NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 141948
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
248 PM CDT Fri Aug 14 2026

.KEY MESSAGES...

- Isolated shower or storm possible ~4-9 PM in the Wisconsin
  Valley & southwest of Madison. Dry conditions elsewhere.

- Scattered showers & embedded thunder tonight (~9 PM & later)
  into Saturday morning. Best potential is along & south of
  I-94. Severe weather isn't expected.

- High swimming risk Saturday at Milwaukee, Ozaukee, and
  Sheboygan County beaches.

- Additional showers & thunderstorms possible Saturday evening
  if enough sunshine occurs during the afternoon hours.

- Drier & more comfortable early next week, with storm chances
  returning by mid-week.

&&

.SHORT TERM...
Issued 252 PM CDT Fri Aug 14 2026

This Afternoon through Sunday:

Synopsis/Mesoanalysis: Satellite shows an MCV centered over the
Omaha, NE vicinity this afternoon, with a compensating area of
shortwave ridging apparent from northeastern Iowa into southern
Wisconsin. Surface observations show a warm front extending from
near Sioux City, IA southeast toward the MO-IA-IL border. An
elongated area of surface high pressure extends from Lake Superior
northwest to the Canadian Rockies. The aforementioned MCV & warm
front will gradually attempt to work toward the area this evening
and tonight, bringing chances for showers and a few embedded
thunderstorms to southern Wisconsin. Best chances for precipitation
will be along and south of I-94, with most severe weather potential
expected to remain over Iowa and Illinois. A cold front will move
into Upper Mississippi Valley Saturday afternoon, and is forecast to
cross southern Wisconsin Saturday evening/night. An additional
scattering of showers and storms is possible along the passing
boundary, though development will be dependent on air mass recovery
in the wake of any earlier day activity. A few showers and storms
could linger into the first part of the day Sunday.

This Afternoon through Tonight: Can't rule out an isolated shower or
thunderstorm in the Wisconsin Valley or along the WI-IL border
southwest of Madison between 4-9 PM as the leading edge of upper
forcing starts to nudge in. Will otherwise be watching for showers
and storms after 9 PM as the core of the MCV & warm front work
north. Due to influences from the shortwave ridge leading the MCV &
surface high pressure over Lake Superior, the northern extent of
precip coverage remains in question. Expecting a southwest to
northeast cutoff to set up somewhere across the region, with early
day forecast guidance depicting I-94 being a relatively good
separator between steadier showers south & sparser activity north.
Have thus reflected this in afternoon precip probs, and will be
monitoring for any additional southern shifts into this evening.
Could see occasional moderate/heavy downpours & lightning in
activity, though more organized severe weather potential is expected
to remain confined to Iowa and Illinois.

Saturday & Saturday Night: High waves will lead to dangerous
swimming conditions at Milwaukee, Ozaukee and Sheboygan County
beaches, where a Beach Hazards Statement is now in effect between 8
AM and 7 PM. Exercise extreme caution if heading lakeside.
Anticipating that showers & embedded thunderstorms will be around
through the first part of the morning (~10 AM) as the upper forcing
affiliated with the MCV shifts east, with drier conditions settling
in for the afternoon. Depending on sunshine & moisture recovery
during the dry period, could then see additional scattered
showers/storms along the inbound cold front during the
evening/overnight. In the event afternoon recovery is poor,
evening/overnight precip coverage would be poor to negligible. Have
held precip probs in the 40-50% range given this uncertainty, and
will continue to refine through tomorrow. Widespread severe weather
is unlikely in the event storms develop, though an isolated storm
with gusty winds couldn't be ruled out.


Quigley

&&

.LONG TERM...
Issued 252 PM CDT Fri Aug 14 2026

Sunday Night through Friday:

Synopsis: The surface front bringing impacts during the short term
will shift south of the region Sunday night, bringing a drier air
mass into the area for Monday. The drier air will lead to pleasant
and comfortable conditions on Monday afternoon. Moisture will
gradually work back into southern Wisconsin Tuesday through
Wednesday, leading to muggier conditions. A cold front will swing
through the western Great Lakes Tuesday evening into Wednesday,
triggering the next round of shower and thunderstorm development as
it impinges upon the returning humid air mass. Tuesday evening &
night currently appears to be most favored for storms in southern
Wisconsin, though timing trends will continue to be monitored over
coming forecasts. If the front lingers across the region long
enough, additional storm development would be possible on Wednesday
afternoon. Noticeably cooler and drier air will filter into the
Upper Midwest behind the departing front Thursday into Friday, which
will combine with passing high pressure to create dry and
comfortable conditions for the end of next week.

Tuesday Evening into Wednesday: Next shower and storm chances enter
the forecast given returning humidity & a passing cold front. Global
deterministic/ensemble guidance is in reasonable agreement regarding
cold frontal timing, with a Tuesday evening & overnight frontal
passage being the currently favored/consensus solution. Current
precip probabilities from the NBM thus appear well-calibrated, as
they reach their highest values (~50-70+%) over southern Wisconsin
during the overnight hours on Tuesday. Have maintained these values
in the afternoon update, with further refinements coming in later
forecasts. Overnight frontal timing & lingering questions regarding
the exact quality of moisture return leave the potential for
strong/severe storms uncertain at this time, with more clarity
anticipated by later in the weekend. Will be monitoring trends and
providing additional updates. Whether or not storm chances linger
into Wednesday afternoon will depend on frontal progression speed,
with considerably higher disagreement apparent in global guidance at
this time. Have thus maintained chance (~30-50%) precip
probabilities from the NBM in this update & will refine as this
portion of the period draws closer.

Quigley

&&

.AVIATION...
Issued 252 PM CDT Fri Aug 14 2026

VFR flight categories prevail at eastern terminals this afternoon.
Low clouds based between FL020 and FL030 & attendant MVFR categories
linger further west, with impacts continuing in the vicinity of JVL
and just west of MSN. Have accounted for these observational trends
in the 18Z update at both terminals. Have held the forecast at VFR
in MSN, but will be closely watching CIG trends through this
afternoon. In the event BKN030 or lower CIGs are realized, TEMPO or
prevailing groups will be added. Current expectation is for CIGs to
trend comfortably above FL030 by late afternoon/early evening as
easterly flow brings modestly drier air in from the east, though
trends will need to be monitored. In the event drier air doesn't
make it far enough west, amendments for lower CIGs into the evening
may become necessary.

Continue to expect increasing shower potential later this evening &
tonight as an upper disturbance & warm front attempt to work into
southern Wisconsin. Early day forecast guidance has trended drier
and a touch further south with the disturbance & front, which has
been reflected with continued PROB30 -SHRA mentions at SBM and the
removal of -TSRA PROB30 groups at MSN, UES and MKE in the 18Z
update. If southward trends continue, precip mentions may need to be
pulled back further at some terminals, particularly along and north
of I-94. Will be watching conditions through this evening &
adjusting the forecast where necessary.

Quigley

&&

.MARINE...
Issued 252 PM CDT Fri Aug 14 2026

Periods of storms are expected to cross the southern half of Lake
Michigan through Sunday as a front remains stalled south over
Illinois and Indiana. Low pressure of 1005 mb over Kansas will track
to the northeast and east toward southern Lake Michigan tonight into
Saturday. This low should help to bump up winds and waves across the
southern two thirds of Lake Michigan into Saturday. Beyond this
system, a broad ridge of high pressure of 1020 mb will push into the
Great Lakes early next week before another potential front moves
through the region midweek.

Periods of showers and thunderstorms will continue in nearshore
zones this evening into the weekend. While widespread severe weather
is not anticipated in any activity, an isolated stronger storm with
hail and gusty winds can't be ruled out, particularly on Saturday
afternoon and evening. A Small Craft Advisory is now in effect from
8 AM to 7 PM CDT Saturday from Milwaukee north to Sheboygan due to
elevated waves and gusty winds. Additional periods of showers and
storms are possible Tuesday night into Wednesday. Whether or not any
of these storms could be severe remains uncertain at this time, with
trends being monitored over coming updates.

Quigley

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066...8 AM Saturday
     to 7 PM Saturday.

LM...Small Craft Advisory...LMZ643-LMZ644...8 AM Saturday to 7 PM
     Saturday.

&&

$$

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