658
FXUS63 KMKX 222006
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
306 PM CDT Sun Sep 22 2024

.KEY MESSAGES...

- Light rain and drizzle will continue through the remainder of
  the afternoon, diminishing from west to east this evening into
  tonight.

- Cooler/near normal temps are expected behind the cold front
  today through the start of the week with daily highs in the
  upper 60s and lower 70s.

- High uncertainty in timing and placement for precipitation
  next weekend (15 to 30 percent chance).

&&

.SHORT TERM...
Issued 306 PM CDT Sun Sep 22 2024

Tonight through Monday night:

A Beach Hazards Statement is in effect from this afternoon
through Monday afternoon due to gusty winds producing 3 to 5 ft
waves along Lake Michigan beaches and therefore producing a high
swim risk.

Based on observations, the cold frontal feature has almost
completely pushed through southern Wisconsin (indicated by
northwesterly wind gusts of 15 to 20 mph). Satellite indicates
clearing skies and dry air intruding from the northwest, which
will shut off drizzle production in the subsidence region of the
frontal passage within the next few hours in southwestern
Wisconsin. That being said, drizzle has been efficient so far this
afternoon, and the subsidence region and its associated drizzle
is therefore expected to propagate eastward into southeastern
Wisconsin as steady rainfall ends in that region. Clouds will
break up from west to east late this evening into tonight, and
winds will diminish overnight as well. Expect overnight lows in
the 40s, with the coolest temperatures in the lower 40s in the
Wisconsin River Valley region.

Dry conditions with northeasterly breezes expected Monday as high
pressure nudges southward from the northern Plains. Partly cloudy
skies will combat the cooler airmass, allowing for highs in the
upper 60s to near 70 degrees. Overnight Monday, high pressure
lifts back into Canada as a developing surface low in the Middle
Mississippi Valley propagates northeastward. This low may produce
rain and showers overnight into Tuesday, although confidence
remains low (15 to 35 percent, with the highest chances in
southeastern Wisconsin). Low temperatures in the upper 40s to
lower 50s are expected, with higher lows in the upper 50s near
Lake Michigan.

MH

&&

.LONG TERM...
Issued 306 PM CDT Sun Sep 22 2024

Tuesday through Sunday:

Low pressure exits to the east slowly on Tuesday as it interacts
with a Canadian surface high, producing a few more chances for
rain and showers through the day in southeastern Wisconsin (15 to
35 percent). After this low exits, a cooler airmass and high
pressure will dominate through much of the week as a Rex
blocking pattern sets up across the central U.S.

Uncertainty increases going into the weekend, as global models
indicate potential for a system of tropical origin nudges
northward into the Great Lakes region. Timing, intensity, and
precipitation amounts will be highly dependent on the evolution of
this system in the Gulf of Mexico, and therefore my confidence for
this timeframe is low. Kept NBM PoPs, which generally show a 15 to
30 percent chance from Friday through Sunday. That being said, the
strength of the high pressure and blocking pattern will likely
shift the timeframe of these chances farther into the future with
additional model runs.

MH

&&

.AVIATION...
Issued 306 PM CDT Sun Sep 22 2024

Low ceilings between 500 ft and 1500 ft will slowly rise from
west to east tonight, with clouds breaking up into the overnight
hours. Light rain and drizzle will continue through this
evening, tapering off from west to east as well. Cold frontal
passage has almost completed its passage through southern
Wisconsin (draped from west of SBM to JVL currently), with gusts
up to 20 kt along and immediately behind the front. Winds will
remain northerly and gusty into this evening before slowly
tapering off overnight into Monday morning. Winds shift to
become northeasterly Monday as well, with VFR conditions
expected throughout Monday.

MH

&&

.MARINE...
Issued 306 PM CDT Sun Sep 22 2024

Gusty northerly winds in the northern half of the open waters will
spread southward through the remainder of the open waters this
evening into tonight, with gusts up to 30 kt expected through
the overnight hours in the southern two-thirds, including in the
nearshore regions. An occasional gale force gust is possible in
this region of the open waters. A Small Craft Advisory is in
effect this afternoon through Monday afternoon for these elevated
wind and wave conditions. Northerly winds will diminish Monday
morning through Monday afternoon as high pressure builds into
the northern Great Lakes region. As high pressure pushes
eastward into Canada, expect winds to shift to easterly Monday
night into Tuesday. Weak low pressure is then expected to
develop in the Middle Mississippi Valley and lift into the
eastern Great Lakes on Tuesday, leading to northeasterly winds.
A few thunderstorms are possible across the southern half as
this low develops.

MH

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066 until 1 PM
     Monday.

     Beach Hazards Statement...WIZ071-WIZ072 until 4 PM Monday.

LM...Small Craft Advisory...LMZ643-LMZ644 until 1 PM Monday.

     Small Craft Advisory...LMZ645-LMZ646 until 4 PM Monday.

&&

$$

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