FXUS63 KMPX 221840
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
140 PM CDT Sat Aug 22 2026

.KEY MESSAGES...

- Seasonable temperatures expected through the end of the month.

- Chance for rain in SW Minnesota Sunday night/Monday morning 
  and a more widespread chance Monday night into Tuesday.

&&

.DISCUSSION...
Issued at 140 PM CDT Sat Aug 22 2026

This Weekend... High pressure overhead today allowed for clear 
skies this morning into the early afternoon. The heating of 
atmosphere then allowed for two thing to occur: diurnal fair 
weather cumulus clouds and mixing. Winds have varied across the 
broader region due to the winds aloft available to mix down. We
have good mixing everywhere, but it is more from central 
Minnesota to western Wisconsin that has higher winds aloft and 
therefore higher winds brought down to the surface. As we start 
to cool this evening along the usual diurnal curve the skies 
will clear and the winds will become light. With clear skies and
light winds we will see ample radiational cooling tonight. 
This will allow temperatures to fall into the mid 40s to mid 
50s. For these cooler areas, east central MN and northwest WI, 
some fog formation is possible. Sunday during the day will be a
similar setup to Saturday with the high pressure system starting
to move out, but still present. Another day warming up into the
upper 70s, but there are not as high of winds aloft as the 
upper air pattern shifts and it will therefore not be as gusty 
outside. This shift in the pattern will have a bigger impact on 
Sunday night. Temperatures will not cool as much over western 
Minnesota as clouds move in. This will provide for a wider 
temperature gap with lows near the SD/MN border near 60 and in 
western WI temperatures will fall into the 40s. These clouds are
tied to a larger system over the High Plains. Some of the rain 
showers associated with this system could impact parts of the 
southern Minnesota River Valley Sunday night into Monday 
morning. Due to the time of day there is little instability, so
rain showers are most likely rather than thunderstorms.

Next Week... The main driver early in the week on Monday and
Tuesday will be a shortwave moving across the Canadian Prairies.
The associated surface low and its fronts will be the main 
source for lift driving the weather. The biggest question for us
here continues to be moisture, as many forecast soundings 
continue to show lots of dry air to overcome. The timing of the 
frontal passage will limit much of the strong to severe storm 
chances. However a weak jet streak across North Dakota into 
northwest Minnesota (better shear) combined with a slightly 
earlier timing (more instability) could allow for some stronger
storms in parts of west central Minnesota. For this reason SPC 
has a marginal severe risk out for this area. On the larger 
scale synoptic impacts there are still differences between the 
timing of the frontal passage and amount of moisture between 
ensemble members. For this reason any specific 6 hour period is 
hard to provide much more than a 40 percent chance. When the 
whole window is taken into account the grand majority of members
provide at least some QPF. So bottom line, we will have to get 
into the higher resolution windows to gain more confidence on 
details but confidence on seeing rain across these two days has
gone up. Past this it looks fairly quiet for the rest of the 
week with maybe some signal for something at the end of the 
week, but it is a little early to say much about that.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 1206 PM CDT Sat Aug 22 2026

Generally clear sky VFR over most of the period. Some diurnal 
cumulus this afternoon, but coverage should keep us VFR. Ample 
mixing will allow for gusty winds this afternoon up to around 20
to 25 knots. Winds will calm along the usual diurnal curve this
evening into the following morning.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
MON...VFR, chc -SHRA late. Wind SE 5-10 kts.
TUE...VFR, chc -SHRA early. Wind SW 10-20 kts.
WED...VFR. Wind NW 10-20 kts.

&&

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

&&

$$

DISCUSSION...NDC
AVIATION...NDC