635
FXUS63 KMKX 240230 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
930 PM CDT Mon Jun 23 2025

.KEY MESSAGES...

- An area of thunderstorms into the overnight hours may produce
  heavy rainfall and localized flash flooding, mainly southwest
  of Madison. Minor flooding in low lying and urban areas may
  result.

- Multiple rounds of thunderstorms and a level 2 out of 4 risk
  for excessive rainfall will be present Tuesday through
  Thursday, as the surface front stalls overhead.

&&

.UPDATE...
Issued 930 PM CDT Mon Jun 23 2025

The more organized showers and thunderstorms continue generally
from the Beaver Dam area southwest to Monroe and into
Darlington and southwest from there. This activity is being
driven mainly by the southwesterly low level jet pointing into
the area, and is slowly shifting eastward.

CAMs generally have this convection slowly weakening into the
overnight hours, as the low level jet slowly weakens. Will
follow this general trends in the forecast into the overnight
hours, with southeast parts of the area possibly remaining dry.

Precipitable water values around 2.00 inches are combining with
the training storms into the southwest parts of the area to
bring locally heavy rainfall. Isolated flash flooding may occur,
especially southwest of Madison, along with minor flooding of
low lying and urban areas. Will continue to monitor this
potential, especially southwest of Madison, into the overnight
hours.

Wood

&&

.SHORT TERM...
Issued 320 PM CDT Mon Jun 23 2025

Tonight through Tuesday night:

A Severe Thunderstorm Watch is in effect west of a Monroe to
Sheboygan line at the moment as we monitor a broken line of
showers and thunderstorms approaching from central WI. With
roughly 3000 joules MLCAPE, and over 1000 joules of DCAPE
(strong cold pooling expected due to dry air aloft), the primary
hazard with these storms will be damaging wind gusts. The line
of storms is expected to track southeastward through the
remainder of this afternoon and evening before weakening into
tonight.

Heat headlines expire at 7 PM CDT today as convection and the
shutdown of daytime heating work together to cool things off.
Even with the stalling cold front and convection, we only drop
to around 70 degrees flat for an overnight low temp tonight.
Though it will be noticeably cooler Tuesday, the air will
remain warm and muggy (dewpoints in the low 70s and highs), with
the warmest temperatures (highs in the upper 80s) expected
further south (pending frontal boundary placement).

Additional rounds of showers and thunderstorms expected on
Tuesday, primarily (but not exclusively) in the afternoon and
early evening hours. Though the severe weather threat decreases
to a level 1 out of 5, the excessive rainfall risk remains a
level 2 out of 4 given the high PWAT values (around 2") overhead
and the potential for training convection.

Sheppard

&&

.LONG TERM...
Issued 320 PM CDT Mon Jun 23 2025

Wednesday through Monday:

As high pressure over Canada interacts with subtropical high
pressure over the southeastern CONUS, the surface baroclinic zone
remains stalled nearby. Periods of showers and thunderstorms are
expected to continue developing along the boundary Wednesday and
Wednesday night (widespread 40-75% rain chances). Exact rain chances
/ amounts, and storm intensity will depend on the exact location of
the boundary (how close it is) and the timing of perturbations
triggering convection along it, both of which are uncertain. With
any convection overhead, training storms and localized heavy
rainfall will remain a possibility (level 2 out of 4 risk, highest
further north). If a lull in activity were to occur in the morning /
early afternoon (allowing for diurnal destabilization) a few
stronger storms could occur. For the time being, most models are
placing the theta-e gradient (boundary) further north, allowing the
majority of Wednesday / Wednesday night`s rain to fall closer to
Wausau, though this could easily change, and even those solutions
still place some rain in our region.

For Thursday, a 500-250mb trough in the jet begins to interact with
the baroclinic zone, developing a surface low pressure to our west.
This could allow southwesterly sfc flow to develop and lift a warm
sector nearby / overhead. The approach of the low and advection of
unstable air from the south allows for continued 50-80% rain
chances, and exactly how this shakes out will again depend on
initial surface boundary placement and low pressure track.

Precip chances decrease to 20-35% for Friday, given that the
favored model solution is for us to be in the wake of the
departing low pressure, leaving potential for us to be in the
dry slot of the system. Some model solutions do leave the
baroclinic zone nearby (and some additional shower / storm
chances).

Light southerly flow likely to continue into Saturday along with the
25% chances for showers / storms. Low predictability from this
period onwards, but a trough in the jet would suggest an
increase in precip chances into Sunday.

Sheppard

&&

.AVIATION...
Issued 930 PM CDT Mon Jun 23 2025

The more organized showers and thunderstorms continue generally
from the Beaver Dam area southwest to Monroe and into
Darlington and southwest from there. This activity is slowly
shifting eastward. This activity should slowly weaken into the
overnight hours. Southeast parts of the area, including the
Milwaukee and Kenosha terminals, may remain dry for the rest
of the night. Heavy rainfall may reduce visibility to 1 to 2
miles at times, with ceilings possibly falling into the 2000 to
3000 foot AGL range.

Winds will remain light and gradually become westerly overnight
into Tuesday morning, then shift east to northeast by middle to
late morning and lingering into the evening, as the front slowly
sags south across the area.

There are chances for showers and storms at times Tuesday into
Tuesday night, with the better chances during peak heating in
the middle to late afternoon. 2 to 5 mile visibility reductions
are possible in any storms. A period of lower ceilings
overnight into Tuesday are expected, falling to around 1200 feet
AGL Tuesday morning, before rising to around 2500 feet AGL in
the afternoon.

Wood

&&

.MARINE...
Issued 930 PM CDT Mon Jun 23 2025

A cold front will gradually stall across the southern end of
Lake Michigan overnight into Tuesday morning. Scattered showers
and some thunderstorms may linger into the overnight hours at
times across the lake.

The front may linger across the southern portions of the lake
through at least Thursday. As a result, winds will be modest,
with generally north winds through the week. South winds may
return on Thursday, as the front briefly lifts north ahead of
approaching low pressure. With the presence of the front,
multiple rounds of showers and thunderstorms are expected at
times.

Sheppard/Wood

&&

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

$$

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