547 FXUS63 KUNR 022259 AFDUNRArea Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 459 PM MDT Thu Oct 2 2025
.KEY MESSAGES...
- Above normal temperatures and dry conditions continue through Friday.
- Elevated to critical fire weather conditions through Friday.
- Pattern change over the weekend toward cooler temperatures and increasing chances for precipitation.
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.DISCUSSION...(This Evening Through Thursday) Issued at 141 PM MDT Thu Oct 2 2025
Current Water Vapor and upper air models show upper ridge over the Great Lakes region flattening out, as the upper trough slides over the west coast, with southwest flow over the forecast area. Surface analysis shows a low over eastern North Dakota, while surface high sits over MT/WY region. Winds currently are mainly out of the south to southeast, with temperatures in the upper 70s and 80s.
Upper ridge builds into the northern and central plains later today into Friday, prompting an increase in temperatures. Some record daily highs could be possible on Friday, with HREF probabilities of 90 degrees or higher in the afternoon reaching into the 60-95 percent range for much of the western SD plains. Deep mixing will also allow for some breezy winds Friday afternoon, with gusts 25 to 35 mph over some areas of the plains.
We`ll start to see a pattern shift Saturday, as upper trough digs into the Rockies Saturday and over the northern plains by Sunday. A shortwave and associated cold front is expected to move through around this same time frame. Models show a 15-20 degree change, with highs on Sunday only in the 50s to mid 60s. Better forcing and moisture with this wave will bring a good chance for wetting precipitation later Saturday into Sunday. LREF probabilities for 0.5" QPF or greater show a widespread signal of 50-70% chances later Saturday into Sunday. The Black hills will see low temperatures in the 30s Sunday morning, with some higher elevation areas potentially seeing a transition to some light snow in the coldest hours. Strong pressure rises behind the front will also prompt gusty northwest winds that may require wind advisory headlines.
This pattern looks to stick around at least through early next week, with temperatures staying at or below normal, and perhaps a few chances for precipitation. Models diverge greatly the middle of next week, bringing some uncertainty to any local weather impacts.
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.AVIATION...(For the 00Z TAFS Through 00Z Friday Evening) Issued At 457 PM MDT Thu Oct 2 2025
VFR conditions will continue through the forecast period. South- southwesterly winds will increase after 15-17z Friday morning, with gusts 20 to 30 knots expected across NE WY and the western SD plains.
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.FIRE WEATHER... Issued At 141 PM MDT Thu Oct 2 2025
Elevated fire weather conditions can be expected today mainly across northeast WY and southwest SD. Although RH`s will drop to around 15 to 20 percent, winds will be generally light today. Warmer temperatures, deeper mixing, and breezy southwest winds are expected Friday for much of the area. RH`s will fall to around 10 to 15 percent across parts of northeast WY and southwest SD in the afternoon with breezy southwest winds developing (frequent gusts over 25 mph likely). Given dry fuels and these concerns, issued a Red Flag Warning for Friday afternoon for much of northeast WY and southwest SD.
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.UNR WATCHES/WARNINGS/ADVISORIES... SD...Red Flag Warning from noon to 7 PM MDT Friday for SDZ321-322- 324>326-329-332. WY...Red Flag Warning from noon to 7 PM MDT Friday for WYZ314>317. &&
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DISCUSSION/KEY MESSAGES...Dye AVIATION...SE FIRE WEATHER...Dye
NWS UNR Office Area Forecast Discussion