992 FXUS63 KMPX 291934 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 234 PM CDT Sat Jun 29 2019 .SHORT TERM...(This evening through Sunday night) Issued at 235 PM CDT Sat Jun 29 2019 An impressive MCS moved across North Dakota, and into northwest Minnesota this afternoon. It continued to produce isolated severe wind gusts across eastern North Dakota through 2 pm. However, this complex was running into more stable air which should decrease the overall intensity and coverage as it moves eastward toward Duluth this afternoon. The main effect on our region was more cloud cover in central Minnesota which kept temperatures cooler than expected. However, dew points continued to rise in central/southern Minnesota which allowed for heat indices/WBGTs to rise into dangerous levels by this afternoon. This values will likely hold in the 90s, to around 100 through the early evening so the heat advisory will continue. As for reissuing the heat advisory for Sunday, there are still more problems with convection and cloud cover. So, have kept it below criteria. However, the excessive heat warning for the Twin Cities still looks valid based on overnight temperatures near 75 degrees, and values once again approaching 100 degrees Sunday afternoon. The main forecast concern is whether another complex of storms develops across North Dakota, and moves east/southeast across central Minnesota overnight, and into east central Minnesota/west central Wisconsin toward sunrise. The old ways of forecasting the southern extent of the MCV was using the 700MB temperature of +12 to +14C which is a good source for a strong cap in place. This parameter has done quite well this afternoon along the southern extent of the activity in northwest Minnesota. However, temperatures do drop to +10 to +12C in east central Minnesota, and west central Wisconsin tonight. This is where storms could follow this gradient as they redevelop across North Dakota, and move east/southeast into west central/central, and into east central Minnesota toward sunrise. The best potential of convection looks to be north of I-94 after midnight, and east of I-35 toward sunrise. Thus, the bulk of the activity will stay north of the Twin Cities. Far southern Minnesota will keep the strong cap which will inhibit convection until the frontal boundary moves into the region Sunday afternoon. Percentages are based on the evolution of the MCS overnight, and along the frontal boundary Sunday afternoon. As for Sunday night, the frontal boundary will hold near the region keeping high probabilities of precipitation in the forecast through early Monday morning. .LONG TERM...(Monday through Saturday) Issued at 235 PM CDT Sat Jun 29 2019 The weather pattern looks to stay active through the start of next week as the frontal boundary loiters across southern MN. Monday night and Tuesday brings the next chance for widespread showers and thunderstorms as mid-level shortwave energy comes into play. Given precipitable water values circa 2 inches and the potential for storms to train along the boundary, heavy rainfall and flooding will be of continued concern. Tuesday night through Wednesday the boundary sags south of the area, so this should be a dry time frame overall. Thursday and Friday become active again as an inverted trough noses into the area, and another shortwave passes. Confidence is still rather low on timing/placement however. Near to slightly above normal temperatures in the low to mid 80s are expected through most of the upcoming week, and then models trend toward cooler/drier high pressure of Canadian origin for next weekend. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1220 PM CDT Sat Jun 29 2019 Convection moving eastward across northwest Minnesota should hold north of MPX TAF sites through the afternoon. Concerns develop across west central Minnesota after sunset and KAXN could see TSRA as early as 3z, but more than likely it will be after 6z with a period of MVFR/IFR conditions. How far southeast these storms continue remain questionable, but I can't rule out any TSRA after 9z in central/east central Minnesota, and west central Wisconsin as these storms will likely move east/southeast along the moisture gradient overnight. IFR/MVFR cigs/vsbys are possible Sunday morning due to the proximity of the TSRA in east central Minnesota, and west central Wisconsin. Winds will remain from the south/southeast through this evening, and become northwest over the northwestern MPX TAF area by 12z. KMSP... Confidence remains high that any TSRA will hold off until after 9z, with the best time frame Sunday afternoon along the frontal boundary. As said before, I can't rule out any TSRA after 9z due to the proximity of the moisture gradient which will be across east central Minnesota Sunday morning. Any TSRA that develop will be capable of MVFR/IFR cigs/vsbys. /OUTLOOK FOR KMSP/ Sun night...VFR. Chc TSRA. Winds SW-W 5-10 kts. Mon-Tue...VFR. Chc MVFR/TSRA. Winds LGT and VRB. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...Heat Advisory until 9 PM CDT this evening for MNZ047-054>059- 064>067-073>077-082>084-091-092. Excessive Heat Warning until 9 PM CDT Sunday for MNZ060>063- 068>070. && $$ SHORT TERM...JLT LONG TERM...LS AVIATION...JLT