NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 020558
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1158 PM CST Sun Mar 1 2026

.KEY MESSAGES...

- Light rain chances (~20-40%) return Monday night through
  Tuesday morning. Some light snow or freezing drizzle could
  briefly mix in at the onset of precip, though widespread
  impacts aren't currently anticipated.

- Temperatures trending well above normal Tuesday through the
  end of the week.

- Additional periods of rain forecast Wednesday-Thursday
  (~30-50% chances) & Friday-Saturday (~60-80% chances). Some
  thunderstorms are possible in each round of rain.

&&

.SHORT TERM...
Issued 1159 PM CST Sun Mar 1 2026

Tonight through Monday:

Synopsis/Mesoanalysis: High pressure is migrating into Ontario this
evening, allowing for a mixture of light but persistent
northeasterly to southeasterly surface winds across southern
Wisconsin. Pockets of earlier day lake effect clouds remain along
the Kettle Moraine vicinity, but have been trended progressively
more scattered as the evening has progressed. Expect this trend to
continue through the overnight hours tonight as light low level
breezes persist. Currently near the Saskatchewan-Manitoba border,
low pressure will progress east toward the Hudson Bay on Monday as
high pressure stalls near Lake Ontario. Said progression of the two
surface features will maintain broad south to southeasterly winds
regionally. Attendant warm air advection & mostly sunny skies will
thus support milder high temperatures Monday afternoon, with most
locations expected to climb into the low to mid 40s. Anticipate
cooler temperatures in the mid-upper 30s near the Lake Michigan
shoreline.

Quigley

&&

.LONG TERM...
Issued 1159 PM CST Sun Mar 1 2026

Monday night through Sunday:

Synopsis: The upper pattern will trend more active Monday night
into next weekend, with several disturbances bringing a trio of
rain chances to southern Wisconsin. The first is forecast to
arrive late Monday night into Tuesday morning, with precip
focusing along/ahead of increasing low level warm advection.
Depending on temperature trends ahead of the arriving precip,
some light snow or freezing drizzle could mix in at the start of
rainfall during the predawn hours Tuesday, with continued
warming of the column allowing for a changeover to all rain
near & after sunrise. Affiliated with upper level energy
currently over northern California, a shortwave trough will
eject into the Central Plains Wednesday afternoon, bringing the
second rain chance of the period Wednesday night into Thursday
as it moves across the western Great Lakes. The third and likely
greatest rain chance of the period arrives Friday into Saturday
as a dynamic upper jet, trough, and affiliated surface front
move through the region. Embedded thunderstorms are possible
with rain Wednesday night-Thursday & Friday-Saturday. With
surface winds largely ranging between easterly and southerly
ahead of & between systems, temperatures will steadily trend
upward through mid-week, with readings climbing well above
early March normals by Friday. Following a minor cool down
behind the Friday-Saturday cold front, southwest winds will
return by Sunday, allowing for a return of well above normal
temperatures.

Monday night into Tuesday morning: The first rain chance of the
period arrives during the predawn hours. Of the three systems
bringing rain chances to southern Wisconsin this week, synoptic
forcing will be most marginal during this round, with precip also
needing to overcome lingering dry air in the low levels. Best
chances for precip will thus focus where warm advection overlaps
with a band of decaying frontogenesis in the 850-700 mb layer, with
the precise track of said frontogenesis still uncertain as of this
forecast. Have continued to carry broad 20-40% precip probabilities
in light of location uncertainties, with the expectation that a
narrower area of higher probabilities will be introduced as
frontogenesis placement clarifies over coming forecasts. As stated
above, will continue monitoring for potential light freezing drizzle
or snow briefly mixing in with rain at the onset of precipitation,
as temperatures will be hovering just above or at the freezing mark.
Current thinking is that is that any mix would be short-lived, with
continued low level warming allowing for a changeover to all rain by
sunrise. Thus don't anticipate widespread impacts in the event that
brief rain-snow-freezing drizzle mix occurs, but will be closely
watching trends. If surface temps were to trend colder,
potential for a light glaze of ice or dusting of snow would
increase. Will provide additional updates as necessary in coming
forecasts.

Wednesday into Thursday: Expect the next round of rain as a
shortwave trough moves across southern Wisconsin. MUCAPE forecasts
from the LREF hint at some weak (~100-250 J/kg) elevated instability
across parts of the region, particularly Wednesday afternoon and
evening as the upper wave & coldest mid-level temperatures pass
overhead. Thus can't rule out a few thunderstorms Wednesday
afternoon and evening. Not currently anticipating any hazards
outside of some lightning, but will nevertheless be monitoring
trends.

Friday through Saturday: The best precip chances of the period
arrive ahead of pronounced upper level dynamics & an accompanying
surface cold front. Mild surface temps will allow for all rain, with
LREF soundings suggesting a touch more instability (~250-500 J/kg).
Thus anticipate additional embedded thunderstorm potential during
the Friday-Saturday time frame. Will need to monitor these
instability trends in coming forecasts, as the encroaching upper jet
will provide plenty of deep layer shear to allow for a few stronger
storms in the event instability trends up. Tend to agree with
current machine learning guidance, which holds better potential for
strong storms from Illinois into the Ohio Valley (where instability
will be higher). Will also need to monitor for heavy downpour
potential in embedded thunderstorms, as precipitable water values
will be approaching 1 inch/3 standard deviations above early March
normals.

Quigley

&&

.AVIATION...
Issued 1159 PM CST Sun Mar 1 2026

VFR flight categories prevail through the period at all southern
Wisconsin terminals. Earlier lake effect clouds have eroded near
Lake Michigan, with mostly clear skies anticipated through most of
the day Monday. Scattered upper clouds based between FL020 and FL250
will move in from the southwest Monday evening ahead of the next
disturbance. Clouds will gradually thicken later Monday night, with
CIGs dropping to/below FL100 nearing daybreak Tuesday. Some light
precipitation is possible as the aforementioned disturbance crosses
southern Wisconsin late Monday night/early Tuesday morning. Have
accounted for this potential with a PROB30 group nearing the end of
the 30 hour period at MKE, with mentions anticipated in later
forecasts at other fields. Currently anticipate mainly -RA, though
will be monitored for some light -SN or -FZDZ at the immediate onset
of precipitation. Confidence in any wintry precip is too low to
justify any mentions at this time.

Quigley

&&

.MARINE...
Issued 1159 PM CST Sun Mar 1 2026

1036 mb high pressure is centered over southern Ontario late this
evening, resulting in generally light winds across the open waters
of Lake Michigan. Winds will trend southerly through the second half
of the overnight hours as the high continues east and 1006 mb low
pressure moves across northern Manitoba. Said low will move into the
Hudson Bay Monday afternoon, resulting in breezy winds across Lake
Michigan. Gusts between 25-30 knots are possible over the northern
third of the open waters, though gales are not expected at this
time. Winds will subside Monday night through Tuesday as low
pressure shifts into Quebec and 1032 mb high pressure builds into
Ontario, with light and variable winds continuing into Tuesday
evening.

Winds will trend east-northeasterly across the open waters late
Tuesday night through Wednesday as 1012 mb low pressure develops in
the southern Great Plains and shifts northeast toward the
Mississippi River. The low will approach and ultimately pass near or
just south of the southern open waters Wednesday night into Thursday
morning, with gales not expected at this time. Periods of rain will
accompany the approaching/passing low Wednesday into Thursday, with
a few thunderstorms possible over southern Lake Michigan Wednesday
afternoon and evening. Severe weather is not anticipated at this
time.

Another area of 1002 mb low pressure will form in the central Great
Plains Thursday night, and is forecast to progress toward the Upper
Mississippi River Valley during the day on Friday. The low's
approach will bring increasing southerly winds to the open waters on
Friday, along with widespread areas of rain and embedded
thunderstorms. The low will move from the Upper Peninsula of
Michigan toward the southern Hudson Bay Friday night through
Saturday, dragging a cold front across Lake Michigan in the process.
Additional rain is expected during the frontal passage. Winds will
veer southwest to westerly as the front passes. A few gales are
possible, with more widespread gale potential depending on the still
uncertain precise track & central pressure of the passing surface
low. Will continue to monitor trends in coming forecasts.

Widespread rain & a few thunderstorms are possible in nearshore
zones Wednesday into Thursday as low pressure passes over or just
south of southern Lake Michigan. Additional rain and thunder are
expected Friday into Saturday as a second area of low pressure moves
from the central Great Plains toward Lake Superior. Waves and wind
gusts could approach Small Craft Advisory thresholds ahead of the
approaching/passing surface low Friday into Saturday, with trends
being monitored for potential headlines in coming forecasts.

Quigley

&&

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

$$

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