Alert archive / Tennessee / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 12, NWS Nashville, TN

February 11, 20097 counties in Tennessee

NWS Nashville, TN issued this severe thunderstorm warning at Feb 11, 2009, 1:41 PM CST for 7 counties in Tennessee. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Feb 11, 2009, 1:41 PM CST (19:41 UTC)
Expired: Feb 11, 2009, 2:30 PM CST
In force: 49 min
Issued by: NWS Nashville, TN
Area: Storm-based polygon

Counties Cumberland County, TN, Fentress County, TN, Overton County, TN, Pickett County, TN, Putnam County, TN, Van Buren County, TN, White County, TN

The radar

The Nashville radar (KOHX), 119 km from the middle of the area, began a volume at 19:41 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.

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, 7.7 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-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

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, 3 hours 3 minutes earlier.

Area forecast discussion, Feb 11, 10:38 AM CST, 3 hours 3 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, 9 hours 33 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, 12:31 PM CST, 1 hour 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
1231 PM CST WED FEB 11 2009

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

1130 AM     TSTM WND DMG     SPRING HILL             35.74N 86.92W
02/11/2009                   MAURY              TN   LAW ENFORCEMENT

            TREES WERE BLOWN DOWN IN SPRING HILL AND COLUMBIA.

&&

TJOHNSTO

Local storm report, Feb 11, 1:09 PM CST, 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
109 PM CST WED FEB 11 2009

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

1235 PM     TSTM WND DMG     HARTSVILLE              36.39N 86.16W
02/11/2009                   TROUSDALE          TN   CO-OP OBSERVER

            SEVERAL TREES WERE BLOWN DOWN.

1240 PM     TSTM WND DMG     LAFAYETTE               36.52N 86.03W
02/11/2009                   MACON              TN   UTILITY COMPANY

            TREES WERE BLOWN DOWN COUNTYWIDE.

1240 PM     TSTM WND DMG     WARTRACE                35.53N 86.33W
02/11/2009                   BEDFORD            TN   EMERGENCY MNGR

            MINOR ROOF DAMAGE TO A HOME WAS REPORTED. TREES WERE
            BLOWN DOWN COUNTY WIDE.

&&

TJOHNSTO

Local storm report, Feb 11, 1:18 PM CST, 23 minutes before

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Local storm report, Feb 11, 1:25 PM CST, 16 minutes before

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Local storm report, Feb 11, 1:35 PM CST, 6 minutes before

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Local storm report, Feb 11, 1:39 PM CST, 2 minutes before

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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, 11:05 AM CST	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Robertson, Williamson	55 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, 1:59 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.