Alert archive / Maryland / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

April 29, 2017Caroline County, Maryland

NWS Philadelphia/Mount Holly issued this special weather statement at Apr 29, 2017, 3:39 AM EDT for Caroline County, Maryland. It was in force for 36 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: Apr 29, 2017, 3:39 AM EDT (07:39 UTC)
Expired: Apr 29, 2017, 4:15 AM EDT
In force: 36 min
Issued by: NWS Philadelphia/Mount Holly

County Caroline County, MD

The radar

The Dover AFB radar (KDOX), 17 km from the middle of the area, began a volume at 07:43 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 7.7 hours before the alert went out and 116 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: 1170 J/kg
Mixed-layer CIN: -111 J/kg
Mixed-layer LCL: 934 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 119 m²/s²
0-3 km storm-relative helicity: 191 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

As transmitted.

376 
WWUS81 KPHI 290739
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
339 AM EDT SAT APR 29 2017

DEZ002-003-MDZ020-NJZ024-290815-
Inland Sussex-Kent-Caroline-Atlantic Coastal Cape May-
339 AM EDT SAT APR 29 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL SUSSEX...SOUTHERN
KENT...NORTHEASTERN CAROLINE AND SOUTHWESTERN CAPE MAY COUNTIES...

At 338 AM EDT, a strong thunderstorm was located near Harrington, or
13 miles south of Dover, moving east at 45 mph.

Winds in excess of 30 mph and pea size hail are possible with this
storm.

Locations impacted include...
Milford, Denton, Harrington, Greensboro, Oakland, Ridgely, Bowers,
Viola, Big Stone Beach, Sandtown, Andrewsville, Felton, Frederica,
Houston, Magnolia, Farmington, Riverview and Woodside East.

Heavy rain is also occurring with this storm, and may cause 
localized flooding. Do not drive your vehicle through flooded 
roadways.

LAT...LON 3901 7590 3909 7540 3907 7541 3903 7534
      3898 7531 3895 7532 3894 7531 3893 7532
      3887 7525 3883 7590
TIME...MOT...LOC 0738Z 263DEG 39KT 3897 7551 

$$

SFJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 29, 2:54 AM EDT	Special Weather Statement	PHI	Burlington	36 min
Apr 29, 4:14 AM EDT	Special Weather Statement	PHI	Hunterdon, Middlesex, Somerset	46 min
Apr 29, 4:20 AM EDT	Severe Thunderstorm Warning	PHI	Burlington, Hunterdon, Mercer, Middlesex, Monmouth, Somerset	40 min
Apr 29, 4:22 AM EDT	Special Weather Statement	PHI	Burlington, Camden, Gloucester	38 min
Apr 29, 4:29 AM EDT	Areal Flood Advisory	PHI	Hunterdon, Mercer, Middlesex, Morris, Somerset	4 hr
Apr 29, 4:32 AM EDT	Severe Thunderstorm Warning	PHI	Hunterdon, Mercer, Middlesex, Monmouth, Morris, Somerset	43 min
Apr 29, 4:56 AM EDT	Special Marine Warning	PHI		64 min
Apr 29, 4:56 AM EDT	Special Weather Statement	PHI	Burlington, Mercer, Monmouth, Ocean	49 min
Apr 29, 5:16 AM EDT	Special Marine Warning	PHI		29 min
Apr 29, 6:16 AM EDT	Special Marine Warning	PHI		29 min
Apr 29, 7:04 AM EDT	Areal Flood Warning	PHI	Hunterdon, Somerset	4 hr
Apr 29, 3:12 AM EDT	Areal Flood Advisory	PHI	Berks	4 hr
Apr 29, 3:20 AM EDT	Special Weather Statement	PHI	Berks, Lehigh, Northampton	40 min
Apr 29, 3:51 AM EDT	Special Weather Statement	PHI	Berks, Bucks, Chester, Delaware, Montgomery	39 min
Apr 29, 2:57 AM EDT	Special Weather Statement	PHI	Queen Anne's	48 min

Nearby

Special Weather Statements in Maryland, 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.