NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 071021
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
521 AM CDT Tue Apr 7 2026

.KEY MESSAGES...

- A mix of light rain and light snow is forecast overnight (30
  to 60 percent chances) in south central Wisconsin, with some
  light freezing rain mixed in over areas mainly northwest of
  Madison. Any light ice accumulation would be on elevated
  surfaces.

- Milder temperatures return on Wednesday, with widespread
  showers (around 85 percent) forecast late Wednesday
  afternoon during the passage of a cold front.

- Another round of showers with a few storms (40 to 65 percent)
  should occur Thursday night, followed by an active weather
  pattern of warmer temperatures and more showers and storms
  Sunday into Monday.

&&

.UPDATE...
Issued 521 AM CDT Tue Apr 7 2026

Skies are clear across Wisconsin early this morning and the
northerly winds continue to diminish. It is cold, with
temperatures in the lower to mid 20s. Locations toward central
WI will bottom out closer to 20, with a few pockets of upper
teens possible in low-lying areas.

Sunshine will prevail today, but temperatures will only rebound
into the mid/upper 30s near Lake Michigan to mid 40s well
inland. Thankfully, the winds will be light.

Precipitation will spread into southern WI from the southwest
around midnight tonight as the nose of the low level jet
pushes into southern MN and southwest WI. The better LLJ forcing
will be over MN, but a weak mid level shortwave will be tracking
over southern WI during this time.

Model forecast profiles show dry air in the low levels,
especially over southeast WI. This will keep the precip amounts
light, and potentially only sprinkles in the southeast. As for
the temperature profiles, models have a range of solutions, but
generally indicate snow transitioning to freezing rain/sleet
(min temps in the mid 20s to lower 30s) and then quickly over
to light rain as the temps warm. So we have a brief period
where a wintry mix is possible, mainly north of Madison to West
Bend where we could see a light glaze on elevated surfaces
during the overnight hours. Pavement temperatures should inhibit
travel impacts, but bridges and overpasses could be susceptible
for a few hours before the temperatures warm above freezing.
Elsewhere, while a brief wintry mix is possible, it should be
too light to accumulate in any way.

Cronce

&&

.SHORT TERM...
Issued 1221 AM CDT Tue Apr 7 2026

Overnight through Tuesday night:

Some middle to high clouds may linger in southern portions of
the area overnight. Otherwise, mostly clear skies are expected
to linger overnight into most of Tuesday. Any lingering gusty
winds should gradually weaken overnight and become northeast to
east on Tuesday, as high pressure moves across the region. Lows
tonight should drop into the upper teens to lower 20s, with
highs Tuesday in the lower 40s well inland and middle 30s closer
to the lakeshore.

Winds will shift southeast Tuesday night and gradually
increase, with warm air advection at 850 mb developing with a
south southwesterly low level jet. The best moisture transport
and upward motion should be just west of the area, but enough of
this should move through south central Wisconsin to bring 30 to
60 percent chances for precipitation there.

Forecast soundings and wet bulb temperatures suggest a
transition from light snow to a wintry mix of light snow, light
freezing rain and light rain to mainly light rain by Wednesday
morning for areas northwest of Madison. Areas to the south and
east of there should be more of a light snow to light rain
transition, as temperatures warm up after 06Z Wednesday. The far
southeast parts of the area may not see much precipitation, as
the air column there is drier.

There remains a risk for light ice accumulations northwest of
Madison later Tuesday night, perhaps a light glazing mainly on
elevated surfaces. Will continue to message this potential. It
should transition to all light rain by 12Z Wednesday.

Wood

&&

.LONG TERM...
Issued 1221 AM CDT Tue Apr 7 2026

Wednesday through Sunday:

As low pressure tracks eastward across southern Canada mid
week, gusty southerly winds and a warming trend arrive, with
Wednesday's high temps soaring into the low to mid 60s inland,
some 50s along the shoreline with the cooling influence of the
lake. Rain chances (30-50%) linger north of a Monroe to West
Bend line through the day Wednesday with all of the WAA aloft,
with a cold front tracking west to east through the region
Wednesday evening/night and boosting rain chances to ~75% area-
wide. Likely a widespread wetting rainfall.

A light southwest to west breeze continues behind that cold
front Thursday, though temperatures remain around 60 to the mid
60s with the warmth likely spreading to the shoreline. A surface
trough develops south of the region, with only ~20% chances for
associated rain showers to reach southern Wisconsin Thursday
afternoon.

The trough and associated rainfall wobble north Thursday
evening/night delivering 40-65% rain chances (highest further
south and east in our region) before high pressure builds into
the upper Great Lakes region and forces the baroclinic zone
clear of our region. Hence, dry weather likely for much of
Friday and into the daytime hours of Saturday. Inland highs in
the 50s to around 60 expected, with east flow off the lake
leading to cooler shoreline temps.

A more organized low pressure system is then expected to
develop over the Rockies and track eastward over the northern
Great Plains this weekend, likely dragging a potent warm sector
into Wisconsin Sunday/Monday. Ensemble temperature IQRs
indicate relatively high confidence for highs in the 70s these
two days, possibly even the low 80s. The presence of this warm
sector brings with it a chance for showers and thunderstorms.

Sheppard

&&

.AVIATION...
Issued 521 AM CDT Tue Apr 7 2026

Clear skies and light winds are expected through the day. Look
for winds to become southerly this evening as mid level clouds
begin to spread in from the west. A period of snow/freezing
rain/sleet is likely during the overnight hours, mainly north of
Madison to West Bend between 1 and 4 AM (08-11Z). A brief and
very light wintry mix is possible south of there, but dry air in
the low levels will keep it lighter than toward central WI.
Ceilings and visibility are expected to remain VFR during the
precip, but conditions may briefly become MVFR.

Cronce

&&

.MARINE...
Issued 521 AM CDT Tue Apr 7 2026

The Small Craft Advisory will be allowed to expire at 7 AM as
winds and waves diminish. Another Small Craft Advisory will be
needed for increasing southerly winds on Wednesday. A few gale
force gusts are possible.

Gusty northerly winds will decrease through the morning as high
pressure around 30.6 inches moves across central Lake Michigan
into the early afternoon. Low pressure around 29.5 inches will
then track along the Northern Plains/Canadian border tonight and
Wednesday, then track north of Lake Superior Wednesday night into
Thursday morning. This will result in breezy southerly winds over
Lake Michigan on Wednesday with gale force gusts up to 40 kt. A
Gale Watch is in effect for the northern three quarters of the
lake.

Much weaker winds will then take hold by Thursday afternoon into
Friday as high pressure around 30.4 inches slowly moves through
the region.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 AM
     Tuesday.

     Gale Watch...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
     LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874...7 AM
     Wednesday to 4 AM Thursday.

&&

$$

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