NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 150318 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
1018 PM CDT Thu May 14 2026

.KEY MESSAGES...

- Shower & thunderstorm chances (30 to 60 percent) tonight.

- There is a 40 to 60 percent chance for showers and storms
  Friday night into early Saturday, though a lot of uncertainty
  remains with the development and placement of these storms.

- Warm and increasingly humid conditions this weekend into early
  next week along with additional shower/storm chances. There
  will be a chance for strong to severe storms on Sunday and
  Monday.

&&

.UPDATE...
Issued 1018 PM CDT Thu May 14 2026

The warm air advection is aiding a narrow line of thunderstorms
that are tracking through eastern Iowa this evening. The bulk of
these storms are trending into northern IL, but some lightning
will make it into south central WI with this batch of showers.
There should be a weakening trend as they get into southeast WI
around midnight.

Cronce

&&

.SHORT TERM...
Issued 1225 PM CDT Thu May 14 2026

Tonight through Friday night:

There will be a chance for showers tonight as moisture and warm
air advection aloft increase with the passage of a shortwave.
Models are still showing a lot of dry air in the lowest 10 kft
though, with model QPF also limited. Kept precip chances around
50 percent for now as a result. This will probably be a
situation where precip chances are adjusted higher or lower
based on if much rain is hitting the ground upstream as the
precip approaches.

It should be mainly dry and warm on Friday behind the departing
wave. Clouds will probably linger through the morning as the 850
mb trough exits, but there should be increasing sunshine in the
afternoon. The afternoon sun in combination with breezy
southerly winds should result in high temps in the mid 70s to
around 80 most places.

Confidence is increasing in a round of showers and storms Friday
night into early Saturday morning. The gradient of deeper
moisture and higher instability is expected to be across
southern Wisconsin, which will open the door for upstream
convection to roll through the forecast area overnight. There is
still some uncertainty with storm timing and placement, but
precip chances are on the upward trend for this period.

DDV

&&

.LONG TERM...
Issued 1225 PM CDT Thu May 14 2026

Saturday through Thursday:

Saturday still looks warm and mainly dry, though the chance for
showers and storms continue to gradually increase. This is
because models continue to trend northward with the higher
dewpoints, bringing a more unstable environment into southern
Wisconsin. That said, the Fri night precip may shut down storm
chances for much of Saturday, especially if showers/storms
don't exit until early to mid-morning. Though the moisture and
instability may be in place, there might not be much of a
trigger to kick off storms during the daytime hours.

Storm chances will increase Saturday evening into Sunday as the
deeper moisture and widespread instability return to southern
Wisconsin along with a shortwave lifting through the area.
Above normal temps are expected Sunday, though there is some
uncertainty with afternoon highs, depending on the timing of
clouds and precip. Instability, lapse rates, and shear on Sunday
suggest a severe storm potential as the wave lifts through
during the morning and early afternoon hours.

Monday into Monday night continues to look like the most likely
period for widespread showers and storms, with southern
Wisconsin solidly in the warm sector of an approaching low.
Though shear doesn't look as strong as expected Sunday, moisture,
instability, and forcing look solid enough for another severe
storm potential.

Confidence is on the lower end with precip chances for Tuesday
into mid-week given model timing differences with the exit of
the early week system and the arrival of a mid-week shortwave.
Temps look cooler, with highs likely back near normal by
Wed/Thu.

DDV

&&

.AVIATION...
Issued 644 PM CDT Thu May 14 2026

VFR conditions expected throughout tonight into Friday, with a
brief period of MVFR conditions near Lake Michigan Friday
morning/midday. Scattered showers are expected during the late
overnight hours tonight into the early morning hours Friday,
with the lower ceilings moving in thereafter. Minimal impacts to
operations are expected, with VFR visibilities likely within any
showers that move over terminals.

Expecting southeasterly winds to persist throughout tonight,
shifting to become southwesterly behind the scattered showers.
Southerly winds may continue along Lakeshore terminals into
midday before shifting to become southwesterly as well. Gusty
conditions are expected throughout the day Friday. Winds
diminish and become southerly overnight Friday ahead of the next
potential round of precipitation.

MH

&&

.MARINE...
Issued 1225 PM CDT Thu May 14 2026

High pressure of 30.1 inches overhead this morning will
continue to shift eastward this afternoon into tonight, with
southerly winds developing on the back side of the high. These
winds will increase on Friday behind the departing high and low
pressure of 29.1 inches moving from central Manitoba into
Ontario. A few gale force gusts will be possible in northern
portions of the lake tomorrow afternoon and evening, though this
setup looks too borderline for a Gale Watch at this point. A
Small Craft Advisory will be needed north of Milwaukee tomorrow
due to increasing waves, with a few gusts to advisory levels
possible too.

Southerly winds will persist on Saturday, while becoming lighter
as the low pulls away to the northeast. Southerly winds will
then pick back up Sunday into Monday ahead of approaching low
pressure. Multiple rounds of showers and storms will be possible
this weekend into early next week.

DDV

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...10 AM
     Friday to 4 AM Saturday.

&&

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, X, and YouTube at:
www.facebook.com/NWSMilwaukee
www.x.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee