Waukesha, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

735
FXUS63 KMKX 041017
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
517 AM CDT Mon May 4 2026

.KEY MESSAGES...

- Special Weather Statement in effect for elevated fire weather
  concerns today given warm and dry conditions with breezy
  winds.

- Chances for showers and thunderstorms (30 to 50 percent
  chances) remain for Monday afternoon and evening, as a cold
  front moves through the area. Gusty winds could occur with
  stronger storms.

- Warmer and breezy Monday, then cooler the rest of the week.

- Frost may occur toward the middle to later portions of the
  week.

&&

.UPDATE...
Issued 515 AM CDT Mon May 4 2026

The primary update for today is the issuance of a special
weather statement regarding the elevated fire weather conditions
expected today. Refer to the fire weather tab for more
information.

Otherwise latest trends in the short term models has been
suggestive of a much drier low level environment that may play a
role in significantly inhibiting potential convection later
today. While showers and a few storms should still be expected
it is a trend worth monitoring that may lead to less convection
overall today. At the same time the drier low levels may cause
storms to bring stronger gusts.

Kuroski

&&

.SHORT TERM...
Issued 1206 AM CDT Mon May 4 2026

Tonight through Monday Night:

Outside of scattered high clouds overnight, expect mostly clear
skies to continue into Monday morning. Light winds tonight will
increase by daybreak, becoming breezy out of the southwest
mid/late morning it the afternoon. Gusts of 25 to 35 mph are
likely as a cold front approaches. It still looks like there is
a potential for scattered showers and a few thunderstorms as the
front moves through mid-afternoon into the evening. Kept precip
chances capped at 50 percent though given the concern of dry air
in the lower levels. A few models such as the GFS and NAM had
much too high dewpoints this last afternoon into the evening
compared to observations, and these models push the dewpoints
into the mid 50s tomorrow and are thus higher with the precip
chances. The RAP/HRRR dewpoints were closer to reality over the
last several hours and are also lower tomorrow, with lower
precip chances as a result. Though there will be some increased
moisture ahead of the front, leaned the forecast towards the
drier solutions. Still think a few storms could produce some
gustier winds given the drier low levels.

Think the lower dewpoints and deeper mixing will result in temps
a bit milder than previously expected, with highs likely
approaching 80 across south and east portions of the forecast
area.

There is still the potential for some post frontal showers
tomorrow evening into tomorrow night, given some lingering
frontogenesis aloft. Confidence isn`t high in this second round
of rain, so kept precip chances in the 20-30 percent range.

DDV

&&

.LONG TERM...
Issued 1206 AM CDT Mon May 4 2026

Tuesday through Sunday:

Dry weather is expected Tuesday through Wednesday night under
high pressure. Could see some frost Tue night and Wed night
given the cooler/drier airmass in place and a decent
radiational cooling potential both nights.

A more active shortwave pattern is expected later in the week
and into the weekend, bringing shower chances to southern
Wisconsin Thursday, Friday, and again on Sunday. Temps are
expected to warm back to around normal by the end of the week.

DDV

&&

.AVIATION...
Issued 515 AM CDT Mon May 4 2026

Southwest winds will become breezy mid/late morning through the
afternoon, with gusts of 25 to 30 knots likely ahead of a cold
front. Scattered showers and a few thunderstorm will then be
possible along and ahead of the cold front mid-afternoon into
the evening. A few of the storms could produce some gustier
winds. Ceilings will likely remain VFR with the showers/storms
given a fair amount of dry air in the lower levels. Light rain
chances will linger into at least the evening due to the
potential for some post frontal showers. Winds will be lighter
and out of the northeast behind the cold front Monday evening.

Kuroski

&&

.MARINE...
Issued 1206 AM CDT Mon May 4 2026

Southwest winds will increase Monday morning ahead of a cold
front in association with low pressure of 29.0 inches moving
across Ontario. A short 6 hour period of Gales is anticipated
over the northern third of Lake Michigan between 10am and 4pm
CDT. Small Craft Advisory conditions are expected for the
nearshore waters tomorrow. Winds then ease through the
afternoon from north to south over the lake as the cold front
moves south. Winds behind the front will become northwesterly.

The pressure gradient will then ease over the lake Tuesday
through Thursday, with light and persistent west to northwest
winds occuring. Light and variable winds may briefly occur at times
as various weak surface ridges move across the lake.

DDV

&&

.FIRE WEATHER...
Issued 140 AM CDT Mon May 4 2026

Warm, dry and breezy conditions today will lead to an elevated
concern for fire weather across southern WI. Given recent rains
and green up largely being complete, it is not thought that fuels
are at a near critical level but the weather conditions are. Highs
in the upper 70s, relative humidities falling to the 20-30 percent
range and sustained winds around 15-20 mph with gusts to 35 mph
all contribute to the increased fire weather concerns. The
showers and storms potential later today may raise dewpoints in
those areas but those chances remain uncertain and at best
scattered and thus the risk will persist for all of southern
WI.

Kuroski

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Gale Warning...LMZ261-LMZ362-LMZ364-LMZ563...10 AM Monday to 4
     PM Monday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...10 AM
     Monday to 7 PM Monday.

&&

$$

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