NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 091027 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
527 AM CDT Thu Apr 9 2026

.KEY MESSAGES...

- Another round of showers (60-90+ percent) is forecast tonight.

- An active weather pattern returns late this weekend into next
  week. Warm and humid conditions and more showers and storms
  are expected.

&&

.UPDATE...
Issued 527 AM CDT Thu Apr 9 2026

Clear skies are expected across southern WI for most of the day.
Expect westerly winds up to 15 kt this afternoon. A lake breeze
may develop in southeast WI but not make it very far inland.
Temperatures will be cooler than yesterday, but still above
normal, especially in southeast WI with highs in the lower/mid
60s.

Widespread rain (light to moderate) will quickly spread into
southern WI from the southwest this evening and then end from
west to east through 7 AM Friday. The NBM in the previous
forecast had higher rainfall amounts than the 00Z DESI Grand
Ensemble so I trended the forecast totals downward. Highest
amounts of up to a half inch (58% chance of greater than 0.5
inch) will be southeast of a Janesville to Milwaukee line. There
is high confidence (50-70%) of less than a half inch north of a
line from Mineral Point to Beaver Dam to southern Sheboygan
County. The chance for a few rumbles of thunder in the moist
adiabatic profile tonight is also trending southward, south of
the IL border.

Cronce

&&

.SHORT TERM...
Issued 1150 PM CDT Wed Apr 8 2026

Today through Saturday:

Two distinct sw-ne bands of showers are prevalent over srn WI.
The initial band over far se WI is associated with warm, moist
advection in the low to mid level thermal ridge. The second band
from sw WI to the Fond du Lac area is associated with sfc-850 mb
frontogenesis. The cold front and rainfall will move esewd
through the early morning ending at MSN around 07Z and MKE
around 10Z.

Weak sfc ridging and a wly sfc flow can be expected for Thu with
cooler temps than Wed, but still on the mild side. A wave of low
pressure supported by a weak shortwave trough will then track
from the central Great Plains into far srn lower MI Thu nt.
PWATs of 0.75-1.00 inches will shift back north into the region.
Well organized 850-700 mb frontogenesis and the nose of a low
level jet near the IL border will support widespread showers
and a few rumbles of thunder during this time. 0.50-0.90 inches of
rain are forecast along and south of a line from Mineral Point to
Madison to Port Washington.

High pressure will then track from ern SD to the Upper MS River
Valley on Fri, then across srn WI Fri nt. The high will then
reach the Mid Atlantic States around 00Z Sun. Pleasant wx will
prevail with high temps Fri-Sat in the middle to upper 50s well
inland, with upper 40s at the Lake MI shoreline. The onset of
low to mid level warm, moist advection will bring 20-30 percent
chances for showers Sat afternoon over south central WI.

Gehring

&&

.LONG TERM...
Issued 1150 PM CDT Wed Apr 8 2026

Saturday night through Wednesday:

This period will see a pattern change to swly flow aloft with
low pressure areas developing over the high plains and tracking
to the north or over srn WI. Relatively warm and humid air will
arrive for Sun-Tue with repeated rounds of showers and storms
from Sat nt-Tue. Showers may linger into Wed along with somewhat
cooler temps. Will be monitoring rivers for a possible return
of some flooding to some degree.

Gehring

&&

.AVIATION...
Issued 527 AM CDT Thu Apr 9 2026

Clear skies are expected across southern WI for most of the day.
Expect westerly winds up to 15 kt this afternoon. A lake breeze
may develop in southeast WI but not make it very far inland, so
did not include it in the MKE TAF but there is uncertainty.

Widespread rain (light to moderate) will quickly spread into
southern WI from the southwest this evening and then end from
west to east through 12Z/7AM. IFR ceilings are expected in
southeast WI after midnight but will return to VFR by mid-late
morning.

Cronce

&&

.MARINE...
Issued 527 AM CDT Thu Apr 9 2026

Low pressure around 29.7 inches over far western Ontario will
track north of Lake Superior through late morning. The winds
behind the associated front dropping down Lake Michigan early this
morning will be westerly and light. The Gale Warning will be
allowed to expire at 4 AM.

Light and variable winds will prevail this afternoon through
Saturday morning, until breezy southerly winds return later in the
weekend. Southerly gales are possible over the north half
Sunday into Monday morning.

Cronce

&&

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

&&

$$

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