718
FXUS63 KMPX 171832
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
132 PM CDT Sun May 17 2026

.KEY MESSAGES...

- Severe thunderstorms likely this evening, with the highest
  risk across southern Minnesota (level 3 out of 5).

- Initial storms will have potential for large to very large
  hail (2-3") and tornadoes.

- Individual storms will quickly form into a line as they
  progress through MN and WI. Significant severe wind (70-80+
  mph) will become the primary hazard with brief QLCS tornadoes
  possible across south-central MN.

- Another round of thunderstorms is likely Monday night. Severe
  thunderstorms are possible across southeast Minnesota &
  western Wisconsin.

&&

.DISCUSSION...
Issued at 124 PM CDT Sun May 17 2026


Today is setting up to have potential to be a higher end day for
portions of the Enhanced Risk area. Latest visible satellite
imagery shorting plenty of clearing with the low-level cloud
deck through much of MN, but especially across the southern
portion of the state. A bubbling cu field is beginning to
develop ahead of ongoing convection tied to the surface low near
the NE/SD state line. Surface winds are largely out of the
SE/ESE for MN and western WI, and dewpoints have been steadily
increasing through the day so far. The best environment is
across southern MN where dewpoints have climbed into the 60s
already and plenty of clearing is allowing for efficient
daytime heating, priming the environment for intense convection
later today.

Based on satellite and hi-res model data, we expect timing to be
maybe slightly earlier than forecast this morning, but generally
along the same timeframe. Supercells and storm clusters will
develop across Nebraska and South Dakota during the afternoon
(around 3-5pm) and progress slightly northeastward into
southwest MN and northern IA (around 6-7pm). At this point,
storms will be tied to the triple point and situated in a
favorable environment for large to very large hail (2-3" in
diameter) and damaging wind gusts (60+ mph). Storms will quickly
develop into a line along the cold front and turn into a
significant wind (70-80+ mph), QLCS setup with line-embedded
tornadoes possible within that Enhanced Risk area (stretching
from Redwood Falls, MN over to Owatonna, MN and south). Forecast
soundings show increasing low-level shear and humped hodographs
in the region ahead of the line, which is also reflected in
models like the RRFS and HRRR producing a zone of STP values of
5+ across southern MN. Typically QLCS tornadoes are weaker than
supercell tornadoes, so we really want to highlight that there
is higher- end potential with today`s environment compared to
your average QLCS setup. Any tornadoes that develop will likely
still be brief, like any typical QLCS setup, though the strength
of the tornadoes may be capped at an EF2 level rather than EF1.
This is all in general-speak, but the point is that the higher-
end environment warrants being prepared for slightly stronger
tornadoes than you typically get with linear setups (around
here at least). The main time window for this to move through is
between 7-10pm. The faster the line develops, the quicker it
will move east.

To the north of the main line, we should still see a surge of
low-level moisture as the low tracks northeast. The overall
environment just is not as impressive north of the Enhanced Risk
region, due to the limited northern progression of the warm
front today. It will be high shear/low CAPE setup for much of
our forecast area today, but especially for areas north of the
Redwood Falls to Owatonna line. A Slight Risk (level 2/5)
remains in place to cover this threat for scattered severe storm
potential. The primary hazards will be damaging wind (60+ mph)
and large hail (1"+ in diameter). Any high end potential will be
limited, including the tornado risk. Storms will move through
the western MN to St Cloud, MN region around 6-8pm, the Twin
Cities metro and eastern MN around 9-11pm, and eventually
progress through western WI around 11pm-1am. The severe threat
will begin to decrease as the line progresses into WI given that
there will likely be scattered storms ahead the cold front,
limiting the environment.

The severe threat for Monday continues to decrease, and although
there is still a Slight Risk (level 2/5) extending from south-
central MN into west-central WI, we expect that region to shift
even further southeast after we realize our round of storms this
evening. We will struggle to build in any real instability and
deep layer shear will become more limited as well. In reality,
tomorrow will likely feel like a typical rainy Spring day with
cool showers and storms through much of the second half of the
day. Isolated chances for severe weather will exist, mainly for
areas along I-35 and east during the evening.

A much drier, and seasonably cool pattern will set up for the
rest of the week. Temperatures on Tuesday will be about 10-15
degrees below average, and we could once again have concern for
patchy frost overnight (lows in the mid-low 30s) into Wednesday
for areas in west- central MN near Stevens, Douglas, and Todd
counties. It won`t be until Friday that we see our next notable
chance for rain as a shortwave develops over the Northern
Plains. It looks to be a slow- progressing pattern that would
provide us with additional chances for showers and storms
throughout the rest of Memorial Day weekend, though confidence
is low at this time.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1233 PM CDT Sun May 17 2026

Broken sky cover thanks to a mid-level deck to start the
period. We`ll see ceilings steadily decrease and hit MVFR by
late afternoon/early evening. I have delayed the arrival of MVFR
& IFR cigs vs the 12z TAFs based on latest trends and forecast
soundings.

Attention turns to the afternoon TS that will develop after 20z
across eastern SD. This should congeal into a line of TS by this
evening before tracking eastward across the area. Timing of the
TS line may need adjusted. TS moves into SW MN around 00z and
tracks northeast through 06z where it begins to weaken over W
WI.There is still a signal for strong warm advection east across
S MN/W WI that may result in showers developing this evening
ahead of the TS coming out of SD. Another change was to swap
out PROB30 for TEMPO at all sites but AXN & EAU. These two
locations have some uncertainty if we`ll see TS vs SHRA, but can
AMD later. TSRA ends after 06z and SHRA by 08z as the complex
exits our area. MVFR and IFR cigs linger through the end of the
TAF. Sites should remain dry after daybreak Monday through end
of TAF.

KMSP... East winds will gradually shift to ESE winds this
afternoon. Sporadic gusts around 25kts are likely through early
evening. There is some uncertainty regarding the arrival &
intensity of any TS this evening. Opted for a TEMPO and will AMD
to tweak timing as necessary. Winds shift to the west-northwest
by daybreak Monday. I have opted to leave out any mention of
SHRA or TS Monday afternoon. Best signal for any precipitation
will be just after end of TAF Monday evening.


/OUTLOOK FOR KMSP/
TUE...MVFR. Wind NW 10-15G25kts.
WED...VFR. Wind NNW 5-10kts.
THU...VFR. Wind S 10-15G25kts.

&&

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

&&

$$

DISCUSSION...BED
AVIATION...BPH