NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 050656
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1256 AM CST Thu Mar 5 2026

.KEY MESSAGES...

- Widespread fog with visibilities around 1-2 miles expected
  through this morning, with patchy dense fog possible. Dense
  fog is possible again overnight into Friday morning.

- Light rain or drizzle is possible through this morning across
  southeastern Wisconsin (~40 percent chance).

- Moderate to briefly heavy rainfall rates are possible Friday
  into Friday night, with embedded thunderstorms expected. A few
  strong to potentially severe storms may be possible Friday
  evening into Friday night.

- Very mild Friday and again Monday and Tuesday.

- Rain with perhaps a few embedded thunderstorms Tuesday into
  Tuesday night, with snow developing Tuesday night into
  Wednesday.

&&

.SHORT TERM...
Issued 1256 AM CST Thu Mar 5 2026

Today through Saturday:

Light easterly winds near Lake Michigan will bring in continued
low stratus and fog. Although confidence is high in widespread
fog development across southeastern Wisconsin into far south-
central Wisconsin, visibilities in the 1/2 to 1/4 mile
categories (dense fog) have considerably less confidence. Areas
to the south within the core of low pressure have certainly
seen dense fog develop, but in southern Wisconsin, farther away
from the core and mainly advection off Lake Michigan driven,
thinking only patchy dense fog is possible at this time. Still,
with very low stratus, and dew points near the temperatures,
could still see stratus build down to the surface by daybreak,
primarily in Ozaukee to Waukesha to Rock Counties south and
eastward.

Low stratus and patchy fog remain in place throughout the
remainder of today and tonight as southern Wisconsin remains in
light easterly flow within a seasonably warm airmass. Conditions
will improve through the day, with highs in the 40s to low 50s.
Overnight, as temperatures begin to fall again, patchy dense fog
becomes likely again. Widespread dense fog is possible late
tonight into Friday morning.

Friday morning, gusty southerly winds develop as a warm front
lifts through southern Wisconsin and brings a round of showers
and thunderstorms (80-100% chances). As this round of storms
progresses eastward into midday, more widespread thunder
activity is possible as MUCAPE values increase into the 750-1000
J/kg range. With a strong warm nose, the majority of this
activity will remain elevated, so strong to severe storms are
not expected during the morning hours.

Although capping remains in place in the low levels through much
of Friday afternoon, expecting temperatures to rise into the
mid to upper 60s across all of southern Wisconsin as stiff
southerly winds continue. If any sunlight is able to enhance the
warming, this capping whittles away quickly and creates a
surface-based thunderstorm. Regardless of capping, MUCAPE of
1000-1500 J/kg, 700-500 mb lapse rates of 7-8 degrees C/km, bulk
shear of 40-50 kt, and freezing levels near 700 mb will all
allow for hail potential in stronger storms. Any storms that do
become surface based will also be capable of producing gusty and
damaging winds, although these will likely much more isolated.

Storm coverage will become more isolated into the late afternoon
and evening hours Friday as the warm front lifts north into
northern Wisconsin. A cold front and associated pre-frontal
convection will then form the basis for the next round of
thunderstorms late Friday night into early Saturday morning.
MUCAPE will be lower (currently progged at 500-750 J/kg), but
bulk shear increases to 50-60 kt and a LLJ as high as 60 kt
noses into southern Wisconsin along with the front. In other
words, dynamic forcing is great, while instability may prevent
storms from tapping into the dynamics and becoming strong to
severe.

Cold front completes its progression through southern Wisconsin
by daybreak Saturday, with some lingering rain and storms into
this period. Lingering lighter showers may continue into
Saturday afternoon, but not anticipating any additional strong
or severe storms. Highs in the 50s are expected.

MH

&&

.LONG TERM...
Issued 1256 AM CST Thu Mar 5 2026

Saturday night through Thursday:

High pressure builds back into the region Saturday night as low
pressure exits, bringing clearing skies and lows in the mid to low
30s. Light winds will gradually turn southwesterly into Sunday
morning as a low pressure system pivots through southern
Manitoba into the Hudson Bay. This will result in warming
temperatures to near 60 degrees, potentially all the way to Lake
Michigan as a strong offshore component is expected. Winds
remain southwesterly through Sunday night, with lows in the 40s
expected. Southwesterly winds continue into Monday, bringing
highs in the upper 60s, and perhaps a few places nearing 70
degrees.

More uncertainty in the forecast develops Monday night, as model
solutions diverge on strength and therefore timing of a shortwave
propagating across the northern Plains into the Upper Midwest. The
GFS prefers a faster, stronger solution across northern Minnesota,
dragging a weak front through southern Wisconsin during the
early evening hours. Euro and Canadian prefer a weaker solution,
phasing with a developing low in the Montana Rockies and allowing
it to eject eastward into the Upper Midwest during this same time
frame. With these solutions at play, GFS brings precipitation
into southern Wisconsin as early as Monday night, while the Euro
and Canadian hold off until Tuesday afternoon into Tuesday night.
Have kept NBM PoPs in for this forecast cycle due to this
uncertainty, with high confidence (70% or higher) in Tuesday night
precipitation. Depending on timing and strength of this system,
the back side may see a rain snow mix to a brief period of
snowfall into Wednesday morning. Precipitation may still linger
into Wednesday afternoon if stronger solutions prevail, as wrap-
around precipitation will continue for several hours as low
pressure slowly moves out (30-40% chances).

Model solutions continue to show an amplified pattern through late
week, with confidence high in a low pressure system propagating
through the Upper Midwest in some capacity on Thursday, but low
confidence in exact placement and timing. Therefore, continued
with NBM output through late week.

MH

&&

.AVIATION...
Issued 1256 AM CST Thu Mar 5 2026

Light easterly winds off Lake Michigan will continue to bring in
IFR stratus through this morning and even throughout much of the
day into tonight. Widespread fog is expected from MKE to JVL
southward this morning, with patch dense fog (1/4 SM) possible.
Visibilities will improve briefly during the midday to afternoon
hours, before lowering again after sunset and spreading farther
inland. Ceilings and lowered visibilities are only expected to
begin to lift into Friday morning as gusty southerly winds
develop and scour out the low lying clouds. However, going into
Friday morning, a round of rain and thunderstorms is expected to
develop.

MH

&&

.MARINE...
Issued 1256 AM CST Thu Mar 5 2026

Weak low pressure around 29.9 inches over southern Illinois will
progress through the Ohio Valley today as high pressure around
30.7 inches lingers over the Hudson Bay, bringing increasing
easterly winds. Warm airmass will allow for dense fog (less than
1 NM) across southwestern portions of the Lake, with potential
to spread through the remainder of the southern third of the
lake through today into late tonight. Fog is expected to
continue through Friday morning, before winds shift to southerly
and become gusty ahead of low pressure of 29.4 inches developing
in the central Plains. Conditions may become hazardous for small
craft during this time. Rounds of rain and thunderstorm, with a
few storms becoming strong to severe, will progress through the
Lake Friday afternoon through Friday night as low pressure
progresses northeastward into Lake Superior. Late Friday night
into Saturday morning, a cold front will progress southeastward
through the Lake, bringing a final round of rain and storms and
turning winds to northwesterly. Winds remain light and
northwesterly through Saturday night. Winds turn back
southwesterly into Sunday morning as low pressure develops in
the Plains.


MH

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Dense Fog Advisory...LMZ644-LMZ645-LMZ646-LMZ671-LMZ673-LMZ675-
     LMZ777-LMZ779 until 6 AM Friday.

&&

$$

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