NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 270801
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
301 AM CDT Sat Jul 27 2024

.KEY MESSAGES...

- Quiet and warm weather expected today.

- Scattered thunderstorms expected Sunday, with locally heavy
  rain possible. Not anticipating severe weather with this
  activity.

- Heat returns Monday with heat index values in the lower 90s
  through most of the week.

- On and off thunderstorm chances are expected to continue
  through next week as several shortwaves and frontal features
  affect southern Wisconsin.

&&

.SHORT TERM...
Issued 301 AM CDT Sat Jul 27 2024

Today through Sunday night:

Patchy fog in low-lying areas will clear rapidly into this
morning. Otherwise, breezy southerly winds and mostly clear
skies today will allow temperatures to climb into the mid-80s
away from Lake Michigan. A lake breeze is expected to develop in
the afternoon and drop temperatures near the Lake back into the
mid to upper 70s.

Cloud cover will increase overnight as an upper level low and
associated WAA progress into southern Wisconsin. This will serve
to keep low temperatures in the mid-60s. A few showers may
develop during the late overnight hours to the early morning
hours on Sunday as mid-level WAA and Gulf-origin moisture push
into far southern Wisconsin.

Weak shear around 20 kt and CAPE values of 500 to 750 J/kg imply
severe threat is minimal on Sunday. However, strong WAA and a
decaying, closed upper level low lifting into southern Wisconsin
will provide enough lift to produce showers and thunderstorms
throughout the afternoon. Activity generally looks to be
scattered, although in some areas the slow-moving nature of
these thunderstorms may result in longer duration rainfall in
localized areas. Rainfall may also be heavy, as PWAT values near
2 inches. Outside of rain and storms, expect high temperatures
in the low to mid-80s and southerly breezes.

Showers and storms may linger into the overnight hours Sunday,
but will lose instability into the evening hours. Still, lift
remains in place with the upper level low through the late
overnight hours before exiting to the east. Therefore, remaining
showers and storms will end from west to east during the late
overnight hours. Lows in the upper 60s and southerly winds are
expected through the overnight hours.

MH

&&

.LONG TERM...
Issued 301 AM CDT Sat Jul 27 2024

Monday through Friday:

Upper level ridging in the central to southern Plains will nose
into the Upper Midwest next week, leading to rising temperatures
and humidity, as well as putting southern Wisconsin into the
path of ridge-riding shortwaves once again. Plenty of warmth and
humidity will set the stage for instability to build in between
rounds of storms. Although confidence in placement and timing of
these shortwaves remains low at this time, confidence in a more
active pattern has continued to increase with consistency in
modeling continuing. Therefore kept NBM PoPs of generally 20 to
40 percent through the week. PWATs of 1.5 to 2 inches are
indicated on major models through the week as well, indicating
heavy downpours with any thunderstorms that do develop.

With building ridging, heat becomes a concern once again across
southern Wisconsin. Heat index values in the mid 90s are
possible by midweek.

MH

&&

.AVIATION...
Issued 301 AM CDT Sat Jul 27 2024

Light to calm winds early this morning will become southerly
around 10 kt by mid morning. A few southeasterly gusts between
15 and 20 kt are possible along lakeshore terminals this
afternoon as a lake breeze pushes inland. Clear skies are
expected, with a few diurnal cumulus around 3000 ft developing
around midday. Winds and cloud cover diminish into the evening
hours, with high clouds moving in around 10 kft across
southwestern Wisconsin late tonight. Cloud cover will increase
through the overnight hours, with rainfall and lower ceilings
developing into the morning hours Sunday.

MH

&&

.MARINE...
Issued 301 AM CDT Sat Jul 27 2024

High pressure will continue to retreat into the Northeast
today, while low pressure moves from northern Saskatchewan into
northern Manitoba. South winds will gust around 20 knots,
mainly across the north half. On Sunday, low pressure will
develop in the central Plains and south breezes will continue as
a warm front develops across the Lake. Weaker low pressure will
move across the lake early Tuesday, shifting winds to
southwesterly. Thunderstorms are possible throughout Sunday,
with additional thunderstorm chances continuing through midweek.

MH

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

$$

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