Hail and Damaging Winds in South Dakota, August 6, 2017

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
314 PM MDT Sun Aug 6 2017

.DISCUSSION...(This Evening Through Sunday)
Issued at 258 PM MDT Sun Aug 6 2017

Upper level analysis has broad trof across the northern CONUS with
weak cyclonic flow across the northern Plains. Skies are partly
sunny to mostly cloudy this afternoon with scattered showers and
thunderstorms across the area. At the surface, weak high pressure
was located across the area, with temperatures in the upper 60s to
mid 70s. Winds were mainly out of the north at 10 to 20 mph.

Weak cyclonic flow will continue into tonight as widely scattered
showers, and a few thunderstorms, will slowly shift eastward and
diminish during the evening hours. Another cool night is in store,
with temperatures falling into the 50s across much of the area.
Some 40s will be possible in the Black Hills, and low lying areas
across the plains.

Monday into Tuesday will be drier as weak forcing aloft will limit
isolated activity to mainly the Black Hills. Chances for pcpn will
increase again late Tuesday into midweek as additional disturbances
slide southeast across the region. Better chances right now look
to be Wednesday afternoon and then late Thursday afternoon into
Thursday night. Temps through Thursday will remain slightly below
average, mostly 70s and lower 80s for highs. Will likely see at
least a temporary shift in the pattern toward the weekend as a
ridge is progged to build over the Rockies. This would bring
mostly dry weather and a warming trend. Highs look to be in the
80s across much of the area for the weekend.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Monday)
Issued At 1108 AM MDT Sun Aug 6 2017

Gusty winds to 30 mph will persist over the eastern slopes and
adjacent plains of the Black Hills through this afternoon.
Otherwise, isolated to scattered thunderstorms will develop over
the Black Hills this afternoon and move southeast, diminishing
this evening. Elsewhere, some isolated to scattered showers and
thunderstorms are possible this afternoon and evening.

MVFR ceilings over parts of the SD and far northeastern WY plains
may expand a bit in coverage tonight as a relatively cool and
moist air mass remains in place with a slight upslope flow,
possibly reaching the KRAP site by 12z Monday. Patchy fog will
again be possible by Monday morning. Otherwise, VFR conditions
will predominate for most places.

&&

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

DISCUSSION...15
AVIATION...Bunkers

Hazardous Weather Outlook
National Weather Service Rapid City SD
445 AM MDT Sun Aug 6 2017

SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058-
071-071300-
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-
445 AM MDT Sun Aug 6 2017 /545 AM CDT Sun Aug 6 2017/

This Hazardous weather outlook is for western South Dakota and
Northeastern Wyoming.

.DAY ONE...Today and Tonight

There is a chance of thunderstorms today and tonight for most of
the area. Severe weather is not expected.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There are periodic chances for thunderstorms much of this week.
Isolated severe weather is possible.

.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

Special Weather Statement
National Weather Service Rapid City SD
409 PM CDT SUN AUG 6 2017

SDZ046-049-062200-
Tripp SD-Mellette SD-
409 PM CDT SUN AUG 6 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN TRIPP AND EASTERN
MELLETTE COUNTIES UNTIL 500 PM CDT...

At 409 PM CDT, Doppler radar was tracking a strong thunderstorm near
Westover, or 12 miles southeast of Murdo, moving southeast at 30 mph.

Dime size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Wood.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4339 10054 4372 10078 4371 10068 4375 10064
      4374 10064 4377 10058 4372 10047 4374 10036
      4370 10029 4371 10023 4369 10021 4371 10018
      4368 10011 4371 10004 4370 9990
TIME...MOT...LOC 2109Z 316DEG 26KT 4375 10055

Eagan