462 FXUS63 KUNR 132342 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 542 PM MDT Wed Mar 13 2024 .KEY MESSAGES... 204 PM MDT Wed Mar 13 2024 -Lower potential snow accumulations this aftn/tonight due to farther southwest track of weaker low pressure system -Splitting upper-trough brings windy and cooler weather tonight and Thursday -Dry weather returns with breezy/windy spots over the weekend && .DISCUSSION...(This Evening Through Wednesday) Issued at 204 PM MDT Wed Mar 13 2024 20Z analysis shows an upper trough to the west of the forecast area with a closed upper low dropping southward from Idaho into Utah. The surface low is centered over southwestern Kansas. Precipitation, mostly rain, has developed in the area of enhanced lift to the east of the upper low, over northeastern Wyoming and far western South Dakota. Some light rain is also moving northward out of Nebraska and into southwestern and south central south Dakota, but due to the relatively dry lower levels, much of what is being seen on radar is not reaching the ground. Due to the upper low track remaining farther to the southwest than previously indicated, have again lowered the potential snow accumulation for the rest of this afternoon and tonight, now with less than an inch over the northern Black Hills and an inch or two in the higher elevation areas of southwestern Campbell county. No snow accumulation is anticipated over the rest of the area. Breezy/windy conditions will develop tonight, and on Thursday, as the surface pressure gradient tightens. Northeasterly winds tonight may lead to gusty areas over the southern Black Hills and also on the plains adjacent to, and southeast of, the Black Hills into Thursday morning. During the day on Thursday, northerly wind gusts approaching 40 mph are possible over parts of western South Dakota, generally along, and to the south of, I-90. Breezy conditions are possible over much of the region on Friday, becoming windy over parts of northwestern South Dakota due to pressure falls over eastern North Dakota. Temperatures will be a little warmer on Friday, mainly in the 50s on the plains. A cold front associated with an upper trough dropping from Manitoba toward the Great Lakes will provide a glancing blow of cooler air to at least the SD side of the forecast area this weekend. Temperatures will rebound for the first half of next week as upper ridge builds over the western CONUS. && .AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening) Issued At 536 PM MDT Wed Mar 13 2024 Areas of MVFR/IFR conditions in SHRA/SN will expand across northeastern WY and the Black Hills region this evening. MVFR/IFR conditions are expected to persist into the morning hours, mainly north of I-90 in SD through much of northeast WY. VFR conditions will return through the day tomorrow. Gusty north winds will also develop tomorrow across the western SD plains. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...10 AVIATION...13