NWS Forecast Discussion
664 FXUS63 KMPX 291949 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 249 PM CDT Fri Aug 29 2025 .KEY MESSAGES... - Mostly dry conditions expected through Labor Day, with a lower end chance for a few isolated storms this this evening through Sunday. - Best chance for organized precipitation comes with a cold front Tuesday night into Wednesday. - Mild, near-normal temperatures will persist through Tuesday, then noticeably cooler behind the cold front for the latter half of next week. && .DISCUSSION... Issued at 243 PM CDT Fri Aug 29 2025 Residual cloud cover from this morning`s rainfall across western Wisconsin slowly erodes this afternoon and is expected to allow for some partial sunshine later this evening as subsidence moves in from our northeast. Visible satellite shows two boundaries that are located to our northeast and southwest. The source of the diurnal cu field across southwestern MN is from a remnant stationary boundary where the other is a weakening wave to our northeast. The weakening wave is expected to continue moving southward this evening and expected to converge with the residual stationary boundary. With latest CAM guidance, any sort of convective behavior that does occur is expected along a line from Alexandria down to Rochester. Coverage once again to remains isolated to scattered at best hence 30-40% PoPs. Any area that does manage to see rain may hear a few rumbles of thunder given ~500 to 1000 J/kg of instability, although limited shear, severe storms are not expected but a funnel cloud or two cannot be ruled out. Lows tonight will range in the 50s across western WI and near 60 across western MN. For Labor Day weekend, surface high pressure will maintain its strength over the Great Lakes Region which will help redirect a mid-level wave that will be slowly moving across South Dakota and then eventually into Iowa. The good news with this system is that with its current track, the best moisture support and forcing are kept to our southwest. However, did maintain slight chance PoPs across southwestern and southern MN for any isolated showers or thunder that could develop. Rainfall accumulations overall look to be less than a tenth of an inch with a few isolated higher amounts from stronger cells. Temperatures through Labor Day will continue to range in the upper 70s for highs and lows in the 50s. Looking towards the middle of next week, the forecast remains on track for low pressure to sink in from the north Tuesday into Wednesday. ECMWF and the Canadian ensemble guidance going more aggressive with cooler temps as compared to the GFS but the takeaway here is that temperatures will be noticeably cooler on Wednesday as highs will only reach the lower 60s. Stronger CAA will keep temps potentially cooler through Thursday and Friday before h85 ridging will aid in temperatures rebounding back to normal values by the following weekend. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1203 PM CDT Fri Aug 29 2025 The two main considerations for the TAF period are how to handle isolated -TS chances from roughly 21-03z and also BR overnight. Generally, -TS chances will be maximized for MKT after 22z as the boundary slides south of the Twin Cities, with a low but non-zero chance for -TSRA at MSP for a 1 to 2 hour window. BR becomes most likely after 07-09z lingering through 14-15z, with the chance for MVFR/IFR highest for RNH/EAU. KMSP...The prob30 window for -TSRA is realistically more of a prob15 as the likelihood seems fairly low given the suite of CAM guidance, with the most likely scenario being -TSRA forming south and west of the Twin Cities and continuing to move south with the boundary. A brief window of MVFR due to BR is possible overnight, however being radiation driven fog we likely remain VFR the majority of the time given the heat island. /OUTLOOK FOR KMSP/ SUN...VFR. Wind SE 5kts. MON...VFR, chc -TSRA/MVFR PM. Wind S 5kts. TUE...VFR, chc -TSRA/MVFR PM. Wind SW 5-10kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...Dunleavy AVIATION...TDH
NWS MPX Office Area Forecast Discussion