NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 101106
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
606 AM CDT Tue Mar 10 2026

.KEY MESSAGES...

- Scattered thunderstorms are expected to develop after 4 PM and
  last through the evening. Large hail is possible with the
  greatest threat over southeast WI.

- Rain and a wintry mix of precipitation is forecast Wednesday
  morning. This will include a period of freezing drizzle or
  drizzle, then changing to light snow by mid to late morning.
  Up to a glaze of icing is possible west and north of the MKE
  metro area. Up to an inch of snow is possible toward central
  Wisconsin, with southern Wisconsin seeing less than an inch of
  snow.

- High precip chances (65-85%) Thursday evening/night, with
  expectations for some snow to mix in with rain late overnight
  into Friday morning. Practically no snow accumulation
  expected.

- Additional precipitation chances develop Saturday into Sunday.
  High confidence in precipitation, but confidence in
  precipitation type and placement is lower. Snow is possible
  Sunday.


&&

.UPDATE...
Issued 605 AM CDT Tue Mar 10 2026

The cold front is near the IL border and will continue to drift
swd this morning. This will aid in ending the areas of dense
fog over Rock and Walworth Counties.

A wave of low pressure is still expected to track along the
front from KS to far srn Lower MI today into Wed AM. This keeps
srn WI entrenched in nely winds and a strong frontal inversion,
but the nose of a 30-40 kt LLJ and associated warm, most
advection and frontogenesis will support widespread showers and
scattered thunderstorms for the late afternoon and evening.
Elevated CAPE around 1000 J/KG, possibly higher toward IL,
combining wrain
  then snow toward central Wisconsin, with rain and snow farther
  south.ith mdt effective shear will support a large hail
threat mainly over se WI.

For the overnight, expect areas of very light rain or drizzle
but nely winds and cold advection will drop temps below freezing
north and west of the MKE metro area. Thus freezing drizzle and
light glazing is a concern for the Wed AM commute. It will
change to all light snow during the day when a shortwave trough
and associated PVA and mid level frontogenesis shifts across srn
WI. The light snow will likely continue into the early
afternoon. Possibly an inch may accumulate toward central WI
with under an inch elsewhere.

Gehring

&&

.SHORT TERM...
Issued 1100 PM CDT Mon Mar 9 2026

Today (Tuesday) through Wednesday:

A backdoor cold front is currently moving southward across
southern WI, with northeast winds arriving behind it. The initial
passage of this front (ongoing as of ~10:30 PM Monday) is
practically cloud free as seen on GOES Nighttime Microphysics, with
just a few unrelated high-altitude clouds passing by, but through
this morning we expect a gradual onset of low-altitude clouds
(moving in off the lake), which slowly spread inland through the
course of the daytime hours. Some marine fog might briefly mix
into the shoreline of far southeastern WI this morning, though
most guidance prefers to keep it just offshore. CAA behind the
backdoor front reinforced by the cooling effect of Lake MI will
hold shoreline and east-central WI daytime high temps to the 40s
today, moderating up to the low to mid 50s further inland and
further southwest. Dry weather expected this morning and early
afternoon despite the approaching clouds.

Low pressure will track northeastward from the central Great
Plains today, dragging a warm front into Illinois. The
aforementioned northeasterly CAA will stall this front in
Illinois, likely around the I-80 corridor, with numerous showers
and thunderstorms firing up along it. The marine layer (covering
our region north of the front) will be extremely stable, reducing
the tornado threat to zero, and significantly reducing the wind
gust threat as well. That said, plenty of MUCAPE will be present
north of the front (perhaps 1,000 to 2,000 joules near the WI/IL
border, locally higher) allowing elevated thunderstorms with a
hail threat to drift north towards our region. This threat is
conditionally dependent on the exact placement of the front,
which has changed from one model initialization to the next, but
the I-80 corridor of Illinois seems to be a strong consensus
for the warm front placement on the latest (00z) CAMs,
especially given that the WRF-ARW (which handles early-season
marine backdoor cold fronts well due to it's special boundary
layer scheme) came into agreement with the HRRR, NAM, and WRF-
FV3 on the 00z run. The NAM-NEST and RRFS favor roughly 1 county
further south, but still roughly agree with this assessment.
With the aforementioned levels of CAPE encroaching into far
southern WI (mainly along and south of the I-94 corridor), and
mostly unidirectional effective shear (~60 knots convective
cloud-layer shear, 40-60 knot EBWD), the ingredients are
forecast to be in place for a strong to severe storm with hail
and frequent lightning, especially for the first 1 or 2 waves
of storms reaching us (maybe even a left or right-moving
supercell or two if all the ingredients align). We assess this
threat as a level 1 out of 5 for much of the aforementioned
area, with a level 2 out of 5 risk in the vicinity of the WI/IL
borderline in southeastern WI.

As the low pressure system slowly ejects northeastward Tonight,
light stratiform rain continues. A NW to SE rain to snow
transition unfolds roughly 4 AM to Noon Wednesday, with slushy
accumulations 1 inch or less possible north of I-94 and west of
Madison, along with some slick travel possible for the Wednesday
AM commute. A thin glaze of freezing rain ice accretion cannot
be ruled out either. Further south and east, a transition to
snow is not guaranteed, but we expect a few flakes to fly (with
practically no snow or ice accumulation due to warm surface
temps). Precip should slow down towards noon Wednesday, ending
shortly thereafter. Though some flurries or drizzle might linger
into the afternoon, air temps should be in the mid 30s to
around 40, thus our best guess is smooth sailing for the
Wednesday PM commute.

Sheppard

&&

.LONG TERM...
Issued 1100 PM CDT Mon Mar 9 2026

Wednesday night through Monday:

Overall an active pattern is expected for the end of the week into
the weekend.

Wednesday night into Thursday will see CAA behind the departing
trough and see temps drop closer to normal as high pressure works
across the region through the day Thursday. Looking at overnight
lows Wednesday in the 20s and high temps only in the 40s for
Thursday.

Meanwhile, a mid-level shortwave trough will begin to dig
across the northern Plains through the day Thursday and trek across
the Upper Midwest overnight into Friday morning. Models continue to
track a sub-990mb low across northern WI. A bulk of the precip will
be more anchored to the center of this clipper to our, but still
will be a glancing blow of lighter precip across our neck of the
woods. Best chances continue to be across our central WI counties,
with diminishing chances further south. Thinking it will mild enough
 for initial round to start off as rain and stay mostly rain south
of I-94, while looking a bit colder north of I-94 and mainly
expecting wintry mix of rain and snow and potential for some all
snow overnight into early Friday morning. Overall accumulations and
amounts will be toward the lower end, but still could result in
some pockets of travel impacts. Otherwise, this wound up system
will also bring strong, gusty southwest winds turning west-
northwesterly into Friday with winds gusts of 25-35 mph through
the afternoon.

Will see a brief reprieve in the active pattern Friday night into
Saturday as high pressure quickly works through the region and
continuing the near normal temp trend.

Looking ahead to the weekend there continues to be signal for
another deepening upper-level trough to develop across the central
Plains and traverse into the Midwest. However, there continues to be
a wide spread from the ensembles in the system's track, strength, as
well as QPF amounts. The GFS, AIGEFS, and GEFS trends a bit weaker
with a more elongated system, while the ECMWF, EPS, and AIFS trend
stronger with the surface low undergoing cyclogenesis as it lifts
across the Midwest. Additionally the spread in for the weekend
system's QPF ranges from a few hundredths of an inch to over 2
inches with the largest spread seen on the NBM and GEFS members.
Despite the varying solutions and uncertainty, will need to keep
an eye on this system as still expecting increase precip chances
with potential impacts.

Otherwise, cluster analysis and ensemble trends continue to favor
Colder airmass to settle across the region into early next
week with below normal temps.

Wagner

&&

.AVIATION...
Issued 605 AM CDT Tue Mar 10 2026

Areas of Cigs below 1 kft over se WI this morning along with
dense fog over Rock and Walworth Counties. The Cigs should
mostly rise to MVFR Cigs and expand across all of srn WI this
afternoon. Cigs below 1 kft and some fog will return to se WI by
late afternoon then expand across all of srn WI this evening.
Widespread showers and scattered thunderstorms will develop
during this time becoming drizzle or freezing drizzle early Wed
AM. The drizzle will then change to snow from west to east
across srn WI through the morning. Cigs will rise to 1-2 kft
during the afternoon. Vsbys with the snow will range from 1-3SM.

Gehring

&&

.MARINE...
Issued 1100 PM CDT Mon Mar 9 2026

A backdoor cold front will continue southward across Lake Michigan
through the overnight hours, bringing breezy northeasterly winds
behind it. Pockets of marine dense fog may develop over southern
portions of the lake overnight into Tuesday morning (mainly ahead
of the front). Northeast winds behind the front should gradually
clear out the fog (if applicable) by mid day Tuesday.

Low pressure around 29.6 inches develops in the central Great
Plains and progresses into northern Illinois Tuesday night. There
is some potential for thunderstorms across the southern third of
the lake north of the associated warm front late Tuesday
afternoon through Tuesday evening, with a continued northeast
breeze. Low pressure ejects to the lower Great Lakes into
Wednesday morning, turning winds northwesterly and allowing rain
to slowly transition to snow. North to northwest gales are
possible Wednesday morning through Wednesday afternoon, mainly
over the south half of the lake. Winds gradually diminish into
Thursday morning.

Another round of gales is possible Thursday night into Friday as a
compact clipper low of 29.2 inches crosses northern Lake
Michigan.

Sheppard

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Dense Fog Advisory...WIZ069-WIZ070 until 11 AM Tuesday.

LM...Small Craft Advisory...LMZ643-LMZ644 until 7 PM Wednesday.

     Small Craft Advisory...LMZ645-LMZ646 until 7 PM Wednesday.

&&

$$

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