Hail in Wyoming, August 14, 2019

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
528 PM MDT Wed Aug 14 2019

.DISCUSSION...(This Evening Through Wednesday)
Issued at 302 PM MDT Wed Aug 14 2019

Low amplitude ridging continues across the southwestern CONUS, with
west/northwest flow across the northern Plains. A weak wave is
pushing across south central SD, which triggered strong isolated
convection across the central Black Hills earlier this afternoon. A
much stronger wave is pushing across the northern Rockies and is
expected to cross the CWA later this evening through the overnight
hours. Surface high is sitting across the eastern Dakotas. Decent
theta E advection overnight will work with the approaching upper
wave, resulting in overnight convection again. CAMs have been
showing strong storms affection portions of northeast WY through
southwest SD in the late evening to early morning hours. Increasing
shear will result in some severe weather, mainly in the evening.
Next wave will push through Thursday morning into the early
afternoon...bringing an earlier start to the convection. Best
chances will be across western to central South Dakota,
transitioning eastward through the late afternoon hours. MLCAPE of
2000 J/kg and 40kt of wind shear will result in severe storm
potential, ending in the early evening as weak upper ridging begins
building in. The next wave is expected to push through late Thursday
night, which will bring another round of overnight
convection...persisting into the Friday morning daytime hours. A
drier pattern is expected toward the end of the week into early
next week as upper ridging strengthens across the central CONUS,
also bringing warmer temperatures.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening)
Issued At 524 PM MDT Wed Aug 14 2019

Isolated TSRA early this evening over the Black Hills will become
isolated to scattered TSRA over northeast WY into western SD later
this evening through early Thursday morning. MVFR conditions are
expected in/near storms. A frontal boundary moves through Thursday
shifting winds to the northwest as well as bring local MVFR CIGS
behind it. Additional TSRA will develop Thursday afternoon.

&&

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

DISCUSSION...13
AVIATION...Helgeson

Hazardous Weather Outlook
National Weather Service Rapid City SD
526 AM MDT Wed Aug 14 2019

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-151300-
Harding-Perkins-Butte-Northern Meade Co Plains-Ziebach-
Northern Black Hills-Northern Foot Hills-Rapid City-
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Pennington Co Plains-Haakon-Fall River-
Oglala Lakota-Jackson-Bennett-Mellette-Todd-Tripp-
Sturgis/Piedmont Foot Hills-Southern Meade Co Plains-
Hermosa Foot Hills-Northern Campbell-Southern Campbell-
Western Crook-Wyoming Black Hills-Weston-Northeastern Crook-
526 AM MDT Wed Aug 14 2019 /626 AM CDT Wed Aug 14 2019/

This Hazardous Weather Outlook is for western South Dakota and
northeastern Wyoming.

.DAY ONE...Today and Tonight

Showers and thunderstorms are expected today. Strong to severe
thunderstorms are expected late this afternoon and this evening,
mainly across northeast Wyoming and southwestern South Dakota.
Large hail, damaging winds, and heavy rain will be the main
concerns. An isolated tornado is also possible.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Showers and thunderstorms are expected Thursday and Friday,
mainly during the afternoon and evening hours. Strong to severe
storms are expected again on Thursday. A few stronger storms will
be possible on Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed today.

&&

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

Special Weather Statement
National Weather Service Rapid City SD
903 PM MDT Wed Aug 14 2019

WYZ054-150330-
Northern Campbell WY-
903 PM MDT Wed Aug 14 2019

...STRONG THUNDERSTORM OVER NORTHWESTERN CAMPBELL COUNTY...

At 902 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles west of Spotted Horse, or 38 miles northwest of Gillette,
moving east at 45 mph.

Penny size hail and wind gusts up to 50 mph will be possible with
this storm.

Locations impacted include...
Spotted Horse and Recluse.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek safe shelter inside a building or vehicle until this storm has
passed.

&&

LAT...LON 4476 10548 4446 10572 4458 10601 4484 10602
      4485 10601
TIME...MOT...LOC 0302Z 290DEG 38KT 4469 10599

JC