NWS-Milwaukee/Sullivan Forecast Discussion
FXUS63 KMKX 060011 AAA
AFDMKX
Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
711 PM CDT Sun Apr 5 2026
.KEY MESSAGES...
- A round of rain showers will move southeast through the area
this evening, with perhaps a little light snow showers mixed
in toward central Wisconsin.
- Increasing potential for pop-up/convective snow showers
Monday afternoon and evening, especially over east central
Wisconsin. Some late afternoon/evening commute impacts may
occur, caused by visibility drops and light slushy
accumulations on roadways.
- Active pattern continues Tuesday night into next weekend,
with multiple additional chances for mainly rain and a few
thunderstorms. Some wet snow is possible Tuesday night.
&&
.UPDATE...
Issued 711 PM CDT Sun Apr 5 2026
A round of rain showers will continue to move southeast toward
and through the area this evening, exiting to the southeast
after midnight. This is being driven by some differential CVA
from a passing vorticity maximum, along with some low level
frontogenesis response. Forecast soundings are supportive of the
showers, with enough low level moisture within somewhat steep
low level lapse rates. There may be a little light snow shower
or graupel activity that occurs, mainly toward central
Wisconsin, as thermal profiles cool down to web bulb
temperatures with the showers.
There continues to be potential for pop-up/convective snow
showers Monday afternoon and evening, mainly toward east central
Wisconsin and possibly affecting areas to the southwest of
there. There is decent upward vertical motion from more
differential CVA aloft, with low level frontogenesis response
with the cold front passing through eastern parts of the area.
Forecast soundings are showing steep low level lapse rates with
perhaps up to around 100 J/kg of mean layer CAPE toward the
Sheboygan area, with lower instability values to the southwest.
HREF has been showing potential for convective snow showers
with snowfall rates up to one half inch per hour, which seems
reasonable given the setup. There should also be mild ground
temperatures that drop quickly Monday evening, with some flash
freeze potential.
This does not seem to be a classic snow squall setup at this
time, but certainly may see these convective snow showers occur
and possibly reduce visibility to 1 to 2 miles or less. Any
accumulations may be tough on the warmer roads at first in the
afternoon, but may see wet, slushy accumulations under an inch
into the evening if these persist.
Thus, some impacts to the late afternoon/evening commute are
possible, especially toward east central Wisconsin. Will
continue to monitor this potential and message accordingly.
Wood
&&
.SHORT TERM...
Issued 251 PM CDT Sun Apr 5 2026
Tonight through Monday night:
A weak front is expected to pass through the area late this
evening bringing chances for rain provided enough saturation is
reached through our dry low level. While forecast soundings
support mostly rain, there is a bit of CAPE aloft, which could
allow for isolated graupel or snow to mix in at times.
Following the front, breezy northwest winds will then linger
into tomorrow. Another cold front is expected to sink south
across the area, with the best convergence and lapse rates over
east central to southeast WI. Convective snow showers are
expected along the front and with deeper CAPE aloft, some brief
half inch per hour rates may occur with some of the stronger
snow showers, causing drops in visibility. Slushy accumulations
on roads may also occur, although how much accumulation actually
occurs on roads will be highly dependent upon pavement
temperatures. Peak timing will be toward the end of the evening
commute, with temperatures then dipping into the 20s following
the snow.
CMiller
&&
.LONG TERM...
Issued 301 PM CDT Sun Apr 5 2026
Tuesday through Sunday:
Warm advection will drive another area of rain/snow over
central Wisconsin Tuesday night into Wednesday. Current NBM PoPs
range from 40 to 60%, with the highest PoPs in that range over
central WI. Rain may then continue north and west of Madison
through the day, with some thunderstorms becoming possible
Wednesday afternoon. With the surface warm advection,
temperatures are expected to rise into the low 60s. A cold front
will then pass Wednesday night, pushing rain east through the
area.
Rain chances then linger Thursday through Sunday as the cold
front then stalls over the eastern Corn Belt. While we'll
technically be on the cold side of this stationary boundary,
temperatures will stay mild in the mid 50s to low 60s.
CMiller
&&
.AVIATION...
Issued 711 PM CDT Sun Apr 5 2026
A round of rain showers, with ceilings dropping to around 3500
feet AGL and visibility of 4 to 6 miles, will continue to move
southeast toward and through the area this evening. This
activity will exit to the southeast after midnight. There may
be a little light snow shower or graupel activity that occurs,
mainly toward central Wisconsin, but not expecting any
accumulations.
Gusty west winds into early evening should become northwest by
middle to late evening into the overnight hours. Northwest winds
will remain gusty into Monday. Ceilings behind the showers
should drop to 2000 to 2500 feet AGL into the overnight hours.
These may linger into Monday morning, before rising above 3500
feet AGL by midday into the afternoon.
There continues to be potential for pop-up snow showers Monday
afternoon and evening, mainly toward the Sheboygan terminal and
possibly affecting areas to the southwest of there. Snow
showers with snowfall rates up to one half inch per hour are
possible.
May see visibility drop quickly to 1 to 2 miles or less at
times, with ceilings varying between 2000 and 3500 feet AGL.
There should also be mild ground temperatures that drop quickly
Monday evening, with some quick freezing potential. May see wet,
slushy accumulations under an inch into the evening toward the
Sheboygan terminal if these persist.
Wood
&&
.MARINE...
Issued 253 PM CDT Sun Apr 5 2026
Low pressure will drag a cold front over the lake tonight, with
winds becoming breezy and northwesterly into tomorrow. While
not widespread, a few gales may occur over the northern end of
the lake. Winds then taper on Tuesday as high pressure settles
into the Upper Great Lakes region.
Winds then quickly come around to southerly for Wednesday as
another low approaches, with southerly Gales looking possible
Wednesday afternoon into Thursday morning.
CMiller
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...4 PM
Monday to 7 AM Tuesday.
&&
$$
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