078 FXUS63 KUNR 081109 AFDUNRArea Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 509 AM MDT Wed Oct 8 2025
.KEY MESSAGES...
-Mild and mostly dry the rest of the work week with temps above normal
-Breezy at times in the period, especially today toward central SD
-An upper level trough and cold front will bring chances for rain this weekend with cooler weather to start next week
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.DISCUSSION...(Today Through Tuesday) Issued at 108 AM MDT Wed Oct 8 2025
Upper low will stall in the Pac NW this week and support downstream ridging over the central CONUS. This will allow for mainly dry weather and above normal temps. Expect highs in the 70s and a few 80s the rest of the week. Southerly LLJ will develop today as a lee-side trough deepens, supporting breezy weather across the region. Near adv level winds are expected in scentral SD with winds gusting over 40 mph there. An upper trough will top the ridge and drop a weak backdoor cool front into the area Thurs. This will support a slightly cooler day Friday, esp over northeast areas, but temps will still be above normal. Monsoon moisture accentuated by a tropical system off the coast of Baja will get caught up in SW flow aloft and may support a few showers later in the day Friday and Friday night. Not expecting a whole lot with this system, but a few places may see a few hundredths. Pac NW upper trough will begin to shift east by this weekend, phasing with a deeper northern stream trough. This will allow for local shortwave ridging Sat, supporting the warmest day in the period as temps will climb into the 80s many places. It will also be breezy per south winds ahead of the expected cold front. Cold front will then move into the area by Sun, with increasing chances for showers Sat night into Sunday. Cooler and unsettled weather looks likely next week, with mean upper level troughing progged over the western and central CONUS. Confidence drops off wrt to details after Monday given model indications for potential flow blocking over both the east and west coasts per closed upper troughs.
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.AVIATION...(For the 12Z TAFS Through 12Z Thursday Morning) Issued At 507 AM MDT Wed Oct 8 2025
VFR conditions through the forecast period. Gusty southerly winds can be expected on the SD Plains today, with gusts over 35 knots possible, strongest toward central SD.
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.UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. &&
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DISCUSSION/KEY MESSAGES...JC AVIATION...JC
NWS UNR Office Area Forecast Discussion