485
FXUS63 KUNR 101041
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
441 AM MDT Thu Oct 10 2024

.KEY MESSAGES...

- Above average temperatures today, ahead of a cold front
- Elevated fire weather conditions continue
- Cooler temperatures through the rest of this week

&&

.DISCUSSION...(Today Through Wednesday)
Issued at 319 AM MDT Thu Oct 10 2024

Upper air analysis shows weak ridging across the upper Midwest. A
shortwave over the NW CONUS will continue within the
southwesterly flow over the Pac NW through the northern Rockies.
This SW flow will allow even warmer air to advect in this morning,
supporting temperatures of 15 to 25 degrees above the seasonal
average. The front will cross NW SD late this morning, Rapid City
around 18z, then nearing the Neb border by mid to late afternoon.
This will allow temperatures to reach into the upper 80s and 90s
across southwest to central SD, potentially breaking some daily
record highs. No precipitation is expected with this frontal
passage. Smoky conditions are expected again today, but then some
clearing is expected behind the front.

More seasonable temperatures are expected Friday, with highs in the
60s to low 70s. High pressure will cross North Dakota tomorrow, then
return flow quickly sets up Friday night. Models show westerly flow
heading into Saturday, then a shortwave will cross central Canada
and push into northern MN, then the Great Lakes region on Sunday.
Another cold front will cross the region late Saturday, bringing
cooler temperatures to the forecast area. High pressure then sets
up over the Dakotas, which will allow for good radiational
cooling. This Sunday morning may be the next decent attempt for
many locations to reach the freezing mark for the first time this
season. The GFS and ECM show strong upper ridging developing
across the western CONUS for the first half of next week, perhaps
even a Rex block setting up, which will slow down the pattern and
bring the region another round of dry weather and above-average
temperatures.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Friday Morning)
Issued At 440 AM MDT Thu Oct 10 2024

Mainly VFR conditions will persist through the forecast period.
Smoke from western wildfires may result in some visibility
restrictions across portions of northeast Wyoming and far western
South Dakota through this afternoon.

&&

.FIRE WEATHER...
Issued At 319 AM MDT Thu Oct 10 2024

Near critical fire weather conditions are expected today, as a dry
cold front crosses the area. The lowest RH of 11-16% will be ahead
of the front, where winds will be weaker. The stronger winds will be
behind the front, where higher RH is expected. Right now it looks
like a marginal event at best, since the wind and RH thresholds do
not line up well. So will not issue a Red Flag Warning today, but
attention should still be given to the near critical conditions
today. Temperatures will be cooler on Friday through the weekend.

&&

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

$$

DISCUSSION/KEY MESSAGES...13
AVIATION...Helgeson
FIRE WEATHER...13