Tornado Watch 518

Issued

Dec 17, 2016, 8:58 PM CST (02:58 UTC)

Expired

Dec 18, 2016, 2:46 AM CST

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

1 in

Strongest gust expected

60 kt

The Memphis radar (KNQA), 131 km from the middle of the area, began a volume at 02:58 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

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

10%

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

30%

• Mesoscale Discussion 1892Dec 17, 5:45 PM CST
• Mesoscale Discussion 1893Dec 17, 6:44 PM CST
• Mesoscale Discussion 1894Dec 17, 8:28 PM CST
• Mesoscale Discussion 1895Dec 17, 11:48 PM CST
• Mesoscale Discussion 1898Dec 18, 2:30 AM CST

602 
WWUS20 KWNS 180256
SEL8  
SPC WW 180256
ALZ000-ARZ000-LAZ000-MSZ000-TNZ000-180900-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 518
NWS Storm Prediction Center Norman OK
855 PM CST Sat Dec 17 2016

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Northwestern Alabama
  Southeastern Arkansas
  Northeastern Louisiana
  West-central through northern Mississippi
  Southwestern and middle Tennessee

* Effective this Saturday night and Sunday morning from 855 PM
  until 300 AM CST.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...A band of strong to locally severe storms near an intense
cold front will move across the watch area through much of the
overnight hours, offering a risk of sporadic damaging winds and a
couple of tornadoes possible.  Isolated severe storms still may form
ahead of that band also.  See SPC mesoscale discussions 1893-1894
for initial meteorological reasoning.

The tornado watch area is approximately along and 55 statute miles
either side of a line from 25 miles west northwest of Monroe LA to
15 miles east of Nashville TN. For a complete depiction of the watch
see the associated watch outline update (WOUS64 KWNS WOU8).

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...This tornado watch replaces tornado
watch number 517. Watch number 517 will not be in effect after
855 PM CST. 

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 23035.

...Edwards

Tornado Watches in Mississippi, 2016Tornado Watches in Tennessee, 2016Tornado Watches in Louisiana, 2016Every tornado watch in 2016

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.