Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
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313 FXUS63 KUNR 310848 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 248 AM MDT Fri May 31 2024 .KEY MESSAGES... - Cooler and showery weather for much of the area today. - Warmer over the weekend with daily chances for showers and thunderstorms. Some storms could be strong to severe. - Warm weather expected for much of next week with drier conditions mid to late week. && .DISCUSSION...(Today Through Thursday) Issued at 248 AM MDT Fri May 31 2024 Current surface analysis shows cold front just south and east of the forecast area, with weak high pressure over WY. Upper level analysis shows low over south central Canada, with trough extending southward into the northern and central Plains. Weak disturbance moving through the area is bringing showers to portions of northeast WY and western SD. Temps are cool, mostly 40s and lower 50s, with light west to northwest winds. Near zonal flow aloft over the next several days will keep the weather unsettled at times as embedded weak disturbances cross the region. Current shower activity will persist through the morning hours, mainly from the Black Hills area into southwest and south central SD, with activity starting to taper off during the midday and afternoon. There could be some thunder later this morning into the afternoon, but forecast CAPE is minimal today across our area. Highs will stay on the cooler side today, 60s and lower 70s, with some 50s across the higher Black Hills. Another cooler night expected with lows mostly in the 40s early Saturday. A few showers/storms could clip far southern SD late tonight as modest Theta-e advection develops over NE. Warm advection aloft starts to take place later tonight and especially on Saturday as trough shifts east-northeast of the region. Saturday will see highs in the 70s to near 80 degrees, with 80s to the south and east of the Black Hills on Sunday. Developing south to southeast winds will bring increasing low level moisture into most of the area, especially east of the Black Hills. Main chances for a few storms later on Saturday look to be southeast of the Black Hills and especially into south central SD as surface trof sets up over the central high Plains and low level jet intensifies further to the east. MUCAPE values of 1000 to 2000 j/kg toward south central SD and moderate shear will increase potential for strong to marginally severe storms with hail and gusty winds. The better chances for more widespread showers and storms should be on Sunday as a cold front approaches the area. Timing of the front and associated energy aloft with determine where and when any stronger storms could develop, which is still uncertain right now. However, the better chances for stronger storms right now would look to be east of the Black Hills and especially toward central SD. Outlook for much of next week is still for seasonably mild to warm conditions. Upper level pattern during the first half of the week is more uncertain, with many ensemble solutions showing a shortwave trough crossing the northern Plains/south central Canada late Monday into Tuesday. Better chances for showers and storms would generally be from northeast WY to northwest SD during this time. Majority of model solutions have a building ridge over the western US and large trough covering the eastern US mid to late week. This would bring above average temperatures, 70s and 80s for highs most days, and mostly dry conditions for this time. && .AVIATION...(For the 06Z TAFS Through 06Z Friday Night) Issued At 1038 PM MDT Thu May 30 2024 Showers and isolated thunderstorms will continue to develop through the nighttime hours across portions of northeastern WY and western SD. This may result MVFR conditions, mainly near the Black Hills through Friday morning. Then drier air will return after 18z Friday, with VFR conditions again expected. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...26 AVIATION...13