Alert archive / Maryland / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 13, NWS Philadelphia/Mount Holly

May 12, 2018Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Sussex County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 12, 2018, 9:27 PM EDT for Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Sussex County, Delaware. It was in force for 63 min. 6 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, 9:27 PM EDT (01:27 UTC)
Expired
May 12, 2018, 10:30 PM EDT
In force
63 min
Issued by
NWS Philadelphia/Mount Holly
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

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

The radar

The Dover AFB radar (KDOX), 48 km from the middle of the area, began a volume at 01:28 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, 9:37 PM EDTTSTM WND DMG1 Se Kirkham, MDTREES DOWN ON TRAVELERS REST ROAD NEAR MAXMORE CREEK ROAD. TIME APPROXIMATED FROM RADAR.
May 12, 9:40 PM EDTMRN TSTM WIND 451 Nw Lewes Beach, DE
May 12, 9:55 PM EDTMRN TSTM WIND 46Bethany Beach, DE
May 12, 9:55 PM EDTMARINE TSTM WIND 46Bethany Beach, DE
May 12, 10:06 PM EDTMRN TSTM WIND 394 S Dewey Beach, DE
May 12, 10:06 PM EDTMARINE TSTM WIND 394 S Dewey Beach, 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

Wallops Is Stn, VA (KWAL), launched 00:00Z, 1.5 hours before the alert went out and 106 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 2018-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1641 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 2018-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 159 square meters per square second.193958Sfc1 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
1641 J/kg
Mixed-layer CIN
-127 J/kg
Mixed-layer LCL
1626 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
159 m²/s²
0-3 km storm-relative helicity
220 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

051 
WUUS51 KPHI 130127
SVRPHI
DEC001-005-MDC011-035-041-130230-
/O.NEW.KPHI.SV.W.0013.180513T0127Z-180513T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
927 PM EDT SAT MAY 12 2018

The National Weather Service in Mount Holly NJ has issued a

* Severe Thunderstorm Warning for...
  Sussex County in southern Delaware...
  Southwestern Kent County in central Delaware...
  Talbot County in eastern Maryland...
  Southwestern Queen Anne's County in northeastern Maryland...
  Southern Caroline County in eastern Maryland...

* Until 1030 PM EDT.

* At 926 PM EDT, severe thunderstorms were located along a line
  extending from near Smithville to Talbot, moving east at 45 mph.

  HAZARD...60 mph wind gusts and quarter 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...
  Easton, Georgetown, Talbot, Milford, Seaford, Denton, Millsboro,
  Laurel, Harrington, Romancoke, Lewes, Federalsburg, Milton,
  Bridgeville, Trappe, St. Michaels, Dagsboro, Preston, Sharptown and
  Millville.

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
southern Delaware...and eastern and northeastern Maryland.

LAT...LON 3869 7577 3868 7594 3857 7604 3876 7622
      3871 7628 3878 7629 3876 7632 3867 7634
      3893 7636 3896 7633 3896 7631 3886 7634
      3878 7621 3889 7620 3892 7626 3888 7573
      3895 7533 3876 7505 3846 7504 3846 7569
TIME...MOT...LOC 0126Z 282DEG 29KT 3879 7568 3882 7627 

HAIL...1.00IN
WIND...60MPH
 
$$

JRK
3 follow-up statements
800 
WWUS51 KPHI 130148
SVSPHI

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

DEC001-MDC035-130157-
/O.CAN.KPHI.SV.W.0013.000000T0000Z-180513T0230Z/
Kent DE-Queen Anne's MD-
948 PM EDT SAT MAY 12 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN KENT AND
SOUTHWESTERN QUEEN ANNE'S COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 3864 7571 3869 7577 3868 7594 3857 7604
      3876 7622 3869 7634 3872 7630 3873 7633
      3873 7628 3878 7629 3875 7632 3876 7633
      3882 7631 3878 7621 3883 7619 3882 7515
      3876 7505 3846 7504 3846 7569
TIME...MOT...LOC 0147Z 282DEG 29KT 3875 7547 3879 7606 

$$

DEC005-MDC011-041-130230-
/O.CON.KPHI.SV.W.0013.000000T0000Z-180513T0230Z/
Sussex DE-Talbot MD-Caroline MD-
948 PM EDT SAT MAY 12 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR SUSSEX...CENTRAL TALBOT AND SOUTHERN CAROLINE COUNTIES...

At 947 PM EDT, severe thunderstorms were located along a line
extending from near Ellendale to Easton, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Easton, Georgetown, Seaford, Millsboro, Laurel, Lewes, Federalsburg,
Milton, Bridgeville, Trappe, Dagsboro, Preston, Millville, Ellendale,
Henlopen Acres, Smithville, Gumboro, Copperville, Agner and Choptank.

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.

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 southern
Delaware...and eastern Maryland.

LAT...LON 3864 7571 3869 7577 3868 7594 3857 7604
      3876 7622 3869 7634 3872 7630 3873 7633
      3873 7628 3878 7629 3875 7632 3876 7633
      3882 7631 3878 7621 3883 7619 3882 7515
      3876 7505 3846 7504 3846 7569
TIME...MOT...LOC 0147Z 282DEG 29KT 3875 7547 3879 7606 

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

JRK
017 
WWUS51 KPHI 130218
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1018 PM EDT SAT MAY 12 2018

MDC011-041-130227-
/O.CAN.KPHI.SV.W.0013.000000T0000Z-180513T0230Z/
Talbot MD-Caroline MD-
1018 PM EDT SAT MAY 12 2018

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL TALBOT AND SOUTHERN
CAROLINE COUNTIES IS CANCELLED...

The storms which prompted the warning have weakened. Therefore, the 
warning has been cancelled.

LAT...LON 3858 7538 3869 7512 3869 7505 3846 7504
      3846 7569
TIME...MOT...LOC 0217Z 270DEG 29KT 3871 7519 3875 7578 

$$

DEC005-130230-
/O.CON.KPHI.SV.W.0013.000000T0000Z-180513T0230Z/
Sussex DE-
1018 PM EDT SAT MAY 12 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT
FOR SOUTHEASTERN SUSSEX COUNTY...

At 1017 PM EDT, severe thunderstorms were located along a line
extending from near Lewes to Agner, moving east at 35 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...
Millsboro, Dagsboro, Millville, Gumboro, Long Neck, Ocean View,
Frankford, South Bethany and Dewey Beach.

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.

&&

LAT...LON 3858 7538 3869 7512 3869 7505 3846 7504
      3846 7569
TIME...MOT...LOC 0217Z 270DEG 29KT 3871 7519 3875 7578 

HAIL...0.75IN
WIND...60MPH
 
$$
187 
WWUS51 KPHI 130228
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
1028 PM EDT SAT MAY 12 2018

DEC005-130237-
/O.EXP.KPHI.SV.W.0013.000000T0000Z-180513T0230Z/
Sussex DE-
1028 PM EDT SAT MAY 12 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SUSSEX COUNTY
WILL EXPIRE AT 1030 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 3858 7538 3869 7512 3869 7505 3846 7504
      3846 7569
TIME...MOT...LOC 0227Z 282DEG 29KT 3870 7511 3874 7570 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 8:11 PM EDTSevere Thunderstorm WarningPHICaroline, Cecil, Kent, Queen Anne's49 min
May 12, 8:40 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's, Talbot50 min
May 12, 8:50 PM EDTFlash Flood WarningPHICaroline, Kent, Queen Anne's3 hr
May 12, 8:51 PM EDTSevere Thunderstorm WarningPHICaroline, Kent, Queen Anne's39 min
May 12, 9:14 PM EDTAreal Flood AdvisoryPHICaroline, Kent, Queen Anne's, Talbot2 hr
May 12, 10:28 PM EDTAreal Flood AdvisoryPHISussex65 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.