Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
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996 FXUS63 KUNR 051555 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 955 AM MDT Fri Jul 5 2024 .KEY MESSAGES... - Milder through Sunday with chances for thunderstorms - Hot/dry weather develops next week && .DISCUSSION...(Today Through Thursday) Issued at 109 AM MDT Fri Jul 5 2024 07z surface analysis had weak high over the CWA. Water vapour had upper low spinning over MN with weak shortwave over central WY, which is creating a small patch of showers/TS just southwest of the CWA per regional radar loop. Western CONUS upper ridge continues with northwest flow over southwest Canada into the northern Plains - our main weather maker through the weekend. Today through Sunday, a series of weak shortwaves will slide through the northern Plains. The first wave arrives late this afternoon/evening, second later Saturday, and third early Sunday. Buoyancy/shear today and Sunday not conducive to active convection. But for Saturday, HREF suggests 0.5-1KJ/kg SBCAPE with 35-45kt 0-6km bulk shear over southern SD may support isolated severe thunderstorms. Have painted slight chance/chance pops to reflect thoughts. Temperatures will be near guidance. Next week, high confidence that western CONUS upper/thermal ridge builds from the Rockies into the plains. Result will be significantly warmer/drier and eventually hot temperatures. Probability of 90F+ highs >75% by the end of the week for most of the CWA. Some 100F readings expected. && .AVIATION...(For the 18Z TAFS Through 18Z Saturday) Issued At 952 AM MDT Fri Jul 5 2024 Scattered TSRA/SHRA with associated LCL MVFR conditions are expected to develop through this afternoon and evening. Otherwise, VFR conditions expected through the TAF period. && .FIRE WEATHER... Issued At 109 AM MDT Fri Jul 5 2024 Confidence is high that a pattern change next week will result in increasingly hot weather. Minimum afternoon relative humidities in the 20s will be common by Wednesday, with some teens over northeastern WY/far southwest SD. Elevated fire weather conditions are expected. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...Helgeson AVIATION...Wong FIRE WEATHER...Helgeson