Alert archive / Maryland / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 86, NWS Philadelphia/Mount Holly

July 13, 2017Kent County, Delaware; Caroline County, Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 13, 2017, 5:14 PM EDT for Kent County, Delaware; Caroline County, Kent County, Queen Anne's County, Maryland. It was in force for 46 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 13, 2017, 5:14 PM EDT (21:14 UTC)
Expired
Jul 13, 2017, 6:00 PM EDT
In force
46 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Kent County, DE, Caroline County, MD, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 61 km from the middle of the area, began a volume at 21:15 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, 9.2 hours before the alert went out and 119 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, Washington/Dulle, VA at 12:00Z on 2017-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 135 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, Washington/Dulle, VA at 12:00Z on 2017-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
135 J/kg
Mixed-layer CIN
-77 J/kg
Mixed-layer LCL
1715 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

722 
WUUS51 KPHI 132114
SVRPHI
DEC001-MDC011-029-035-132200-
/O.NEW.KPHI.SV.W.0086.170713T2114Z-170713T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
514 PM EDT THU JUL 13 2017

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Western Kent County in central Delaware...
  Queen Anne's County in northeastern Maryland...
  Northeastern Caroline County in eastern Maryland...
  Central Kent County in northeastern Maryland...

* Until 600 PM EDT

* At 514 PM EDT, a severe thunderstorm was located over Old Town, or
  near Centerville, moving east at 35 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to trees and power lines. 

* Locations impacted include...
  Centerville, Chestertown, Centreville, Greensboro, Oakland,
  Ridgely, Church Hill, Millington, Sudlersville, Goldsboro, Hartly,
  Old Town, Grasonville, Starr, Jumptown, Hazlettville, Morgnec,
  Crumpton, Sandtown and Langford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

In addition to damaging winds...frequent cloud to ground lightning 
is occurring with this storm. Move indoors immediately. 
Remember...if you can hear thunder...you are close enough to be 
struck by lightning.

&&

LAT...LON 3898 7628 3897 7622 3900 7617 3903 7624
      3909 7623 3911 7625 3921 7617 3932 7576
      3929 7576 3930 7570 3929 7565 3894 7558
      3896 7629
TIME...MOT...LOC 2114Z 258DEG 32KT 3911 7614 

HAIL...<.75IN
WIND...60MPH
 
$$

JRK
2 follow-up statements
314 
WWUS51 KPHI 132143 RRA
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
543 PM EDT THU JUL 13 2017

DEC001-MDC011-029-035-132200-
/O.CON.KPHI.SV.W.0086.000000T0000Z-170713T2200Z/
Kent DE-Queen Anne's MD-Caroline MD-Kent MD-
543 PM EDT THU JUL 13 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR WESTERN KENT...NORTHEASTERN QUEEN ANNE'S...NORTHEASTERN CAROLINE
AND EAST CENTRAL KENT COUNTIES...

At 542 PM EDT, severe thunderstorms were located along a line
extending from Sudlersville to near Centerville, moving east at 35
mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to trees and power lines. 

Locations impacted include...
Centerville, Centreville, Greensboro, Oakland, Ridgely, Millington,
Sudlersville, Goldsboro, Hartly, Starr, Jumptown, Hazlettville,
Sandtown, Carville, Hope, Kenton, Henderson, Marydel, Templeville and
Barclay.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

In addition to damaging winds...frequent cloud to ground lightning 
is occurring with this storm. Move indoors immediately. 
Remember...if you can hear thunder...you are close enough to be 
struck by lightning.

&&

LAT...LON 3896 7615 3908 7606 3910 7597 3923 7591
      3930 7570 3929 7565 3894 7558
TIME...MOT...LOC 2142Z 258DEG 30KT 3919 7585 3899 7607 

HAIL...<.75IN
WIND...60MPH
 
$$

JRK
249 
WWUS51 KPHI 132157
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
557 PM EDT THU JUL 13 2017

DEC001-MDC011-029-035-132206-
/O.EXP.KPHI.SV.W.0086.000000T0000Z-170713T2200Z/
Kent DE-Queen Anne's MD-Caroline MD-Kent MD-
557 PM EDT THU JUL 13 2017

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN KENT...NORTHEASTERN
QUEEN ANNE'S...NORTHEASTERN CAROLINE AND EAST CENTRAL KENT COUNTIES
WILL EXPIRE AT 600 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire. However gusty winds 
to 45 mph are still possible with these thunderstorms.

LAT...LON 3896 7615 3908 7606 3910 7597 3923 7591
      3930 7570 3929 7565 3894 7558
TIME...MOT...LOC 2156Z 258DEG 32KT 3921 7571 3901 7593 

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 4:50 PM EDTSpecial Weather StatementPHIQueen Anne's40 min
Jul 13, 7:23 PM EDTSpecial Weather StatementPHIKent52 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2017Severe Thunderstorm Warnings in Delaware, 2017Every severe thunderstorm warning 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.