266
FXUS63 KUNR 250513
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1113 PM MDT Mon Jun 24 2024

.KEY MESSAGES...

- Above normal temperatures continue through mid-week.

- Daily isolated storms possible through mid-week, with limited
  moisture and a chance for severe.

- More active weather towards the end of the week.

&&

.DISCUSSION...(This Evening Through Monday)
Issued at 154 PM MDT Mon Jun 24 2024

Current surface analysis shows the low over eastern SD, with a
weak cold front stretching into southwestern SD. Water Vapor and
upper air models show near zonal flow over the forecast area
today. Temperatures currently sit in the upper 80s to upper 90s
across the region this afternoon. Frontal boundary is expected to
stall around the NE/SD border later this afternoon. With the
better forcing over that area, could see some storm development
late afternoon early evening timeframe. Plenty of CAPE and modest
shear, however a strong cap is expected to limit storm
development. Any storms that are able to develop, should have
supercell potential with severe hail/wind threats. Main timing for
severe potential looks to be around 6 to 10 pm MDT. Some modest
850mb theta-e lingering on could allow for showers/storms to
continue into the overnight hours, however severe threat is not
expected with any nocturnal storms.

Similar pattern continues for Tuesday, though with the lack of
forcing mechanism that exists over southern SD today. Cannot rule
out some daytime heating or Black Hills upslope convection, with
an isolated severe storm or two possible. A mid-level wave passing
through on Wednesday will continue our chances for daily storms,
but lack of moisture continues until later towards the weekend.
Mild upper ridge slides over the Rockies and into the
northern/central plains Wednesday into Thursday, followed by an
upper trough moving across southern Canada later Thursday into the
weekend, bringing increasing chances for storms with more
available moisture. Cooler temperatures move in as well, though
still at or just below normal for this time of year. Models show
upper ridge building back in early next week, with a return to
above normal temperatures.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night)
Issued At 1111 PM MDT Mon Jun 24 2024

Scattered showers/thunderstorms with local MVFR conditions will
slowly subside through early Tuesday morning. Additional storms
may develop later Tuesday afternoon with hail and gusty, erratic
winds, especially over southern South Dakota. Otherwise, VFR
conditions will prevail through the period.

&&

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

$$

DISCUSSION/KEY MESSAGES...Dye
AVIATION...Helgeson