652
FXUS63 KUNR 160811
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
211 AM MDT Thu May 16 2024

.KEY MESSAGES...

- Unsettle pattern continues through the period

- Warm Friday. Late day thunderstorms with cold front could bring
  some locally strong wind gusts.

&&

.DISCUSSION...(Today Through Wednesday)
Issued at 147 AM MDT Thu May 16 2024

Current surface map places weak trough across the western Dakotas.
Weak shortwave moving through the area is producing a few light
rain showers over southeastern Montana. The showers will clip far
northwestern South Dakota early this morning. Second shortwave
arrives later today with isolated showers/thunderstorms over the
Black Hills and northwestern South Dakota.

For Friday, stronger upper trough moves through the Northern
Plains. Low level thermal ridge peaks, with highs reaching the
upper 70s to upper 80s. Surface trough pushes through Friday
afternoon with deeper boundary layer moisture in central/eastern
South Dakota. Lack of buoyancy will initially limit thunderstorm
development to Black Hills Friday afternoon. Better chance of
thunderstorms comes with increasing mid level forcing and cold
frontal passage. Front arrives in northeastern Wyoming and
northwestern South Dakota late afternoon and moves through the
rest of western South Dakota Friday evening. 3-5mb/3hr pressure
rises will bring a period of gusty northwest winds with the cold
front. Enhanced downdrafts with thunderstorms may produce some
locally strong winds.

In wake of the upper trough, Saturday will be cooler and breezy.
Next upper trough will bring showers and thunderstorms
Sunday/Monday, followed by another for the middle of the week.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Thursday Night)
Issued At 1017 PM MDT Wed May 15 2024

Isolated showers will be possible again Thursday afternoon and
evening across the western SD plains. Other than any brief MVFR
conditions in showers, VFR conditions are expected through the TAF
period.

&&

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

$$

DISCUSSION/KEY MESSAGES...7
AVIATION...Pojorlie