Tornado Watch 9

Issued

Jan 20, 2017, 7:32 PM CST (01:32 UTC)

Expired

Jan 21, 2017, 2:00 AM CST

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Jefferson County, TX, Orange County, TX

The Lake Charles radar (KLCH), 6 km from the middle of the area, began a volume at 01:32 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

50%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 80Jan 20, 6:37 PM CST
• Mesoscale Discussion 81Jan 20, 10:04 PM CST
• Mesoscale Discussion 84Jan 21, 1:41 AM CST

871 
WWUS20 KWNS 210120
SEL9  
SPC WW 210120
LAZ000-TXZ000-CWZ000-210800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 9
NWS Storm Prediction Center Norman OK
720 PM CST Fri Jan 20 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southwestern and south-central Louisiana
  Extreme southeast Texas
  Coastal Waters

* Effective this Friday night and Saturday morning from 720 PM
  until 200 AM CST.

* Primary threats include...
  A few tornadoes possible
  Scattered damaging wind gusts to 70 mph possible
  Isolated very large hail events to 2.5 inches in diameter
    possible

SUMMARY...A cluster of thunderstorms over southeast Texas appears to
be the start of a more expansive overnight severe-storm event moving
east-northeastward through this watch (and eventually beyond). 
Additional, more isolated severe storms also may form ahead of the
main complex, along and south of a returning marine/warm frontal
zone.  The tornado threat, while marginal at first, will increase
with time and with eastward extent across the watch area tonight,
into southern Louisiana, as shear and instability increase.

The tornado watch area is approximately along and 50 statute miles
north and south of a line from 20 miles southwest of Port Arthur TX
to 25 miles northeast of Lafayette LA. 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 2.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 25030.

...Edwards

Tornado Watches in Louisiana, 2017Tornado Watches in Texas, 2017Every tornado watch in 2017

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.