Severe Thunderstorm Watch 21

Issued

Mar 27, 2018, 9:51 PM CDT (02:51 UTC)

Expired

Mar 28, 2018, 3:00 AM CDT

In force

5 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Austin/San Antonio radar (KEWX), 112 km from the middle of the area, began a volume at 02:52 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

20%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 183Mar 27, 9:23 PM CDT
• Mesoscale Discussion 184Mar 27, 11:58 PM CDT

244 
WWUS20 KWNS 280249
SEL1  
SPC WW 280249
TXZ000-280800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 21
NWS Storm Prediction Center Norman OK
950 PM CDT Tue Mar 27 2018

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  South Central Texas

* Effective this Tuesday night and Wednesday morning from 950 PM
  until 300 AM CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible
  A tornado or two possible

SUMMARY...Thunderstorms are intensifying along the Rio Grande River,
and will spread northeastward across the watch area.  Large hail and
damaging winds are the main threat, but an isolated tornado cannot
be ruled out.

The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 55 miles west southwest
of Cotulla TX to 60 miles north of Victoria TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU1).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for 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. Severe thunderstorms can and occasionally do produce
tornadoes.

&&

AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 450. Mean storm motion vector
24035.

...Hart

Severe Thunderstorm Watches in Texas, 2018Every severe thunderstorm 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.