Severe Thunderstorm Watch 607

Issued

Aug 20, 2019, 3:03 PM MDT (21:03 UTC)

Expired

Aug 20, 2019, 11:00 PM MDT

In force

8 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

Counties Morgan County, CO, Weld County, CO, Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sioux County, NE, Goshen County, WY, Laramie County, WY, Niobrara County, WY, Platte County, WY

The Cheyenne radar (KCYS), 132 km from the middle of the area, began a volume at 21:03 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

40%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

40%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1813Aug 20, 2:30 PM MDT
• Mesoscale Discussion 1820Aug 20, 6:00 PM MDT
• Mesoscale Discussion 1821Aug 20, 9:05 PM MDT
• Mesoscale Discussion 1822Aug 20, 10:34 PM MDT

069 
WWUS20 KWNS 202059
SEL7  
SPC WW 202059
COZ000-NEZ000-WYZ000-210500-

URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 607
NWS Storm Prediction Center Norman OK
300 PM MDT Tue Aug 20 2019

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of 
  Extreme northeast Colorado
  The western Nebraska Panhandle
  Southeast Wyoming

* Effective this Tuesday afternoon and evening from 300 PM until
  1100 PM MDT.

* Primary threats include...
  Scattered large hail and isolated very large hail events to 2.5
    inches in diameter possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Scattered thunderstorm development is expected late this
afternoon/evening from extreme northeast Colorado into southeast
Wyoming.  The storm environment will favor discrete supercells with
isolated very large hail initially, and upscale growth into a
cluster is possible late this evening with some damaging wind
potential.

The severe thunderstorm watch area is approximately along and 50
statute miles east and west of a line from 45 miles west northwest
of Chadron NE to 65 miles southeast of Cheyenne WY. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU7).

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 604...WW 605...WW 606...

AVIATION...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 550. Mean storm motion vector
29010.

...Thompson

Severe Thunderstorm Watches in Nebraska, 2019Severe Thunderstorm Watches in Wyoming, 2019Severe Thunderstorm Watches in Colorado, 2019Every severe thunderstorm watch in 2019

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.