574
FXUS63 KUNR 110455
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1055 PM MDT Sun May 10 2026

.KEY MESSAGES...

- A hot, dry, and breezy weather pattern is expected this week
  resulting in near-critical to critical fire weather conditions.

- The next real chance of passing showers and thunderstorms holds
  off until at least Thursday, if not Friday. That being said,
  there is a small possibility of isolated light showers near the
  Black Hills Monday night.

- Slightly cooler temperatures and slightly higher relative
  humidities behind the front may result in a modest lull in fire
  weather conditions Tuesday, before conditions worsen again for
  Wednesday and Thursday.

&&

.UPDATE...
Issued at 1053 PM MDT Sun May 10 2026

Low level southwest return flow will ramp up overnight through
Monday morning ahead of a surface low north of Montana. This will
bring well above-average temps to the region tomorrow. Highs will be
near record levels across much of the western SD plains, especially
along the interstate corridor and southward. The record highs at
both UNR and KRAP are 95 (from 2025) so don`t think those records
will be broken. The big concern continues to be fire weather
conditions. Will continue the Red Flag Warning where it is already
issued.. The question is what to do with the Fire Weather Watch.
Higher RHs across far NW SD and Quickly greening grasslands would
hinder fire growth, but there are still dead fuels around.
Additionally, while RH may not quite reach criteria, with gusty
winds expected, especially directly behind the front will still
support near-critical fire weather conditions. Will move forward
with upgrading the watch to a Red Flag Warning after coordinating
with neighboring offices. Also, will cancel the Fire Weather Watch
for the Black Hills. While RFW criteria is not expected to be met
due to weaker winds compared to the plains, fire weather conditions
will still be elevated to near-critical. Cooler temps are expected
Tuesday, with highs in the 70s...still 5-10 degrees above seasonal
averages. Strong upper ridging will build across the region for
midweek another round of hot temperatures. Temps on Thursday look
similar to Monday. Elevated to potentially critical fire weather
conditions will continue through Thursday.

&&

.DISCUSSION...(This Evening Through Sunday)
Issued at 104 PM MDT Sun May 10 2026

Forecasted upper level ridging will bring back the dry and hot
weather to the area.

Starting with tonight, continued northwest flow has kept the
slight chances (10 to 20%) for light rain showers near the Black
Hills for the rest of this afternoon. So far, any returns on the
radar have been short lived, weak, and elevated. Rain chances
diminish late this afternoon, overnight lows will be in the 40s,
winds will remain on the lighter side at around 5 to 10 mph out of
the east-to-southeast.

The heat is on tomorrow. Warm air will move into the area, driven
by southerly winds, causing afternoon highs to reach the 80s and
90s. With low humidity and strong winds, fire weather is looking
likely. Then, a passing cold front will swing winds to the west-
to-northwest and cause winds to pick up speed. Gusts upwards of 30
to 40 mph are likely, high-end, isolated gusts near 45 to 50 mph
are possible. As the front tracks over the Black Hills, isolated
showers are possible, low end chances again due to lack of
moisture, late Monday into Monday night.

Tuesday looks to be cooler, due to Monday`s front. Highs will be
back in the 70s with decreasing wind speeds through the day.

The rest of the week looks hot and breezy with highs back into the
80s to low 90s. Next chance for passing showers and storms is late
Thursday into Friday. But these chances are low-end again.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Monday Night)
Issued At 1049 PM MDT Sun May 10 2026

VFR conditions are expected through the forecast period. Windy
conditions will arrive tonight across most of the area. Wind
direction will be shifting slowly through Monday ahead of a cold
front anticipated in the evening.

&&

.FIRE WEATHER...
Issued At 104 PM MDT Sun May 10 2026

A near-critical to critical fire weather pattern is forecast to
develop across western South Dakota starting Monday and continue
through much of the week. The most critical days at this time
appear to be Monday, Wednesday, and Thursday.

Upper level ridge will push very warm air into the plains,
expected highs will reach the 80s to 90s. With no real push of
extra moisture, relative humidities will drop to well below 20%.
A passing front will kick wind speeds up. Ahead of the front,
winds will be out of the south-to-southwest at around 10 to 20
mph. But as the front tracks through, winds will swing to the
west-to-northwest at around 15 to 25 mph with gusts near 30 to 40
mph. Some high-end gusts could be even higher, nearing 45 mph.

With all that in mind, a Red Flag Warning has replaced the Fire
Weather Watch for several counties in western SD. Other counties
in western SD are still in the Fire Weather Watch.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...     Red Flag Warning from 11 AM MDT /noon CDT/ to 9 PM MDT /10 PM
     CDT/ Monday for SDZ322>335.
WY...&&

$$

UPDATE...13
DISCUSSION/KEY MESSAGES...GS
AVIATION...Schweigert
FIRE WEATHER...GS