Hail in Minnesota, April 17, 2026

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
643 AM CDT Fri Apr 17 2026

.KEY MESSAGES...

- The passage of a strong cold front will spawn showers and
  thunderstorms across eastern MN and western WI today. Strong
  to severe thunderstorms are possible along and east of a line
  from Mankato to Mora, with the highest severe potential across
  western WI.

- Large hail and damaging winds are the primary hazards across
  eastern MN and points east. The risk of tornadoes increases
  over western WI, along with the intensity of each hazard.

- Much colder air is expected for the weekend with possibly a
  few snow showers but with no snow accumulation.

&&

.DISCUSSION...
Issued at 304 AM CDT Fri Apr 17 2026

It's a quiet and mild start to Friday, as temperatures remain in
the 60s following yesterday's beautiful weather conditions. As
often seems to be the case in Spring, the taste of Summer will
be short- lived as a strong cold front passes through the region
today, ultimately ushering in much cooler air for the weekend.
The frontal passage will be our primary focus for the
development of strong to severe thunderstorms this afternoon.
Temperatures will crash behind the front, sending Saturday
morning lows below freezing across much of the forecast area --
widespread 24-hour temperature changes are forecast to run
between 30-40 degrees!

As of 2 AM, surface observations reveal that the frontal
boundary is on our doorstep. Current temperatures in the lower
40s paired with northwesterly surface flow at Morris and
Madison suggests that the front has already moved into western
MN. For reference, both locations observed highs in the mid to
upper 80s Thursday afternoon and are both running ~40+ degrees
cooler at this hour! Surface analysis shows two areas of low
pressure, one located in the MN Arrowhead with a cold front
extending to the SW to another surface low in western NE. Our
focus will be on the surface low in western NE, which is
forecast to translate east into IA as an upper trough
strengthens over the northern CONUS today. The cold front will
take a north/south orientation in response to the advance of the
surface low. Warm advection ahead of the frontal boundary will
work to establish a fairly potent warm sector across portions of
the Upper Midwest. However, the early timing of the frontal
passage is a key feature is evaluating today's severe weather
threat locally -- Simply put, the farther east communities are
in eastern MN/western WI, the higher the threat is. SPC's latest
Day 1 Outlook featured little change in the risk areas:
Enhanced Risk (Level 3/5) for the far eastern sliver of Eau
Claire/Chippewa WI, Slight Risk (Level 2/5) along and east of a
line from Freeborn - Goodhue - Barron (WI), and a Marginal Risk
(Level 1/5) along and east of a line from Martin - Hennepin -
Isanti. The greatest risk of large hail/tornadoes is located
across the Slight & Enhanced Risk areas.

This will be an event that likely gets going in the first few
hours after daybreak across south central MN. Recent CAMs have
depicted isolated elevated convection blossoming on the leading
edge of the northward surging plume of 60s Tds (currently
sampled in eastern NE and forecast to advect northeast into
southern MN). As these storms intensify, they will likely pose
the threat of hail and damaging winds, but the elevated nature
will limit tornadic activity. The initial round of convection is
forecast to move towards the TC Metro/I-35 corridor around
~10/11 AM or so. The severe weather threat ramps up as the
surface front moves into southeastern MN/ western WI early this
afternoon, where more hours of surface heating and ongoing
moisture advection will yield a warm sector characterized by
MLCAPEs of 2000+ J/kg, steep lapse rates, and curved hodographs
supported by slight backing of the surface winds and elongated
by 40-50kts of southwesterly 850mb flow. It's this combination
that will support the higher severe weather probabilities
(including a greater threat of tornadoes) across our WI
counties. Some uncertainty remains with regard to storm mode &
how quickly cells will grow upscale into a linear system. That
being said, the quick progression of the cold front will make
the mid afternoon hours the most likely for severe weather
across western WI, as guidance advertises that the front will be
east of Eau Claire by 3 PM or so. For reference, the threat of
large hail and strong tornadoes is even higher across
central/southern WI, eastern IA, and northern IL.

Winds quickly turn northwesterly behind the frontal passage and
are forecast to gust between 30-40 mph. Strong cold advection
will drop temperatures into the 40s for most locations by mid to
late afternoon. As referenced above, it looks like most
locations are in for a night with temperatures below the
freezing mark. Continued northwesterly flow will keep things
cool and breezy this weekend, with forecast highs are in the 40s
& 50s. Oh, and if that wasn't enough -- we could see a few
snowflakes fly as the upper low/vort max pivots north of the
International Border on Saturday. Fortunately, we're only
talking about conversational snowflakes that will not
accumulate.

We'll start to head back in the upward direction early next week
as large scale western ridging/height rises build towards the
Upper Midwest. Latest NBM features highs in the 60s Monday and
the 70s Tuesday, Wednesday, & Thursday. Most of next week's warm
up appears dry under the influence of high pressure and large
scale subsidence. However, unsettled western troughing will
become more of a focus by the end of next week and long term
global ensembles advertise the return of wet weather during this
time period.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 638 AM CDT Fri Apr 17 2026

Aside from low stratus this morning in far W/NW MN, only
impacting AXN, VFR conditions are expected at the remaining
TAF sites to start. Few more hours of LLWS conditions in eastern
MN into western WI until deeper mixing allows surface winds to
increase. High clouds will filter in from the west through late
morning in advance of a low pressure center along a progressing
N-to-S oriented frontal boundary. Convection is expected to
develop over south-central MN by late morning then shift NNE
along the front late this morning through the afternoon hours.
Higher confidence in central-southern-eastern MN into western WI
has allowed precip mention to be upped to TEMPO groups in lieu
of former PROB30 groups. Have kept conditions no lower than MVFR
but visibilities could/would be the first culprit in dropping
to IFR should brief heavy rain cross any given terminal.
Frequent lightning, strong winds and large hail may be possible
from around MSP eastward during the middle part of the day.
Going into the evening, MVFR ceilings will linger in the wake of
the front while winds snap around from S to NW with the frontal
passage with continued breezy/gusty speeds. Conditions return
to VFR by sunset at the MN sites and by late evening at the WI
sites.

KMSP...Still looking at the 15z-19z timeframe as the best timing
for any convection. There is still a shot of frequent lightning,
brief heavy rain and hail with the storms later this morning
but the better chances for severe weather are east of MSP.
Besides the precip/TS timing, the other issue is the timing of
the strong wind shift. Wind speeds will still be breezy
throughout, generally around 15G25kts, but the wind shift will
occur between 15z-19z (essentially on the backside of the
convection that moves through MSP). In addition, MVFR ceilings,
including sub-2000ft ceilings, are expected mid-to-late
afternoon.

/OUTLOOK FOR KMSP/
SUN...VFR. Wind NW 5-10kts.
MON...VFR. Wind SE 5-10kts becoming S 10-15kts.
TUE...VFR. Wind SW 5-10kts becoming NW.

&&

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

&&

DISCUSSION...Strus
AVIATION...JPC

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
413 AM CDT Fri Apr 17 2026

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
180900-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa-
Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington-
Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota-
Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth-
Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk-
St. Croix-Pierce-Dunn-Pepin-Eau Claire-
413 AM CDT Fri Apr 17 2026

This Hazardous Weather Outlook is for portions of central and
southern Minnesota, and west central Wisconsin.

.DAY ONE...Today and Tonight.

A strong cold front will push across the area today. A line of
strong to severe thunderstorms will develop along it across
eastern Minnesota late this morning into early this afternoon,
then track quickly across western Wisconsin. Large hail, damaging
winds, and a tornado or two are possible, especially in Wisconsin.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed this afternoon, mainly in
eastern Minnesota into western WI.