FXUS63 KUNR 271935 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 135 PM MDT Mon Oct 27 2025 .KEY MESSAGES... - Slowly clearing out overnight into Tuesday morning - Staying breezy Tuesday - Dry for the remainder of the week, with another cold front moving through Thursday && .DISCUSSION...(This Evening Through Monday) Issued at 131 PM MDT Mon Oct 27 2025 Latest water vapor imagery shows closed 500hpa low happily spinning across nrn Sask with long wave trough axis extending south toward 4-corners area. Another closed low is spinning across the KY/TN area well to the southeast of our area, with high pressure entrenched across the Great Lakes region. At the surface, a cold front is draped from just east of BIS to near DEN with low pressure located along the front in the vcnty of Eagle Butte. Light -shra are located along and behind the front, while -shra are also located in the warm sector ahead of the cold front across south central SD. At 18Z temps range from around 60F in the warm sector to the mid to upper 30s across northeast WY and the Black Hills. Main fcst concern is showers overnight and convective possibilities in the warm sector ahead of the cold front this evening. Visible sat pix show clear slot has established itself along the southern tier of counties in SD ahead of cold front...and now beginning to see initial development of cumulus field in the dry slot. HRRR is showing 850hpa-500hpa lapse rates > than 7C/km through 00Z along with showing minimal values, although non-zero, amounts of CAPE. As the cold air filters in behind the exiting sfc low/cold front, mid-level lapse rates also steepen across northeast WY. However, all of this being said, feel that by 00Z, most of the thunder threat will be over with just showers associated with the main 700hpa and 500hpa troughs as they push through this evening. Once the CWA gets on the backside of the main upper level troughs, downglide on the theta-e surfaces combined with a general drying trend seen in the RH values should ensure a general clearing trend overnight for much of the area from west to east. Winds will decouple overnight, but expect them to trend upwards during the morning hours on Tuesday. Things then look to remain dry and seasonable for the remainder of the week, short of another front that is progged to drop through the area during the day Thursday. Right now it appears that the only effect on the sensible weather will be another breezy northwest wind day and a slight drop in temperatures from the previous day. && .AVIATION...(For the 18Z TAFS Through 18Z Tuesday) Issued At 1113 AM MDT Mon Oct 27 2025 An area of low pressure is located in central SD with a cold front draped northeast to southwest through the dakotas. Scattered -shra will be found along and behind the front as it moves east through the region...along with MVFR cigs/vsbys in -shra/br. Pockets of light snow are possible in the higher elevations of the Black Hills. Gusty NW winds will also be found behind the front, where winds could gust to 35 kts. Conditions will improve overnight as drier air moves in from the northwest. It will be breezy again on Tuesday with NW winds gusting to 25 to 35 kts. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...Hintz AVIATION...Hintz