Alert archive / Maryland / Special Weather Statements in 2017

Special Weather Statement, NWS Philadelphia/Mount Holly

May 20, 2017Caroline County, Maryland; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this special weather statement at May 20, 2017, 12:09 AM EDT for Caroline County, Maryland; Kent County, Delaware. It was in force for 21 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
May 20, 2017, 12:09 AM EDT (04:09 UTC)
Expired
May 20, 2017, 12:30 AM EDT
In force
21 min
Issued by
NWS Philadelphia/Mount Holly

Counties Kent County, DE, Caroline County, MD

The radar

The Dover AFB radar (KDOX), 28 km from the middle of the area, began a volume at 04:08 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, 4.2 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-pSkew-T log-p diagram, Wallops Is Stn, VA at 00:00Z on 2017-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1860 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 00:00Z on 2017-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1860 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
1241 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

055 
WWUS81 KPHI 200409
SPSPHI

Special Weather Statement
National Weather Service Mount Holly NJ
1209 AM EDT SAT MAY 20 2017

DEZ002-003-MDZ019-020-NJZ021-200430-
Inland Sussex-Kent-Talbot-Caroline-Cumberland-
1209 AM EDT SAT MAY 20 2017

...A GUST FRONT WILL AFFECT NORTHWESTERN SUSSEX... 
KENT...SOUTHEASTERN TALBOT...CAROLINE AND SOUTHERN CUMBERLAND 
COUNTIES...

At 1206 AM EDT, radar indicated a gust front along a line extending 
from Hazlettville to Denton to Tanyard. Movement was east at 35 mph.

Winds up to 40 mph are possible with this gust front. Behind the 
gust front, scattered thunderstorms with occasional lightning are 
expected.

Locations impacted include...
Dover, Easton, Milford, Seaford, Denton, Harrington, Camden,
Federalsburg, Milton, Bridgeville, Greensboro, Cheswold, Trappe,
Preston, Oxford, Ellendale, Bowers, Woodside, Viola and Hartly.

LAT...LON 3864 7571 3869 7577 3868 7580 3871 7584
      3868 7594 3857 7602 3863 7608 3864 7615
      3868 7617 3868 7621 3871 7622 3890 7584
      3924 7570 3921 7540 3907 7541 3901 7533
      3893 7532 3887 7526 3878 7530 3852 7570
TIME...MOT...LOC 0406Z 286DEG 29KT 3915 7564 3889 7576 3875 7601 

$$

SFJ

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 9:39 PM EDTSpecial Marine WarningPHI66 min
May 19, 9:55 PM EDTSpecial Weather StatementPHICape May, Cumberland50 min
May 19, 8:13 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot32 min
May 19, 8:47 PM EDTSpecial Weather StatementPHICaroline, Talbot43 min
May 19, 11:51 PM EDTSpecial Weather StatementPHIQueen Anne's24 min
May 19, 9:24 PM EDTSpecial Weather StatementPHIKent36 min
May 19, 10:00 PM EDTSpecial Weather StatementPHISussex30 min
May 19, 10:35 PM EDTSpecial Weather StatementPHISussex25 min

Nearby

Special Weather Statements in Maryland, 2017Special Weather Statements in Delaware, 2017Every 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.