Alert archive / Tennessee / Tornado Watches in 2012
Tornado Watch 659
The Storm Prediction Center issued this tornado watch at Oct 1, 2012, 8:06 PM EDT for 4 counties in Kentucky; 24 counties in Tennessee. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Oct 1, 2012, 8:06 PM EDT (00:06 UTC)
- Expired
- Oct 1, 2012, 10:47 PM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 28 counties
McCreary County, KY, Pulaski County, KY, Wayne County, KY, Whitley County, KY, Anderson County, TN, Bledsoe County, TN, Bradley County, TN, Campbell County, TN, Cumberland County, TN, Fentress County, TN, Grundy County, TN, Hamilton County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Van Buren County, TN, White County, TN
The radar
The Knoxville radar (KMRX), 139 km from the middle of the area, began a volume at 00:07 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 30%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 40%
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Nashville Metro, TN (KBNA), launched 00:00Z, 0.1 hours before the alert went out and 148 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.
- Mixed-layer CAPE
- 911 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 463 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 149 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 3.3
The text
As transmitted, in the capitals the NWS used until 2016.
671
WWUS20 KWNS 020007
SEL9
SPC WW 020007
KYZ000-TNZ000-020600-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 659
NWS STORM PREDICTION CENTER NORMAN OK
805 PM EDT MON OCT 1 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHEAST KENTUCKY
MIDDLE AND EAST TENNESSEE
EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 805 PM UNTIL
200 AM EDT.
TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES EAST AND WEST OF A LINE FROM 70 MILES NORTH NORTHEAST OF
CROSSVILLE TENNESSEE TO 5 MILES EAST SOUTHEAST OF CHATTANOOGA
TENNESSEE. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.
OTHER WATCH INFORMATION...CONTINUE...WW 658...
DISCUSSION...NNE-SSW SQLN IN ERN PART OF MIDDLE TN EXPECTED TO
CONTINUE ADVANCING SLOWLY EWD...WHILE EMBEDDED STORMS MOVE MORE
RAPIDLY NNE ALONG IT. AMPLE DEEP SHEAR WILL PERSIST FOR SUSTAINED
STORMS. IN ADDITION...SUFFICIENT LOW-LVL SHEAR WILL EXIST FOR
OCCASIONAL LOW-LVL MESOCYCLONES/POSSIBLE TORNADOES GIVEN CONTINUED
NNE MOTION OF 50 KT SSWLY LLJ ACROSS E TN...AND MOISTENING NEAR-SFC
ENVIRONMENT.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 21030.
...CORFIDINearby
Tornado Watches in Tennessee, 2012Tornado Watches in Kentucky, 2012Every tornado watch in 2012
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.