896
FXUS63 KUNR 300825
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
225 AM MDT Tue Apr 30 2024

.KEY MESSAGES...

- Cold front today with scattered showers. Gusty northwest winds
  behind the front.

- Cool and unsettled through Saturday.

&&

.DISCUSSION...(Today Through Monday)
Issued at 215 AM MDT Tue Apr 30 2024

Current surface map places low across southeastern Montana with
cold front extending through eastern/central Wyoming. Showers are
increasing in coverage across western South Dakota with an uptick
in QG forcing as shortwave mCurrent surface map places low across southeastern Montana with
cold front extending through central Wyoming. Showeres increasing
in coverage across western South Dakota oves into eastern
Wyoming. For today, shortwave moves through this morning, with
most of the shower activity shifting east of the forecast area
this afternoon. Steep lapse rates/marginally buoyancy may result
in a few rumbles of thunder, mainly east of the Black Hills. Cold
front moves into western South Dakota shortly after daybreak and
through central South Dakota early this afternoon. 3mb/3hr
pressure rises behind the front with modest cold advection will
result in a period of gusty northwest winds. HREF paints 70-100%
probability of wind gusts >40mph along and north of I-90. The peak
in wind will come this morning with best pressure rises and
stronger winds at the top of the mixed layer. Have issued a Wind
Advisory for northwestern South Dakota extending east of the Black
Hills along I-90. Upper low lingers across the southern Canadian
Prairies through the end of the week with shortwaves rotating
through the Northern Plains. Strongest impulses move through late
Wednesday/early Thursday and on Friday. QPF amounts will generally
be on the light side...though LREF 24-hour precipitation is
showing 30-50% probability of >0.25" QPF on Thursday.

Upper low eventually shifts east this weekend, allowing ridge
to build over the plains as next trough digs over the western
CONUS. Robust warm advection over the plains should push highs
back into the 70s on Sunday/Monday. Overall, it will be drier over
the weekend but there could be some terrain induced
showers/thunderstorms around the Black Hills.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night)
Issued At 1045 PM MDT Mon Apr 29 2024

Isolated light rain showers will move back into the area
overnight into Tuesday morning. Mainly VFR conditions are
expected through 09z Tuesday morning. After 09z Tuesday, an area
of MVFR CIGS will move into northeastern WY and northwestern SD
along with a cold front. Gusty west to northwest winds will
develop over the area after 10Z Tuesday and will continue into the
afternoon.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 8 AM this morning to 6 PM MDT this evening
     for SDZ001-002-012>014-031-032-073-078.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...7
AVIATION...15