	64 min
Jul 23, 4:21 PM EDT	Areal Flood Advisory	PHI	Kent	3 hr
Jul 23, 4:44 PM EDT	Special Weather Statement	PHI	New Castle	16 min

Nearby

Special Weather Statements in Delaware, 2017 Every special weather statement in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.