949 FXUS63 KUNR 141927 AFDUNRArea Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 127 PM MDT Sun Sep 14 2025
.KEY MESSAGES...
- Pockets of moderate to heavy rain mainly east of the Black Hills, will tapper off this evening.
- Dry and warmer conditions Monday.
- Cooler and unsettled weather returns by mid-week.
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.DISCUSSION...(This Evening Through Sunday) Issued at 1242 PM MDT Sun Sep 14 2025
Latest satellite and surface analysis (1:13 PM MDT) shows a weakening 500mb closed low lifting northeast across the central plains with an abundant amounts of moisture streaming into central and eastern South Dakota. Radar imagery confirms scattered light to moderate rain across the eastern half of the CWA.
Cloud cover remains extensive across much of western South Dakota but further to the west across eastern Wyoming 700mb theta-e subsidence is beginning to erode cloud decks from west to east, and this trend will continue into the evening. This will also mean that a gradual end to ongoing precipitation is expected by the evening across much of western South Dakota with lowered PoPs down to around 20%.
Upper-level ridging builds in with warming 850mb temperatures jumping to around 20 Celsius. Highs on Monday will warm, especially across southwestern South Dakota where ensemble guidance is showing highs could exceed 85F. The dry and warm conditions will be short lived as another 500mb trough moves across the Pacific Northwest and will continue to deepen as it moves inland. Increasing cloud cover with the return of precipitation is expected by Tuesday night. NBM probabilities increase PoP chances across the region for Wednesday and Thursday with 40-60% chances for rain. Temperatures will also trend cooler with temperatures retreating back into the upper 60s to low 70s for much of mid-week onward.
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.AVIATION...(For the 18Z TAFS Through 18Z Monday) Issued At 1122 AM MDT Sun Sep 14 2025
MVFR conditions will continue at RAP through around 20Z. VFR conditions are then expected to prevail through across the airspace. Isolated showers will impact RAP through 01Z, aided by a frontal movement. Northeast winds will shift south/southwest this evening behind showers.
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.UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. &&
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DISCUSSION/KEY MESSAGES...Woodward AVIATION...Herdliska
NWS UNR Office Area Forecast Discussion