Alert archive / Tennessee / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 255, NWS Nashville, TN

July 12, 2009Cheatham County, Dickson County, Tennessee

NWS Nashville, TN issued this severe thunderstorm warning at Jul 12, 2009, 3:27 PM CDT for Cheatham County, Dickson County, Tennessee. It was in force for 33 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: Jul 12, 2009, 3:27 PM CDT (20:27 UTC)
Expired: Jul 12, 2009, 4:00 PM CDT
In force: 33 min
Issued by: NWS Nashville, TN
Area: Storm-based polygon

Counties Cheatham County, TN, Dickson County, TN

The radar

The Nashville radar (KOHX), 53 km from the middle of the area, began a volume at 20:30 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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 nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 8.5 hours before the alert went out and 49 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: 2256 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 694 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 84 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 122027
SVROHX
TNC021-043-122100-
/O.NEW.KOHX.SV.W.0255.090712T2027Z-090712T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NASHVILLE TN
327 PM CDT SUN JUL 12 2009

THE NATIONAL WEATHER SERVICE IN NASHVILLE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN CHEATHAM COUNTY IN MIDDLE TENNESSEE...
  EAST CENTRAL DICKSON COUNTY IN MIDDLE TENNESSEE...

* UNTIL 400 PM CDT

* AT 326 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 6 MILES
  NORTH OF WHITE BLUFF...OR 10 MILES SOUTHWEST OF ASHLAND CITY...AND
  MOVING SOUTHEAST AT 5 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WHITE BLUFF BY 355 PM CDT...
  6 MILES NORTHWEST OF KINGSTON SPRINGS BY 400 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

&&

LAT...LON 3621 8699 3605 8712 3614 8736 3628 8725
TIME...MOT...LOC 2027Z 301DEG 5KT 3619 8720

$$

13

1 follow-up statement

000 
WWUS54 KOHX 122051
SVSOHX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
351 PM CDT SUN JUL 12 2009

TNC021-043-122100-
/O.CON.KOHX.SV.W.0255.000000T0000Z-090712T2100Z/
DICKSON TN-CHEATHAM TN-
351 PM CDT SUN JUL 12 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM CDT
FOR SOUTHERN CHEATHAM AND EAST CENTRAL DICKSON COUNTIES...

AT 350 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED NEAR WHITE BLUFF...OR 9 MILES SOUTHWEST OF ASHLAND CITY...
MOVING SOUTHEAST AT 5 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  KINGSTON SPRINGS BY 400 PM CDT...

LAT...LON 3619 8701 3605 8712 3614 8736 3623 8727
TIME...MOT...LOC 2051Z 301DEG 5KT 3617 8716

$$

13

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 Jul 12, 2:20 PM CDT, 1 hour 7 minutes earlier.

Area forecast discussion, Jul 12, 2:20 PM CDT, 1 hour 7 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
220 PM CDT SUN JUL 12 2009

.DISCUSSION...
CURRENT...CONVECTION INCREASING IN COVERAGE/INTENSITY AS EXPECTED
THIS AFTERNOON. TEMPS IN LOWER 80S TO NEAR 90.

MODELS HINTING AT ANOTHER MCS TO DEVLOP TONITE AFFECTING MAINLY SW
1/2 OF CWA. FRONT WILL MOVE DOWN INTO MID STATE TOMORROW AND WILL
GO WITH 50% POP EVERYWHERE. THEN LO POPS FOR MON NITE WITH HIEST S
AS FRONT CONTINUES TO SAG S.

SLITE RISK SEVERE STORMS...MAINLY SW 1/2 TONITE AND MON...WITH
DAMAGING WINDS THE MAIN THREAT.

NEXT FRONTAL SYSTEM TO BE IN POSITION FOR CHANCE POPS WED-FRI TIME
FRAME. WARM ON TUE AND WED...THEN COOL-OFF WITH NEXT FRONT.
&&

.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE      70  88  70  93 /  70  50  20  10
CLARKSVILLE    68  87  68  92 /  70  50  20  10
CROSSVILLE     65  82  65  87 /  50  50  20  10
COLUMBIA       71  88  71  93 /  70  50  30  10
LAWRENCEBURG   72  88  72  92 /  70  50  30  10
WAVERLY        70  88  70  92 /  70  50  20  10
&&

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

17/MAG

Hazardous weather outlook, Jul 12, 5:02 AM CDT, 10 hours 25 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
502 AM CDT SUN JUL 12 2009

TNZ005>011-022>034-056>066-075-077>080-093>095-131030-
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-
502 AM CDT SUN JUL 12 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...TONIGHT

A COLD FRONT WILL MOVE INTO MIDDLE TENNESSEE THIS TODAY, BRINGING
WIDESPREAD THUNDERSTORMS TO THE MID STATE. THERE IS THE
POSSIBILITY THAT SOME OF THESE STORMS WILL BECOME SEVERE. MOST OF
MIDDLE TENNESSEE WEST OF THE CUMBERLAND PLATEAU IS UNDER A SLIGHT
RISK OF SEVERE WEATHER TODAY AND TONIGHT AS A RESULT, WITH THE
PRIMARY THREATS BEING DAMAGING WIND AND LARGE HAIL.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THUNDERSTORM ACTIVITY WILL CONTINUE INTO MONDAY, WHEN, ONCE AGAIN,
THERE IS THE POSSIBILITY THAT SOME STORMS COULD REACH SEVERE
LIMITS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER AND EMERGENCY MANAGER ACTIVATION MAY BE NEEDED TODAY AND
AGAIN ON MONDAY.

ROSE

In the hours before

Local storm report, Jul 12, 3:24 PM CDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
324 PM CDT SUN JUL 12 2009

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

0315 PM     TSTM WND DMG     2 NE LEWISBURG          35.47N 86.76W
07/12/2009                   MARSHALL           TN   LAW ENFORCEMENT

            A TREE FELL ON A HOUSE ON HOLLY GROVE ROAD.

&&

SHERRON

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 2:51 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Davidson	24 min
Jul 12, 2:57 PM CDT	Areal Flood Advisory	OHX	Cheatham	3 hr
Jul 12, 3:11 PM CDT	Severe Thunderstorm Warning	OHX	Bedford, Marshall	22 min
Jul 12, 3:48 PM CDT	Areal Flood Advisory	OHX	Cheatham, Dickson	3 hr
Jul 12, 4:23 PM CDT	Severe Thunderstorm Warning	OHX	Williamson	37 min
Jul 12, 6:29 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Dickson, Houston, Montgomery, Robertson, Stewart	46 min
Jul 12, 6:50 PM CDT	Severe Thunderstorm Warning	OHX	Cheatham, Davidson, Dickson, Robertson, Sumner, Williamson	40 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.