Alert archive / Maryland / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 10, NWS Philadelphia/Mount Holly

May 12, 2018Kent County, New Castle County, Delaware; 4 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 12, 2018, 8:11 PM EDT for Kent County, New Castle County, Delaware; 4 counties in Maryland. It was in force for 49 min. 9 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 12, 2018, 8:11 PM EDT (00:11 UTC)
Expired
May 12, 2018, 9:00 PM EDT
In force
49 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
2.0 in
Wind
60.0 mph

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

The radar

The Dover AFB radar (KDOX), 59 km from the middle of the area, began a volume at 00:10 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.

What was reported inside it

TimeReportWhereRemark
May 12, 8:12 PM EDTHAIL 12 Ese Lambson, MDPHOTO OF QUARTER SIZED HAIL SOUTH OF GALENA. LOCATION AND TIME APPROXIMATED BASED ON RADAR.
May 12, 8:22 PM EDTHAIL 1.75Butlertown, MDGOLF BALL SIZED HAIL REPORTED FOR SEVERAL MINUTES NORTH OF CHESTERTOWN. TIME APPROXIMATED FROM RADAR.
May 12, 8:27 PM EDTTSTM WND DMGReba L Anthony Estates, MDDOWNED TREE BLOCKED ROAD NEAR INTERSECTION OF MD-213 AND RIVERVIEW RD
May 12, 8:35 PM EDTHAIL 1.75Chestertown, MD
May 12, 8:36 PM EDTTSTM WND DMG1 Se Centreville, MDNUMEROUS BRANCHES AND GUTTERS DOWN FROM SEVERAL HOUSES.
May 12, 8:46 PM EDTTSTM WND DMGCamden, DETREES AND WIRES DOWN IN CAMDEN. TIME APPROXIMATED FROM RADAR.
May 12, 8:47 PM EDTHAIL 1.25Wyoming, DE
May 12, 8:52 PM EDTHAIL 1Highland Acres, DEPHOTO OF QUARTER SIZED HAIL IN HIGHLAND ACRES. TIME APPROXIMATED FROM RADAR.
May 12, 8:56 PM EDTHAIL 1.51 Nne White House Landi, DE

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 12, 4:58 PM EDTTornado WatchSPC5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.2 hours before the alert went out and 134 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 00:00Z on 2018-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1175 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 00:00Z on 2018-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 132 square meters per square second.19395878Sfc1 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
1175 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
2284 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
132 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.4

Open this sounding in Storm Lab

The text

As transmitted.

139 
WUUS51 KPHI 130011
SVRPHI
DEC001-003-MDC011-015-029-035-130100-
/O.NEW.KPHI.SV.W.0010.180513T0011Z-180513T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
811 PM EDT SAT MAY 12 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...
  Queen Anne's County in northeastern Maryland...
  Northeastern Caroline County in eastern Maryland...
  Kent County in northeastern Maryland...
  Southeastern Cecil County in northeastern Maryland...

* Until 900 PM EDT.

* At 811 PM EDT, severe thunderstorms were located along a line
  extending from near Millington to near Dundalk, moving east at 35
  mph.

  HAZARD...Two inch hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Wind 
           damage to roofs, siding, trees, and power lines is 
           possible.

* Locations impacted include...
  Dover, Centerville, Smyrna, Chestertown, Centreville, Camden,
  Clayton, Cheswold, Rock Hall, Church Hill, Millington,
  Sudlersville, Betterton, Goldsboro, Woodside, Hartly, Old Town,
  Hazlettville, Morgnec and Delaney Corner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large 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 these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

A tornado watch remains in effect until 100 AM EDT for central and
northern Delaware...and eastern and northeastern Maryland.

LAT...LON 3926 7622 3929 7617 3932 7618 3933 7614
      3937 7611 3937 7606 3941 7603 3934 7543
      3932 7542 3933 7539 3931 7541 3928 7538
      3908 7537 3906 7562 3901 7581 3901 7600
      3904 7624 3909 7623 3917 7628
TIME...MOT...LOC 0011Z 270DEG 29KT 3929 7589 3926 7655 

HAIL...2.00IN
WIND...60MPH
 
$$

JRK
1 follow-up statement
322 
WWUS51 KPHI 130031
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
831 PM EDT SAT MAY 12 2018

DEC001-003-MDC011-015-029-035-130100-
/O.CON.KPHI.SV.W.0010.000000T0000Z-180513T0100Z/
New Castle DE-Kent DE-Queen Anne's MD-Caroline MD-Kent MD-Cecil MD-
831 PM EDT SAT MAY 12 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM EDT
FOR SOUTHWESTERN NEW CASTLE...NORTHERN KENT...QUEEN ANNE'S...
NORTHEASTERN CAROLINE...KENT AND SOUTHEASTERN CECIL COUNTIES...

At 830 PM EDT, severe thunderstorms were located along a line
extending from near Delaney Corner to near Bowleys Quarters, moving
east at 35 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to vehicles is possible. Wind damage to roofs, 
         siding, trees, and power lines is possible.

Locations impacted include...
Dover, Centerville, Smyrna, Chestertown, Centreville, Camden,
Clayton, Cheswold, Rock Hall, Church Hill, Millington, Sudlersville,
Betterton, Goldsboro, Woodside, Hartly, Old Town, Hazlettville,
Morgnec and Delaney Corner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In addition to large 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 these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

A tornado watch remains in effect until 100 AM EDT for central and
northern Delaware...and eastern and northeastern Maryland.

LAT...LON 3926 7622 3929 7617 3932 7618 3933 7614
      3937 7611 3937 7606 3941 7603 3934 7543
      3932 7542 3933 7539 3931 7541 3928 7538
      3908 7537 3906 7562 3901 7581 3901 7600
      3904 7624 3909 7623 3917 7628
TIME...MOT...LOC 0030Z 270DEG 29KT 3929 7569 3926 7635 

TORNADO...POSSIBLE
HAIL...1.25IN
WIND...60MPH
 
$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 8:50 PM EDTFlash Flood WarningPHIKent, New Castle3 hr
May 12, 8:51 PM EDTSevere Thunderstorm WarningPHIKent, Sussex39 min
May 12, 9:14 PM EDTAreal Flood AdvisoryPHIKent2 hr
May 12, 9:27 PM EDTSevere Thunderstorm WarningPHIKent, Sussex63 min
May 12, 10:28 PM EDTAreal Flood AdvisoryPHISussex65 min
May 12, 8:40 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot50 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.