NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 201858
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
158 PM CDT Fri Mar 20 2026

.KEY MESSAGES...

- Chance for some fog, possibly dense, toward central WI
  tonight.

- Above average temperatures through the middle of next week
  with highest temperatures expected Saturday.

- Next chances (10-25%) for precipitation mainly into Sunday.
  Next best chances (25-40%) likely for next Thursday

&&

.SHORT TERM...
Issued 200 PM CDT Fri Mar 20 2026

Tonight through Saturday night:

Late tonight there will potential for patchy fog that may become
dense toward central WI as moisture from snow may be trapped
under a fairly significant inversion layer. Fog from this may
bleed into parts of southern WI. Fog should quickly dissipate as
the sun rises.

Quiet conditions in the short term expected as large scale
ridging in the southwest US keeps our region warm and dry with
any system pushing through well to the north of the CWA. Highs
Saturday will be on the warm side with a chance for mid 70s in
parts of southwest WI. Otherwise at the surface, low pressure
swings through the central Great Lakes today with weak high
pressure developing into the region tonight while another low
pressure system swings into WI Saturday bringing southerly flow
back to southern WI, which will aid in the warm temperature
trends for Saturday. The low will swing through overnight but we
will likely remain on the dry side of the low at least through
Saturday night.

Kuroski

&&

.LONG TERM...
Issued 200 PM CDT Fri Mar 20 2026

Sunday through Friday:

Quite a bit of uncertainty with this Sunday system particularly
as it relates to low to midlevel moisture. With the low pressure
system coming through precip chances seem fairly high across
northern WI but chances further south across southern WI are more
dicey. This is primarily due to less upper level forcing in a
zonal flow regime in combination with limited 700mb moisture and
questionable low level moisture. On the other hand fairly
substantial midlevel Fgen and WAA will bring increased forcing in
the low to mid levels. This looks like the precip potential for
this event will come down in large part to midlevel moisture and
whether the 700mb band of moisture can hold on long enough before
it dries out. Best precip chances in the CWA look likely to be in
east central WI.

Early next week looks largely dry as a result of dry air and the
fact that a weak ridge will be sliding into the region along with
high pressure sliding through the region. Any precip chances
likely remain well north of the CWA until at least midweek.
Tuesday night through Thursday chances will begin to increase as
shortwave activity increases with increased moisture in the
midlevels. Still plenty of uncertainty as some models suggest
moisture and better forcing at various times but precip chances at
least mildly increase for that period. The best chance for precip
next week looks to be Thursday related to a fairly strong surface
low and upper level shortwave swing through. Current dryness in
the models complicates precip chance for this time but the forcing
is plenty and moisture can always be a bit more questionable in
the long term. In any case things would be expected to dry out
behind the front Friday as strong high pressure pushes in. Next
weekend shows a bit more potential for activity behind the higher
pressure.

On the temperature front, the next week or so looks to be on the
warmer side as the jet remains north of the region in addition to
the impact of the large scale ridging in the the southwest US.
Best chance for a widespread return to more normal temperatures
comes after the frontal passage Thursday. Onshore lake winds may
keep northeast CWA cooler some days over the next week but the
predominant temperatures are expected to be above normal.

Kuroski

&&

.AVIATION...
Issued 200 PM CDT Fri Mar 20 2026

A few pockets of VFR/MVFR CIGS may push through later this
afternoon though current satellite imagery suggests this is less
likely at this point. Then later tonight into early Saturday
morning, moisture from linger snow in central WI may get trapped
under and inversion. This will likely lead to MVFR/IFR
CIGS/VSBYS over central WI. However some models suggest this may
very well bleed into some of southern WI. Otherwise the sun is
expected to quickly dissipate fog and low clouds Saturday
morning with light to modest southerly winds Saturday. Front
Saturday night will bring winds back to the north to northeast
Sunday.

Kuroski

&&

.MARINE...
Issued 200 PM CDT Fri Mar 20 2026

Tonight winds will become light as high pressure around 30.3
inches builds in from Ontario. Low pressure around 29.5 inches
develops in the lee of the Wyoming Rockies Saturday morning,
shifting winds south. The low should move southeastward Saturday
night, allowing winds to increase and shift to the north and
northeast across the northern half of the lake.

The low should move across central Illinois into Indiana Sunday,
as it deepens to around 29.4 inches. This should lead to northerly
winds backing to northwesterly Sunday into Sunday night across the
lake. A few gales are possible during this timeframe. A Small
Craft Advisory will likely be needed Sunday as a result of
breezy north to northeast winds. High pressure around 30.5
inches should then bring decreasing winds for Monday.

Kuroski

&&

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

$$

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