492 FXUS63 KMPX 312318 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 618 PM CDT Sat Aug 31 2019 .UPDATE... Issued at 617 PM CDT Sat Aug 31 2019 Updated to include 00Z aviation discussion below. && .SHORT TERM...(This evening through Sunday night) Issued at 232 PM CDT Sat Aug 31 2019 A weak shortwave trough was moving across the Upper Midwest, and that meant clouds for most locations across the southern half of Minnesota and Wisconsin. There were a few light rain showers scattered about as well, but overall it was mainly just some sprinkles for locations north of I-90, and nothing for locations north of I-94. On Sunday another shortwave trough will move across the region, only this time a bit farther north. This will keep more small chances for rain for parts of the forecast area. Forecast soundings show little in the way of instability, so do not have any thunder mentioned for Sunday. Temperatures tomorrow afternoon will be a bit more mild than today as warm air advection overspreads the region. .LONG TERM...(Monday through Saturday) Issued at 232 PM CDT Sat Aug 31 2019 Overall the threat for severe weather continues for Monday night, but it does appear that the higher likelihood is generally north of I-94. Can't rule out that storms will develop in eastern North Dakota and dive south east along the CAPE gradient. Cooler weather will follow for the rest of the week. The main thing that is different between today's model runs and yesterday's model runs is the orientation of the shortwave trough that is forecast to move along the international border. If this wave takes on a more positive tilt, then the downstream ascent and low level convergence along the cold front will be less, and probably not enough to break through the capping inversion that will be in place across the warm sector. If this wave takes on a more neutral and negative tilt, then the forcing will be stronger, and we will be more likely to develop storms across the forecast area. These storms will have several thousand J/kg of MUCAPE, and also a more favorable shear profile meaning the potential for severe weather. Compared to yesterday's run, the models seem to be trending toward a more positive tilt which would decrease the overall threat for storms over the forecast area. A good proxy for this is the fact that the surface low isn't deepening as fast on today's model runs as it did yesterday. As mentioned earlier, can't latch on to one particular solution so the Day3 slight risk of severe weather still holds true across the region. Looking ahead, confidence beyond Wednesday is a on the lower side of the spectrum, so did not make any changes to the blended forecast. Overall the rest of the week looks dry, with another chance for rain toward the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 617 PM CDT Sat Aug 31 2019 VFR conditions will prevail through most of the period, although some MVFR conditions could occur late Sunday morning into the afternoon. The surface high to our east will continue to move away and warm advection will result in extensive mid/high clouds tonight into Sunday. A weak surface trough will try to push through on Sunday leading to an increase in lower clouds, with some MVFR conditions possible along with a few sprinkles. Stayed somewhat optimistic on ceilings for now and left out any precipitation mention, but those things will need to be watched. Winds will generally veer through the period and remain light. KMSP...Main issue of uncertainty/concern is the timing and height of lower ceilings on Sunday. Timing could vary by a few hours from what is indicated, and it's possible ceilings could briefly get down to near 020. /OUTLOOK FOR KMSP/ Sunday overnight...VFR. Calm wind. Monday...VFR. Variable wind less than 5 kt becoming southeast 10 to 15 kt. Monday night...MVFR possible with a chance of showers and thunderstorms. Southeast wind 10 to 20 kt shifting west. Tuesday...MVFR possible early. West wind 15 to 25 kt becoming northwest. Tuesday night...VFR. Northwest wind 15 to 25 kt decreasing to around 10 kt and becoming north. Wednesday...VFR. North wind 5 kt or less. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ UPDATE... SHORT TERM...JRB LONG TERM...JRB AVIATION...