NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 141052 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
552 AM CDT Thu May 14 2026

.KEY MESSAGES...

- Shower chances (30 to 60 percent) continue across the area
  tonight, with the highest chances in northern parts of the
  area.

- There are small chances for showers and storms later Friday
  night into early Saturday morning. There is a lot of
  uncertainty if and where any showers and storms may develop.

- Warm and breezy conditions are expected Friday, with warm and
  increasingly humid conditions this weekend into early next
  week.

- Chances for showers and storms (30 to 50 percent-plus
  chances) are forecast at times this weekend into early next
  week.

&&

.UPDATE...
Issued 552 AM CDT Thu May 14 2026

High pressure moving southeast of the area today will bring dry
and pleasant conditions. A southeast lake breeze is expected by
midday into the afternoon near Lake Michigan. Highs in the upper
60s to lower 70s inland are forecast, with cooler values near
the lake.

Some low level warm air advection and a low level jet may bring
some moisture into the area tonight, with a passing 500 mb
vorticity maximum. CAMs are showing some light showers moving
east northeast across the area, with the better chances in far
northern portions of the area where better upward motion
resides. Kept 30 to 60 percent chances, highest in the far
north, for tonight.

Warm air advection on breezy south winds Friday should bring
warm temperatures into the middle to upper 70s, with some lower
80s in northwest parts of the area. There may be some cooler
temperatures right along the lakeshore north of Milwaukee.

There are chances for showers and small chances for storms later
Friday night into early Saturday morning (30 to 60 percent
chances for showers, highest west of Madison, with 20 percent
chances for storms). The higher PoPs were cut back to just areas
west of Madison.

There is a lot of uncertainty if and where any showers and
storms develop. It will depend on where the low level jet nose
sets up and if any storms develop to the west and move east into
the area. There are indications that this activity may remain
to the south of the area, if the low level jet focuses more
there.

SPC has a marginal severe risk in western portions of the area
later Friday night, as there could be enough elevated CAPE and
effective shear in that layer to support some hail. However,
there is a fairly large cap that may limit any elevated storms,
so a lot of uncertainty remains for this period.

Wood

&&

.SHORT TERM...
Issued 1121 PM CDT Wed May 13 2026

Overnight through Friday:

Skies cleared and the northerly winds diminished quickly this
evening with the sunset. High pressure, clear skies, calm wind,
and dewpoints in the mid 30s will allow temps to cool into the
upper 30s tonight. There will be a few pockets of cooler temps,
closer to 36. Thus, patchy frost is possible late tonight,
especially within the Rock River valley and toward central WI.

High pressure will slowly cross Wisconsin and lower Michigan
tonight through Thursday night. This means light winds for
southern WI with a lake breeze developing by early afternoon,
pushing inland in the late afternoon and early evening. The
return flow around the high will give us high temps in the lower
70s west of Madison.

An upper trough associated with a closed upper low tracking
across the Canadian Plains will cross MN and WI Thu nt into Fri
morning. The strongest mid level forcing will be closest to this
upper low, so over northern WI, but weak 850mb warm air
advection will be ongoing over southern WI. In addition, a weak
shortwave will be crossing IA and northern IL. So the forecast
6-hrly precip fields in the models shows up as a north-south
band of rain crossing WI Thu nt into Fri morning. However, the
precip should be light, scattered, and probably with the
steadier precip focused toward northern WI and northern IL
(splitting around southern WI). This event is not a promise for
a soaking rain for us.

Once the trough clears us by mid morning, expect sunshine and
high temps in the upper 70s to around 80 on increasing southerly
winds.

Cronce

&&

.LONG TERM...
Issued 1121 PM CDT Wed May 13 2026

Friday night through Wednesday:

Thunderstorms are looking more likely to develop in the Plains
(Kansas/northern MO/southeast IA) Friday evening on the nose of
the low level jet. If a large complex develops, it would track
into northern IL and may be clip southern WI late Fri nt. There
is uncertainty in how far north this complex could get, so
southwest WI and portions of south central WI were included in
the afternoon Day 3 SPC Convective outlook. Models seem to favor
the southern route at this time (not in WI).

The Midwest weather pattern will become more active Saturday
through Monday as an upper trough develops in the western US.
Southern WI has chances for thunderstorms each
afternoon/evening/overnight, but our chances will be closely
tied to where the previous complex diminished, and where the
effective warm front sets up. The day with the strongest forcing
closest to southern WI will be Monday.

Saturday highs will be in the lower 80s. With westerly winds of
10 mph or less, the lake breeze may be able to overcome it by
late afternoon, but that will be late enough for lakeshore highs
in the upper 70s. Sunday will be a reload day in terms of heat
and humidity, and we may see some showers and thunderstorms with
warm air advection, mainly in south central WI. Highs Sunday
should have a large gradient across southern WI, ranging from
the lower 60s near Sheboygan to the lower 80s near Darlington
(Lafayette county).

Monday looks very warm (highs in upper 80s), but only if the
warm front can get all the way up into northern WI and if the
precip holds off until the afternoon.

Cronce

&&

.AVIATION...
Issued 552 AM CDT Thu May 14 2026

High pressure moving southeast of the area today will bring dry
and pleasant conditions. A southeast lake breeze is expected by
midday into the afternoon for terminals near Lake Michigan, with
light south winds inland.

Some light showers (30 to 60 percent chances, highest far
northern areas) are forecast tonight. May add in PROB30 groups
for some terminals. Ceilings and visibility should remain VFR
category. South winds should gradually increase tonight.

Breezy south winds are expected Friday, with gusts up to 25
knots at times in the afternoon. Some diurnal cumulus clouds
around 3500 feet AGL may develop during the day.

Wood

&&

.MARINE...
Issued 552 AM CDT Thu May 14 2026

Northwest winds will weaken later this morning into this
afternoon, as high pressure around 30.1 inches moves southeast
over Lake Michigan. The high will move southeast tonight, with
breezy southerly winds developing on Friday and lingering into
Friday night.

A few gales are possible Friday afternoon and evening in
northern portions of the lake. A Small Craft Advisory may be
needed for Friday into Friday night for the nearshore waters of
Lake Michigan.

Southwest to south winds may linger into Saturday, before
northeast to east winds develop Saturday night into Sunday and
increase, as a warm front develops to the south of the region.
The increasing winds should then become southeast Sunday night
and south into Monday, as the warm front moves northward across
the region. Showers and thunderstorms may accompany the warm
front as it moves northward Sunday night into Monday.

Winds and waves may reach Small Craft Advisory levels Monday
for the nearshore waters of Lake Michigan, perhaps lingering
Monday night into Tuesday.

Cronce/Wood

&&

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

$$

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