NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 091921
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
221 PM CDT Mon Mar 9 2026

.KEY MESSAGES...

- Record high temperatures in the upper 60s to around 70 today.
  The relative humidity values are running lower than previously
  forecast and gusty southwest winds are expected to continue
  into mid-afternoon.

- Rain and embedded thunderstorms are expected to develop
  Tuesday evening, with the first round of rain producing
  isolated strong to severe storms with the primary threats
  being hail 0.5 to 1 inch in diameter and frequent lightning.

- Rain will transition to a brief period of freezing rain and
  snow late Tuesday night as low pressure exits. Up to a glaze
  of icing and up to an inch of snow possible in central
  Wisconsin, with southern Wisconsin (I-94 southward) seeing
  less than an inch of snow.

- Increased precipitation chances (70-80%) Thursday
  evening/night, with expectations for some snow to mix in with
  rain overnight into Friday morning.

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

&&

.SHORT TERM...
Issued 220 PM CDT Mon Mar 9 2026

This afternoon through Wednesday:

The forecasted weak front is slowly working its way eastward
through southwestern Wisconsin this afternoon, with wind gusts
finally diminishing across south-central Wisconsin. Temperatures
continue to climb, with current temperatures ranging from 60
degrees in Sheboygan to 69 degrees in low lying and downsloping
areas. Will likely see records broken this afternoon as we still
have a few more hours of rising temperatures. In addition,
expecting relative humidities to continue to fall, with minimums
in the low 30s.

Tonight, winds will briefly become light and variable before
turning northeasterly as a back-door cold front progresses
southwestward through the region. This will bring in cooler air
and temperatures in the mid 30s to low 40s.

Tuesday, expecting northeasterly winds to continue as low
pressure develops in the central Plains and lifts northeastward
into northern Illinois. Warm frontogenesis will create the first
waves of precipitation across southern Wisconsin Tuesday
afternoon into Tuesday evening. Very strong WAA aloft (850-700
mb) will contribute to a strong warm nose in the mid-levels and
therefore MUCAPE in the 1000-2000 J/kg range. The first waves
of storms to develop along the nose of this MUCAPE boundary in
the mid-levels look to become capable of producing hail up to 1
inch in diameter (bulk shear in the 60 to 80 kt range and
freezing levels around 700 mb while storm top nears 250 mb based
on sounding data). Expecting storms to quickly devolve into
multicellular clusters due to shear largely parallel to the
frontal boundary, therefore then preventing storms from
remaining severe through the overnight hours. However, an
isolated stronger storm cannot be ruled out.

Cold air advection at the surface takes hold going into the late
overnight hours Tuesday (after midnight), as low pressure ejects
into Lower Michigan. The 850 mb warm nose is strong enough to
linger through Wednesday morning, allowing for a period of freezing
rain in regions that surface temperatures fall below freezing,
then a transition to snow as the warm nose whittles away into
the morning hours. Currently, temperatures are forecast to fall
below freezing mainly north of I-94, but a slight shift in low
track may allow for freezing temperatures through the I-94
corridor as well and therefore lead to impacts through the
Madison and Milwaukee metros during the morning commute. Gusty
northwesterly winds are also expected during this time.
Temperatures are expected to rise slightly during the day to
above freezing, which would allow for a transition to a mix of
snow and rain through at least midday. A minor shortwave
wrapping around the mean flow may contribute to snow/rain
showers into the afternoon hours before tapering off.

MH

&&

.LONG TERM...
Issued 220 PM CDT Mon Mar 9 2026

Wednesday night through Monday:

Low pressure exits eastward into southern Quebec Wednesday
night, continuing to deepen as it ejects, leading to continued
steady northwesterly winds throughout Wednesday night. Expecting
lows in the mid-20s as high pressure builds into Thursday
morning.

Winds shift southwesterly into Thursday afternoon ahead of an
approaching low pressure system from the northern Plains.
Temperatures will rise back into the mid-40s Thursday afternoon
within the warm sector of this low, allowing for precipitation
along the warm front in the afternoon hours to start as rain.
Modeling currently indicates southern Wisconsin will remain in
the warm sector through the late overnight hours, transitioning
to a mix of rain and snow behind a cold front during the early
morning hours Friday. Expecting this mix to produce minimal
accumulations at this time. Modeling has been trending southward
with the parent low, and a slight shift farther south could
result in an inch or two in central Wisconsin.

Low pressure sweeps eastward out of the Upper Midwest by Friday
afternoon, with high sun angle allowing for temperatures to
recover into the low 40s even with gusty northwest winds. Winds
will diminish into the evening under a ridge of surface high
pressure, with overnight lows in the mid 20s again.

Saturday, low pressure will deepen in the lee of the Wyoming
Rockies as a shortwave rides southeastward through the northern
High Plains. This low will allow for warm frontogenesis to
develop across southern Wisconsin, bringing chances for
precipitation (20-40%). Precipitation will likely start as snow
during the early morning hours, but transition to rain into
midday Saturday as the warm front lifts northward. Saturday
night into Sunday morning, low pressure deepens and ejects
northeastward into northern Illinois. This will serve to enhance
CAA across Wisconsin, and may bring a return to snow across
central to southern Wisconsin through the late overnight hours
into Sunday morning. Precipitation chances are high (~80%) at
this time. Current modeling indicates low pressure progressing
right through southern Wisconsin, which may bring more of a
drizzle/warm sector scenario to the area before the cold front
brings back snow during the afternoon to evening hours. Ensemble
guidance is indicating a moderate (50-70% chance) for totals
around 3 inches, so keep an eye on the forecast as the event
nears. Gusty northwest winds will also develop Sunday afternoon
after the low passes eastward.

Snow tapers off into Monday morning as low pressure ejects
eastward into the Northeast U.S., with a brief wave of Arctic
high pressure bringing highs in the mid-20s. High pressure
lingers through Monday night.

MH

&&

.AVIATION...
Issued 220 PM CDT Mon Mar 9 2026

VFR through tonight. Gusty southwest winds are lingering through
the afternoon and will diminish quickly around sunset as a weak
cold front approaches. That front will slowly drop through
southern WI overnight, with winds switching to the northeast and
becoming gusty before dawn Tuesday morning and inland areas
having the wind shift after dawn.

Marine fog over southern Lake Michigan may impact Kenosha, Racine
and Milwaukee counties Tuesday morning. Reduced visibilities and
IFR stratus are possible. This potential for fog looks brief, as
northerly winds will help dry out the low levels, but stratus may
linger.

Look for showers and isolated thunderstorms to push into southern
WI late Tuesday afternoon. Any stronger storms could produce hail
through midnight. Rain will persist overnight, but then gradually
switch over to snow northwest of Madison from early to mid Wed
morning. IFR ceilings are expected with the rain Tuesday evening,
and then LIFR is possible Tuesday night through Wednesday morning.

Cronce

&&

.MARINE...
Issued 220 PM CDT Mon Mar 9 2026

Breezy southwest winds will diminish through this evening as high
pressure around 29.9 inches pushes into the Upper Great Lakes.
Marine dense fog may develop over far southern Lake Michigan early
Tuesday morning with the lull in the winds. A cold front will
gradually bring a wind shift to the west- northwest and eventually
north- northeast. This front will accelerate from north to south
overnight down Lake Michigan overnight. Brisk northeast winds of
15 to 25 KT developing Tuesday morning will persist through
Tuesday night.

Low pressure around 29.6 inches then develops in the central Great
Plains and progresses into northern Illinois Tuesday night. There
is some potential for isolated thunderstorms across the southern
third of the Lake. Low pressure ejects to the lower Great Lakes
into Wednesday morning, turning winds northwesterly. 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.

Cronce

&&

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

$$

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