Alert archive / Tennessee / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 21, NWS Morristown, TN

February 28, 20116 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Feb 28, 2011, 12:43 PM CST for 6 counties in Tennessee. It was in force for 32 min. 4 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: Feb 28, 2011, 12:43 PM CST (18:43 UTC)
Expired: Feb 28, 2011, 1:15 PM CST
In force: 32 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon

Counties Bledsoe County, TN, Hamilton County, TN, Marion County, TN, Meigs County, TN, Rhea County, TN, Sequatchie County, TN

The radar

The Northeast Alabama radar (KHTX), 88 km from the middle of the area, began a volume at 18:46 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
Feb 28, 1:00 PM CST	TSTM WND DMG	1 N Jasper, TN	FEW TREES DOWN.
Feb 28, 1:00 PM CST	TORNADO	1 W South Pittsburg, TN	EF0. MAXIMUM WIND SPEED 70 MPH. PATH WIDTH 20 YARDS. PATH LENGTH 0.1 MILE. TREES DOWN.
Feb 28, 1:25 PM CST	TSTM WND DMG	Chattanooga, TN	FEW TREES DOWN NEAR INTERSECTION OF HOOKER AND WILSON ROADS.
Feb 28, 1:25 PM CST	TORNADO	Signal Mountain, TN	EF1. MAX WIND SPEED 90 MPH. PATH LENGTH 2.2 MILES. PATH WIDTH FROM 60 TO 90 YARDS. NUMEROUS TREES DOWN. ESTIMATED 25 HOMES WITH MINOR DAMAGE.

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
Feb 28, 12:29 PM CST	Tornado Watch	SPC	7 hr

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 6.7 hours before the alert went out and 138 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: 948 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 795 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 369 m²/s²
0-3 km storm-relative helicity: 404 m²/s²
Significant tornado parameter: 2.6
Supercell composite: 9.4

Open this sounding in Storm Lab

The text

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

253 
WUUS54 KMRX 281843
SVRMRX
TNC007-065-115-121-143-153-281915-
/O.NEW.KMRX.SV.W.0021.110228T1843Z-110228T1915Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MORRISTOWN TN
1243 PM CST MON FEB 28 2011

THE NATIONAL WEATHER SERVICE IN MORRISTOWN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BLEDSOE COUNTY IN EAST TENNESSEE...
  HAMILTON COUNTY IN EAST TENNESSEE...
  MARION COUNTY IN EAST TENNESSEE...
  MEIGS COUNTY IN EAST TENNESSEE...
  RHEA COUNTY IN EAST TENNESSEE...
  SEQUATCHIE COUNTY IN EAST TENNESSEE...

* UNTIL 115 PM CST/215 PM EST/

* AT 1241 PM CST...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 10 MILES NORTH OF PIKEVILLE TO 12 MILES WEST OF BRIDGEPORT...
  AND MOVING EAST AT 65 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  PIKEVILLE...DUNLAP...JASPER...DAYTON...CHATTANOOGA...DECATUR...
  SOUTH PITTSBURG...WHITWELL...SPRING CITY...SIGNAL MOUNTAIN...
  SODDY-DAISY...HARRISON...GRIFFITH CREEK...PALIO...CARTWRIGHT...
  MELVINE...MARTIN SPRINGS...POWELLS CROSSROADS...BRAYTON AND
  HALETOWN (GUILD).

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM CST MONDAY EVENING/800
PM EST MONDAY EVENING/ FOR SOUTHWEST NORTH CAROLINA AND CENTRAL
TENNESSEE.

&&

LAT...LON 3525 8584 3523 8574 3531 8570 3533 8558
      3537 8551 3542 8550 3552 8559 3556 8555
      3557 8543 3578 8525 3576 8500 3582 8481
      3572 8470 3572 8462 3566 8462 3536 8484
      3528 8495 3499 8512 3499 8588 3518 8588
TIME...MOT...LOC 1843Z 276DEG 58KT 3573 8522 3496 8589

$$

The office that day

Everything else NWS Morristown, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 27, 7:21 PM CST	Dense Fog Advisory	MRX	Anderson, Blount, Campbell, Carter, Claiborne, Cocke and 17 more	8 hr
Feb 28, 7:38 AM CST	Severe Thunderstorm Warning	MRX	Campbell, Scott	52 min
Feb 28, 8:28 AM CST	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Claiborne, Hancock, Scott, Union	47 min
Feb 28, 9:00 AM CST	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Morgan, Scott	30 min
Feb 28, 9:15 AM CST	River Flood Warning	MRX	Claiborne, Grainger, Hancock	47 hr
Feb 28, 9:15 AM CST	River Flood Warning	MRX	Sevier	17 hr
Feb 28, 9:15 AM CST	River Flood Warning	MRX	Claiborne, Hancock	27 hr
Feb 28, 9:26 AM CST	Areal Flood Advisory	MRX	Morgan, Scott	3 hr
Feb 28, 9:40 AM CST	Severe Thunderstorm Warning	MRX	Campbell, Claiborne, Hancock, Union	50 min
Feb 28, 9:56 AM CST	Areal Flood Warning	MRX	Anderson, Campbell, Claiborne, Morgan, Scott, Union	6 hr
Feb 28, 10:15 AM CST	Severe Thunderstorm Warning	MRX	Bledsoe, Rhea	45 min
Feb 28, 11:23 AM CST	Severe Thunderstorm Warning	MRX	Anderson, Knox	37 min
Feb 28, 11:48 AM CST	Tornado Warning	MRX	Anderson, Blount, Cocke, Jefferson, Knox, Sevier	42 min
Feb 28, 12:02 PM CST	Areal Flood Warning	MRX	Blount, Cocke, Grainger, Greene, Hamblen, Hancock and 8 more	12 hr
Feb 28, 12:17 PM CST	Tornado Warning	MRX	Cocke, Grainger, Greene, Hamblen, Hawkins, Jefferson and 1 more	25 min
Feb 28, 12:48 PM CST	Tornado Warning	MRX	Hamilton, Marion, Sequatchie	42 min
Feb 28, 1:22 PM CST	Tornado Warning	MRX	Bradley, Hamilton	38 min
Feb 28, 1:33 PM CST	Severe Thunderstorm Warning	MRX	Bradley, Hamilton, McMinn, Meigs, Monroe, Rhea	42 min
Feb 28, 1:47 PM CST	Tornado Warning	MRX	Bradley, Monroe, Polk	43 min
Feb 28, 2:08 PM CST	Severe Thunderstorm Warning	MRX	Blount, Monroe	37 min
Feb 28, 3:42 PM CST	Areal Flood Warning	MRX	Anderson, Campbell, Claiborne, Grainger, Hancock, Knox and 4 more	3 hr

Nearby

Severe Thunderstorm Warnings in Tennessee, 2011 Every severe thunderstorm warning in 2011

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.