Janesville, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

452
FXUS63 KMKX 222359
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
559 PM CST Sun Feb 22 2026

.KEY MESSAGES...

- Lingering light snow/flurries for east central and
  southeastern WI into the early evening.

- Brisk tonight with sub-zero wind chills.

- Chances (40-70%) for accumulating snow, generally less than an
  inch, across east-central WI Tuesday afternoon/evening and may
  impact evening commute. Wintry mix possible further south.

- Additional snow chances possible Wednesday night Thursday
  (30-50%).

&&

.UPDATE...
Issued 559 PM CST Sun Feb 22 2026

Breezy winds and flurries continue across southern Wisconsin
early this evening. A dusting of snow remains possible with the
intermittent flurries this evening, but with the blowing snow
its going to be difficult to measure. As high pressure builds
in from the northeast (Northern Plains/southern Canada),
moisture and lift will diminish finally bringing an end to the
flurries. The pressure gradient between the incoming high and
strong low along the east coast will keep winds breezy into
tonight. These breezy winds combined with the falling
temperatures will drop wind chills below zero into the negative
single digits. The winds will gradually diminish tonight
through Monday until the high moves overhead. This will make
winds light and variable Monday night. No major changes to the
forecast.

Patterson

&&

.SHORT TERM...
Issued 155 PM CST Sun Feb 22 2026

Tonight through Monday night:

Backside of the departing trough continues to bring light snow
showers/flurries to east central and southeastern WI through the
remainder of the afternoon. What you see is what you get and
expecting a dusting of snow, but a few spots may pick up a 0.1
of an inch or so with brief drop in visibility. Tight gradient
between the weakening low and incoming high pressure will keep
the gusty winds around through the evening, but should gradually
weaken as the high shifts further east and winds decouple
through the night. Will be chilly tonight as subsidence from the
high clears the clouds out and looking at temps to drop into
the single digits to mid-teens under these conditions. Lingering
wind will also contribute to sub-zero winds chills into Monday
morning.

Greater influence from the building high pressure across the
Upper Midwest for Monday with lighter northwesterly winds
through the day lessening and becoming variable overnight
Monday. Will see temps rebound into the 20s with mostly sunny
and dry conditions. Another chilly night, but not as brisk with
lows across southern WI in the teens Monday night.

Wagner

&&

.LONG TERM...
Issued 155 PM CST Sun Feb 22 2026

Tuesday through Sunday:

Will see a more active pattern return to the region Tuesday
through the middle of the week. There are a few systems to focus
on that will bring increased snow chances to southern WI,
Tuesday afternoon/ evening, another one late overnight Wednesday
into Thursday quickly followed by a clipper into Friday.

Tuesday will see a mid-level shortwave trough dig into the
Upper Midwest tracking its associated surface low from the
Dakotas into northern WI. Overall models agree on this trek of
the low passing to the north and will see warmer than normal
temps given the southerly flow before dragging a cold front
across our CWA. There looks to be ample forcing along the front
with mid-level dCVA, 850mb WAA, and the nose of a 35-45kt LLJ
aligning with a slug of Pacific moisture (PWATs around 0.3-0.5
inches). However, the more favorable setup with better/higher
snow chances look to remain to our north. Timing of this system
remains in question with the ECMWF and GFS are a bit faster than
the NAM. Nevertheless, still looking at a 20-40% chance of
seeing measurable snow at this time with this frontal passage,
mainly for our central and east-central WI counties, while other
areas may see more of a wintry mix.

There will be a brief reprieve in activity through Tuesday
night into the day Wednesday as high pressure fills in behind
the cold front. Then another trough is progged to dig across the
central CONUS Wednesday night into Thursday. However, the
latest trends keep the surface low south of WI and continue to
vary on the strength of the system with the latest 12z ECMWF
coming in weaker than the GFS. Regardless will continue to
monitor trends over the coming days as being on the north side
of this system could bring another round of accumulating snow
to southern WI. Then shortly behind it models hint at another
clipper tracking across the Upper Great Lakes region for Friday.
Otherwise return to more zonal flow through the weekend with a
less active pattern and limited to no precip chances.

Wagner

&&

.AVIATION...
Issued 559 PM CST Sun Feb 22 2026

MVFR to VFR conditions are expected through the period. MVFR
ceilings around 2 to 3 kft will continue to move in from the
northwest tonight. There are patchy breaks in the clouds and
some slightly higher cloud decks around 3 to 4 kft in
northwestern Wisconsin and eastern Minnesota that should slowly
move in over time. Breezy northwest winds with gusts around 30
MPH (26 kts) will persist into tonight before slowly diminishing
after midnight. Area wide VFR conditions are not expected until
Monday morning as clouds dissipate and mostly clear skies
return. Terminals along Lake Michigan will continue to battle
few to sct lake effect clouds as winds become more northerly.

Clouds return Monday night ahead of the next approaching low
pressure system. As the clouds begin to return the axis of high
pressure will move overhead creating a brief period of light and
variable winds Monday evening then light south to southwest
winds Monday night into Tuesday morning. Dry weather is expected
through the period with chances for snow expected just beyond
the TAF period Tuesday.

Patterson

&&

.MARINE...
Issued 155 PM CST Sun Feb 22 2026

Stronger northwesterly winds will continue to pick up across
southern Lake Michigan this evening as low pressure deepens to
around 28.6 inches off the Mid-Atlantic coast while high
pressure over Manitoba builds to around 31.1 inches as it pushes
eastward into Ontario tonight. Gales are expected across the
southern two- thirds of the open waters of Lake Michigan, thus a
Gale Warning remains in effect from this evening into midday
Monday. With the brisk conditions, moderate freezing spray is
expected, with brief periods of heavy freezing spray possible in
the central to northern third of the lake.

Weakening high pressure to around 30.6 inches continues to push
eastward through the day Monday with winds gradually easing
overnight. Southerly winds look to develop across the lake
Tuesday as a low pressure deepening to around 29.3 inches builds
down from the Dakotas and across Lake Superior/northern Lake
Michigan Tuesday afternoon and evening. Will see winds shift
more west-northwest behind the low and associated cold front.
Will see strong winds gusts up to around 30 knots for this
timeframe, and while potential is lower, still cannot rule out a
few gale force gusts later Tuesday into early Wednesday
morning.

Wagner

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Gale Warning...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-
     LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-
     LMZ876-LMZ878 until noon Monday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 6 PM
     Monday.

&&

$$

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