000 FXUS63 KABR 170433 AAB AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 1133 PM CDT Thu May 16 2024 .KEY MESSAGES... - Above average temperatures can be expected on Friday with highs in the 80s. A few locations may reach 90 degrees. - A frontal boundary crossing the area late Friday afternoon and Friday night will be the focus for a 40 to 70 percent chance (northern SD) for thunderstorms. Some may be severe across parts of central South Dakota, with gusty winds around 60 mph the main threat. - Strong west to northwest wind gusts between 30-45mph will be possible on Saturday. Highest probabilities for the strongest gusts are across our northern tier of counties along the ND border. && .UPDATE... Issued at 628 PM CDT Thu May 16 2024 Made some hourly tweaks to pops based on latest radar trends. Isolated to scattered thunderstorms will continue to move east across the northern cwa this evening. && .SHORT TERM /THIS EVENING THROUGH FRIDAY NIGHT/... Issued at 339 PM CDT Thu May 16 2024 Weak disturbance aloft passing across the Dakotas while at the surface, a boundary/wind shift is noted across western SD. We've seen a cumulus field develop across central SD over the past couple hours, with a couple towering/agitated areas across Corson/Dewey counties. We do have two weak cells showing up on radar (as of 3PM), with weak instability (500-1000 J/KG MLCAPE) and shear (~25kt 0-6km) in place. Mid-level lapse rates are modest, around 7 C/km. Latest HRRR runs do continue to show widely scattered activity across central SD over the next couple hours, and has taken a noticeable shift southward with potential activity, something to watch as current precip chances do not quite go that far south. Had already earlier this afternoon added 20% chances to north central SD as the cumulus field was growing and HRRR starting hinting at possible development. Previous forecast did not have things going until later in the afternoon and closer to 00Z. Really don't expect things to get out of hand, as severe parameters stay mostly in check through the evening, but would not be surprised to get some gusty winds over 40 mph with any stronger cores that develop. As we head into Friday, will be watching the arrival of a cold front into the western Dakotas by late afternoon/evening. Better upper level support as well, with only modest low-level moisture return. The strong cold front will provide good lift for convection though, and CAMs continue to show development reaching the western CWA around 00Z. Severe parameters show mostly a wind threat with any storms that move into central SD Friday evening, with steep lapse rates developing in a deeply mixed environment. Marginal risk (level 1 out of 5) continues to be in place across central SD as the front makes its way through the region during the evening hours. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 339 PM CDT Thu May 16 2024 This period will begin Saturday morning with a cold front departing east of our forecast area while sfc high pressure shifts south and east out of the Rockies and Northern High Plains toward Nebraska and Kansas during the day. Cooler and drier conditions will be setting in for the first half of the weekend. In addition, much stronger winds out of the west-northwest are expected on Saturday. With a tight pressure gradient in place, strong wind gusts in excess of 40 mph will be possible for some of our forecast zones. In fact, the EC ensemble data suggests the probabilities of wind gusts exceeding 40 mph is highest(40-50 percent) from north central SD eastward along our northern tier of counties along the ND border into the James Valley. NBM probabilities of gusts exceeding 40 mph are higher in these same locales on the order of a 70-95 percent range. So, this lends some confidence that windy conditions will be the feature of the day on Saturday. At this point, we would anticipate wind gusts will be somewhere in the range of 30-45mph. We'll have to watch trends over the next 24 hrs to see if a wind headline would be warranted. An unsettled pattern returns by early next week. A reinforcing mid level trough will shift into the western CONUS maintaining southwesterly flow aloft across our region. Deterministic and ensemble solutions prog a disturbance to shift northeast into parts of the Central and Northern Plains on Sunday into Monday. Shower and thunderstorm chances will be on the upswing Sunday into Sunday night. The western CONUS upper trough is progged by guidance to shift into the north central CONUS by the middle of next week. This will maintain our unsettled weather with more on again, off again chances for showers and storms through the end of the period. Temperature trends through this period should maintain near normal to slightly above normal values with overnight lows in the 40s and 50s and daytime highs in the 60s and 70s. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1131 PM CDT Thu May 16 2024 Terminals KABR,KATY,KPIR,KMBG VFR conditions are expected through Friday afternoon. Showers and thunderstorms will move into central SD Thursday evening. VCTS/TSRA may need to be added to KMBG after 0z Friday, but confidence in timing and extent is too low at this time to add a mention. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Wise SHORT TERM...TMT LONG TERM...Vipond AVIATION...Wise