Alert archive / Maryland / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 11, NWS Philadelphia/Mount Holly

May 12, 20184 counties in Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at May 12, 2018, 8:40 PM EDT for 4 counties in Maryland. It was in force for 50 min. 5 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, 8:40 PM EDT (00:40 UTC)
Expired: May 12, 2018, 9:30 PM EDT
In force: 50 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

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

The radar

The Dover AFB radar (KDOX), 64 km from the middle of the area, began a volume at 00:40 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

Time	Report	Where	Remark
May 12, 8:45 PM EDT	TSTM WND GST 58	Kent Narrows, MD
May 12, 8:50 PM EDT	TSTM WND GST 60	Kent Narrows, MD
May 12, 9:02 PM EDT	TSTM WND DMG	Woodland, MD	DEBRIS ON THE ROADWAY CAUSED BY THUNDERSTORM WINDS CAUSED LANE RESTRICTIONS ON STATE HIGHWAY 309 AT RABBIT HILL ROAD.
May 12, 9:10 PM EDT	TSTM WND DMG	Woodland, MD	DOWNED TREE ON ROADWAY RESULTED IN LANE RESTRICTIONS ON STATE HIGHWAY 309 AT RABBIT HILL ROAD.
May 12, 9:37 PM EDT	TSTM WND DMG	1 Se Kirkham, MD	TREES DOWN ON TRAVELERS REST ROAD NEAR MAXMORE CREEK ROAD. TIME APPROXIMATED FROM RADAR.

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.

Issued	Product	Office	Lasted
May 12, 4:58 PM EDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.7 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

390 
WUUS51 KPHI 130040
SVRPHI
MDC011-029-035-041-130130-
/O.NEW.KPHI.SV.W.0011.180513T0040Z-180513T0130Z/

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

The National Weather Service in Mount Holly NJ has issued a

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

* Until 930 PM EDT.

* At 840 PM EDT, severe thunderstorms were located along a line
  extending from near Overton to near Arnold to near Bowie, 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, Talbot, Denton, Centreville, Greensboro, Oakland, Ridgely,
  Trappe, St. Michaels, Preston, Queen Anne, Grasonville, Starr,
  Copperville, Jumptown, Agner, Choptank, Windyhill, Tanyard and
  Harmony.

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 3883 7630 3885 7627 3879 7620 3879 7619
      3894 7621 3897 7625 3894 7625 3894 7636
      3904 7631 3897 7622 3900 7617 3904 7621
      3902 7574 3882 7572 3869 7581 3863 7605
      3878 7629 3868 7634 3875 7637
TIME...MOT...LOC 0040Z 287DEG 32KT 3906 7616 3903 7646 3891 7668 

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

JRK

1 follow-up statement

251 
WWUS51 KPHI 130104
SVSPHI

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

MDC011-029-035-041-130130-
/O.CON.KPHI.SV.W.0011.000000T0000Z-180513T0130Z/
Talbot MD-Queen Anne's MD-Caroline MD-Kent MD-
904 PM EDT SAT MAY 12 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM EDT
FOR TALBOT...SOUTHWESTERN QUEEN ANNE'S...CAROLINE AND SOUTHWESTERN
KENT COUNTIES...

At 902 PM EDT, severe thunderstorms were located along a line
extending from near Oakland to Grasonville to near South River,
moving east at 35 mph.

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

SOURCE...Public. At 850 PM, a 60 mph wind gust was reported at Kent 
         Narrows. At 842 PM, a 62 mph win gust was reported on the 
         western side of the Chesapeake Bay at Annapolis.

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

Locations impacted include...
Easton, Talbot, Denton, Centreville, Greensboro, Oakland, Ridgely,
Trappe, St. Michaels, Preston, Queen Anne, Grasonville, Starr,
Copperville, Jumptown, Agner, Choptank, Windyhill, Tanyard and
Harmony.

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 3883 7630 3885 7627 3879 7620 3879 7619
      3894 7621 3897 7625 3894 7625 3894 7636
      3904 7631 3897 7622 3900 7617 3904 7621
      3902 7574 3882 7572 3869 7581 3863 7605
      3878 7629 3868 7634 3875 7637
TIME...MOT...LOC 0102Z 287DEG 32KT 3900 7593 3897 7623 3885 7645 

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

JRK

The office that day

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

Issued	Product	Office	Counties	Lasted
May 12, 8:11 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Cecil, Kent, Queen Anne's	49 min
May 12, 8:50 PM EDT	Flash Flood Warning	PHI	Caroline, Kent, Queen Anne's	3 hr
May 12, 8:51 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's	39 min
May 12, 9:14 PM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	2 hr
May 12, 9:27 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	63 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2018 Every 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.