Alert archive / Maryland / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 221, NWS Philadelphia/Mount Holly

September 18, 2012Cecil County, Kent County, Queen Anne's County, Maryland

NWS Philadelphia/Mount Holly issued this severe thunderstorm warning at Sep 18, 2012, 3:51 PM EDT for Cecil County, Kent County, Queen Anne's County, Maryland. It was in force for 84 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: Sep 18, 2012, 3:51 PM EDT (19:51 UTC)
Expired: Sep 18, 2012, 5:15 PM EDT
In force: 84 min
Issued by: NWS Philadelphia/Mount Holly
Area: Storm-based polygon

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

The radar

The Dover AFB radar (KDOX), 73 km from the middle of the area, began a volume at 19:54 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
Sep 18, 4:45 PM EDT	TSTM WND DMG	North East, MD	TREES DOWN ON WIRES.

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
Sep 18, 12:10 PM EDT	Tornado Watch	SPC	9 hr

The nearest sounding before it

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 7.9 hours before the alert went out and 38 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: 330 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 519 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 265 m²/s²
0-3 km storm-relative helicity: 275 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

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

395 
WUUS51 KPHI 181951
SVRPHI
MDC015-029-035-182115-
/O.NEW.KPHI.SV.W.0221.120918T1951Z-120918T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
351 PM EDT TUE SEP 18 2012

THE NATIONAL WEATHER SERVICE IN MOUNT HOLLY NJ HAS ISSUED A

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

* UNTIL 515 PM EDT

* AT 350 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 AROUND BALTIMORE TO EAST OF WASHINGTON...AND MOVING NORTHEAST
  AT 45 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  CHESTER AND STEVENSVILLE AROUND 410 PM EDT...
  GRASONVILLE...ROCK SPRINGS...OVERTON AND OCTORARO AROUND 415 PM
  EDT...
  RICHARDSMERE AND ROCK HALL AROUND 420 PM EDT...
  CENTREVILLE AND WEST NOTTINGHAM AROUND 425 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS...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.

&&

LAT...LON 3884 7638 3904 7632 3899 7627 3900 7618
      3902 7624 3909 7625 3914 7629 3926 7623
      3943 7600 3952 7599 3954 7607 3972 7623
      3972 7579 3919 7575 3892 7621 3894 7624
      3890 7625 3892 7628 3889 7627 3890 7632
TIME...MOT...LOC 1950Z 232DEG 44KT 3977 7641 3889 7661

$$

IOVINO

1 follow-up statement

265 
WWUS51 KPHI 182028
SVSPHI

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
428 PM EDT TUE SEP 18 2012

MDC015-029-035-182115-
/O.CON.KPHI.SV.W.0221.000000T0000Z-120918T2115Z/
CECIL MD-KENT MD-QUEEN ANNE'S MD-
428 PM EDT TUE SEP 18 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM EDT
FOR QUEEN ANNE'S...KENT AND CECIL COUNTIES...

AT 425 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG THE 
UPPER PART OF CHESAPEAKE BAY...MOVING NORTHEAST AT 45 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  CHURCH HILL...ZION...LOMBARD AND BLAKE BY 435 PM EDT...
  BARCLAY...PLEASANT HILL...MORGNEC AND KENNEDYVILLE BY 440 PM EDT...
  SUDLERSVILLE AND CHERRY HILL BY 445 PM EDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. IF A TORNADO
IS SPOTTED... ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A STURDY
STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE 
IMMEDIATELY FOR DAMAGING WINDS...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.

&&

LAT...LON 3884 7638 3904 7632 3899 7627 3900 7618
      3902 7624 3909 7625 3914 7629 3926 7623
      3943 7600 3952 7599 3954 7607 3972 7623
      3972 7579 3919 7575 3892 7621 3894 7624
      3890 7625 3892 7628 3889 7627 3890 7632
TIME...MOT...LOC 2028Z 232DEG 44KT 4005 7593 3918 7614

$$

IOVINO

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 18, 4:13 AM EDT	Coastal Flood Advisory	PHI	Caroline, Cecil, Kent, Queen Anne's, Talbot	21 hr
Sep 18, 3:32 PM EDT	Special Weather Statement	PHI	Cecil, Kent, Queen Anne's, Talbot	58 min
Sep 18, 4:35 PM EDT	Areal Flood Advisory	PHI	Cecil, Kent	55 min
Sep 18, 4:42 PM EDT	Severe Thunderstorm Warning	PHI	Caroline, Queen Anne's, Talbot	78 min
Sep 18, 5:57 PM EDT	Severe Thunderstorm Warning	PHI	Caroline	78 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.