427 FXUS63 KMPX 130909 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 409 AM CDT Mon Jul 13 2020 .SHORT TERM...(Today through Tuesday) Issued at 409 AM CDT Mon Jul 13 2020 Thunderstorms are ongoing across North Dakota early this morning and a cirrus shield is spreading east over the northern half of Minnesota. This complex will weaken during the next few hours and abundant sunshine is expected for much of the day. Highs could get quite warm today in the absence of any convection. 925 mb temps increase to +28C across western MN late this afternoon, and could rise to +25C farther east. It's possible highs reach the mid 90s across far western Minnesota, while the rest of the area climbs into the upper 80s. Moisture will be increasing throughout the day. The atmosphere should remain capped until late afternoon when supercell development is possible as the cap begins to break in spots. All severe hazards are possible with this initial development. The best forcing will be across the northern half of Minnesota, while the most robust instability will be south. CAMs seem to favor the forcing more than the higher instability and the most widespread convection is advertised to the north. However, the best possibility of discrete convection will be over west central MN and thus better potential for higher end severe. A secondary area of convective development could occur along the surface warm front over central and eastern Minnesota very late this afternoon or early evening. Some guidance indicates this possibility for a short time before either fading or shifting to the northeast. Convection will continue for much of the night, growing upscale into complexes this evening and tracking east or southeast. Damaging winds will eventually become the main threat before storms weaken late tonight. Another disturbance will slide east northeast along the cold front across southern Minnesota Tuesday morning. Additional convection is expected to form and could train along the front, bringing the risk of heavy rainfall in a swath across east central MN into northern WI. Farther south, instability will recover during the afternoon and a few stronger storms could develop. The best severe potential will be southeast of the area. Activity will shift south and east in the afternoon and will be exiting by Tuesday evening. Highs were reduced a bit due to the clouds and showers/storms. .LONG TERM...(Tuesday night through Sunday) Issued at 409 AM CDT Mon Jul 13 2020 Tuesday evening will have residual moisture along the frontal boundary which could keep occasional showers/storms in south central Minnesota, and west central Wisconsin. However, the progressive nature of this system will quickly dry things out by Wednesday morning. Wednesday and Thursday will be the driest and most comfortable as a modified Pacific/Canadian air mass moves overhead. Both the EC/GFS have similar 50H with a deep upper trough centered across central Canada later this week. The northern tier of the nature will remain in a progressive west to east flow aloft with strong westerlies expected. Thus, once return flow develops and the air mass becomes more tropical in nature next weekend, several short waves will ride along the northern edge of the strengthening ridge in the central part of the country. Timing of these short waves, and the subtle boundaries from residual thunderstorm outflow, will dictate the chances of precipitation later this week, and into the weekend. I wouldn't be surprised to see a strengthening cap especially early in the weekend as mid- level temperatures rise significantly, and limit updrafts. Still, based on the amount of instability expected as dew points rise back into the 70s, and the stronger westerlies, severe weather potential is possible if and when the cap breaks. Based on dew points rising into the 70s Saturday, the actual temperatures around 90 to 95 degrees, heat indices will likely surpass 100 degrees. WBGT numbers rise to around 83 degrees which is a more effective means of assessing heat risk to person involved in physical activity. Once the WBGT rise above 85 degrees, conditions worsen. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1145 PM CDT Sun Jul 12 2020 VFR conditions will prevail through the early afternoon with increasing southeasterly winds, along with gusts of 20 to 30 kts in western Minnesota. Between 21-00z, TSRA will begin to develop in west central Minnesota and build southeast during the evening. Timing and areal extent remain questionable but the amount of forcing should allow for TSRA to develop. The biggest factor will be duration of the heaviest rainfall where some sites will likely see IFR vsby at times, along with gusty winds in the vicinity of the TSRA. KMSP... Timing of TSRA looks to be after 04z/14, with the best period between 6-12z. MVFR/IFR conditions will likely develop in the vicinity of the TSRA along with gusty winds. /OUTLOOK FOR KMSP/ Tue...RA/TSRA/MVFR likely, mainly in the morning. Wind SW 5-10 kts bcmg NW. Wed...VFR. Wind NW 5 kts. Thu...VFR. Wind SW 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...Borghoff LONG TERM...JLT AVIATION...JLT