882
FXUS63 KMKX 102142
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
442 PM CDT Sun Aug 10 2025

.KEY MESSAGES...

- Flood Watch continues over all of southern Wisconsin now until
  7 AM CDT Monday. Showers with the potential for thunderstorms
  and heavy rain are expected over southern Wisconsin tonight.
  Flash flooding is possible if the steadier showers and storms
  make it into the urban areas of southeast Wisconsin including
  the Milwaukee metro area.

&&

.SHORT TERM...
Issued 442 PM CDT Sun Aug 10 2025

Tonight and Monday:

The morning rain finally exited eastern WI early this afternoon,
and rainfall rates were not as high as last night since there
was not a lot of instability or forcing left to work with. Now
we are watching an area of thunderstorms develop near Waterloo,
IA this afternoon. These should track into south central WI
early this evening, similar to what the HRRR model suggests.
With the clouds thinning out over south central WI and dewpoints
still around 70, the instability is increasing and could sustain
thunderstorms that move into the area. The HRRR suggests that
the area of storms should weaken in intensity as they track into
southeast WI later this evening and this scenario makes sense.

The synoptic setup that is causing all of this rain is a
stationary upper trough that is sitting over the Upper Midwest.
Since northeast IA and southern WI are on the eastern edge of
that upper trough, we are in the area of vorticity advection,
the low level jet, and upper divergence with the right entrance
region of the upper jet.

The low level jet will be steady overhead tonight and then shift
to the east Monday morning. There will be a small chance for
showers and maybe a rumble of thunder Monday, but most models
and the lack of forcing point to only low chances during the
day. I lowered the precip chances and forecast precip amounts.

Cronce

&&

.LONG TERM...
Issued 442 PM CDT Sun Aug 10 2025

Monday night through Sunday:

That upper trough that is stationed over the Upper
Midwest will not swing across WI and Lake Michigan until Tuesday
evening. Therefore, we will have a chance of showers and
thunderstorms until that trough moves through. There are hints
of an MCS that could develop over IA and MO on Monday and then
track through southern WI Monday evening. Therefore, we are
holding on to the likely pops for the Monday night period. If
this begins to look like a more certain scenario, we may need
to extend our flash flood watch past Monday morning, or reissue
one.

High pressure will give us a couple days of dry weather. Our
next chance for showers and thunderstorms will be along a weak
trough that is expected to drop through WI Friday night or
Saturday. Unfortunately, the extended model setup kind of looks
like WI could be within the region of ridge riders early next
week.

Cronce

&&

.AVIATION...
Issued 442 PM CDT Sun Aug 10 2025

There is a chance of showers and perhaps a rumble of thunder
through Monday night. The first higher chance will be as an area
of thunderstorms that is over northeast Iowa tracks across
south central WI and into central WI this evening. Currently,
there are some pockets of MVFR diurnal cumulus clouds over south
central WI.

Weather should be fairly quiet overnight, but ceilings are
expected to drop to MVFR with bases around 2000 ft during the
early morning hours. Winds will remain steady out of the south.
Patchy dense fog will be possible due to the abundant moisture
in the environment.


Cronce

&&

.MARINE...
Issued 442 PM CDT Sun Aug 10 2025

Light to modest southerly winds will continue this weekend into
early next week. Showers are possible through the evening, with
thunderstorms possible overnight. The chance for showers and
thunderstorms continues Monday through Tuesday until a low
pressure trough of 29.8 inches and the associated cold front sweep
across the Upper Great Lakes Tuesday night. Patchy dense fog may
occur at times due to the abundant moist conditions. Web cams
showed fog along the shoreline of Sheboygan and Two Harbors, so
we issued a Marine Dense Fog Advisory for the nearshore zone
that Sheboygan is centered within until 09Z. There is low
confidence in how long these areas of fog will last.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Flood Watch...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-WIZ058-
     WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-WIZ067-
     WIZ068-WIZ069-WIZ070-WIZ071-WIZ072 until 7 AM Monday.

LM...Dense Fog Advisory...LMZ643 until 4 AM Monday.

&&

$$

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