Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
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617 FXUS63 KUNR 301103 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 503 AM MDT Tue Apr 30 2024 .KEY MESSAGES... - Cold front today with scattered showers. Gusty northwest winds behind the front. - Cool and unsettled through Saturday. && .DISCUSSION...(Today Through Monday) Issued at 215 AM MDT Tue Apr 30 2024 Current surface map places low across southeastern Montana with cold front extending through eastern/central Wyoming. Showers are increasing in coverage across western South Dakota with an uptick in QG forcing as shortwave moves into eastern Wyoming. For today, shortwave moves through this morning, with most of the shower activity shifting east of the forecast area this afternoon. Steep lapse rates/marginally buoyancy may result in a few rumbles of thunder, mainly east of the Black Hills. Cold front moves into western South Dakota shortly after daybreak and through central South Dakota early this afternoon. 3mb/3hr pressure rises behind the front with modest cold advection will result in a period of gusty northwest winds. HREF paints 70-100% probability of wind gusts >40mph along and north of I-90. The peak in wind will come this morning with best pressure rises and stronger winds at the top of the mixed layer. Have issued a Wind Advisory for northwestern South Dakota extending east of the Black Hills along I-90. Upper low lingers across the southern Canadian Prairies through the end of the week with shortwaves rotating through the Northern Plains. Strongest impulses move through late Wednesday/early Thursday and on Friday. QPF amounts will generally be on the light side...though LREF 24-hour precipitation is showing 30-50% probability of >0.25" QPF on Thursday. Upper low eventually shifts east this weekend, allowing ridge to build over the plains as next trough digs over the western CONUS. Robust warm advection over the plains should push highs back into the 70s on Sunday/Monday. Overall, it will be drier over the weekend but there could be some terrain induced showers/thunderstorms around the Black Hills. && .AVIATION...(For the 12Z TAFS Through 12Z Wednesday Morning) Issued At 501 AM MDT Tue Apr 30 2024 A cold front will move through the area by 18z leaving gusty northwest winds (gusting around 40kts) in it`s wake through this afternoon, especially across northwest SD. A period of MVFR CIGS just behind the front over northeastern WY/northwest SD is expected this morning. Otherwise, VFR conditions will prevail. A few showers this morning associated with the front will wane this afternoon. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory until 6 PM MDT this evening for SDZ001-002-012>014- 031-032-073-078. WY...None. && $$ DISCUSSION/KEY MESSAGES...7 AVIATION...Helgeson