Alert archive / Maryland / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 73, NWS Philadelphia/Mount Holly

August 11, 2018Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Delaware

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Aug 11, 2018, 6:55 PM EDT for Caroline County, Queen Anne's County, Talbot County, Maryland; Kent County, Delaware. It was in force for 50 min. 1 report 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
Aug 11, 2018, 6:55 PM EDT (22:55 UTC)
Expired
Aug 11, 2018, 7:45 PM EDT
In force
50 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, Queen Anne's County, MD, Talbot County, MD

The radar

The Dover AFB radar (KDOX), 53 km from the middle of the area, began a volume at 22:58 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
Aug 11, 6:58 PM EDTTSTM WND DMGGrasonville, MDSOCIAL MEDIA PHOTOS OF SEVERAL LARGE TREE BRANCHES DOWN AT A RESIDENCE NEAR GRASONVILLE. TIME APPROXIMATED FROM RADAR.

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

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.9 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 2018-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 963 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 2018-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 59 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
963 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1021 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
59 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

As transmitted.

452 
WUUS51 KPHI 112255
SVRPHI
DEC001-MDC011-035-041-112345-
/O.NEW.KPHI.SV.W.0073.180811T2255Z-180811T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Mount Holly NJ
655 PM EDT SAT AUG 11 2018

The National Weather Service in Mount Holly NJ has issued a

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

* Until 745 PM EDT.

* At 654 PM EDT, severe thunderstorms were located along a line
  extending from near Woodland Beach to near Cheswold to Starkey
  Corner to near Romancoke, 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, Easton, Centerville, Talbot, Smyrna, Chestertown, Denton,
  Centreville, Camden, Clayton, Greensboro, Oakland, Ridgely,
  Cheswold, St. Michaels, Church Hill, Preston, Millington,
  Sudlersville and Bowers.

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 also occurring with these storms, and may 
lead to flash flooding. Do not drive your vehicle through flooded 
roadways.

&&

LAT...LON 3891 7637 3921 7607 3937 7545 3939 7546
      3933 7540 3936 7544 3906 7537 3894 7564
      3872 7589 3871 7624 3879 7632 3886 7626
      3879 7620 3879 7619 3897 7625 3889 7629
      3890 7629 3893 7631 3896 7631 3885 7637
TIME...MOT...LOC 2254Z 313DEG 11KT 3930 7547 3920 7564 3910 7603 3889
7627

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

JRK
2 follow-up statements
666 
WWUS51 KPHI 112319
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
719 PM EDT SAT AUG 11 2018

DEC001-MDC011-035-041-112345-
/O.CON.KPHI.SV.W.0073.000000T0000Z-180811T2345Z/
Kent DE-Talbot MD-Queen Anne's MD-Caroline MD-
719 PM EDT SAT AUG 11 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM EDT
FOR KENT...TALBOT...QUEEN ANNE'S AND CAROLINE COUNTIES...

At 718 PM EDT, severe thunderstorms were located along a line
extending from 7 miles southeast of Woodland Beach to Dover Speedway
to near Hope to Talbot, moving southeast at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

These severe storms will be near...
  Dover, Camden, Cheswold, Woodside, Dover Speedway and Hazlettville 
  around 725 PM EDT.
  Dover Base Housing, Rising Sun-Lebanon and Rising Sun around 730 
  PM EDT.
  Easton, Greensboro, Bowers, Goldsboro and Sandtown around 745 PM 
  EDT.

Other locations impacted by these severe thunderstorms include
Kenton, Barclay, Leipsic, Rodney Village, Wyoming, Kent Acres,
Magnolia, Riverview, Templeville and Highland Acres.

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 also occurring with these storms, and may 
lead to flash flooding. Do not drive your vehicle through flooded 
roadways.

&&

LAT...LON 3895 7633 3899 7618 3904 7619 3925 7581
      3930 7543 3906 7537 3895 7563 3872 7589
      3871 7624 3876 7622 3873 7626 3878 7631
      3885 7627 3879 7619 3896 7625 3891 7631
      3895 7632 3885 7637 3886 7637
TIME...MOT...LOC 2318Z 297DEG 14KT 3927 7537 3917 7554 3907 7593 3883
7631

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

JRK
298 
WWUS51 KPHI 112342
SVSPHI

Severe Weather Statement
National Weather Service Mount Holly NJ
742 PM EDT SAT AUG 11 2018

DEC001-MDC011-035-041-112352-
/O.EXP.KPHI.SV.W.0073.000000T0000Z-180811T2345Z/
Kent DE-Talbot MD-Queen Anne's MD-Caroline MD-
742 PM EDT SAT AUG 11 2018

...THE SEVERE THUNDERSTORM WARNING FOR KENT...TALBOT...QUEEN ANNE'S
AND CAROLINE COUNTIES WILL EXPIRE AT 745 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 and heavy rain are still possible with these thunderstorms.

To report severe weather, contact your nearest law enforcement
agency or the National Weather Service in Mount Holly, NJ.

LAT...LON 3895 7633 3899 7618 3904 7619 3925 7581
      3930 7543 3906 7537 3895 7563 3872 7589
      3871 7624 3876 7622 3873 7626 3878 7631
      3885 7627 3879 7619 3896 7625 3891 7631
      3895 7632 3885 7637 3886 7637
TIME...MOT...LOC 2342Z 313DEG 11KT 3923 7531 3913 7548 3903 7587 3879
7625

$$

JRK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 3:24 AM EDTFlash Flood WatchPHICecil, Kent, Queen Anne's20 hr
Aug 11, 4:19 PM EDTAreal Flood AdvisoryPHICecil3 hr
Aug 11, 4:19 PM EDTSevere Thunderstorm WarningPHICecil29 min
Aug 11, 5:20 PM EDTAreal Flood AdvisoryPHICecil, Kent, Queen Anne's4 hr
Aug 11, 5:24 PM EDTSpecial Weather StatementPHICecil36 min
Aug 11, 6:08 PM EDTSevere Thunderstorm WarningPHIKent, Queen Anne's52 min
Aug 11, 6:12 PM EDTFlash Flood WarningPHICecil, Kent, Queen Anne's3 hr
Aug 11, 6:45 PM EDTFlash Flood WarningPHICaroline, Queen Anne's, Talbot5 hr
Aug 11, 7:42 PM EDTSpecial Weather StatementPHICaroline, Queen Anne's, Talbot48 min
Aug 11, 4:26 AM EDTCoastal Flood AdvisoryPHIKent, New Castle, Sussex24 hr
Aug 11, 1:23 PM EDTSevere Thunderstorm WarningPHISussex37 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.