NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 210526
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1226 AM CDT Sat Mar 21 2026

.KEY MESSAGES...

- Patchy fog should linger in northern parts of the area
  overnight into early Saturday morning. Some dense fog may
  occur in low lying areas.

- Warm temperatures are expected Saturday across most of the
  area, as gusty southwest winds develop. Highs may rise into
  the lower to middle 70s over most of the area.

- Some chances (around 20 to 30 percent) for light rain to occur
  later Saturday night into Sunday morning, as a cold front
  shifts southward through and south of the area. Cooler
  temperatures and gusty winds are expected.

- Chances (mainly 20 to 30 percent) for precipitation returns
  to the area for middle to later portions of next week.

&&

.SHORT TERM...
Issued 1226 AM CDT Sat Mar 21 2026

Overnight through Tuesday:

Patchy fog should linger overnight into early Saturday morning,
as a sharp inversion develops over these areas with a solid
snowpack on the ground. Some dense fog may occur, mainly in low
lying areas. The middle to high clouds that are moving through
may deter some of the fog development. These clouds should move
out of the area by later Saturday morning.

Warm air advection continues into Saturday, as winds shift from
the southeast and south to southwest. Gusty southwest winds
should develop by midday and should push to most of the
lakeshore areas by middle afternoon. Areas toward Port
Washington and Sheboygan may remain onshore until the southwest
winds arrive by 00Z Sunday. This should allow for warm highs
into the lower 70s to reach most of the lakeshore areas, with
lower to middle 70s inland.

A cold front will push south through the area Saturday evening,
with north to northeast winds increasing overnight into Sunday.
Cold air advection will bring cooler temperatures into the area.
A low cloud deck should push southward into the area during
this time as well. There remains some low to mid level
frontogenesis response that shifts southward through the area
during this time.

Forecast soundings remain mixed with the amount of deep
moisture available, so there is uncertainty with how much
precipitation may occur. For now, kept the 20 to 30 percent
chances for light rain later Saturday night into Sunday morning.
A little light snow may mix in on the back end of the
precipitation Sunday morning, though this potential is rather
small (under 20 percent).

High pressure will then move across the region Sunday night and
Monday, then to the east Monday night. South to southwest winds
Tuesday may usher milder temperatures back into the area with
some warm air advection.

Wood

&&

.LONG TERM...
Issued 1226 AM CDT Sat Mar 21 2026

Tuesday night through Friday night:

Synopsis: Modestly cooler conditions will prevail Wednesday
afternoon behind a late Tuesday/Tuesday night frontal passage.
Significantly colder conditions continue to appear unlikely,
with winds shifting out of the southeast by the afternoon hours.
Loose consensus amongst the global ensemble suite suggests that
broad low pressure will develop in the Central Plains Wednesday
afternoon and night, with surface pressure falls elongating
across the eastern half of the CONUS through Thursday night.

Said surface evolution thus continues to put a cold front on
track to move through the western Great Lakes during the day
Thursday. Precip chances return to the forecast Wednesday night
into Thursday along and ahead of the front. Global guidance
suggests that seasonably strong high pressure will settle into
the western Great Lakes Thursday night through Friday night
behind the departed front, resulting in a more noticeable cool
down at the end of next week.

Wednesday Night into Thursday: Precip chances return to the
forecast along and ahead of a passing cold front. Could see
precipitation focus along pre-frontal warm advection Wednesday
evening/night, with chances continuing into the day Thursday as
the passing surface boundary. Current temperature forecasts and
probabilistic p-type forecasts continue to point toward all
rain, with trends continuing to be monitored in coming updates.

Initial forecasts from the LREF suggest that instability for
convection will remain largely south of the region, which is the
likely outcome if the surface progression currently projected
by the ECMWF and Canadian ensemble systems verifies. It is
worth noting, however, that the GEFS presents a deeper and more
northeast progression of surface low pressure, which would open
the door for a slower frontal passage and more time for
instability to build into southern Wisconsin. Will be treating
this solution as an outlier for the time being and leaving any
thunder mentions out of the forecast, but will be watching for
any changes over coming updates.

Quigley

&&

.AVIATION...
Issued 1226 AM CDT Sat Mar 21 2026

Patchy fog with 2 to 6 mile visibility should linger overnight
into early Saturday morning over these areas with a solid
snowpack on the ground. Some dense fog with visibility down to
1/4 mile may occur, mainly in low lying areas. The middle to
high clouds that are moving through may deter some of the fog
development. These clouds should move out of the area by later
Saturday morning.

Winds will shift from the southeast and south to southwest on
Saturday. Gusty southwest winds should develop by midday
Saturday and should push to most of the lakeshore terminals by
middle afternoon. Areas toward Sheboygan may remain south until
the southwest winds arrive by 00Z Sunday. This should allow for
warm temperatures to move into most of the area.

A cold front will push south through the area Saturday evening,
with north to northeast winds increasing overnight into Sunday.
Colder air will move into the area. A low cloud deck with
ceilings around 1000 to 1500 feet AGL should push southward
into the area during this time as well.

There are generally 20 to 30 percent chances for light rain
later Saturday night into Sunday morning. A little light snow
may mix in on the back end of the precipitation Sunday morning,
though this potential is rather small (under 20 percent).

High pressure will then move across the region Sunday night and
Monday, with lighter winds and dry conditions.

Wood

&&

.MARINE...
Issued 1226 AM CDT Sat Mar 21 2026

Winds will become light overnight, as high pressure around 30.3
inches builds in from Ontario. The high will move east into
Saturday, allowing winds to shift southeast to south. Low
pressure around 29.5 inches developing in eastern Wyoming
Saturday morning will move east southeast Saturday night to the
south of Lake Michigan. This will allow southwest winds to shift
to the north and northeast and become gusty later Saturday
night into Sunday morning.

Gusty southwest winds this afternoon and early evening may reach
Small Craft Advisory levels for the nearshore waters.

The low should move across central Illinois into Indiana Sunday,
as it deepens to around 29.4 inches. A few northerly gales are
possible Sunday, mainly over southern portions of the lake.
Gusty north to northeast winds and building waves will likely
reach Small Craft Advisory levels Sunday into Monday morning.

High pressure around 30.4 inches should then bring decreasing
winds for Monday.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

$$

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