864 FXUS63 KMPX 151140 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 640 AM CDT Thu Aug 15 2019 .Updated for 12Z Aviation Discussion... Issued at 637 AM CDT Thu Aug 15 2019 && .SHORT TERM...(Today through Friday) Issued at 315 AM CDT Thu Aug 15 2019 Early this morning, a potent short wave was noted on regional satellite imagery across northern Montana, with embedded weaker waves across the Dakotas. Out ahead of these waves, instability is weak which will limit any type of convection until late this afternoon, and into the evening as moisture builds from the south. The aforementioned short wave across Montana will lead to strong lift ahead of it late this afternoon. This should create a widespread area of showers and thunderstorms across western Minnesota by late afternoon, and through the rest of central and southern Minnesota, as well as west central Wisconsin through Friday morning. The only concern is whether a stronger low level jet develops south of Minnesota this evening, and limits the amount of moisture advection across the state during the evening. Thus, will limit percentages to likely. Even if the low level jet sets up south of Minnesota, scattered showers and thunderstorms will still be possible across central/southern Minnesota as the associated short wave provides large scale lift. However, the heaviest precipitation will set up south of Minnesota. As for severe weather, the limiting factor will be weak mid level lapse rates, and only modest instability parameters. See the latest SPC Day 1 outlook which has a marginal risk in far western Minnesota, south of the Minnesota River today. Friday should be mostly dry as weak subsidence behind the short wave will limit large scale lift. However, I can't rule out an isolated storm as instability holds across the region. Temperatures will remain near or slightly below normal but still quite comfortable for mid August. .LONG TERM...(Friday night through Wednesday) Issued at 320 AM CDT Thu Aug 15 2019 This weekend remains questionable in terms of how widespread convection develops, or does most of the energy with the next short wave move south of the region and limit chances? The long wave pattern, and west/northwest flow aloft, remains conducive for at least small chances of precipitation over the weekend. I do believe parts of our region will get hit with another round of storms this weekend. But, timing and areal coverage is too problematic to have anything more than chance percentages. Another reason for uncertainty is that the best height falls will be north of Minnesota, and the low level jet looks to be forming south of Minnesota over the weekend. Past this weekend, building heights and an increasing cap at mid levels should begin to suppress convection across the Upper Midwest. The only concern is a developing low level jet at night which will lead to increasing convection along the nose of this jet. However, timing and where this jet develops 3 to 5 days out is nearly impossible. Currently, and based on a strengthening cap, I have lower percentages to slight or took the chance of precipitation completely out of the forecast. By late next week, height falls across the Pacific Northwest will break down the upper ridge over our region as it moves across the northern tier of the nation. This will increase the chances of precipitation and lower temperatures. Due to increasing thickness values and building heights next week, temperatures will average above normal. Normal temperatures next week are around 80 for highs and near 60 for lows. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 637 AM CDT Thu Aug 15 2019 VFR conditions with patchy fog at KRWF. Clouds will increase today and showers and thunderstorms will spread from west to east later this evening and overnight. Winds will be south at 5 to 10 kts. KMSP... VFR conditions. Clouds will increase today and showers and thunderstorms will spread from west to east later this evening and overnight. Winds will be south at 5 to 10 kts. The highest chance for thunder is after 00Z this evening. /OUTLOOK FOR KMSP/ Fri...VFR with MVFR/TSRA possible early. Wind S 5-10 kts. Sat...VFR with MVFR/TSRA possible. Wind SW 10 kts. Sun...VFR. Wind SW 10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...JLT LONG TERM...JLT AVIATION...JRB