Severe Thunderstorm Watch 479

Issued

Aug 30, 2021, 9:57 PM CDT (02:57 UTC)

Expired

Aug 31, 2021, 5:00 AM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

70 kt

The North Platte radar (KLNX), 209 km from the middle of the area, began a volume at 03:00 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

10%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

50%

Ten or more severe hail reports

60%

One or more hailstones of 2 inches or more

60%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 1655 Severe thunderstorm watch 477Aug 30, 7:25 PM CDT
• Mesoscale Discussion 1656 Severe thunderstorm watch 479Aug 30, 11:35 PM CDT
• Mesoscale Discussion 1657 Severe thunderstorm watch 479Aug 31, 3:02 AM CDT

905 
WWUS20 KWNS 310256
SEL9  
SPC WW 310256
NEZ000-SDZ000-311000-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 479
NWS Storm Prediction Center Norman OK
955 PM CDT Mon Aug 30 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  North-central and northeastern Nebraska
  Western through southern South Dakota

* Effective this Monday night and Tuesday morning from 955 PM
  until 500 AM CDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2.5
    inches in diameter likely
  Scattered damaging winds likely with isolated significant gusts
    to 80 mph possible

SUMMARY...Several ongoing strong to severe thunderstorms  --
including a few supercells -- are expected to aggregate with newer
convection tonight across southern SD and northern NE.  Until that
occurs, large/damaging hail is possible from that activity, as well
as more-isolated convection in northern NE and southeastern SD.  A
thunderstorm complex is forecast to evolve and move southeastward on
either side of a stationary front.  That activity would increase the
 severe-wind threat into southern SD and north-central/northeastern
NE.

The severe thunderstorm watch area is approximately along and 60
statute miles either side of a line from 45 miles north northwest of
Philip SD to 55 miles south of Yankton SD. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU9).

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.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 477...WW 478...

AVIATION...A few severe thunderstorms with hail surface and aloft to
2.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
31030.

...Edwards

Severe Thunderstorm Watches in Nebraska, 2021Severe Thunderstorm Watches in South Dakota, 2021Every severe thunderstorm watch in 2021

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.