Tornado Watch 439

Issued

Dec 20, 2018, 7:55 AM EST (12:55 UTC)

Expired

Dec 20, 2018, 2:43 PM EST

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

0.5 in

Strongest gust expected

60 kt

The Tampa radar (KTBW), 68 km from the middle of the area, began a volume at 12:55 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

60%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

60%

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

70%

• Mesoscale Discussion 1715Dec 20, 6:28 AM EST
• Mesoscale Discussion 1716Dec 20, 7:38 AM EST
• Mesoscale Discussion 1717Dec 20, 10:49 AM EST
• Mesoscale Discussion 1718Dec 20, 1:41 PM EST

942 
WWUS20 KWNS 201252
SEL9  
SPC WW 201252
FLZ000-CWZ000-202100-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 439
NWS Storm Prediction Center Norman OK
755 AM EST Thu Dec 20 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  East-central to west-central and southwest Florida
  Coastal Waters

* Effective this Thursday morning and afternoon from 755 AM until
  400 PM EST.

* Primary threats include...
  A few tornadoes likely
  Scattered damaging wind gusts to 70 mph likely

SUMMARY...Bands of thunderstorms should cross the watch area through
mid-afternoon.  This activity will offer sporadic tornado and
damaging-wind threats in a favorable shear regime, as the inflow air
mass gradually destabilizes.

The tornado watch area is approximately along and 65 statute miles
either side of a line from 35 miles south southeast of Sarasota FL
to 25 miles north northeast of Melbourne FL. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU9).

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.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 0.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean
storm motion vector 22030.

...Edwards

Tornado Watches in Florida, 2018Every tornado watch in 2018

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.