249
FXUS63 KMKX 060253
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
953 PM CDT Wed Jun 5 2024

.KEY MESSAGES...

- Additional showers and a few thunderstorms linger tonight.

- Windy, showery for Thursday. Continued breezy into the
  weekend, but drier.

&&

.UPDATE...
Issued 945 PM CDT Wed Jun 5 2024

The line of showers with an embedded thunderstorm or two will
continue to push east this evening, but will continue to bring
sporadic gusts of 30-40 mph and moderate to heavy rainfall.
there may be another line of showers and a few thunderstorms
stretching across west central WI that looks to move through
between the 03z-07z hours. This will bring additional moderate
to heavy rainfall and another round of sporadic gusts. However,
the latest radar shows this line on a downward/decaying trend as
it moves into our CWA. Nevertheless, it may still be enough to
mix down some stronger gusts just off the deck to the surface.

Otherwise this activity should swing through by the early
morning hours and dry out. However, Thursday will become
increasing breezy given the persistent northwesterly flow
regime. Could also see shallow scattered showers through the day
Thursday as a mid-level impulse ripples around the longwave
trough meandering across the Upper Midwest/Great Lake Region
through the end of the week.

Wagner

&&

.SHORT TERM...
Issued 402 PM CDT Wed Jun 5 2024

Tonight through Thursday night:

A robust shortwave trough currently pushing into west central WI
will be a trigger for thunderstorm development along the leading
edge over the next hour or two. The cluster of showers and
storms will track across southern WI this evening, entering the
Dells area around 6 PM and exiting the Milwaukee area around
midnight. With 500 j/kg CAPE strong synoptic dynamics to support
high bulk shear values, there is a small risk for a severe-
level wind gust or two this evening.

Gusty westerly winds will develop Thursday morning and persist
through late afternoon, with peak gusts around 30 mph. There is
a chance for a few higher gusts if we end up mixing a little
deeper than expected. With steep low level lapse rates, we can
expect shallow showers to develop in the afternoon. The more
widespread showers will be over northern WI where a more robust
shortwave will be tracking.

Cronce

&&

.LONG TERM...
Issued 402 PM CDT Wed Jun 5 2024

Friday through Wednesday:

The closed upper low over the Upper Great Lakes will gradually
shift east Friday, but the cyclonic flow will allow for another
day of diurnal cumulus clouds and fairly gusty northwest winds.
There should be some weak ridging over southern WI Friday night.

For Saturday, we get into a more complicated scenario that will
bring rain chances to southern WI in both the morning and
afternoon. Another upper low will set up over Lake Superior Saturday
morning. A shortwave trough rounding the base of it will slide
across southern WI the first part of the day. Warm air advection
ahead of this shortwave will support development of showers
along a surface front that will likely be draped across northern
IL. Those showers should extend north of the front through a
good portion of southern WI during the morning hours. By the
afternoon, the cyclonic flow over northern and at least part of
southern WI will lead to additional scattered showers. Depending
on the lapse rates and moisture, the conditions may allow for a
few thunderstorms, but confidence is low at this time.

The last gasp of this upper trough will drop through WI Sunday
morning. The cyclonic flow and steep mid level lapse rates will
yet again allow for scattered showers and probably some
thunderstorms.

The next upper trough and associated surface trough is expected
to cross the Upper Great Lakes on Tuesday, bringing a chance for
showers and storms.

Cronce

&&

.AVIATION...
Issued 953 PM CDT Wed Jun 5 2024

Main line of showers are pushing east late this evening with
another line of decaying showers across west-central WI. May see
this line make it into the area and bring another round of
showers and perhaps some gusty winds, especially for our
western terminals. If they make their way in, main timing would
be between 03z and 07z. Outside of showers reducing
visibilities, VFR conditions are expected to prevail. Main
concern for Thursday will be the increasing west-northwesterly
winds with gusts of 20-30 kt possible through the late morning
and afternoon. Again could see some sporadic/scattered showers
develop as well, but coverage and confidence remains limited at
this time to add mentions in this TAF package.

Wagner

&&

.MARINE...
Issued 402 PM CDT Wed Jun 5 2024

Thunderstorms are possible tonight as an upper level disturbance
tracks across Wisconsin and Lake Michigan. A secondary cold front
will move across the lake overnight, with gusty westerly winds
developing Thursday.

A large area of low pressure will gradually move through
southern Canada, just north of the Great Lakes, through the end
of the week. Winds will remain westerly and breezy through this
period. Showers will be possible at times late week as
shortwaves move through the broad cyclonic flow across the
region.

Cronce

&&

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

&&

$$

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