Alert archive / Tennessee / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 2, NWS Nashville, TN

February 11, 20094 counties in Tennessee

NWS Nashville, TN issued this severe thunderstorm warning at Feb 11, 2009, 11:05 AM CST for 4 counties in Tennessee. It was in force for 55 min. 2 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 11, 2009, 11:05 AM CST (17:05 UTC)
Expired: Feb 11, 2009, 12:00 PM CST
In force: 55 min
Issued by: NWS Nashville, TN
Area: Storm-based polygon

Counties Cheatham County, TN, Davidson County, TN, Robertson County, TN, Williamson County, TN

The radar

The Nashville radar (KOHX), 47 km from the middle of the area, began a volume at 17:07 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 11, 11:46 AM CST	TSTM WND DMG	5 Sw Nashville, TN	SEVERAL TREES BLOWN DOWN ON A GOLF COURSE.
Feb 11, 11:52 AM CST	TSTM WND GST 60	5 S Franklin, TN

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this severe thunderstorm warning; the first came 41 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

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 11, 10:38 AM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 5.1 hours before the alert went out and 47 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 722 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 510 m²/s²
0-3 km storm-relative helicity: 444 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.

000 
WUUS54 KOHX 111705
SVROHX
TNC021-037-147-187-111800-
/O.NEW.KOHX.SV.W.0002.090211T1705Z-090211T1800Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NASHVILLE TN
1105 AM CST WED FEB 11 2009

THE NATIONAL WEATHER SERVICE IN NASHVILLE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CHEATHAM COUNTY IN MIDDLE TENNESSEE...
  WESTERN DAVIDSON COUNTY IN MIDDLE TENNESSEE...
  ROBERTSON COUNTY IN MIDDLE TENNESSEE...
  WESTERN WILLIAMSON COUNTY IN MIDDLE TENNESSEE...

* UNTIL NOON CST

* AT 1057 AM CST...DOPPLER RADAR SHOWED A LINE OF SEVERE             
  THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN EXCESS OF  
  70 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM OAK  
  GROVE TO 7 MILES NORTH OF HOHENWALD...AND MOVING NORTHEAST AT 50   
  MPH.

* SEVERE THUNDERSTORMS WILL AFFECT AREAS AROUND SPRINGFIELD, ASHLAND 
  CITY, NASHVILLE, AND FRANKLIN BY NOON CST...

DAMAGING WINDS UP TO 70 MPH HAVE BEEN REPORTED IN ADDITION TO 
STRUCTURAL DAMAGE. SEEK SAFE SHELTER AND STAY AWAY FROM WINDOWS

LAT...LON 3666 8673 3574 8682 3579 8695 3578 8696
      3586 8721 3617 8717 3618 8714 3621 8719
      3624 8716 3626 8719 3630 8713 3633 8728
      3641 8721 3642 8715 3645 8716 3646 8712
      3654 8711 3657 8714 3665 8711
TIME...MOT...LOC 1702Z 231DEG 15KT 3667 8741 3567 8750

$$

ROSE

2 follow-up statements

000 
WWUS54 KOHX 111720
SVSOHX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
1120 AM CST WED FEB 11 2009

TNC021-037-147-187-111800-
/O.CON.KOHX.SV.W.0002.000000T0000Z-090211T1800Z/
WILLIAMSON TN-DAVIDSON TN-CHEATHAM TN-ROBERTSON TN-
1118 AM CST WED FEB 11 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL NOON CST FOR
ROBERTSON...CHEATHAM...WESTERN DAVIDSON AND WESTERN WILLIAMSON
COUNTIES...

AT 1115 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A LINE OF STRONG TO SEVERE THUNDERSTORMS CAPABLE OF 
PRODUCING DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THESE STORMS WERE 
LOCATED ALONG A LINE EXTENDING FROM 9 MILES NORTHEAST OF CLARKSVILLE 
TO 11 MILES EAST OF CENTERVILLE...MOVING EAST AT 50 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
KINGSTON SPRINGS...ASHLAND CITY...PEGRAM...CEDAR HILL...
SPRINGFIELD...BELLE MEADE...FOREST HILLS...GREENBRIER...FRANKLIN...
RIDGETOP AND NASHVILLE

AT 1103 AM CST...A STORM SPOTTER IN DICKSON MEASURED WIND GUSTS TO 
64 MPH. 

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. FOR YOUR 
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME 
OR BUSINESS. 

LAT...LON 3666 8673 3574 8682 3579 8695 3578 8696
      3586 8721 3617 8717 3618 8714 3621 8719
      3624 8716 3626 8719 3630 8713 3633 8728
      3641 8721 3642 8715 3645 8716 3646 8712
      3654 8711 3657 8714 3665 8711
TIME...MOT...LOC 1716Z 266DEG 42KT 3662 8713 3581 8718

$$
STEIGERWALDT

000 
WWUS54 KOHX 111744
SVSOHX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
1144 AM CST WED FEB 11 2009

TNC021-037-147-187-111800-
/O.CON.KOHX.SV.W.0002.000000T0000Z-090211T1800Z/
WILLIAMSON TN-DAVIDSON TN-CHEATHAM TN-ROBERTSON TN-
1143 AM CST WED FEB 11 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL NOON CST FOR
ROBERTSON...CHEATHAM...WESTERN DAVIDSON AND WESTERN WILLIAMSON
COUNTIES...

AT 1139 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED
ALONG A LINE EXTENDING FROM 9 MILES NORTH OF SPRINGFIELD TO 6 MILES
SOUTHWEST OF FRANKLIN...MOVING EAST AT 50 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
RIDGETOP AND NASHVILLE

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. FOR YOUR 
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME 
OR BUSINESS. THIS STORM HAS THE POTENTIAL TO CAUSE SERIOUS INJURY 
AND SIGNIFICANT DAMAGE TO PROPERTY.

LAT...LON 3666 8673 3574 8682 3579 8695 3578 8696
      3586 8721 3617 8717 3618 8714 3621 8719
      3624 8716 3626 8719 3630 8713 3633 8728
      3641 8721 3642 8715 3645 8716 3646 8712
      3654 8711 3657 8714 3665 8711
TIME...MOT...LOC 1743Z 266DEG 42KT 3664 8676 3588 8685

$$
STEIGERWALDT

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Nashville, TN wrote its last area forecast discussion before this severe thunderstorm warning went out at Feb 11, 10:38 AM CST, 27 minutes earlier.

Area forecast discussion, Feb 11, 10:38 AM CST, 27 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
1038 AM CST WED FEB 11 2009

.DISCUSSION...
BAND OF SHOWERS/ISOLATED THUNDERSTORMS CONTINUES TO MOVE EAST JUST
AHEAD OF SURFACE FRONT...WHICH EXTENDS FROM CLOSED LOW NEAR STL. UPPER
SYSTEM CURRENTLY MAKING NEGATIVE TILT...WHICH IS EXPECTED TO ACCELERATE
BAND. TIGHT PRESSURE GRADIENT CONTINUES TO PRODUCE WIND GUSTS IN THE
40 TO 50 MPH WELL AHEAD OF PCPN.

LATEST RUNS SHOW LINE INTENSIFYING SOME OVER THE NORTH CENTRAL AND
NORTHEAST MID-STATE AS THE AFTERNOON PROGRESSES AND BAND OF PCPNS SPEED
INCREASES. TREMENDOUS DRYING ALSO SHOWING UP ON WV IMAGERY WHICH
MAY INITIALLY HELP TO INTENSIFY CONVECTION BEFORE SHUTTING IT OFF
LATER THIS AFTERNOON.

WILL CONTINUE WIND ADVISORY THROUGH 00Z AND MAKE ADJUSTMENTS TO
CURRENT FORECAST TO ACCOMMODATE TORNADO WATCH.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR TNZ005>011-
022>034-056>066-075-077>080-093>095.

&&

07

Hazardous weather outlook, Feb 11, 4:08 AM CST, 6 hours 57 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
408 AM CST WED FEB 11 2009

TNZ005>011-022>034-056>066-075-077>080-093>095-121130-
STEWART-MONTGOMERY-ROBERTSON-SUMNER-MACON-CLAY-PICKETT-BENTON-
HOUSTON-HUMPHREYS-DICKSON-CHEATHAM-DAVIDSON-WILSON-TROUSDALE-
SMITH-JACKSON-PUTNAM-OVERTON-FENTRESS-PERRY-HICKMAN-LEWIS-
WILLIAMSON-MAURY-MARSHALL-RUTHERFORD-CANNON-DEKALB-WHITE-
CUMBERLAND-BEDFORD-COFFEE-WARREN-GRUNDY-VAN BUREN-WAYNE-LAWRENCE-
GILES-
408 AM CST WED FEB 11 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

A STRONG LOW PRESSURE SYSTEM AND COLD FRONT WILL BRING THE
POTENTIAL FOR DAMAGING WINDS AND ISOLATED TORNADOES TO MIDDLE
TENNESSEE TODAY.

A LINE OF THUNDERSTORMS IS EXPECTED TO APPROACH THE TENNESSEE
RIVER AROUND 9 AM. IT SHOULD REACH THE I 65 CORRIDOR BETWEEN 10
AM AND NOON...AND THE PLATEAU BY 2 PM. DAMAGING STRAIGHT LINE
WINDS WILL BE THE MAIN HAZARD. HOWEVER...FAVORABLE ATMOSPHERIC
WIND SPEEDS AND DIRECTIONS WILL BRING THE POTENTIAL FOR ISOLATED
TORNADOES.

WINDS WILL ALSO BE STRONG BEFORE AND AFTER THE THUNDERSTORMS.
WIND GUSTS OF 45 MPH WILL BE POSSIBLE THROUGH THE DAY. A WIND
ADVISORY WILL REMAIN IN EFFECT UNTIL 6 PM.

MORE INFORMATION IS AVAILABLE ON THE INTERNET AT WEATHER.GOV OR
BY LISTENING TO NOAA WEATHER RADIO.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER AND EMERGENCY MANAGER ACTIVATION WILL LIKELY BE NEEDED TODAY.

13

In the hours before

Local storm report, Feb 11, 11:03 AM CST, 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
1103 AM CST WED FEB 11 2009

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1007 AM     TSTM WND GST     W CAMDEN                36.06N 88.10W
02/11/2009  M58 MPH          BENTON             TN   PARK/FOREST SRVC

1053 AM     TSTM WND GST     10 N CENTERVILLE        35.94N 87.45W
02/11/2009  E60 MPH          HICKMAN            TN   TRAINED SPOTTER

            TREE BLOWN DOWN.

&&

TJOHNSTO

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 11, 10:46 AM CST	Severe Thunderstorm Warning	OHX	Dickson, Hickman, Lawrence, Lewis, Montgomery	29 min
Feb 11, 11:10 AM CST	Severe Thunderstorm Warning	OHX	Giles, Marshall, Maury	50 min
Feb 11, 11:34 AM CST	Severe Thunderstorm Warning	OHX	Davidson, Robertson, Sumner, Wilson	56 min
Feb 11, 11:39 AM CST	Severe Thunderstorm Warning	OHX	Bedford, Rutherford, Williamson	66 min
Feb 11, 12:01 PM CST	Tornado Warning	OHX	Marshall	14 min
Feb 11, 12:08 PM CST	Severe Thunderstorm Warning	OHX	Macon, Smith, Trousdale, Wilson	37 min
Feb 11, 12:24 PM CST	Severe Thunderstorm Warning	OHX	Cannon, Coffee, DeKalb	36 min
Feb 11, 12:46 PM CST	Tornado Warning	OHX	Cannon, Coffee, DeKalb, Warren	29 min
Feb 11, 12:50 PM CST	Severe Thunderstorm Warning	OHX	Clay, Jackson, Macon, Overton, Putnam, Smith	40 min
Feb 11, 12:58 PM CST	Severe Thunderstorm Warning	OHX	Cannon, Coffee, DeKalb, Grundy, Warren, White	32 min
Feb 11, 1:17 PM CST	Severe Thunderstorm Warning	OHX	Grundy, Van Buren, Warren, White	43 min
Feb 11, 1:24 PM CST	Severe Thunderstorm Warning	OHX	Clay, Overton, Pickett, Putnam	36 min
Feb 11, 1:41 PM CST	Severe Thunderstorm Warning	OHX	Cumberland, Fentress, Overton, Pickett, Putnam, Van Buren and 1 more	49 min
Feb 11, 1:59 PM CST	Tornado Warning	OHX	Cumberland, Fentress	31 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2009 Every severe thunderstorm warning in 2009

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.