Area Forecast Discussion
Issued by NWS Rapid City, SD

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FXUS63 KUNR 220934

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
334 AM MDT SUN MAY 22 2016

.SHORT TERM...(Today Through Monday Night)
Issued at 330 AM MDT Sun May 22 2016

Current surface map shows trof/cold front across far eastern
Montana into northeast Wyoming. Convection lifting north out of
northeast Wyoming with isolated shra/tsra developing across south
central South Dakota. Upper low located in southern Alberta with
110kt jet streak lifting across Utah into Wyoming.

For today, cold front slowly slides through western South Dakota
as jet streak shifts into eastern Wyoming/western Dakotas. MLCAPE
of 2000-3000j/kg forecast along cold front, with 25-35m/s bulk
shear. Model reflectivity suggest discrete supercells developing
this afternoon, mainly east of a line from Pine Ridge to Phillip.
Large hail, greater than 2 inches, and damaging winds likely
across south central South Dakota late this afternoon into this
evening. also some potential for tornado development.
Thunderstorms will push east of the forecast area overnight. As
boundary layer flow turns southwest to west behind cold front,
drier air bring a decrease in low clouds across western South
Dakota. With the additional sunshine, high temperatures across
western South Dakota will be warmer than yesterday even with the
passage of the cold front. Dry weather expected for Monday.

.LONG TERM...(Tuesday Through Saturday)
Issued at 330 AM MDT Sun May 22 2016

Mean upper trough over the western CONUS will change
little through much of the upcoming week. Southwest flow aloft will
prevail over the CWA with periodic shortwaves and a couple of
transient upper lows passing through. Hard to pin point timing at
this point, so PoPs generally broad-brushed. Monday looks to be the
only nearly dry day. The weather does look unsettled with daily
chances for storms Tuesday through next weekend. Temperatures will
be seasonal.


.AVIATION...(For the 12Z TAFS Through 12Z Monday morning)
Issued At 330 AM MDT Sun May 22 2016

MVFR ceilings will linger across much of western SD and
NE Wyoming into the morning hours. A weak surface trough over NE
Wyoming will push east this morning, with winds becoming westerly
behind it. Ceilings should become VFR across NE Wyoming by mid
morning, and across far western SD by late morning. Thunderstorms
are expected to develop over the area this afternoon and evening,
with the strongest storms generally east of the Black Hills.
IFR/MVFR conditions and gusty winds possible with any of the showers
and storms.

.UNR Watches/Warnings/Advisories...


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