562 FXUS63 KUNR 010515 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 1015 PM MST Mon Nov 30 2020 .UPDATE... Issued at 704 PM MST Mon Nov 30 2020 Breezy conds continue across portions of the nern WY plains this evening. Some stronger winds are also expanding to the Black Hills and foothills, particularly the northern foothills and southern to Hermosa foothills. Suspect stronger winds will persist across the southern/Hermosa foothills over the next several hours with sfc low progged to shift east, then southeast, of the hills while pressure rises associated with cold front approach. Downslope winds in these areas, coupled with dry prefrontal air mass, could produce occasional critical fire wx conds thru the night, though obs across the Black Hills indicate some modest cooling and moistening since the 00z UNR RAOB. RH will improve later in the night, particularly after the cold frontal passage around midnight. && .DISCUSSION...This Evening Through Monday Issued at 227 PM MST Mon Nov 30 2020 Upper ridge overhead will move east as an upper low crosses the northern US. Light snow showers are possible over northeastern WY and the northern Black Hills after midnight through Wed morning, with some snow showers possible over southwestern SD Tues night- Wed morning as the upper low deepens over the central Plains. A cold front will cross the area after midnight tonight, bringing strong northwest winds to the area during the day Tue. Forecast soundings show momentum transfer winds over 30kt reaching the surface over the SD plains, so will issue a wind advisory for the afternoon. Upper ridge builds after low moves away, with warm and dry conditions returning toward the end of the week. && .AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night) Issued At 1015 PM MST Mon Nov 30 2020 MVFR to IFR cigs and vsbys in SHSN will gradually overspread nern WY and the Black Hills late tonight into Tuesday AM behind a cold front. By the afternoon, these SHSN and associated reduced cigs/vsbys should be concentrated over the nrn Black Hills. Meanwhile, breezy NW winds will develop behind the front, increasing after daybreak. Gusts to 40-45 kt will be possible from late morning thru the afternoon, particularly over the far wrn SD plains. Winds will diminish after 00z Tuesday. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory from 10 AM to 5 PM MST Tuesday for SDZ001-002- 012>014-025-026-030>032-043-072-073. WY...None. && $$ Update...Sherburn DISCUSSION...55 AVIATION...Sherburn