766 FXUS63 KUNR 091723 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 1123 AM MDT Tue Oct 9 2018 .DISCUSSION...(Today Through Monday) Issued at 413 AM MDT Tue Oct 9 2018 Current upper level analysis has large trof across the western CONUS with strong shortwave ejecting out of the base of the trof across northern Texas, and another shortwave entering the trof across the Pacific Northwest. Weaker upper shortwave is now exiting the area to the north with abundant cloud cover across the Northern Plains. Light snow is also exiting the area to the north. At the surface, high pressure still resides across the Dakotas with light north to northeast boundary layer flow. Temperatures at 4am are in the upper 20s to lower 30s. Current upper shortwave is exiting the area to the north, with light snow winding down across northwest South Dakota. Weak upper energy will keep abundant cloud cover around for much of the day along with areas of light snow. Next shortwave to the south of the area will move north through central SD late today and tonight. Precipitation will begin as rain late this afternoon, but change over to snow by mid evening. Several inches of snow can be expected across south central SD tonight, with snowfall totals expected to mostly be in the 3 to 5 inch range, with 2 to 4 inches further north across Haakon and Ziebach counties. Lows will generally be in the upper 20s to lower 30s. Breezy northwest winds are expected overnight, with the visibility reduced to less than one half mile at times across central SD. A Winter Weather Advisory has been issued for this area from this evening through Wednesday morning. This storm system will exit the area Wednesday morning, with skies remaining mostly cloudy. High temperatures remain very cold for this time of the year, in the 30s. Low temperatures Wednesday night will fall into the upper teens and 20s. Thursday and Friday look to be mainly dry, but it will remain cool. The only chances for any light pcpn will be across south central SD late Thursday night. Highs on Thursday will be in the mid 30s to mid 40s, warming to the 40s to lower 50s on Friday. Previous model runs were showing a warm up for the weekend, but latest guidance has another strong shortwave dropping out of Canada with a strong cold front moving through the Northern Plains early Saturday morning. This latest model solution will keep the weather unsettled and cold across the area for the weekend. && .AVIATION...(For the 18Z TAFS Through 18Z Wednesday) Issued At 1120 AM MDT Tue Oct 9 2018 Widespread IFR/Areas LIFR conditions will continue through tonight. Another disturbance will bring -SN to mainly western and central SD tonight into Wednesday morning. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Winter Weather Advisory from 6 PM MDT /7 PM CDT/ this evening to noon MDT /1 PM CDT/ Wednesday for SDZ014-032-043-044-046- 047-049. WY...None. && $$ DISCUSSION...15 AVIATION...10