Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
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750 FXUS63 KUNR 190823 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 223 AM MDT Sun May 19 2024 .KEY MESSAGES... - Warmer today. Strong to severe thunderstorms this afternoon and evening across western South Dakota. - Widespread showers/thunderstorms late Monday/Monday night. Locally heavy rain south central South Dakota - Active pattern continues through the end of the week into the weekend. && .DISCUSSION...(Today Through Saturday) Issued at 219 AM MDT Sun May 19 2024 Current surface map places high across the eastern Dakotas with weak low across Wyoming. Scattered showers/isolated thunderstorms continue in area of theta-e advection across far northwestern South Dakota. This activity shifts eastward by daybreak, with potential for second area of development early this morning across south central South Dakota. Focus turns to thunderstorm development this afternoon/evening. Lead impulse ejects from upper trough over the Rockies...tracking through the Northern Plains this afternoon into this evening. Surface low deepens over the Central Plains with inverted trough into western South Dakota. Low level moisture and steep mid level lapse rates result in MLCAPE 0f 1000-2000J/KG across western South Dakota. Scattered thunderstorms will develop around the Black Hills early this afternoon and spread eastward this afternoon/evening. Sufficient shear for a few supercells with large hail threat. Storms should become more linear with severe wind threat increasing. Stronger shortwave exits upper trough late Monday/Monday night, moving through Nebraska into eastern South Dakota/Southern Minnesota. This will bring widespread showers/scattered thunderstorms to the southern half of the forecast area. Locally heavy rain possible across south central South Dakota with LREF 60-80% probability of rainfall amounts >1.00" and 30-40% probability of amounts >2.00". Active pattern continues through the remainder of the week series of troughs move through the Rockies into the Northern/Central Plains. && .AVIATION...(For the 06Z TAFS Through 06Z Sunday Night) Issued At 1023 PM MDT Sat May 18 2024 VFR conditions are expected through most of the TAF period. Isolated late night high based showers and thunderstorms will be possible toward central SD. Otherwise, another low pressure system will cross the region Sunday and support breezy winds and scattered afternoon showers and thunderstorms, mainly across SD. Local MVFR conds and gusty winds will be possible INVOF TS. A cold front will move through the region Sunday afternoon, with gusty NW winds developing behind the front. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...7 AVIATION...JC