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000
FXUS63 KMKX 240920
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
420 AM CDT Wed Apr 24 2024

.KEY MESSAGES...

- Freeze Watch later tonight into early Thursday morning for
  below freezing temperatures.

- Active pattern Friday through this weekend. Multiple rounds of
  showers/storms will result in locally heavy rainfall. The
  severe storm risk is more uncertain, but bears monitoring.

&&

.SHORT TERM...
Issued 420 AM CDT Wed Apr 24 2024

Today through Thursday:

Low clouds continue to push southward through the area early
this morning, with lake effect clouds over Lake Michigan. These
clouds should gradually shift southward into this morning, but
may linger in southern and eastern parts of the area, before
exiting to the southeast this afternoon.

These clouds and the northeast winds may limit temperatures
from falling to and below freezing early this morning, so not
anticipating enough of a risk for frost or below freezing
temperatures for a frost/freeze headline.

High pressure will shift to the east of the region today into
Thursday, bringing quiet weather. Northeast winds will gradually
weaken today, with light winds this afternoon and tonight.
Relative humidity values this afternoon and Thursday afternoon
will be very low, in the 20 to 30 percent range away from Lake
Michigan. See Fire Weather section below for more details.

Highs in the 40s near the lake and middle 50s well inland are
expected, as skies gradually clear out. Highs Thursday should
rise into the lower 60s well inland, with upper 40s to 50s near
the lake.

Light winds and generally clear skies tonight should allow for
radiational cooling to set up over the area. Lows are expected
to drop into the upper 20s to around 30 over most of the area.
The signal for these temperatures has been consistent over the
past few days, and the NBM 90th percentile for low temperatures
is around freezing for most of the area. So, enough confidence
to issue a Freeze Watch for later tonight into early Thursday
morning for the entire area.

Wood

&&

.LONG TERM...
Issued 420 AM CDT Wed Apr 24 2024

Thursday night through Tuesday:

Models and ensembles continue to show good confidence with an
active weather period Friday through the upcoming weekend. It
appears that two low pressure systems may shift northeast
through the region. The first one shifts from the Central Plains
into the Upper Midwest Friday into Saturday, with the second one
taking perhaps a little more southerly path as it shifts
northeast through the region Sunday into Monday.

Southwesterly flow at 500 mb lingers during this period, with a
general ridge over the eastern part of the country and a trough
over the west. The low level jet should help transport moisture
into the region by later Friday and into Saturday, with warm
air advection bringing warmer air by Saturday. Temperatures may
rise well into the 70s on Saturday, as we get into the warm
sector with more humid air and southwest winds.

It seems that more elevated storms could occur with the warm
frontal passage later Friday and Friday night, though the dry
southeast flow ahead of it may hold back the advance of the
precipitation to Friday night.

Saturday into Sunday night may be the better potential for
stronger thunderstorms, if any surface boundaries can tap into
the warm, moist and unstable airmass. Details are still in
question this far out, so keep up with the forecast. It also
looks to be a wet period, with rounds of showers and
thunderstorms. Most ensemble members have rainfall during the
Friday night into Sunday night period, and some could be locally
heavy with the rounds of convection. Another thing to watch as
we get closer. Above normal temperatures look to linger into at
least early next week.

Wood

&&

.AVIATION...
Issued 420 AM CDT Wed Apr 24 2024

Low clouds with ceilings of 2000 to 2500 feet AGL will slowly
shift southward and linger, before exiting to the southeast this
afternoon. Gusty northeast winds early this morning will
gradually weaken, becoming light this afternoon and tonight.
Mostly clear skies should then occur tonight into Thursday.
Winds will become southeast on Thursday and remain light.

Wood

&&

.MARINE...
Issued 420 AM CDT Wed Apr 24 2024

North gales should gradually subside early this morning over
the south half of Lake Michigan, and a Gale Warning remains in
effect until 7 AM CDT. High waves should linger into this
morning.

The Small Craft Advisory remains in effect until 10 PM CDT this
evening for the nearshore waters, for gusty northeast winds into
this morning and high waves into early this evening.

Winds and waves will gradually lighten up today into Thursday,
as high pressure around 30.4 inches moves southeast across the
region.

South winds will then increase again Friday and remain gusty
through the upcoming weekend, as multiple low pressure systems
move northeast through the region. There will be additional
chances for gales at times Friday night into Saturday across the
open waters. Building waves are expected as well.

Small Craft Advisory conditions are likely over the nearshore
waters from Friday through the upcoming weekend, with the gusty
winds and building waves.

Wood

&&

.FIRE WEATHER...
Issued 420 AM CDT Wed Apr 24 2024

Northeast winds will gradually weaken today, with light winds
this afternoon and tonight. Winds will shift to the southeast on
Thursday and remain light. Relative humidity values this
afternoon and Thursday afternoon will be very low, in the 20 to
30 percent range away from Lake Michigan. Mixing heights will be
above 2000 feet AGL each afternoon, with smoke dispersal values
only in the fair category today and fair to good Thursday well
inland from Lake Michigan.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Freeze Watch...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-
     WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-
     WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...midnight
     Thursday to 8 AM Thursday.

LM...Gale Warning...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
     LMZ779-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 7 AM
     Wednesday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 10 PM
     Wednesday.

&&

$$

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