588
FXUS63 KMPX 211842
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
142 PM CDT Fri Aug 21 2026

.KEY MESSAGES...

- Seasonable temperatures over the next week with both highs and
  lows within a few degrees of normal.

- Chance for some thunderstorms in east central Minnesota this
  evening, next chance for rain early next week.

&&

.DISCUSSION...
Issued at 142 PM CDT Fri Aug 21 2026

As temperatures have risen this afternoon the low morning`s stratus
has lifted and been replaced with fair weather cumulus clouds.
A frontal passage this evening into the early overnight hours
will provide for a chance for a few isolated thunderstorms.
Shear is poor and the thermal profile does not allow for much
instability. So strong storms are not expected. There looks to
be enough instability for some thunderstorms, mainly in east
central Minnesota. By the time it gets into western Wisconsin
the diurnal temperature drop will lower instability such that
chances will decrease further.

Behind this frontal passage high pressure will move in for the
weekend. This will give us a overall very nice weekend with
mostly sunny to sunny skies and highs up near 80 both days.
Clear skies will allow for ample mixing though and we could see
some gusty winds in the afternoon, especially on Saturday.
Nothing super high, with gusts up around 20-25 mph. Clear skies
will allow for ample radiational cooling both Saturday and
Sunday nights. Sunday night will also see some CAA so
temperatures as low as the 40s will be possible in parts of
northeast MN and northwest WI.

On Monday the high pressure will start to move out keeping the
daytime fairly similar to the weekend. Late Monday into Tuesday
is the next anticipated frontal passage. How much moisture this
frontal passage will have to work with is the main question
right now. Forecast soundings from the global deterministic
models show ample high and mid level saturation with less low
level saturation. When looking towards ensemble QPF there is a
good amount of spread still which makes the lower NBM PoPs make
sense. NBM has kept the PoP chances low to reflect this spread
within the ensemble guidance. The spread should decrease over
the weekend and provide for a better idea of when and where rain
chances will be. The next rain chance past Mon/Tue would be
towards the end of the next week and as expected for this time
range there is a large spread on timing and level of impact. All
of the main global deterministic models have something in that
time range though, so it is worth keeping an eye on. Overall no
strong temperature advection over the week next week. Which
supports the overall near normal temperature forecast.

&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 1236 PM CDT Fri Aug 21 2026

Generally observing improvements to the aviation scenario early
this afternoon as the morning cloud shield of MVFR cigs displays
signs of erosion with eastward movement towards RNH. Satellite
captures trailing bands of mostly VFR strato-cu, which will be
the primary focus for an occasional MVFR cig this afternoon.
Afternoon gusts between 15-20kts will diminish this evening with
the loss of diurnal mixing. We`ve maintained a PROB30 for showers
at STC associated with a late-evening frontal passage and may
eventually need mention at RNH per hi-res model trends. Saturday
will be VFR and breezy, with northwesterly winds gusting upwards
of 20kts. Pretty good signal for the development of a diurnal
Cu field between 5-8k feet.

KMSP...Strato-Cu should trend VFR through the afternoon, with
northwesterly gusts approaching 20kts at times. Northwesterly
winds increase tomorrow morning and should yield gusts near
20kts. Daytime VFR Cu ~5k feet forecast to develop by late
Saturday morning.

/OUTLOOK FOR KMSP/
SUN...VFR. Wind N 5 kts.
MON...VFR, chc -SHRA late night. Wind S 5-15 kts.
TUE...VFR, chc -SHRA early. Wind SW 10-15 kts.

&&

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

&&

$$

DISCUSSION...NDC
AVIATION...Strus