740 FXUS63 KMPX 092020 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 320 PM CDT Tue Oct 9 2018 .SHORT TERM...(This evening through Wednesday) Issued at 320 PM CDT Tue Oct 9 2018 Main concern for the short term period remains rainfall and flood headline. Area of rain continues to expand northeast across the CWA. This trend will continue into the evening as the upper trough over Colorado/New Mexico lifts northeast. Forcing associated will drive a surface low from the Oklahoma panhandle are northeast toward northern Iowa by 12z Wed. Warm sector will lift north ahead of the low into southeast MN and western WI by Wednesday morning. Convection over Iowa will lift northeast tonight and should clip the southeast corner of MN into western WI during the night. PW's over 1.5 inches moves over the southeast and combined with the forcing with the upper low, we should see 1 to perhaps 3 inches of rainfall across the eastern portion of the CWA overnight. Still some question as to how far west the low track will be so we will leave the current Flood Watch configuration for now. We will continue the trend of categorical PoPs overnight. Temperatures will likely remain close to early evening values over much of the eastern CWA. We may even see reading rise a bit with the approach of the surface low over the far east. The surface low is forecast to occlude as the upstream trough lifts the system northeast. We may see a dry slot lift into southern MN Wednesday morning and may shut off significant precipitation. We mentioned the drizzle possibility for now. Strong northwest/west winds will develop in the wake of the low and will drive much colder air over the area during the afternoon. We will likely see a transition to at least a rain/snow mix into west central MN during the afternoon as temperatures fall to the lower 30s by late afternoon in the far west and through the 40s east. .LONG TERM...(Wednesday night through Tuesday) Issued at 320 PM CDT Tue Oct 9 2018 The surface low will depart over Lake Superior Wednesday night, with wraparound precipitation on the back side of the low lingering into Thursday morning. 850 mb temperatures well below zero along with near-freezing temperatures near the surface continue to suggest support a rain/snow mix is possible across central Minnesota and northwest Wisconsin. Little to no accumulation is expected with this mix, except along and north of an Ortonville to Mille Lacs line where up to an inch of slushy snow may accumulate on grassy surfaces. The real winter wonderland will exist further north where 6 inches or more of snow is possible across eastern North Dakota and northern Minnesota. As high pressure approaches from the northern plains, a tight pressure gradient will develop across the upper Midwest leading to a cold and blustery day Thursday. A thin but persistent layer of moisture below 850 mb will keep a stubborn layer of stratus over the upper Midwest, along with perhaps a few flurries during the day. The persistent cloud cover along with cold air advection will keep temperatures from rising much out of the 30s during the day. Normal highs for this time of October are around 60 degrees so these temperatures will be at least 20 degrees below normal. As high pressure becomes more established Thursday evening, skies will begin to clear and winds will diminish, leading to a chilly night with temperatures well below freezing down to the Iowa border. This will effectively put an end to the growing season for any areas that avoided a freeze earlier this month. Friday is shaping up to be a cool and quiet day, and may feature our first glimpse of the Sun since last week. Over the weekend, a clipper system passes Saturday night bringing with it another shot of Canadian air along with mentionable precipitation chances. It doesn't look like there will be much moisture to work with across our area so not expecting much precip, if any. Forecast soundings suggest another rain/snow mix early Sunday morning as the primary mode for any precipitation that does develop. Northwest flow aloft then develops on Monday and continues through the week, with the next potential system coming Monday night into Tuesday. temperatures look to remain below normal for mid- October. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1245 PM CDT Tue Oct 9 2018 IFR with LIFR conditions at times will continue. Heavier precipitation should develop later this afternoon into the overnight as widespread rain moves in with the developing surface low to the south. May even see some thunder later this evening. Highest threat of that will be to the east and included a prob30 for KEAU at this time. Winds will be northeasterly throughout, but should increase overnight and become more north/northwest into Wednesday morning, especially in western Minnesota. KMSP... IFR with LIFR conditions at times. May see a period of heavier precipitation this evening eventually tapering off into Wednesday morning. Northeast wind becoming more northwest into Wednesday afternoon with passage of surface low. /OUTLOOK FOR KMSP/ Thu...MVFR cigs. Wind NW 15G25 kts. Fri...VFR. Wind W 10G15 kts. Sat...VFR. Wind S at 15G20 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...Flood Watch through Wednesday morning for WIZ014>016-023>028. MN...Flood Watch through Wednesday morning for MNZ062-063-069-070- 076>078-083>085-091>093. && $$ SHORT TERM...DWE LONG TERM...ETA AVIATION...DWE