446 FXUS63 KMPX 180706 AFDMPXArea Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 206 AM CDT Thu Sep 18 2025
.KEY MESSAGES...
- Chances for showers and thunderstorms continue through the weekend.
- Slow moving storms and high atmospheric moisture content will likely lead to areas of heavy rain totals each of the next few days.
&&
.DISCUSSION... Issued at 206 AM CDT Thu Sep 18 2025
Scattered showers across western MN grow into widespread showers farther west across the Dakotas early this morning. Water vapor imagery highlights several small scale disturbances within the trough across the northern Plains and a dry slot attempting to reach southwestern MN. Pwats are expected to drop today and lapse rates will remain poor, although there will be some modest, skinny, uncapped CAPE this afternoon. Cannot rule out some scattered showers and thunderstorms developing during diurnal peak, but the lack of a trigger should mean another mostly quiet day.
A more substantive shortwave is expected to rotate north from the central Plains this evening to MN by Friday morning. Accompanying it is a recovery of Pwats back to 1.5-1.75 inches. A moist adiabatic profile and very little or no CAPE will keep the thunder threat modest, but wind profiles remain favorable for slow moving or training showers capable of heavy rainfall totals. Coverage should be better than anything we`ve seen so far from this system. By Friday, the core of the upper low will finally begin making progress eastward and should slowly propagate across MN through Friday night, reaching WI Saturday. PoPs will be highest east of the system within the warm conveyor belt. As another trough approaches from the west, it will absorb the week-long upper low by early Sunday over WI and prolong the cyclonic flow and scattered shower threat possibly into Monday.
The rest of next week looks mostly dry with seasonable temperatures, although general troughiness will remain. Another upper low will dive southeast to the central Plains and mid to lower Mississippi Valley midweek. It`s possible we will be on the northern fringe of that system and PoPs may eventually be introduced, but the better chances for any substantial precip should remain well to the south.
&&
.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1249 AM CDT Thu Sep 18 2025
Showers tonight are mainly confined to western MN, although a few are also present just south of EAU. Most of the area will remain dry tonight, with lowering cigs across western and central MN toward the early morning hours. IFR conditions are possible for several hours into mid to late morning, then lifting back to MVFR or VFR for Thursday afternoon. Scattered showers and storms could develop in the afternoon, but the better chance for showers is Thursday night.
KMSP...Expecting to stay dry and VFR overnight with light winds.
/OUTLOOK FOR KMSP/ FRI...MVFR. -SHRA likely, chc -TSRA. Wind SE 5-10 kts. SAT...Chc MVFR/-TSRA. Wind S 5-10 kts. SUN...Chc MVFR/-TSRA. Wind SW 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None.
&&
$$
DISCUSSION...Borghoff AVIATION...Borghoff
NWS MPX Office Area Forecast Discussion