Alert archive / Maryland / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 106, NWS Philadelphia/Mount Holly

July 18, 2012Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Jul 18, 2012, 5:35 PM EDT for Kent County, Queen Anne's County, Maryland. It was in force for 25 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: Jul 18, 2012, 5:35 PM EDT (21:35 UTC)
Expired: Jul 18, 2012, 6:00 PM EDT
In force: 25 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 70 km from the middle of the area, began a volume at 21:35 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
Jul 18, 6:09 PM EDT	TSTM WND DMG	Centreville, MD	SCATTERED TREES DOWN ACROSS THE COUNTY EXTENDING FROM KENT ISLAND TO CRUMPTON.

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
Jul 18, 12:41 PM EDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.6 hours before the alert went out and 53 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: 884 J/kg
Mixed-layer CIN: -169 J/kg
Mixed-layer LCL: 1666 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

482 
WUUS51 KPHI 182135
SVRPHI
MDC029-035-182200-
/O.NEW.KPHI.SV.W.0106.120718T2135Z-120718T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
535 PM EDT WED JUL 18 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  KENT COUNTY IN NORTHEAST MARYLAND...
  QUEEN ANNE'S COUNTY IN NORTHEAST MARYLAND...

* UNTIL 600 PM EDT

* AT 531 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM ROCK HALL TO CHESAPEAKE BAY BRIDGE...OR ALONG A LINE EXTENDING
  FROM 19 MILES SOUTHEAST OF BALTIMORE TO 20 MILES NORTHWEST OF
  EASTON...AND MOVING EAST AT 35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  CHESTER AND ROCK HALL AROUND 540 PM EDT...
  OVERTON...LANGFORD AND GRASONVILLE AROUND 545 PM EDT...
  OLD TOWN AROUND 550 PM EDT...
  WYE MILLS AND CHESTERTOWN AROUND 555 PM EDT...
  STARKEY CORNER AND MORGNEC AROUND 600 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...LARGE HAIL...AND DEADLY CLOUD TO
GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

PLEASE REPORT HAIL OR STRONG WINDS TO THE NATIONAL WEATHER SERVICE BY
CALLING TOLL FREE...1-877-633-6772...WHEN YOU CAN DO SO SAFELY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM EDT
WEDNESDAY EVENING FOR NORTHERN DELAWARE AND NORTHEASTERN MARYLAND AND
NEW JERSEY AND EASTERN PENNSYLVANIA.

&&

LAT...LON 3895 7637 3904 7632 3899 7627 3900 7618
      3902 7624 3909 7625 3914 7629 3926 7623
      3937 7578 3902 7589 3897 7594 3890 7621
      3894 7624 3890 7624 3892 7628 3889 7627
      3890 7632 3887 7633 3886 7637
TIME...MOT...LOC 2135Z 252DEG 31KT 3917 7627 3895 7633

$$

DRAG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 4:37 PM EDT	Special Weather Statement	PHI	Kent	23 min
Jul 18, 4:47 PM EDT	Special Weather Statement	PHI	Cecil	28 min
Jul 18, 5:20 PM EDT	Special Weather Statement	PHI	Queen Anne's	40 min
Jul 18, 6:06 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Kent, Queen Anne's, Talbot	39 min
Jul 18, 6:23 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	37 min
Jul 18, 6:26 PM EDT	Areal Flood Advisory	PHI	Caroline, Kent, Queen Anne's, Talbot	68 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2012 Every severe thunderstorm warning in 2012

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.