Alert archive / Tennessee / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 314, NWS Nashville, TN

October 9, 20094 counties in Tennessee

NWS Nashville, TN issued this severe thunderstorm warning at Oct 9, 2009, 12:02 PM CDT for 4 counties in Tennessee. It was in force for 28 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: Oct 9, 2009, 12:02 PM CDT (17:02 UTC)
Expired: Oct 9, 2009, 12:30 PM CDT
In force: 28 min
Issued by: NWS Nashville, TN
Area: Storm-based polygon

Counties Cheatham County, TN, Davidson County, TN, Dickson County, TN, Robertson County, TN

The radar

The Nashville radar (KOHX), 41 km from the middle of the area, began a volume at 17:03 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 nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 5.0 hours before the alert went out and 41 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: 1183 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 667 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 270 m²/s²
0-3 km storm-relative helicity: 259 m²/s²
Significant tornado parameter: 2.0
Supercell composite: 8.5

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 Oct 9, 10:25 AM CDT, 1 hour 37 minutes earlier.

Area forecast discussion, Oct 9, 10:25 AM CDT, 1 hour 37 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
1025 AM CDT FRI OCT 9 2009

.MESOSCALE UPDATE...
CELLS INTENSIFIED UPON CROSSING THE TN RIVER AROUND 15Z. STRONGER
CELLS SEEM TO BE TIED TO MOISTURE FLUX GRADIENT WHICH BACKED UP
A LITTLE TO THE NORTHWEST DURING THE LAST HOUR. OTHER THAN THE CELL
THAT WAS OVER CARROLL COUNTY EARLIER THERE HAS BEEN LITTLE BOWING
EVIDENT IN THE CELLS. STILL THINK SOME STORMS COULD GO SEVERE
DURING THE DAY...BUT COVERAGE STILL A QUESTION. CELLS SEEM TO BE
STRUGGLING TO GAIN MUCH IN THE WAY OF VERTICAL EXTENT BASED ON
GRANALYST AND MINIMUM LIGHTNING ACTIVITY SO FAR.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

BOYD

Hazardous weather outlook, Oct 9, 5:07 AM CDT, 6 hours 55 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
507 AM CDT FRI OCT 9 2009

TNZ005>011-022>034-056>066-075-077>080-093>095-101000-
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-
507 AM CDT FRI OCT 9 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

AS A STRONG COLD FRONT IS EXPECTED TO MOVE NORTHWEST TO SOUTHEAST
ACROSS MIDDLE TENNESSEE TODAY...THUNDERSTORMS ARE EXPECTED TO
DEVELOP. SOME OF THESE THUNDERSTORMS COULD POSSIBLY BECOME
SEVERE...WITH DAMAGING THUNDERSTORM OUTFLOW WINDS AND THE
POSSIBILITY OF THE DEVELOPMENT OF ISOLATED TORNADOES. THE BEST
POTENTIAL FOR SEVERE WEATHER DEVELOPMENT WILL BE ALONG AND WEST OF
A LAFAYETTE...TO WOODBURY...TO TULLAHOMA LINE. THESE THUNDERSTORMS
WILL ALSO BE CAPABLE OF PRODUCING BREIF HEAVY RAINFALL...WITH
ISOLATED RAINFALL AMOUNTS OF UP TO TWO INCHES POSSIBLE. THE THREAT
FOR SEVERE WEATHER WILL DIMINISH NORTHWEST TO SOUTHEAST TODAY
AFTER LOCATIONS EXPERIENCE THE COLD FRONTAL PASSAGE.

ALONG WITH THESE THUNDERSTORMS...WILL BE DANGEROUS CLOUD TO GROUND
LIGHTNING. EXERCISE CAUTION WITH ANY OUTDOOR ACTIVITIES THAT YOU
MIGHT BE ABLE TO PARTICIPATE IN TODAY. REMEMBER...IF THUNDER
ROARS...GO INDOORS.

EXERCISE CAUTION WHILE DRIVING ON AREA ROADWAYS TODAY AS HEAVY
RAINFALL MIGHT RESULT IN PONDING OF WATER ON THESE ROADWAYS.

STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER UPDATES ON THIS
POSSIBLE DEVELOPING SEVERE WEATHER SITUATION.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER AND EMERGENCY MANAGER ACTIVATION MAY BE NEEDED ON FRIDAY.

31/JBW

In the hours before

Special weather statement, Oct 9, 8:51 AM CDT, 3 hours 11 minutes before

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Special weather statement, Oct 9, 11:47 AM CDT, 15 minutes before

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        The site you requested is temporarily down for maintenance or an unexpected outage.
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The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 9, 12:16 PM CDT	Severe Thunderstorm Warning	OHX	Davidson, Robertson, Sumner	44 min
Oct 9, 12:47 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Dickson, Williamson	28 min
Oct 9, 12:48 PM CDT	Severe Thunderstorm Warning	OHX	Macon, Sumner	27 min
Oct 9, 1:25 PM CDT	Severe Thunderstorm Warning	OHX	Davidson, Sumner, Wilson	35 min
Oct 9, 1:41 PM CDT	Severe Thunderstorm Warning	OHX	Davidson, Williamson	34 min
Oct 9, 2:11 PM CDT	Severe Thunderstorm Warning	OHX	Maury	22 min
Oct 9, 2:20 PM CDT	Severe Thunderstorm Warning	OHX	Wilson	25 min
Oct 9, 2:23 PM CDT	Severe Thunderstorm Warning	OHX	Clay, Jackson, Macon, Smith	22 min
Oct 9, 2:43 PM CDT	Severe Thunderstorm Warning	OHX	Clay, Jackson	32 min
Oct 9, 3:16 PM CDT	Severe Thunderstorm Warning	OHX	Fentress, Pickett	19 min
Oct 9, 3:17 PM CDT	Severe Thunderstorm Warning	OHX	Bedford, Marshall, Maury	28 min
Oct 9, 3:18 PM CDT	Severe Thunderstorm Warning	OHX	Fentress, Pickett	28 min
Oct 9, 3:21 PM CDT	Tornado Warning	OHX	Giles, Marshall	24 min
Oct 9, 3:24 PM CDT	Tornado Warning	OHX	Coffee	36 min
Oct 9, 3:38 PM CDT	Tornado Warning	OHX	Bedford, Marshall	37 min
Oct 9, 3:59 PM CDT	Tornado Warning	OHX	Bedford, Cannon, Coffee, Rutherford	31 min
Oct 9, 4:07 PM CDT	Tornado Warning	OHX	Bedford, Coffee	23 min
Oct 9, 4:23 PM CDT	Tornado Warning	OHX	Coffee, Warren	37 min
Oct 9, 4:51 PM CDT	Severe Thunderstorm Warning	OHX	Grundy	24 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.