960 FXUS63 KUNR 121122 AFDUNRArea Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 522 AM MDT Fri Sep 12 2025
.KEY MESSAGES...
- Unsettled weather heading through the weekend
- Above normal temps to begin the weekend with a cooling temps after the first of next week.
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.DISCUSSION...(Today Through Thursday) Issued at 220 AM MDT Fri Sep 12 2025
Latest satellite imagery shows 500hpa ridge axis nosing up through central MN with western CONUS trough continuing to deepen across the ID/NV areas. SW flow aloft continues to bring ejecting waves out of the 500hpa trough over the CWA. At the surface, low pressure is located in SW SD with an inverted sfc trof poking northeast through central SD and into central ND. All that is left from earlier convection is some light -shra across northern Harding and Perkins counties that will lift into ND shortly.
Pcpn chances will remain across the region as impulses continue to lift northeast through the CWA in SW flow aloft. 700Hpa theta-e forcing returns to our WY counties and the Black Hills area by 21z this afternoon, and continues along and north of I-90 through 06z Saturday. Noted that ensembles are showing probabilities of getting over 1 of rain by 06z Saturday from 20-30% across much of this forcing area, which lines up well with PWATS running 150-200% above normal as well. As dry as things have been the past couple of weeks...flooding isnt a concern, but there could some locally heavy rain with some of the stronger storms later this afternoon and into the evening.
As the upper trof approaches the region Saturday and Sunday, expect widespread cloudiness with Sunday being the cooler and rainier day of the two. As the 500hpa trough exits the region for Monday, expect a brief warmup ahead of the next trough that will move into the central plains for Tuesday and Wednesday. This should result in cooler temps along with another shot of precipitation. However, given blocking flow aloft, exact timing and location remain uncertain.
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.AVIATION...(For the 12Z TAFS Through 12Z Saturday Morning) Issued At 520 AM MDT Fri Sep 12 2025
Isold showers and thunderstorms are expected to develop later this afternoon and evening across the Black Hills region, with local MVFR cigs/vsbys possible with some of the stronger storms. otherwise VFR conditions are expected for the vast majority of the region through the valid forecast period.
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.UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. &&
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DISCUSSION/KEY MESSAGES...Hintz AVIATION...Hintz
NWS UNR Office Area Forecast Discussion