


Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
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319 FXUS63 KUNR 242323 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 523 PM MDT Tue Jun 24 2025 .KEY MESSAGES... - Marginal risk (1 out of 5) of severe thunderstorms this afternoon/evening - Unsettled Wednesday with a marginal risk (1 out of 5) of severe thunderstorms - Warmer temperatures through Saturday, with at least a slight chance for storms each day && .UPDATE... Issued at 510 PM MDT Tue Jun 24 2025 Staunch capping and lack of sig forcing has greatly limited TS development today to just some positive theta-e elevated convection. Where clearing occurred back in WY, isolated storms have developed, but are struggling, likely fighting the same capping as they move off higher terrain. Still low probs for anything this afternoon/early evening and have cut pops and dropped severe wording. Perhaps slightly better chances tonight across the northwest third where a weak impulse will support elevated convection. Elsewhere, showers/storms will be limited in coverage. && .DISCUSSION...(This Evening Through Tuesday) Issued at 105 PM MDT Tue Jun 24 2025 Southwest flow continues over the northern plains, with a jet streak over the Four Corners region. The surface high has shifted into eastern ND, resulting in light easterly winds across our CWA. Satellite depicts persistent low clouds across northeastern WY and southwestern SD, keeping temperatures there cooler (in the 60s). This may inhibit some storm development, but as shortwave energy pushes into the region, a couple of elevated storms have developed above the low clouds. Latest model forecasts of MLCAPE are slightly lower than yesterday`s, but the shear forecast remains high. Forecast ingredients for tornadoes seem to line up better across northeastern WY, but surface-based storms may not be able to develop. A couple CAMs still show potentially strong storms moving through northeastern WY this afternoon, but a couple other CAMs are showing only weak showers, possibly due to the aforementioned low clouds. Nonetheless, much western SD remains fairly capped, so not expecting widespread severe storms there. Plentiful low-level moisture and easterly upslope winds may result in some patchy fog over the Black Hills and eastern foothills early Wednesday morning. Better buoyancy and good shear are expected again on Wednesday. Upper-level pattern would be messy, but models show a slightly stronger signal of a shortwave moving across northwestern SD, which may be a focus for some storms to develop. Warmer and mostly dry weather can be expected Thursday, although cannot rule out the chance for a stray thunderstorm, especially over the Black Hills. Strong southerly flow ahead of an approaching surface trough will bring in warm, moist air across the SD plains. MLCAPE in excess of 2000 J/kg is forecast, along with around 30 kts of 0-6 km shear. Storms may develop along the trough, with the potential for them to become severe. Whether the storms develop within our CWA will depend on the timing of the trough passage. Yet another shortwave moves through Saturday, and ingredients look sufficient for another round of strong to severe storms. Beyond that, models are hinting at an upper ridge developing. && .AVIATION...(For the 00Z TAFS Through 00Z Wednesday Evening) Issued At 510 PM MDT Tue Jun 24 2025 Easterly upslope flow will continue to promote IFR/MVFR CIGS over much of the area later tonight as the BL cools, with patchy fog as well. Storms will be possible late over the northwest third, with isolated activity elsewhere. IFR conds are certainly possible around KRAP Wed morning with upslope flow and a saturated BL in place. Better chance for storms Wed, esp from the BH east where coverage will be the highest. Expect conds to trend VFR by afternoon all places. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ UPDATE...JC DISCUSSION/KEY MESSAGES...Pojorlie AVIATION...JC