North Lake, Wisconsin Weather Forecast Discussion

448
FXUS63 KMKX 181706
AFDMKX
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1206 PM CDT Thu Sep 18 2025
.KEY MESSAGES...
- Chances (20% to 30%) for showers and possibly a storm over
  south central WI this afternoon through Fri AM, then showers
  and storms becoming likely for Fri nt.
- A Small Craft Advisory may be needed from Sheboygan to
  Winthrop Harbor late Friday night into early Saturday
  afternoon due to breezy southeast winds and building waves.
- A Beach Hazard Statement by be needed from Sheboygan County
  south to Kenosha County due to a High Swim Risk late Friday
  night into early Saturday afternoon. Persistent breezy
  southeast winds and building waves are forecast.
&&
.UPDATE...
Issued 1206 PM CDT Thu Sep 18 2025
Another warm day is already underway over srn WI with temps
warming into the lower 80s. Mid level moisture and brief and
light showers will continue to stream nwd from ern IA toward sw
WI this afternoon and evening. This activity is expected to
increase in coverage and intensity tnt over IA and MN as
vorticity maximums continue to stream nwd around the main upper
trough over ern SD. A sly low level jet of 25 kts and
associated thetae advection will aid in this development. South
central WI will remain on the ern fringes of the expected
precipitation with 20-30 percent chances forecast.
Farther to the east this afternoon and evening, a weak backdoor
cold front will gradually push off the lake and move inland.
There currently are showers and storms over central Lake MI
along and behind the front, but the front will become
shallower, and the higher PWS of 1.5 inches to the north will
not translate swd. Thus will maintain a dry frontal passage
this afternoon and evening for east central and se WI.
For Fri-Fri nt the upper trough and weak sfc low over wrn MN Fri
AM will lift into nw MN for Fri nt. A trailing and weak sfc
trough and cold front will move into central or ern IA for Fri
afternoon then to the MS River Fri nt. One or two vorticity
maximums in sly flow aloft will be traversing through the area
along with PWs of 1.3-1.4 inches and MUCAPE of 1000-1500 J/KG.
The models are responding with more greater and more widespread
QPF. Showers will become likely (60%) with chances for storms
Fri afternoon west of Madison then likely for all of srn WI Fri
nt.
Gehring
&&
.SHORT TERM...
Issued 347 AM CDT Thu Sep 18 2025
Today through Friday:
Patchy ground fog will be possible again this morning, with
areas dissipating after dawn. Then, partly sunny skies are
expected through most of today, with highs generally in the
80s, save for areas along the immediate Lake Michigan shoreline.
A lobe of the Upper Low over the northern plains is expected to
dig into Iowa/eastern Nebraska this afternoon and evening,
causing areas of thunderstorms over Iowa. Some of these
thunderstorms may move into areas along and west of a
Monroe/Madison/Fond du Lac line during the late afternoon into
the evening.
Shower and storm chances then slowly begin to progress east on
Friday as the surface low finally meanders into western MN/IA.
Better chances move in (30 to 50%) move in west of the lakeshore
Friday afternoon.
CMiller
&&
.LONG TERM...
Issued 323 AM CDT Thu Sep 18 2025
Friday night through Wednesday:
Low pressure will finally eject out of the central Plains Friday
night, pushing northeastward into Manitoba and slowly dragging a
front through southern Wisconsin. High pressure continuing to sit
just to the east over Quebec and Ontario will result in a
prolonged period of on-and-off showers and thunderstorms through
the weekend (30 to 50 percent chance in any given time frame) as
the front stalls over southern Wisconsin. Expect almost all areas
to see some rainfall over the course of the whole weekend.
As high pressure slowly exits into Monday, the front begins to
shift eastward out of the area. However, a shortwave traveling
southward along the Rockies through the weekend will catch the
southern tail of this front and spin its way into a surface low
pressure system Monday into Tuesday, bringing additional rainfall
chances to the Great Lakes region. However, exactly how this
shortwave will phase with the trough and therefore how much lift
will be brought to southern Wisconsin remains in question. Lowered
confidence results in lower precipitation chances (15 to 30
percent) across the entire Monday to Tuesday timeframe. Model
divergence becomes even more apparent going into Wednesday, with
solutions for low pressure placement ranging from the Great Lakes
(GFS) to the Lower Mississippi Valley (ECMWF) to eastern Ontario
(Canadian). Kept NBM solution for this time frame.
MH
&&
.AVIATION...
Issued 1206 PM CDT Thu Sep 18 2025
VFR conditions this afternoon and evening then areas of MVFR
Cigs and Vsbys developing in the overnight hours mainly north
of Madison and Milwaukee, but also west of Madison. The stratus
clouds will then lift to 3.5-4.5 kft for the afternoon. Isolated
to scattered high based showers will be possible tnt over south
central WI with increasing chances for Fri afternoon and night.
Gehring
&&
.MARINE...
Issued 1206 PM CDT Thu Sep 18 2025
Light to modest northeast winds over the northern half of the
lake will gradually expand into the southern half of the lake this
afternoon with the passage of a weak backdoor cold front. Light
to modest northeast winds are then expected tonight becoming
easterly on Friday. Breezy east to southeast winds will then
prevail Friday night through Saturday morning as Canadian high
pressure strengthens to around 30.4 inches as it moves into the
Lower Great Lakes and southern Quebec, and as low pressure around
29.9 inches moves from the eastern Dakotas into Minnesota.
Intermittent showers and thunderstorms are expected Friday night
through Sunday. A Small Craft Advisory may be needed late Friday
night into early Saturday afternoon from Sheboygan to Winthrop
Harbor due to breezy southeast winds and building waves.
Gehring
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&
$$
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NWS MKX Office Area Forecast Discussion