Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
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385 FXUS63 KUNR 032245 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 445 PM MDT Fri May 3 2024 .KEY MESSAGES... -Rain shifting east out of the forecast area this evening. -Warmer and breezy this weekend. -Strong storm system early next week with the potential for several hazards: locally heavy rain Monday/Tuesday (northeastern Wyoming/northwestern South Dakota), high winds Tuesday/Wednesday, some snow for the Black Hills Tuesday/Wednesday. && .DISCUSSION...(This Evening Through Friday) Issued at 144 PM MDT Fri May 3 2024 Cold upper low across southern Canada continues to lift out of the region this afternoon. Southern periphery impulse along the stalled baroclinic zone has supported rain/snow across the southeast half today and will continue to shift ESE with the associated FGEN area. Expect rain to develop and shift SE across scentral SD this afternoon and taper off by evening. Skies will clear out across most places tonight with dry air spreading into the region. This will allow for a cool night with lows in the 20s/30s and some teens in the Black Hills. Warmer and dry Sat with highs generally in the 60s. Strong western CONUS upper trough will then shift east into the Rockies and support pressure falls over the region Sun. This will force increasing SE winds, becoming quite breezy by afternoon across the NW SD plains where adv winds are likely. Pos theta-e adv with a weakening cap may allow for a thunderstorm or two over NE WY in the afternoon. However, better chances for more widespread rains will arrive Sunday night with the main moisture surge and WAA. Strong storm system will then move onto the plains Monday, with the sfc trough/dryline shifting east across southwest through scentral SD. Current progs suggest that the severe threat will remain south and east of the FA, but if things slow down some, there may be a small window for severe weather across far scentral SD. Further west, deformation rains will spread into the region along with gusty NW winds. Adv to low end warning winds will be possible Monday across much of western SD, with the bulk of wind in NW SD. However, rains may limit mixing and gust potentials. As the upper low stalls and then slowly migrates east, winds, rain, and cool weather will persist through Wed night. Rain will change to snow in the higher elevations of the Black Hills Monday night with some light accums possible. However, the better chance for snow accums looks to be Tue night into Wed when colder air advects into the region. Things will begin to slowly warm up and dry out toward next weekend as the upper low finally exits the region. && .AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening) Issued At 439 PM MDT Fri May 3 2024 Showers are slowly moving out of southwestern and south central SD and will continue to exit the forecast area from west to east through 06z. Locally MVFR/IFR conditions associated with this precip can be expected in southwestern and south central SD, especially near the stronger showers. VFR conditions expected elsewhere in the forecast area. Gradual improvement to VFR area wide will occur overnight and persist through the TAF period. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION/KEY MESSAGES...JC AVIATION...Wong