Tornado Watch 587

Issued

Dec 21, 2013, 8:16 PM CST (02:16 UTC)

Expired

Dec 22, 2013, 2:00 AM CST

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

0.5 in

Strongest gust expected

60 kt

The Nashville radar (KOHX), 59 km from the middle of the area, began a volume at 02:18 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.

Two or more tornadoes

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

20%

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

80%

• Mesoscale Discussion 2104Dec 21, 5:06 PM CST
• Mesoscale Discussion 2105Dec 21, 7:40 PM CST
• Mesoscale Discussion 2106Dec 21, 10:33 PM CST
• Mesoscale Discussion 2109Dec 22, 1:34 AM CST

881 
WWUS20 KWNS 220217
SEL7  
SPC WW 220217
ALZ000-KYZ000-TNZ000-220800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 587
NWS STORM PREDICTION CENTER NORMAN OK
820 PM CST SAT DEC 21 2013

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  WESTERN AND NORTHERN ALABAMA
  SOUTH CENTRAL KENTUCKY
  MIDDLE TENNESSEE

* EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 820 PM
  UNTIL 200 AM CST.

* PRIMARY THREATS INCLUDE...
  SEVERAL TORNADOES POSSIBLE
  SEVERAL DAMAGING WIND GUSTS TO 70 MPH LIKELY

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 75 MILES EAST NORTHEAST OF
BOWLING GREEN KENTUCKY TO 40 MILES SOUTHEAST OF COLUMBUS
MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 583...WW 584...WW
585...WW 586...

DISCUSSION...A WELL-FORMED SQUALL LINE WILL MOVE EWD OVERNIGHT FROM
WRN TN/KY AND NRN MS INTO NW AL...MIDDLE TN AND CENTRAL KY. 
LOW-LEVEL MOISTURE ADVECTION AND MIXING WILL HELP MAINTAIN A
RELATIVELY WARM AND MOIST BOUNDARY LAYER WITH SURFACE-BASED
INSTABILITY AHEAD OF THE SQUALL LINE...WHILE VERTICAL SHEAR WILL
REMAIN STRONG FOR THE NEXT SEVERAL HOURS.  A COUPLE OF TORNADOES
WILL BE POSSIBLE WITH EMBEDDED CIRCULATIONS...WHILE DAMAGING WINDS
WILL BE THE PRIMARY THREAT.

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
450. MEAN STORM MOTION VECTOR 24050.


...THOMPSON

Tornado Watches in Tennessee, 2013Tornado Watches in Alabama, 2013Tornado Watches in Kentucky, 2013Every tornado watch in 2013

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.