Hail and Damaging Wind in Wyoming, July 19, 2020

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
116 PM MDT Sun Jul 19 2020

.DISCUSSION...(This Evening Through Sunday)
Issued at 1259 PM MDT Sun Jul 19 2020

Water vapor shows broad trof extending from the Pac NW through the
Northern Plains. Short wave moving through the Northern Plains
that has been responsible for this mornings convection still
resulting in mostly cloudy skies and a few showers across
western/central SD early this afternoon. Weak inverted trof over
eastern WY resulting in increasing return flow across our western
zones.

Still expecting a strong/severe storm or two to develop along the
inverted trof by later this afternoon, with activity moving into
the Black Hills and far southwest SD. Axis of MLCAPE continues to
increase in that area under return flow, and shear is more than
sufficient for rotating updrafts. Rest of area should remain
largely capped, especially given residual mid-level clouds. Could
see an uptick in elevated activity in our southern zones overnight
given increasing low level jet/theta-e advection.

A stronger northern stream trof will push a cold front through the
Northern Plains on Monday. Timing of front should place the best
severe potential over western/central SD in the afternoon through
early time frame, with lesser chances for severe storms behind the
front across northeast WY.

Should see a return to warmer temps in the mid to late week time
frame as flow aloft transitions from zonal to southwest, although
the flow will remain disturbed for a nearly daily chance of
storms.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Monday)
Issued At 1124 AM MDT Sun Jul 19 2020

Scattered showers and thundershowers will persist into the early
afternoon over mainly western into south central SD. More showers
and thunderstorms are likely to develop by late afternoon over
northeast WY into the Black Hills and track southeast across
mostly northeast WY and southwest SD through the evening. Severe
storms are possible with large hail and strong wind gusts in these
areas, with brief MVFR conditions and heavy rainfall also
possible. Areas of MVFR/IFR conditions are expected to develop
late tonight and persist into Monday morning, especially from the
Black Hills area to south central SD.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

DISCUSSION...Johnson
AVIATION...26

Hazardous Weather Outlook
National Weather Service Rapid City SD
403 AM MDT Sun Jul 19 2020

SDZ012-024>031-041>044-047-072>074-201300-
Butte-Northern Black Hills-Northern Foot Hills-Rapid City-
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Pennington Co Plains-Fall River-Oglala Lakota-
Jackson-Bennett-Todd-Sturgis/Piedmont Foot Hills-
Southern Meade Co Plains-Hermosa Foot Hills-
403 AM MDT Sun Jul 19 2020 /503 AM CDT Sun Jul 19 2020/

This Hazardous Weather Outlook is for portions of northwestern
South Dakota...south central South Dakota...southwestern South
Dakota...and the Black Hills of South Dakota.

.DAY ONE...Today and Tonight

Thunderstorms are expected today through this evening. Some storms
may be severe in the afternoon and evening, with large hail and
damaging winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

An active weather pattern will return for the next few days, with
daily chances for showers and thunderstorms through midweek.
There is a slight risk for severe thunderstorms across western
South Dakota. Large hail and strong wind gusts will be the
primary threats. There is also a marginal risk for severe storms
Tuesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

SDZ001-002-013-014-032-046-049-201300-
Harding-Perkins-Northern Meade Co Plains-Ziebach-Haakon-Mellette-
Tripp-
403 AM MDT Sun Jul 19 2020 /503 AM CDT Sun Jul 19 2020/

This Hazardous Weather Outlook is for portions of western South
Dakota.

.DAY ONE...Today and Tonight

Thunderstorms will be possible this afternoon and evening. Some
storms may be strong, but widespread severe weather is not
expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

An active weather pattern will return for the next few days, with
daily chances for showers and thunderstorms through midweek.
There is a slight risk for severe thunderstorms across western
South Dakota. Large hail and strong wind gusts will be the
primary threats.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

WYZ054>058-071-201300-
Northern Campbell-Southern Campbell-Western Crook-
Wyoming Black Hills-Weston-Northeastern Crook-
403 AM MDT Sun Jul 19 2020

This Hazardous Weather Outlook is for portions of northeast
Wyoming...and the Black Hills of Wyoming.

.DAY ONE...Today and Tonight

Thunderstorms are expected today through this evening. Some storms
may be severe in the afternoon and evening, with large hail and
damaging winds.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

An active weather pattern will return for the next few days, with
daily chances for showers and thunderstorms through midweek.
There is a marginal risk for severe storms Monday and Tuesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity