171
FXUS63 KMKX 240931
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
431 AM CDT Mon Jun 24 2024

.KEY MESSAGES...

-  A strong to severe line of fast moving thunderstorms is
   expected to move across southern WI after midnight. A Slight
   Risk has been outlooked and damaging winds is the primary
   threat.

-  Urban and small stream flooding will be possible after
   midnight due to the already saturated conditions and a quick
   burst of torrential rainfall.

-  River rises will continue early this week and may receive a
   sudden boost from heavy rain after midnight.

-  Heat index values into the 90s will be possible on Tuesday.


&&

.SHORT TERM...
Issued 431 AM CDT Mon Jun 24 2024

Today through Tuesday night:

High pressure will shift ewd today with sly winds developing
this afternoon. Any low lying fog will quickly burn off after
sunset with temperatures returning to the 80s away from the lake
for the afternoon.

Attention then turns to a MCS for after midnight. A shortwave
trough will track from wrn MN to the nrn Great Lakes tonight and
be accompanied by a n-s wave of low pressure. A swly LLJ of
50 kt will develop ahead of the aforementioned features and then
veer into srn WI after midnight. Strong warm, moist advection
from 925-700 MB will support a maturing and fast MCS from ern
MN esewd into srn WI. The strong thetae advection and steep mid
level lapse rates will support elevated CAPE of at least
1500-2000 J/KG and PWs near 2 inches. Despite the elevated
nature of this event, expect pockets of SVR winds to make it to
the surface. The best timing for the MCS would be from
0600-0930 UTC. The sfc trough passage will then quickly follow
on Tue likely setting up any new convection over IL and IA for
later in the day. Wly winds and gradually lowering dewpoints
will lead to a very warm day.

Gehring

&&

.LONG TERM...
Issued 431 AM CDT Mon Jun 24 2024

Wednesday through Sunday:

For Wed a digging shortwave trough will track from wrn Lake
Superior and NW WI to the lower Great Lakes. Its cold front will
pass in the morning including onshore flow from Lake MI. Despite
these features the fcst soundings are fairly dry and will keep
pcpn out of the fcst for now. Pleasant temps in the 70s are
expected, but possibly only upper 60s for east central WI and
near Lake MI. High pressure will then shift across the state
late Wed nt into Thu AM. Another pleasant day in the 70s is
forecast.

Yet another round of strong warm, moist advection and
thunderstorms arrive for Fri followed by a stronger cold front
and more storms Fri nt-early Sat. This will be initiated by an
upper trough and cyclogenesis moving from the nrn Great Plains
to the nrn Great Lakes. Certainly cannot rule out SVR storms
and heavy rain with this scenario. Weakening nly winds and
pleasant temps and humidity for Sun with high pressure arriving
late in the day.


Gehring

&&

.AVIATION...
Issued 431 AM CDT Mon Jun 24 2024

Patchy fog mainly in low lying areas and river valleys through
13Z this morning. Otherwise VFR conditions today and this evening
followed by a strong to severe line of thunderstorms after
midnight. LLWS will develop late this evening into the overnight
via a sswly low level jet of 45-50 kt.

Gehring

&&

.MARINE...
Issued 431 AM CDT Mon Jun 24 2024

High pressure of 29.9 inches will shift east across Lake Michigan
this morning with light and variable winds expected. Modest south
winds will develop this evening, becoming breezy late tonight into
Tuesday morning as low pressure around 29.2 inches moves across
northern Ontario. Modest westerly winds behind the low will then
shift to northerly on Wednesday following the passage of a cold
front. A line of thunderstorms with very gusty winds will move
across Lake Michigan late tonight through Tuesday morning.

Gehring

&&

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

$$

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