NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 091613 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
1113 AM 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 lingering
  into the early afternoon in southeast WI.

- Rain with some embedded thunderstorms expected Tuesday evening
  through Tuesday night (70-90%). Temperatures will drop
  Wednesday morning with a transition to a wintry mix, then
  light snow (40-60%).

- Active pattern for the later half of the week with increased
  precipitation chances Thursday evening/night, and again
  Saturday night into Sunday.

&&

.UPDATE...
Issued 1112 AM CDT Mon Mar 9 2026

Temperatures are rapidly rising this morning and the southwest
gusty winds are persisting a little longer than anticipated,
especially in southeast WI. The main forecast update this
morning was to lower the relative humidity values as dewpoints
are not expected to rise much today. Temperatures may rise a
degree or two higher than previously forecast as well.

Cronce

&&

.SHORT TERM...
Issued 1150 PM CDT Sun Mar 8 2026

Today (Monday) through Tonight (Monday night):

A southwest breeze continues as deep low pressure tracks eastward
across Lake Superior, with strong low-level WAA holding low
temperatures to the 40s early this morning. Forecast soundings hint
at only a few mid to high altitude clouds (over the 700mb level,
mainly further north towards central WI) through the daytime hours
today, leaving skies almost completely clear. Light southwesterly
WAA continues through the morning, then winds decelerate (becoming
light and variable) through the afternoon as a weak frontal boundary
sags southward into the region. Forecast highs are in the mid to
upper 60s across the region. Both the Milwaukee and Madison high
temperature records for March 9th (67 in 2016 and 66 in 1977
respectively) could possibly be tied or broken. The southwesterly
flow will block any attempt at a lake breeze before noon, though one
may develop later in the afternoon as the frontal boundary sags
south, particularly further north

A light northeasterly breeze gradually develops Monday night as high
pressure builds into central Canada and low pressure deepens from
the central Plains to the Mississippi River valley. The cooling
effect of Lake Michigan and mostly clear skies will work together to
rapidly drop temperatures Monday night, with a low in the mid to
upper 30s for much of the region (low 40s towards the IL border).

Sheppard

&&

.LONG TERM...
Issued 1150 PM CDT Sun Mar 8 2026

Tuesday through Sunday:

Low pressure is expected to track east-northeastward from the
central Plains through Ohio mid week, resulting in 60-90% precip
chances on it's closest approach Tuesday into Wednesday. Though the
center of the low is currently expected to pass just south of the
region, and northeasterly winds off Lake Michigan will halt the
advance of the surface warm front well shy of our region, some
elevated convection (thunderstorms) north of the warm front will be
possible in southern WI, especially further south towards the IL
Border where a marginal (level 1 out of 5) risk for severe hail is
present. This activity would likely arrive (roughly) late Tuesday
afternoon, peak in the evening, then transition to light stratiform
precip late Tuesday night. Forecast soundings reveal an LFC above
the 700mb layer, with plenty of stable marine air beneath it. We'll
be watching the track of the low closely, but for the time being
we're mainly looking at small (less than 1 inch) hail potential and
lightning.

Light stratiform precip is likely to continue late Tuesday night
through Wednesday morning (65-90% chance), with ~45% chances to
continue into Wednesday afternoon. A northwest to southeast
transition from rain to light wintry mix or snow is looking likely
early in said period, with a chance for slushy accumulations and
slowdowns on the Wednesday AM commute (particularly for the northern
half of the CWA, north of the I-94 corridor). It's too early to
advertise snow totals with this type of mixed precip event
(especially with the antecedent warm weather and soil / pavement
surface temps), but our best guess is in the ballpark of 1 inch
slushy snow accumulations north of the I-94 corridor, with only a
fraction of an inch to zero accumulation further south due to
melting / later arrival of the cooler temps and rain to snow
transition.

Predominantly dry weather expected Wednesday night into Thursday as
high pressure builds in behind the departed low. A clipper system is
then expected to track eastward into our region, delivering ~60%
precip chances Thursday evening / night. Both rain and wintry precip
are possible with this system, though the ensemble mean system track
is centered further north in the state, hence we're leaning towards
mostly rain and little / no wintry accumulation despite the
nocturnal timing. Additional chances for FGEN or clipper system
driven precip at times this upcoming weekend. Ensemble temperature
IQRs are centered near seasonal norms this weekend, and may trend
colder into the first half of next week.

Sheppard

&&

.AVIATION...
Issued 448 AM CDT Mon Mar 9 2026

LLWS until 15Z today via a swly low level jet of 50 kts over
srn WI. Otherwise VFR conditions today and this evening. Areas
of MVFR Cigs and BR will develop during the overnight mainly
over the ern half of WI. Stratus and areas of fog will then
gradually overspread srn WI on Tue.

Gehring

&&

.MARINE...
Issued 1112 AM CDT Sun Mar 8 2026

Breezy southwest winds will diminish through this afternoon.
Southwest wind gusts are exceeding 20 KT right along the
lakeshore. The expectation was that gusts would diminish by late
morning but they are hanging on a couple hours longer.

A cold front will gradually shift from north to south across
Lake Michigan from late afternoon and through the night. Modest
to brisk northeast winds will develop into Tuesday.

Low pressure around 29.6 inches then develops in the central Great
Plains and progresses into northern Illinois Tuesday night,
keeping winds northeasterly and gusty, with 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. 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.

&&

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

$$

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