Alert archive / Maryland / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 30, NWS Philadelphia/Mount Holly

June 9, 2018Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jun 9, 2018, 3:53 PM EDT for Kent County, Queen Anne's County, Maryland; Kent County, New Castle County, Delaware. It was in force for 37 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
Jun 9, 2018, 3:53 PM EDT (19:53 UTC)
Expired
Jun 9, 2018, 4:30 PM EDT
In force
37 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Kent County, DE, New Castle County, DE, Kent County, MD, Queen Anne's County, MD

The radar

The Dover AFB radar (KDOX), 56 km from the middle of the area, began a volume at 19:53 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, 7.9 hours before the alert went out and 148 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 2018-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 384 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 2018-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
384 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
1106 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

429 
WUUS51 KPHI 091953
SVRPHI
DEC001-003-MDC029-035-092030-
/O.NEW.KPHI.SV.W.0030.180609T1953Z-180609T2030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
353 PM EDT SAT JUN 9 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Southwestern New Castle County in northern Delaware...
  Northern Kent County in central Delaware...
  Northeastern Queen Anne's County in northeastern Maryland...
  Northeastern Kent County in northeastern Maryland...

* Until 430 PM EDT.

* At 351 PM EDT, a severe thunderstorm was located over Green Spring,
  or 10 miles southeast of Middletown, moving southeast at 15 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Dover, Smyrna, Camden, Clayton, Cheswold, Millington, Sudlersville,
  Hartly, Rising Sun-Lebanon, Woodland Beach, Hazlettville, Morgnec,
  Delaney Corner, Dover Base Housing, Crumpton, Dover Speedway,
  Sassafras, Green Spring, Rising Sun and Massey.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to hail and 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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3936 7591 3938 7577 3940 7577 3942 7569
      3937 7546 3936 7546 3927 7537 3906 7537
      3913 7575 3914 7575 3913 7579 3914 7587
      3928 7605 3936 7605
TIME...MOT...LOC 1951Z 304DEG 11KT 3931 7564 

HAIL...0.75IN
WIND...60MPH
 
$$

JRK
2 follow-up statements
313 
WWUS51 KPHI 092009
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
409 PM EDT SAT JUN 9 2018

DEC001-003-MDC029-035-092030-
/O.CON.KPHI.SV.W.0030.000000T0000Z-180609T2030Z/
New Castle DE-Kent DE-Queen Anne's MD-Kent MD-
409 PM EDT SAT JUN 9 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM EDT
FOR SOUTHWESTERN NEW CASTLE...NORTHERN KENT...NORTHEASTERN QUEEN
ANNE'S AND NORTHEASTERN KENT COUNTIES...

At 408 PM EDT, a severe thunderstorm was located over Cheswold, or
near Dover, moving southeast at 20 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Damage to roofs, siding, trees, and power lines is 
         possible.

Locations impacted include...
Dover, Smyrna, Camden, Clayton, Cheswold, Millington, Sudlersville,
Hartly, Rising Sun-Lebanon, Woodland Beach, Hazlettville, Morgnec,
Delaney Corner, Dover Base Housing, Crumpton, Dover Speedway, Green
Spring, Rising Sun, Massey and Kennedyville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to hail and 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.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3934 7589 3936 7564 3934 7544 3927 7537
      3906 7537 3913 7575 3914 7575 3913 7579
      3914 7587 3928 7605 3936 7605
TIME...MOT...LOC 2008Z 315DEG 16KT 3924 7560 

HAIL...0.75IN
WIND...60MPH
 
$$

JRK
712 
WWUS51 KPHI 092025
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
425 PM EDT SAT JUN 9 2018

DEC001-003-MDC029-035-092035-
/O.EXP.KPHI.SV.W.0030.000000T0000Z-180609T2030Z/
New Castle DE-Kent DE-Queen Anne's MD-Kent MD-
425 PM EDT SAT JUN 9 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN NEW CASTLE...
NORTHERN KENT...NORTHEASTERN QUEEN ANNE'S AND NORTHEASTERN KENT
COUNTIES WILL EXPIRE AT 430 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 3934 7589 3936 7564 3934 7544 3927 7537
      3906 7537 3913 7575 3914 7575 3913 7579
      3914 7587 3928 7605 3936 7605
TIME...MOT...LOC 2025Z 304DEG 11KT 3921 7555 

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 9, 1:21 PM EDTSevere Thunderstorm WarningPHICaroline, Queen Anne's39 min
Jun 9, 2:00 PM EDTSpecial Weather StatementPHICaroline30 min
Jun 9, 2:24 PM EDTSevere Thunderstorm WarningPHICaroline51 min
Jun 9, 2:42 PM EDTAreal Flood AdvisoryPHICaroline58 min
Jun 9, 4:24 PM EDTSpecial Weather StatementPHIKent51 min
Jun 9, 5:31 PM EDTSpecial Weather StatementPHICaroline44 min
Jun 9, 12:51 PM EDTSpecial Weather StatementPHISussex24 min
Jun 9, 1:04 PM EDTSpecial Weather StatementPHIKent56 min
Jun 9, 1:25 PM EDTFlash Flood WarningPHISussex4 hr
Jun 9, 1:35 PM EDTAreal Flood AdvisoryPHIKent71 min
Jun 9, 1:35 PM EDTSpecial Weather StatementPHISussex25 min
Jun 9, 2:48 PM EDTSevere Thunderstorm WarningPHISussex42 min
Jun 9, 2:53 PM EDTFlash Flood WarningPHISussex4 hr
Jun 9, 3:06 PM EDTSpecial Weather StatementPHINew Castle24 min
Jun 9, 3:26 PM EDTSpecial Weather StatementPHISussex34 min
Jun 9, 3:45 PM EDTSpecial Weather StatementPHIKent45 min
Jun 9, 3:47 PM EDTAreal Flood AdvisoryPHIKent, New Castle3 hr
Jun 9, 4:06 PM EDTSpecial Weather StatementPHISussex39 min
Jun 9, 4:15 PM EDTFlash Flood WarningPHISussex3 hr
Jun 9, 4:20 PM EDTFlash Flood WarningPHIKent3 hr
Jun 9, 5:44 PM EDTAreal Flood WarningPHISussex4 hr
Jun 9, 6:44 PM EDTAreal Flood WarningPHISussex3 hr

Nearby

Severe Thunderstorm Warnings in Maryland, 2018Severe Thunderstorm Warnings in Delaware, 2018Every severe thunderstorm warning in 2018

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.