951
FXUS63 KMKX 020859
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
359 AM CDT Tue Jul 2 2024

.KEY MESSAGES...

- River flooding and high water levels continue this week.
  Additional rises will be possible with any heavier rainfall
  that occurs through Tuesday night.

- Rain and thunderstorms are expected into through this morning,
  and again later this afternoon into early Wednesday morning.
  Primary concern is heavy rainfall, especially tonight.

- Independence Day forecast trends for widespread showers and
  thunderstorms continue to push later overnight Thursday into
  Friday. However still will be a 20-40% chance for spotty showers
  and thunderstorms with lightning through Thursday
  afternoon/evening.

&&

.SHORT TERM...
Issued 359 AM CDT Tue Jul 2 2024

Today through Wednesday:

Showers and storms early this morning are firing along a surge
of WAA and some mid level frontogenesis. The LLJ is just off to
our west in Iowa and far western Wisconsin this morning which is
where the main area of rain and thunderstorms is located. This
main area of rain/storms will be producing some heavier rainfall
in comparison to what we are seeing here in southern Wisconsin.
Light to moderate rain is expected to gradually move through
this morning pulling out of the forecast area by late this
morning. As these showers moved east they have continued to
fight dry air. Dry air in the low to mid level has caused
showers to become scattered to isolated across far southern and
southeastern Wisconsin. It is likely that some rain will
struggle to reach the ground in those areas until the air
column can become fully saturated. With the ongoing WAA this is
only a matter of time.

As the morning showers and storms pull out of the state later
this morning, a lull in the precipitation is expected. This lull
is expected to start late this morning and persist into the
afternoon hours. Late this afternoon into the evening additional
rain showers will move in from the west. These showers are
expected to be focused along the lead edge of the LLJ and along
the cold front. PWATs will be high (around 2 inches) during
this time which will result in heavy rainfall. There is a
concern for training thunderstorms this afternoon with the slow
moving nature of the cold front and LLJ. With the upper level
jet expected to be overhead during this time, storms could grow
in height and bring some heavy downpours. Southwestern and west
central Wisconsin will have the best potential for rainfall
totals over 2 inches as this system moves through. Keeping a
close eye on the rain early this morning (especially to the
west of our forecast area) as rainfall amounts may overachieve
and lead to growing flooding concerns. Rainfall totals to our
west will highlight the potential for heavy rain for our area
later this afternoon and evening depending on how this system
performs could lead to a potential flood watch for southern
Wisconsin later today.

The severe weather potential will be low (marginal) today
across southern Wisconsin. This is in part due to the fact that
CAPE will be lacking. Skies are expected to stay overcast which
will limit the ability for instability to grow. Any clearing
would help with SBCAPE. Regardless the CAPE profiles are very
long and skinny which doesn`t bode well for strong to severe
storms. Any wet microburst activity isnt out of the question if
a storm gets particularly tall, same goes for small hail.
Flooding is the main concern today.

There is a high swim risk today for all Lake Michigan beaches
due to building waves from the onshore breezy winds. With wind
gusts to 30 mph expected throughout the day waves are expected
to climb to 3-5 feet or greater. Dangerous currents such as
structural and rip currents are possible. The high swim risk
will persist across Sheboygan and Ozaukee Counties through
tonight. Stay out of the water during this time.

Patterson

&&

.LONG TERM...
Issued 359 AM CDT Tue Jul 2 2024

Wednesday night through Monday:

Weak surface high pressure will continue to push east overnight
Wednesday into Thursday morning. Most medium range model guidance
supports the drier trend through the morning of July 4th and even
into the the afternoon. Thus PoPs are lowering for the first part
of the day. Then there are hints of a mid-level ripple of
vorticity to quickly trek across the region through the
afternoon/early evening hours. Paired with a surface warm front
lifting into the area along with increasing PWATs to around 1.5
inches, cannot rule out some spotty showers/thunderstorms for the
second half of the day. At this time this activity does not look
be a wash out, especially given the potential to battle some
lingering dry air and the more favorable upper-level dynamics
remaining further upstream. Nevertheless given the increased
outdoor festivities for Independence Day holiday, a low-end
(<40%) potential remains and cannot rule out some minor impacts
(mainly lightning) for these events through the early evening
hours if anything shall develop.

Given the latest 00z model trends, the better chances to see more
widespread showers and thunderstorms look to be overnight
Thursday after 06z (1 AM CDT) into Friday as the mid-level
shortwave trough axis pushes east. The associated surface low
looks to lift into the region around the same time and trends show
the low meandering over WI through the day Friday as it occludes.
Given the slower movement of this system, shower chances linger
through much of the day Friday. NBM does show some instability
(SBCAPE <500 J/kg) as the low works its way across the region for
Friday, but GFS and ECMWF are not as aggressive, but still would
be able to see some thunderstorms with this activity for Friday.

Otherwise, this system is progged to push out of the area for
Saturday with high pressure and upper-level ridge building behind
it. Thinking Saturday will remain mostly dry given the drier
airmass and subsidence expected over the area. However could see
another round of showers and storms for the later half of the
weekend into early next week as a system treks across the Upper
Midwest.

Wagner

&&

.AVIATION...
Issued 359 AM CDT Tue Jul 2 2024

VFR to IFR conditions are expected to persist through the
period. Ongoing rain showers this morning will gradually become
scattered as they head east. Southeastern Wisconsin will likely
see scattered to isolated rain with this mornings round of
showers. In comparison, areas north and west of Madison will
have the best chances for moderate rain and thunderstorms with
this morning round. MVFR to IFR visibilities may be possible
with any heavier rain with the thunderstorms.

A lull in the precipitation is expected late this morning into
the early afternoon hours. Additional rain and storms will move
in from the west late this afternoon and evening. Rain and
storms will linger into the overnight hours until the cold front
has clear the state. Eastern terminals will see the rain
continue into Wednesday morning. Heavy rainfall will be a
concern with this "second" round of rainfall, with more
widespread MVFR to IFR visibilities and ceilings expected.

South to southeast winds today will increase becoming breezy
later this morning with gusts to 30 mph expected. Winds will
shift to the west to southwest tonight as a cold front passes
through the state.  The south to southwest winds should weaken
tonight into early Wednesday morning. May see some low level
wind shear conditions during this time, with southwest winds
around 35 knots at 2000 feet AGL. West to southwest winds will
persist through Wednesday.

Patterson

&&

.MARINE...
Issued 359 AM CDT Tue Jul 2 2024

South to southeast winds will persist across Lake Michigan into
tonight. Winds will increase becoming breezy later this morning
with gusts of 25-30 kts expected. A Small Craft Advisory is in
effect this morning into tonight due to the breezy winds.
Overnight tonight into Wednesday morning a cold front will move
across the lake bringing rain, thunderstorms and westerly winds.
West to southwest winds are expected through Wednesday. Weak
high pressure returns to the region Wednesday night into
THursday bringing a return of light and variable winds.

Patterson

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060...6 AM Tuesday to 1 AM
     Wednesday.

     Beach Hazards Statement...WIZ066-WIZ071-WIZ072...6 AM Tuesday
     to 7 PM Tuesday.

LM...Small Craft Advisory...LMZ643...6 AM Tuesday to 1 AM Wednesday.

     Small Craft Advisory...LMZ644-LMZ645-LMZ646...6 AM Tuesday to
     7 PM Tuesday.

&&

$$

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