463 FXUS63 KMPX 090409 AAC AFDMPX Area Forecast Discussion...UPDATED National Weather Service Twin Cities/Chanhassen MN 1109 PM CDT Wed May 8 2019 .UPDATE... Issued at 602 PM CDT Wed May 8 2019 Rain has transitioned to all snow in parts of central MN late this afternoon and accumulation has already begun. Numerous spinouts have been reported and roads are slick. With moderate to heavy snow continuing through the evening, it is quite likely we will see several inches of snow in this area, generally from Stearns Co. and northeast, although Montevideo has also dropped to 34 degrees and it may begin accumulating further southwest as well. The forecast was updated quickly to increase snow totals and to post a Winter Weather Advisory. While confidence is high now that snow will accumulate, how much so is still a question based on highly variable boundary layer conditions within this widespread precip band. We also have the mid level dry slot influencing the precip type across eastern MN into WI as well. Even if temps drop into the mid 30s there, lack of ice aloft may prevent much snow from falling. Will continue to monitor and expand the headlines as needed in the next couple hours. && .SHORT TERM...(This evening through Thursday night) Issued at 355 PM CDT Wed May 8 2019 Forecast concern near term is the possibility of accumulating snow across far northern CWA overnight. Then frost/freeze threat for Thursday night. Water vapor satellite imagery showing strong trough lifting northeast across eastern South Dakota/Nebraska region this afternoon. This trough is forecast to lift northeast over southern MN during the night exiting into western WI by Thursday morning. Strong FGEN associated with the trough and exiting northern stream jet focusing over the northern CWA into the evening. Dynamic cooling from the strong forcing will gradually change rain over the wet snow into the early evening across the north central area affecting Kanabec/Mille Lacs and Morrison Co. FB generated around 3 inches of snow over the northern portion of these counties overnight. It looks like the greatest accumulation threat will be this evening as the strongest FGEN moves through. We wont issue a headline for this at this time and watch evening developments. If surface temperatures cool faster, we could see more accumulation in those areas. The remainder of the region will see rain tapering after midnight and any mix or snow should also diminish to the west. Strong east/northeast winds will continue into the night as the surface system moves across southeast MN into WI. The trough exits into western WI Thursday morning and should end precipitation threat through 18z. Clouds will be slow to clear to the east with partial clearing to the west expected in the afternoon. Where sunshine occurs longest, afternoon temepratures should be able to warm into the 50s. Clouds will limit highs in the 40s to the far east. Clearing is expected into Thursday night. Clouds could linger longer into western WI and would limit significant freeze threat. Winds should diminish and with a clear sky, temperatures will approach freezing over the western CWA. Frost is also likely and will be monitored for possible frost headlines for Thursday night for portion of west central and central MN. .LONG TERM...(Friday through Wednesday) Issued at 355 PM CDT Wed May 8 2019 Skies will begin to clear out Thursday evening as cold high pressure settles over the region. With 850 mb temperatures of -2 to -3 C, lows Friday morning look to drop into the mid-upper 30s across the area with a few below-freezing readings possible across central Minnesota. As such, areas of frost look likely across much of the area outside of far-southern Minnesota and the Twin Cities metro. A cool but drier day is in store for Friday with highs around 60 under sunny skies. Our next chance for rain comes Saturday as a shortwave digs out of the canadian prairies. A surface low is forecast to spin up off to our north with a front extending off to the south into our area. Showers and a few thunderstorms are expected to develop along this front and track east across during the day. Instability and lapse rates overall look pretty marginal, but sufficient, for thunder so would expect any thunderstorms to remain fairly limited in coverage. The timing window for this activity should be fairly brief as the front progresses off to the east which will keep rainfall amounts for most areas to 0.25" or less. Beyond the weekend, ridging begins to build into the central Plains which will lead to an overall warmer and drier pattern as we head into the middle of the month. Before the ridge becomes anchored over the region, northwest flow aloft will bring a few impulses across the area with sporadic precipitation chances during the early part of next week. The best chance looks to come Monday night into Tuesday as a more organized shortwave develops, but the best forcing with this system looks to remain well off to our north. Temperatures are expected to return to more seasonable values Monday and Tuesday as warmer low-level SW flow develops with a broad region of high pressure off to the south. Slightly cooler temperatures are expected Wednesday behind a cold front, but how cool will depend largely on the strength of the Monday night/Tuesday system. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1109 PM CDT Wed May 8 2019 MVFR/IFR conditions tonight through Thursday morning with improvement from west to east in the afternoon. Rain expected southeast of MSP-MKT, with a mix of rain and snow or all snow northwest of that line for the rest of the night. Intensity should taper off overnight. KMSP...Light snow and drizzle will continue for much of the overnight. Clouds will lift slowly from IFR levels overnight to MVFR Thursday morning and then VFR by late afternoon. /OUTLOOK FOR KMSP/ Fri...VFR. Wind W at 10 kts bcmg SW. Sat...VFR. Chance -SHRA. Wind SW 15G25 kts bcmg W/NW. Sun...VFR. Wind NW 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...Winter Weather Advisory until 7 AM CDT Thursday for MNZ042>045- 049>051. && $$ UPDATE...BORGHOFF SHORT TERM...DWE LONG TERM...ETA AVIATION...BORGHOFF