286
FXUS63 KMKX 162015
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
315 PM CDT Thu Oct 16 2025

.KEY MESSAGES...

- Light rain remains possible (15-30%) through this evening.

- High temperatures will be well above normal Friday with highs
  in the 70s and will be breezy.

- Showers with a few thunderstorms are expected along a slow-
  moving cold front late Friday night through Saturday night.

- Windy and colder for Sunday with lingering shower chances
  (<60%).

&&

.SHORT TERM...
Issued 310 PM CDT Thu Oct 16 2025

Tonight through Saturday:

Light showers out west continue along the wing of 925mb WAA.
Models prog this activity to gradually spread into western half
of the CWA through the evening with areas along and west of
I-39/90 seeing a trace to a few hundredths of an inch from this
activity. Overall rainfall will be light with any activity given
it will have to battle subsidence from the upper-level ridge
axis overhead along with a dry layer near the surface ahead of
it. May see a bit more saturation in the lower level this
evening through the the night as the upper-level ridge axis
pushes further east while southerly flow advects a bit more
moisture (PWATS >1 inch). However, the low-level forcing
(925-850mb WAA) is progged to be lifting north of the area by
this time so rainfall overnight if any would likely be north of
I- 94 toward central/east-central WI. Cloud cover will linger
overnight and lows will be milder in this pattern with temps
only dipping into the mid to upper 50s tonight.

The upper-level ridge axis will shift further east Friday ahead
of the incoming upstream phasing troughs. This will bring
stronger southerly winds and warmer temps to southern WI Friday
with highs climbing back into the upper 60s into the mid 70s.
May see upper 70s temps with any breaks or clearing in the
clouds. Deeper mixing during the afternoon will taper the
moisture with PWATs falling to around and just below 1 inch
through the afternoon. However, will see moisture return as we
head into Friday evening ahead of the approaching cold front.

An upper-level trough and associated surface low is progged to
continue to deepen and lift across the Northern Plains into
Ontario through Friday evening. This will drag a cold front
across the Upper Midwest and WI through Friday night. Will see
PWATs climb back above 1.0-1.2 inches ahead of the front and
paired with forcing along the boundary as well as 35-45kt LLJ
working through the area will be enough for higher PoP chances.
The main question with this round of showers and a few
thunderstorms will be timing. Models continue to vary on timing
of this shower activity develop ahead/along the front. Some CAMs
(12z NSSL and NAMnest) have things developing and pushing into
the CWA by 00z Saturday, while other HREF members are bit more
delayed with things moving in after 06z Saturday. On the
other hand, mid-range ensembles are trending toward the later
timeframe for onset of the showers and storms. 12z EPS shows the
slower trend in showers favoring onset closer to 09z-12z
Saturday, while the GEFS has been a bit more consistent trend
favoring 06z-09z over the past couple of runs. So overall, while
cannot rule out the earlier arrival by 00z Saturday, do give a
bit more credence to the the later trends seen in the ensembles
over the past couple of runs.

Nevertheless, expect increased PoP chances (>50%) to work their
way west-nortwest to east-southeasst through the day Saturday
as the cold front slowly slides across the area. Slow moving
nature of this boundary will likely bring rain chances through
much of the day and sit over certain areas for a couple hour
period. While not expecting strong forcing and deeper convection
with this activity given lack of instability to build back,
still looking at a steady period of rainfall with 24 hr totals
(00z Sat-00z Sun) ranging from around a tenth to half an inch.
Local pockets of higher amounts will not be out of the question,
especially for southeastern WI where the front may ultimately
end up stalling out Saturday afternoon/evening.

Wagner

&&

.LONG TERM...
Issued 310 PM CDT Thu Oct 16 2025

Saturday night through Thursday:

Cold front extending southward from a low pressure system in
the Hudson Bay into Saturday night will stall and may even lift
back northward slightly, bringing continued precipitation to
southern Wisconsin through the Saturday overnight hours (60-80%
chance).

Currently, major models are indicating a shortwave rounding the
base of an upper level trough digging southward from the
Canadian Prairies Saturday night into Sunday morning, thereby
phasing with the lingering cold front and potentially becoming
enhanced by the frontogenesis along the edges of the Canadian
airmass. Notably, the NAM, although at the end of its run, keeps
the shortwave slower and therefore the phasing farther east and
weaker. Still, as the shortwave pushes through northern
Illinois and southern Wisconsin, expecting additional rainfall
and an increase in northwesterly winds. As the shortwave deepens
into a proper low pressure system over the eastern Great Lakes,
expecting the rainfall to taper off from west to east through
the day Sunday, and for gusty northwest winds to remain
consistent into the evening hours.

Surface high pressure then builds into the region Monday,
bringing a period of dry and clear conditions with highs in the
mid-60s. However, a much more progressive pattern is showing up
in the modeling in the longer range as additional low pressure
systems impact the British Columbia and Alaskan coastlines. The
most likely timeframe for the next round of precipitation with
these systems is Monday night into Tuesday night, with wrap
around precipitation potentially continuing through Thursday as
the low occludes in the Hudson Bay. Otherwise, expect highs in
the mid-50s and lows in the mid-30s to mid-40s with
northwesterly winds dominating Tuesday through Thursday.

MH

&&

.AVIATION...
Issued 310 PM CDT Thu Oct 16 2025

Will see a few isolated to scattered showers work their way
through southern WI this evening. MSN and JVL will have the
greatest potential to see this activity and maybe even SBM, but
given the lighter nature of this activity not expecting much in
the way of aviation impacts other than lower ceilings toward
MVFR and a brief drop in visibility. Otherwise, expect southerly
flow to persist overnight into Friday with VFR conditions
prevailing. Stronger winds with gusts greater than 20 kt are
expected by Friday afternoon.

Wagner

&&

.MARINE...
Issued 310 PM CDT Thu Oct 16 2025

High pressure continue to work eastward across the eastern
Great Lakes. Breezy southeast to southerly winds will continue
tonight and pick up to around 20-30 knots across Lake Michigan
into Friday as a deepening surface low lifts across western
Ontario while dragging a cold front across the western Great
Lakes. Expect small craft conditions to develop in southern WI
nearshore waters overnight through Friday. While cannot rule
out seeing a few gale force gusts across the open waters later
Friday and overnight, think it would be brief, thus will hold
off on any gale headlines from this timeframe. Winds will
briefly weaken as the cold front slides down the lake through
the day Saturday with a northwest wind shift behind it. However,
the front may stall across the southern tip of Lake Michigan
Saturday so may see more southerly flow toward the southern end
during this time. However, another strong, deepening low
pressure is then progged to work its way across Lake Michigan
later Saturday into Sunday. this will bring stronger
northwesterly winds across the lake. Gale force gusts are likely
to develop across eastern portions of the lake and headlines
are looking increasingly likely Sunday into Monday morning.
Expecting to see a brief lull in the winds near but below gale
force on Monday, while there will be another potential for gales
to return for Tuesday with another deepening surface low
traversing across the Upper Great Lake region.

Wagner

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...1 AM
     Friday to 10 AM Saturday.

&&

$$

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