356
FXUS63 KUNR 270833
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
233 AM MDT Sat Apr 27 2024

.KEY MESSAGES...

- Isolated showers/storms possible this morning and afternoon,
  more widespread precipitation moves in this evening through
  Sunday afternoon.

- More seasonable temperatures move in early next week, along with
  near daily chances for showers/storms


&&

.DISCUSSION...(Today Through Friday)
Issued at 134 AM MDT Sat Apr 27 2024


Current Water Vapor and upper air models show first shortwave
over eastern SD into MN, while second wave sits over the four
corners region. At the surface, low pressure sits over the SD/MN
border, with another low over southwestern WY. Low clouds cover
much of the western SD plains. Temperatures currently sit in the
40s across the forecast area this morning.

Out ahead of the next wave, CAMs hint at isolated showers
possible later this morning and afternoon across the western South
Dakota plains, while bulk of expected precipitation moves in this
evening into Sunday as the upper trough swings into NE
eventually eastern SD. Ensembles continue to prog the wave a bit
more to the east, highlighting a sharp cutoff on QPF potential,
with northwestern SD remaining mostly dry. The better forcing
continues to be east and south of our forecast area, however will
be enough lift to see widespread precipitation. Areas east and
south of Rapid City may see amounts 0.25-0.75 inches of rainfall.
Precipitation tapers off from west to east Sunday afternoon.

Behind this weekend system, a more active near-zonal flow sets up
over the region, bringing chances for daily showers/storms. Weak
disturbance is progged to track north of the forecast Monday
evening into Tuesday. Chances for showers and storms will be
possible mainly over the Black Hills and northwestern SD. Weak
instability will keep severe chances low through mid-week.
Deterministic models become more divergent on the overall pattern
later in the week, however still point to potential for active
weather in the region.




&&

.AVIATION...(For the 06Z TAFS Through 06Z Saturday Night)
Issued At 1005 PM MDT Fri Apr 26 2024

MVFR cigs will spread west across the SD plains and into NE WY by
Sat morning. MVFR cigs will linger most of the day Sat on the SD
plains, with some improvement to VFR possible. Isolated showers
are also possible. Widespread MVFR/IFR conds are expected Sat
night on the SD plains as a low pressure system crosses the
region and rain develops.

&&

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

$$

DISCUSSION/KEY MESSAGES...Dye
AVIATION...JC