518 FXUS63 KABR 120025 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 725 PM CDT Wed Jun 11 2025 .KEY MESSAGES... - Elevated smoke remains over the region with an intermittent return of near surface smoke and visibility reductions through Thursday. - Showers and thunderstorms expected Thursday through Friday morning, with the highest chances (60-90%) along and east of the Sisseton Hills Thursday afternoon and evening. - Heavy rain is possible with amounts of 1 to 2+", highest over far northeastern SD into west central MN Thursday through Friday. - There is a marginal risk (1 out of 5) for severe thunderstorms Thursday afternoon and evening along and east of a line from Fort Thompson to Webster. && .UPDATE... Issued at 725 PM CDT Wed Jun 11 2025 The ongoing forecast remains in good shape. A few tweaks were done to the near term chances of precipitation, limiting the potential over the next few hours over north central SD and slowing down the onset of precipitation over our southeastern counties in the next few hours. && .DISCUSSION... Issued at 310 PM CDT Wed Jun 11 2025 As of 3 pm radar indicates the last of the showers have exited our southeastern CWA with some spotty showers occurring over north central SD per the ongoing shortwave energy aloft. Smoke has been intermittent both at the surface and aloft today with visibility jumping between 5-9SM across KMBG, KABR, and KATY with haze reported at times on the ASOS. We will continue with this intermittent smoke tonight through Thursday, which may reduce visibilities at times. Zonal flow aloft continues through tonight with a shortwave just off to our west over MT/WY, and its 700mb low over MT by 06Z. At the surface, a stationary front/warm front sits just along the SD/NE border with a high stretching from northern ND through central MN at 00Z. Most of the area looks to remain dry through 06Z per the majority of the CAMs (maybe some isolated precip at most), however, NBM was a bit more bullish with precip surging northward over our southeastern CWA during this time. So I backed off the pops, and kept them more south, to match what the CAMs are showing. RAP seems to be the quickest on precip entering our western CWA with this shortwave compared to the other models so backed off pops here a bit too. So this may need to be adjusted if we see any changes. Through the day Thursday, the wave/low will continue to track northeast over the Northern Plains. The front to our south will finally lift northward as a warm front/inverted trough, with the northern fringe of this front over our far southeastern CWA with southeastern SD more within the warm sector by Thursday afternoon and evening. We really see surface to mid level moisture increase as 1000-500mb RH is up to to 80+% and widespread over the CWA by the afternoon from this shortwave/mid low and front surging northward. With this, CAMs indicates precip continuing to move in from the south and west and really increasing in coverage by the afternoon with widespread pops of 60-80% (excluding south central SD where pops are less) between 12Z Thursday-00Z Friday. Thursday evening into early Friday the cold front will sweep through eastern/southeastern SD with the center of the low over SD/MN border by 12Z Friday. The bulk of the precip will mainly be along and east of the James River, closer to the low with pops of 75-90%, highest along the SD/MN border between 00-12Z Friday. Precip will exit far northeastern SD/western MN through Friday morning/midday with overall dry weather expected the rest of the day. For Thursday afternoon and evening, the bulk of the MUCAPE (1000 j/kg-1500 j/kg) looks to stay south of our CWA with maybe up to 1000 j/kg over our far southern and southeastern CWA with values up 500 j/kg north of here with more of a skinny cape profile on soundings. Shear will run between 30-40kts out of the west over the entire CWA given the stronger mid/upper level winds. 2-5km UH>75m2s2 paintballs keep much of this stronger convection south of the CWA over southern to southeastern SD into Nebraska, however, HREF shows maybe some isolated organized convection surging a bit northward along and east of the Coteau with a 30-50% chance here. HREF 0-3KM SRH is up to 400- 500 m2s2 in this area with 0-1 SRH of 200 m2s2 over our southeastern CWA which would help aid in vigorous convection. A southwesterly LLJ will be also be over the eastern CWA aiding in lift/energy. So synoptic and meso features along with with dewpoints in the upper 50s and lower 60s and modest lapse rates, some storms could become severe along and south of this warm front. This is highlighted by the SPC with a marginal risk (1/5) for severe storms mainly east of a line from Fort Thompson through Webster. The main threats include large hail of 1" in diameter (stronger storms could produce larger hail) and wind gusts of 60mph. If we see more of a linear growth then winds could gusts to 70mph but this looks to mainly be more south. It is interesting to highlight on NAM soundings over the eastern/southeastern CWA some low level curvature to the hodograph (where we have this better 0-1km SRH), however, STP looks to remain under 1 per HREF. SPC did add a 2% tornado risk with the afternoon update mainly from Chamberlain through Webster and eastward. Discrete cells are possible especially along and south of the warm front in this area. We precip expected for an extended period of time through early Friday, along with the suggestion of training per CAMs, we will also be monitoring the potential for heavy rain/high rainfall rates. PWAT values will range from 1 to 1.25" east of the Missouri River which is about 1 standard deviation above climo, highest over east central SD with EC EFI highlighting 0.5 to 0.6 and a shift of tails of zero in this area. GFS IVT also highlights this increased moisture, south of the warm front, surging northward within this warm sector Thursday afternoon and evening. So this will need to be monitored closer to time. Latest WPC QPF highlights the possibility of 2" or more from Roberts and southward through Deuel Counties into west central MN Looking ahead, a ridge will be overhead for the weekend and breaking down as a -PNA pattern sets up early next week and weakening as it pushes east midweek. Several shortwaves and its surface features will bring periods of showers and thunderstorms Sunday through at least the middle of next week with this ongoing active weather pattern. && .AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 725 PM CDT Wed Jun 11 2025 Terminals KABR,KATY,KPIR,KMBG VFR conditions remain initially, with areas of smoke mainly set up near and north of MBG. Some of this smoke will move over ABR after 06Z. Otherwise we`re looking for showers and the potential for thunderstorms mainly overnight on at ATY and during the daytime hours elsewhere. Ceilings will deteriorate to MVFR and IFR as early as 09Z at PIR and between 12 and 16Z at MBG/ABR/ATY. While thunderstorms have been mentioned in PROB30 groups, we`ll continue to monitor the latest trends to see if they need to mentioned more predominantly at any locations (mainly ATY). && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...06 DISCUSSION...MMM AVIATION...06