219
FXUS63 KMPX 141100
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
600 AM CDT Mon Sep 14 2026

.KEY MESSAGES...

- Widespread rain overspreads the region this morning and
  persists for much of the day. Additional rain chances on deck
  later this week.

- Highs in the 60s to lower 70s through the upcoming weekend.

&&

.DISCUSSION...
Issued at 237 AM CDT Mon Sep 14 2026

COOL MORNING TEMPERATURES...Early morning surface analysis samples
expansive 1020s mb surface high centered over WI. The influence of
the high has supported the continuation of Sunday evening`s clear
skies and light winds, which has resulted in a quick drop in
temperatures. As of 2 AM, several locations across central/eastern
MN (outside of the TC heat island) and western WI are reporting
temperatures in the mid 40s. Increasing clouds over southwestern MN
have worked to slow cooling which is reflected by temperatures in
the 50s at this hour. The tranquil weather conditions will not
persist much longer as an incoming weather system will bring
widespread rain and gusty winds across the Upper Midwest today.

WIDESPREAD RAIN TODAY...The well-advertised incoming round of rain
remains on track with no major changes to the anticipated soggy
start to the workweek. Driving today`s precipitation is an upper-low
that is forecast to deepen as it moves across the International
Border over the next 24-hours. GOES water vapor imagery captures the
upper-low currently over NW Montana, along with a region of broad
ascent moving east of the Rockies into the northern Plains. Ahead of
the upper-low, a strengthening low-level jet is oriented from south
to north across the Plains. The jet is supporting the advection of
anomalous moisture that can be characterized by PWATs of ~1.8" or
so, which is roughly 200% of normal. Guidance remains in solid
agreement with the development of a broad precipitation shield
driven by isentropic ascent that will overspread the forecast area
as the LLJ axis shifts east this morning. We`ve leaned on hi-res
guidance for some minor tweaks to onset times in the grids, so
expect the first raindrops to fall along the MN River in western MN
by 8-9 AM, beginning in Mankato between 9-10 AM, reaching St. Cloud
& the Twin Cities between 11AM-Noon, and Eau Claire around 1-2 PM. A
few rumbles of thunder are possible. We`ve followed the dayshift in
dropping temperatures a few degrees below the NBM to account for
limited heating due to clouds and precipitation.

Rain chances will begin to decrease by late afternoon/early evening
across far western MN as the low-level jet shifts east and the upper-
level dry slot wraps across the Dakotas. However, PoPs remain higher
longer into the evening across eastern MN & western WI given the
position of the LLJ and the northward advance of a warm front out of
northern IA. A renewed band of showers & a few storms is most
likely to extend along and east of a line from Albert Lea to Red
Wing, as highlighted by the HREF. Surface temperatures will warm this
evening across southern MN and western WI as the warm front draws
near. In other words, the true "high temperature" will likely be
observed shortly before midnight and look to be somewhere in the mid-
60s for many locations (compared the 50s expected during the main
precipitation window this afternoon). Rain chances end from west to
east through the late evening. When all is said and done, most
locations will observe at least a half inch of rainfall. Many
locations look to make a run towards 1" or so, with the main axis of
1-1.5" amounts forecast to setup across southeastern MN/western WI
(largely due to the evening rain/storms discussed previously). In
addition to the rain, it will be a windy day as strong southeasterly
winds gust upwards of 30-35 mph.

LOOKING AHEAD...The upper-low and associated surface system will
move north of the Great Lakes by tomorrow morning. A trailing cold
front is progged to move southeastward across the forecast area by
daybreak and will set the stage for a nice Tuesday, owing largely to
the advection of drier air from the northwest. Precipitation chances
return Wednesday as a wave within zonal flow aloft supports the
northward retreat of Tuesday`s front. The highest rain chances exist
across southern MN (60-70%), with PoPs lowering to slight chance (20-
30%) over central MN. The active pattern will send another wave from
the Plains into the Upper Midwest on Friday and it`s looking
plausible that this may be our next round of beneficial rainfall.
We`re still a few days out from having higher confidence, but it`s
important to note that ensemble systems have trended upwards with
prospects of 1"+ rainfall in the Friday-early Saturday timeframe.
NBM has followed this idea with 60-80% PoPs now featured in the
grids. A potentially stronger upper-low is progged to come ashore in
the Pacific NW late this week and may spawn additional rain chances
by the time it reaches the north central CONUS later in the upcoming
weekend. All of this to say the overall forecast looks active, with
a few chances of some much needed rain potentially in the cards.
With multiple precipitation windows and an overall active theme,
don`t see any reason to diverge from NBM`s highs in the low 70s for
much second half of the week and upcoming weekend.

&&

.AVIATION /12Z TAFS THROUGH 18Z TUESDAY/...
Issued at 600 AM CDT Mon Sep 14 2026

Mid and high level clouds are beginning to increase. A line of showers
and thunderstorms across southeastern SD and along the IA/NE
border will continue northeast this morning. Additional
activity is expected to develop over time then spread northeast
through the day. MVFR/IFR conditions are expected with the
steadier showers/storms. The showers will exit to the east
early evening with clouds clearing shortly thereafter. Light
winds overnight will increase markedly with southerly gusts
around 30 kts by late morning and afternoon.

KMSP...On their current trajectory, the showers and a few storms
will begin arriving around 16Z, then become steadier in the
afternoon. The best chance of any TS would be late morning into
mid afternoon when elevated instability is greatest. Cigs will
lower to MVFR in the afternoon, then clear late evening.

/OUTLOOK FOR KMSP/
TUE...VFR. Wind NW 10-15kts.
WED...VFR. Chc MVFR/-SHRA PM. Wind E 5-10kts.
THU...VFR. Wind E 5-10kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...Strus
AVIATION...Borghoff