Alert archive / Tennessee / Tornado Warnings in 2011

Tornado Warning 17, NWS Huntsville, AL

February 28, 2011Franklin County, Tennessee

NWS Huntsville, AL issued this tornado warning at Feb 28, 2011, 12:45 PM CST for Franklin County, Tennessee. It was in force for 15 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Feb 28, 2011, 12:45 PM CST (18:45 UTC)
Expired
Feb 28, 2011, 1:00 PM CST
In force
15 min
Issued by
NWS Huntsville, AL
Area
Storm-based polygon

County Franklin County, TN

The radar

The Northeast Alabama radar (KHTX), 32 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Feb 28, 12:29 PM CSTTornado WatchSPC7 hr

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 6.8 hours before the alert went out and 122 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, Nashville Metro, TN at 12:00Z on 2011-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 948 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, Nashville Metro, TN at 12:00Z on 2011-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 369 square meters per square second.1939587897117136Sfc1 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
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.

998 
WFUS54 KHUN 281845
TORHUN
TNC051-281900-
/O.NEW.KHUN.TO.W.0017.110228T1845Z-110228T1900Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1245 PM CST MON FEB 28 2011

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL FRANKLIN COUNTY IN TENNESSEE...

* UNTIL 100 PM CST

* AT 1240 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR            
  COWAN...OR   ABOUT 7 MILES SOUTHEAST OF WINCHESTER...MOVING EAST   
  AT 45 MPH. DAMAGING STRAIGHT LINE WINDS IN EXCESS OF 80 MPH        
  ARE ALSO LIKELY.

* LOCATIONS NEAR THE PATH OF THIS TORNADO INCLUDE...
  ST. ANDREWS.
  COWAN.
  SEWANEE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM CST MONDAY EVENING FOR
NORTHERN ALABAMA AND CENTRAL TENNESSEE.

&&

LAT...LON 3523 8588 3523 8587 3523 8586 3504 8587
      3505 8608 3524 8606 3523 8589
TIME...MOT...LOC 1845Z 271DEG 38KT 3514 8593

$$
2 follow-up statements
516 
WWUS54 KHUN 281856
SVSHUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1256 PM CST MON FEB 28 2011

TNC051-281900-
/O.CON.KHUN.TO.W.0017.000000T0000Z-110228T1900Z/
FRANKLIN TN-
1256 PM CST MON FEB 28 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 100 PM CST FOR EAST
CENTRAL FRANKLIN COUNTY...

AT 1250 PM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED NEAR SHERWOOD...OR 
ABOUT 12 MILES EAST OF WINCHESTER...MOVING EAST AT 45 MPH. STRAIGHT 
LINE WINDS IN EXCESS OF 70 MPH ARE ALSO LIKELY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY 
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. 

&&

LAT...LON 3523 8588 3523 8587 3523 8586 3504 8587
      3505 8608 3524 8606 3523 8589
TIME...MOT...LOC 1855Z 273DEG 36KT 3513 8584

$$
701 
WWUS54 KHUN 281901
SVSHUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
101 PM CST MON FEB 28 2011

TNC051-281911-
/O.EXP.KHUN.TO.W.0017.000000T0000Z-110228T1900Z/
FRANKLIN TN-
101 PM CST MON FEB 28 2011

...THE TORNADO WARNING FOR EAST CENTRAL FRANKLIN COUNTY EXPIRES AT
100 PM CST...

WEATHER SERVICE DOPPLER RADAR INDICATED THE SEVERE THUNDERSTORM THAT
PROMPTED THE WARNING HAD MOVED OUT OF THE COUNTY. THEREFORE THE 
SEVERE THUNDERSTORM WARNING HAS BEEN ALLOWED TO EXPIRE. MULTIPLE 
REPORTS OF WIND DAMAGE HAVE BEEN RECEIVED ACROSS CENTRAL FRANKLIN 
COUNTY OVER THE PAST HOUR.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM CST MONDAY EVENING FOR
NORTHERN ALABAMA AND CENTRAL TENNESSEE.

LAT...LON 3523 8588 3523 8587 3523 8586 3504 8587
      3505 8608 3524 8606 3523 8589
TIME...MOT...LOC 1856Z 273DEG 36KT 3512 8583

$$

The office that day

Everything else NWS Huntsville, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 28, 11:48 AM CSTSpecial Weather StatementHUNLincoln, Moore42 min
Feb 28, 11:56 AM CSTTornado WarningHUNLincoln25 min
Feb 28, 12:07 PM CSTSevere Thunderstorm WarningHUNFranklin, Lincoln, Moore23 min
Feb 28, 12:12 PM CSTTornado Warning EmergencyHUNFranklin, Moore18 min
Feb 28, 12:19 PM CSTTornado WarningHUNFranklin, Lincoln28 min
Feb 28, 12:27 PM CSTTornado Warning EmergencyHUNFranklin, Moore18 min
Feb 28, 12:36 PM CSTSevere Thunderstorm WarningHUNFranklin24 min
Feb 28, 12:44 PM CSTTornado WarningHUNFranklin46 min

Nearby

Tornado Warnings in Tennessee, 2011Every tornado warning in 2011Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.