261
FXUS63 KMPX 312347
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
647 PM CDT Sun May 31 2026

.KEY MESSAGES...

- Chances for scattered showers and isolated thunderstorms will
  continue through Monday.

- Better chance of widespread rainfall arrives Wednesday into
  Thursday.

- Extended forecast features an above normal temperatures trend
  through the first portion of June.

&&

.DISCUSSION...
Issued at 110 PM CDT Sun May 31 2026

It`s one of those days where the weather varies quite a bit from
west to east across the area! Afternoon radar displays waves of
scattered showers (some of which have been very efficient rain
producers -- FCM measured 0.4" in one hour!) lifting northward
across MN within a region of ascent ahead of an elongated
trough that spans much of the NW CONUS. Conversely, dry weather
is continues east of the MN/WI state line. Over the past few
days, the Upper Midwest has been positioned south of a blocking
high over south central Canada in an omega block pattern. We`re
seeing a slight breakdown of this pattern today, as stronger
forcing rounding the trough has resulted in an eastward push of
a moisture plume (characterized by PWATs of 1-1.5") that spans
from central MN all the way to Gulf. Additional waves of showers
are likely this afternoon and evening as synoptic forcing
increases. Widespread cloud cover and ongoing showers have
worked to slow warming and will likely play a role in lowering
chances of thunderstorms later today. However, any additional
showers that take on a more convective look will have the
potential to produce lightning and efficient rainfall rates
given a couple hundred joules of MUCAPE and high PWATs
referenced above. We have overhauled the short term grids to
better reflect observational trends, which included lowering
temperatures and an eastward expansion/increase in PoPs. CAM
guidance remains rather messy given the weaker forcing regime,
but there is a signal for a band rain/isolated thunder moving
from southwest to northeast across the region this evening so
have worked that idea into the latest forecast. We`ll likely
have to refine the PoP windows with several updates through the
evening and into the night in this regime.

Large scale blocking will result in the maturation of an upper-low
over the northwestern CONUS Monday and the reestablishment of
ridging across the Upper Midwest. Forcing for additional
showers and thunderstorms will become displaced to the
northwest, which has yielded lower PoPs for the opening of the
work week. Still, HREF advertises a plume of MUCAPEs on the
order of 1000-1500 J/kg across the western half of the forecast
area tomorrow afternoon which will work in tandem with PWATS
~1-1.25" to support isolated showers and perhaps a thunderstorm
or two. Coverage of precipitation is forecast to be much lower
than today/tonight, so we`ve opted to only roll with 20-30 PoPs
in the grids. SPC has maintained a Marginal (Level 1/5) risk
area across far southwestern MN where instability is forecast to
be the strongest. Isolated damaging wind and large hail are the
primary threats. Given the expectation of a drier picture
Monday, temperatures are forecast to climb back into the lower
80s for afternoon highs.

Tuesday & Wednesday should be warm and dry for most locations as the
ridge axis remains positioned over the region. High temperatures are
forecast to climb into the mid 80s both days. A more notable pattern
change is set to take place Wednesday PM onward, as the early week
omega block breaks down. The development of a strong zonal Pacific
jet will send the remnant upper-low (still spinning over the NW
CONUS by mid-week) eastward along the International Border. In
response, a surface low and attendant cold front will advance across
the Upper Midwest and bring widespread precipitation chances to the
region. There is strong ensemble support for a widespread
precipitation which is reflected by 60-70 PoPs in the NBM forecast
grids late Wednesday into early Thursday. We`re still putting the
QPF forecast together, but confidence is increasing the potential
for 0.25-0.75" of rain.

Looking ahead to next weekend, guidance advertises a deeper trough
digging over the western CONUS and large scale ridge amplification
over the Upper Midwest/Great Lakes. Would tend to like this look for
a continued trend of above normal temperatures, which is highlighted
with highs in the mid 80s in the NBM. However, global models feature
a shortwave or two advancing northeast within large scale
southwesterly flow ahead of the western trough which could
promote additional precipitation chances. There is at least some
support for more measurable precipitation tied to the shortwaves
in the ensemble guidance, so that will bear watching. Otherwise,
the pattern looks to remain warm through the first portion of
the month.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 638 PM CDT Sun May 31 2026

A band of showers will continue across parts of MN this
evening as it slowly moves northward. I have opted to go
prevailing at sites vs a TEMPO group given the slow progression
of the SHRA. I have maintained MVFR cigs at most MN terminals.
The band of rain should stall out and dissipate overnight
somewhere from east-central MN into extreme western WI. For
AXN, RWF, and MKT, MVFR to possibly IFR cigs are likely. Low
level moisture with light winds will be a perfect set up for low
stratus and possibly patchy BR. I have adjusted timing in the
PROB30 for scattered showers progged to develop around sunrise.
VFR cigs become more likely the farther east one goes. Winds
slow to near 5 knots/variable tonight. Winds return to a more
easterly direction at or below 10 knots on Monday. VFR
conditions are likely at all sites by early afternoon. Added a
PROB30 for Monday PM at AXN for isolated -TSRA that will develop
across W MN.

KMSP...Visibilities remain VFR from the rain but low VFR to
MVFR cigs are expected this evening. I have maintained low VFR
but will AMD if MVFR cigs can build this far north/east.  Rain
will end after 05z and VFR should prevail for the rest of the
period. Southeasterly to 5-10 knots turning more due easterly on
Monday.

/OUTLOOK FOR KMSP/
TUE...VFR. Wind SE 5-10 kts.
WED...Mainly VFR. CHC P.M. -SHRA/MVFR. Wind S 10G20 kts.
THU...SHRA likely. CHC TSRA/MVFR. Wind SW 10-15G25 kts.

&&

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

&&

$$

DISCUSSION...Strus
AVIATION...BPH