Area Forecast Discussion
Issued by NWS Rapid City, SD
Issued by NWS Rapid City, SD
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452 FXUS63 KUNR 042306 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 506 PM MDT Sat May 4 2024 .KEY MESSAGES... -Becoming windy Sunday. -Strong storm lifts into Northern Plains Monday/Tuesday; Thunderstorms late Sunday/Monday, windy Tuesday/Wednesday, some snow for the higher Black Hills Monday night-Thurs. && .DISCUSSION...(This Evening Through Saturday) Issued at 148 PM MDT Sat May 4 2024 Deep upper low is moving onshore in the western CONUS and will provide windy and unsettled weather for most of next week starting Sunday night. Sfc high pressure is shifting SE as pressure falls ensue this afternoon per the approaching massive closed upper low in the western CONUS. Winds will begin to increase from the SE tonight, with some accentuated flow downwind the Pine Ridge in SW SD where a few gusts over 40 mph will be possible late tonight. Strong western CONUS upper trough will then shift east into the Rockies and support continued pressure falls over the region Sun. This will force increasing SE winds, becoming quite breezy by afternoon across the western SD plains where adv winds are expected. Have issued a wind adv given expected sustained winds of 30 to 35 mph, with gusts over 50 possible at times in the afternoon. Winds will taper off some most places in the evening, but may persist/increase downwind the Pine Ridge Sunday night. Pos theta-e adv with a weakening cap will allow for a thunderstorm or two over NE WY in the late afternoon, with convection developing and shifting NE across NE WY and far western SD Sunday night. Increased chances for more widespread showers Sunday night with the main moisture surge and WAA, although the best chances will be across mainly NW SD. Strong storm system will then move into the plains Monday, with the sfc trough/dryline shifting east across southwest through scentral SD. Model trends suggest that the severe threat will remain south and east of the FA, although gusty winds are likely along the sfc trough which may spawn some weak convection across scentral SD. Further west, deformation rains will spread into the region along with gusty westerly winds. Adv 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 there. As the upper low stalls and then slowly migrates east, winds, rain showers, and cool weather will persist through Wed night, with near warning level winds Tues across NW SD as dry slotting interacts with fast flow aloft through diurnal mixing. 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 still looks to be Tue night into Wed when colder air advects into the region, with snow lingering into Thur. Things will begin to slowly warm up and dry out toward next weekend as the upper low finally exits the region and a ridge of high pressure builds across the western CONUS. && .AVIATION...(For the 00Z TAFS Through 00Z Sunday Evening) Issued At 505 PM MDT Sat May 4 2024 VFR conditions will persist through the TAF period. Some low- level wind shear may develop after 06Z Sunday morning, especially over the foothills and western SD plains. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory from noon MDT /1 PM CDT/ to 11 PM MDT /midnight CDT/ Sunday for SDZ001-002-012>014-030>032-042>044-046-047- 049-073-075>078. WY...None. && $$ DISCUSSION/KEY MESSAGES...JC AVIATION...SE