746 FXUS63 KMPX 201117 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 617 AM CDT Thu Jun 20 2019 .SHORT TERM...(Today through Friday) Issued at 453 AM CDT Thu Jun 20 2019 Light showers have already began to spread into western Minnesota this morning, with a widespread area of thunderstorms ongoing farther west across the central Dakotas into Nebraska. The shortwave responsible for kicking off this precipitation will continue to track east this morning. before shunting off to the north as it pivots around the base of a trough digging into the northern Rockies. This will rob these showers and thunderstorms of their upper level support as they spread east through the day, with the bulk of the activity expected to dissipate as it reaches the I-35 corridor later this afternoon. It'll rain across western and west- central Minnesota but continued the trend of having PoPs diminish to around 30-40% across eastern Minnesota as any remaining activity should be pretty well scattered. Precipitation amounts look to be fairly light with the upper level support weakening during the day, amounts of 0.25-0.5" are generally expected across western and west- central Minnesota Tonight looks fairly quiet as precipitation from earlier in the day totally dissipates, and 8a brief period of shortwave ridging builds into the region. A few spotty showers are possible overnight on the nose of a low-level jet and increasing warm-air advection, but at speeds of only 15-20 kts forcing does not look strong enough to generate off anything widespread. However, the LLJ really strengthens through the day on Friday in response to cyclogenesis over the northern plains, with a fairly strong cap building over the region by Friday afternoon. This cap will influence how early we may see another round of showers and thunderstorms tomorrow, as a second shortwave pivots around the trough. Guidance has trended stronger with the cap this evening with precipitation now likely holding off until Friday evening, if storms are even able to initiate this far north at all. The best instability is expected to remain south across NE/IA, but MUCAPES of 1000-2000 J/kg nosing up into western minnesota and 30-40 kts of effective bulk shear suggest at least a conditional thereat for severe weather from southern into western Minnesota. Temperatures will remain fairly steady today and tomorrow with highs in the mid-upper 70s and lows in the mid 50s to low 60s. Humidity will be noticeable on the rise however as dewpoints generally in the 50s today increase into the upper 50s and low 60s by tomorrow afternoon thanks to increasing southeasterly winds. Wind speeds will increase to 10-20 mph this afternoon and become even stronger on Friday with gusts up to 25-30 mph expected. .LONG TERM...(Friday night through Wednesday) Issued at 335 AM CDT Thu Jun 20 2019 The occluded front will slowly push east Friday night and could stall over eastern MN Saturday and Saturday night as a secondary low pressure tracks northeast along it. Showers and thunderstorms across western MN Friday will build east with the front Friday night and Saturday. The severe threat by Friday night should be waning as the activity pushes into increasing heights. The very impressive EML to the south will lift north some Saturday, along with the secondary low by Saturday night. This could rejuvenate some convection across southern MN into WI, but extensive cloud cover should limit that potential. Another low ejecting from the trough over the western U.S. will pass to the southeast of the area Sunday night into Monday night, keeping the shower and thunderstorm chances around. The early week system will be the last of the energy from the western trough and ridging will quickly build over the central U.S. during the middle to latter parts of next week. The degree to how much heat and humidity will increase will depend on where the ridge center sets up. The GFS is a bit more aggressive than the ECMWF, EPS, and GEFS with heights over the Great Lakes region. However, most of the guidance largely maintains northwest flow and a stormy ring of fire pattern from the Dakotas into the Great Lakes. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 617 AM CDT Thu Jun 20 2019 Showers and thunderstorms will continue to spread east across Minnesota this morning, but are expected to dissipate later this afternoon as the enter central and eastern Minnesota. Feel confident in precipitation falling at AXN/RWF/MKT, but still uncertain whether it holds together long enough to impact STC/MSP. Activity would be fairly scattered by the time it reaches eastern Minnesota so kept a VCSH going to cover this threat. Ceilings will lower as the day progresses, with MVFR ceilings and visibilities expected in areas that see rain, and VFR further east. Light easterly winds become southeasterly through the morning, with speeds increasing to around 10 kts, with higher speeds and gusts up to 20 kts at western and central MN terminals. KMSP...Precipitation looks to dissipate right as it enters the metro later this afternoon. Continued the VCSH mention to cover any scattered showers that may still approach the terminal. Southeasterly winds will increase to around 10 kts today, with some gusts around 20kts developing by Friday morning. /OUTLOOK FOR KMSP/ Fri...VFR. SHRA/TSRA/MVFR likely late. Wind SE 10G20 kts. Sat...MVFR likely. Chc SHRA/TSRA. Wind SE 5-10 kts. Sun...VFR. Chc MVFR/SHRA/TSRA early. Wind SW 5 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...ETA LONG TERM...BORGHOFF AVIATION...ETA