135 FXUS63 KMPX 110358 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1058 PM CDT Sun Aug 10 2025 .KEY MESSAGES... - Wildfire smoke moves back in tonight and Monday. - Increasing signal for the potential for a few rounds of heavy rain starting Wednesday night and continuing into early the following week as a frontal boundary gets hung up over the region. && .DISCUSSION... Issued at 243 PM CDT Sun Aug 10 2025 RAP h5 analysis shows a longwave trough in place this afternoon from a low over western Hudson Bay, back southwest into Colorado. The primary warm sector and deep tropical moisture is off over eastern WI back into MO. With that said, SPC mesoanalysis does highlight a very weak surface boundary that stretches from Fairmont, northeast through the Twin Cities and up to the Bayfield peninsula. The RAP based mesoanalysis has shown 2000 j/kg of sbCAPE along this boundary, with the HRRR showing the potential for some isolated showers developing along it this afternoon. The main limiting factor for seeing deep convection though is the lack of convergence along the boundary, with light west winds behind the front running into calm winds east of the surface theta-e gradient. Any showers that do develop will quickly diminish with the setting sun, with the only concern for tonight being the possibility for more patchy fog, mainly for eastern MN and western WI where high surface dewpoints will remain in place. For Monday, the weather would be spectacular, if it wasn`t for the wildfire smoke. Visible satellite along with visibility observations shows a pretty dense area of surface based smoke over the Dakotas which will drift into MN overnight into Monday, with the AQA still in effect for that reason. Aloft, we`ll see a strong shortwave swing across southern Canada within the mean longwave trough. This will allow a surface cold front to develop in the Dakotas Monday afternoon, that will swing through the MPX area Monday evening/night. Given the timing of the front coming well after peak heating Monday afternoon, and the better vorticity advection at h5 going across northern MN, this front looks to produce spotty light showers at best this far south. Behind this front, we`ll get dry weather Tue and Wednesday as a surface high moves through. However, the active weather looks to get going again Wednesday night as a LLJ and associated warm front move into western MN. As this warm front arrives, we`ll see upper ridging build across the central CONUS, with not much forcing aloft to push this front anywhere, with this front likely to be bouncing around the region through the end of the upcoming week and into early the following week. This far out, it`s hard to pinpoint where/when individual waves and the front will be on a daily basis, but the large scale pattern looks to support the potential for heavy rainfall via multiple rounds of showers and storms. Something to keep a close eye on as we go through the week and start to gain a bit more confidence in the details. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1058 PM CDT Sun Aug 10 2025 There are still two main concerns. One is another round of early morning fog in central and eastern MN and western WI. The most significant fog should be in KEAU. The other issue is that it is looking likely that there will be some reduced visibility on Monday due to incoming smoke. The area of surface or near surface smoke has been very slow to move east, owing to light winds. There have been some locales in central/eastern ND and central SD with IFR visibility, and even some in eastern SD. Will indicate MVFR visibility from smoke for our western sites starting around sunrise, then gradually moving east. It may not reach western WI until late Monday. Otherwise, dry weather is expected through Monday evening with winds under 10 knots. KMSP...Ground fog still looks likely, developing just prior to the Monday morning push. Have advertised MVFR at this point but IFR visibility still cannot be ruled out. Also have added 6SM in smoke by late morning Monday, based on observations in the Dakotas and forecast trajectories. /OUTLOOK FOR KMSP/ TUE...VFR. Wind SW 5-15 kts bcmg NW. WED...VFR. Wind NW 5-10 kts bcmg S. THU...VFR. Wind SE 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...MPG AVIATION...TDK