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000
FXUS63 KMKX 171519
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1019 AM CDT Wed Apr 17 2024

.KEY MESSAGES...

- Light scattered showers continuing through the day, with
  additional light rain possible on Thursday.

- Gusty west winds this afternoon and again Friday.


&&

.UPDATE...
Issued 1018 AM CDT Wed Apr 17 2024

The occluded front has completed its passage through southern
Wisconsin, with southwesterly winds gusting between 25 and 35
mph through the remainder of the day. Winds are expected to
slowly shift westerly this afternoon as the occluded low lifts
northward through Lake Superior into Ontario. A few wrap around
showers are progressing eastward through southern Wisconsin now,
and a couple more rounds are possible, although they will remain
more isolated. A few breaks in the clouds in southeastern
Wisconsin may allow temperatures to rise into the low 60s.
However, this break looks to be short lived and westerly winds
may result in lower high temperatures this afternoon.

MH

&&

.SHORT TERM...
Issued 422 AM CDT Wed Apr 17 2024

Today and Tonight:

The occluded front made it to our western county warning area
and is slowly making it way across southern WI this morning.
Cells are tracking north and the line is moving east. Occluded
fronts are notorious for severe surprises so we are watching the
radar closely for any brief spinning cells. There is a lot of
low level shear and helicity, as well as decent CAPE up to 1000
j/kg, but there is also CIN present. Gusty winds and small hail
are the main threats, but can`t rule out a weak tornado.

The line of showers and storms should clear east central WI by
14z/9AM. After that, a few showers may still rotate through the
area as the occluded low tracks across the center of the state.
Look for westerly winds to ramp up this afternoon with gusts up
to 35 mph possible into the early evening hours.

Cronce

&&

.LONG TERM...
Issued 422 AM CDT Wed Apr 17 2024

Thursday through Tuesday:

A shortwave trough digging through the Central Plains from NE to
IL tonight into Thursday will be the focus for our next chance
of rain across southern WI. A narrow area of 600-700mb
frontogenesis is expected to slide across southern WI Thursday
afternoon. This should be enough to saturate the mid levels and
then in turn the low levels, and light rain showers are
expected for much of the day.

Models have been fairly consistent with this signal of light
QPF, and precip amounts should be less than 0.25 inch. It seems
like the mid level baroclinic zone has shifted a little farther
north and there is better interaction between the system over
the Ohio River Valley and the shortwave that will be passing
over us. This gives higher confidence in measurable rain,
especially toward the IL border (>90%).

We will enter into a lengthy period of fairly dry northwest flow
from Friday through Thursday. Temperatures will be at or below
normal for most of the period, with normal highs in the upper 50s
to around 60 for mid to late April. Lows will be in the 30s Friday
night and through Sunday night. Saturday night looks the coldest
with below freezing temps possible.

Gusty westerly winds are expected Friday as broad low pressure
over Ontario exits the region. Deep mixing is the main reason
for those gusty winds, with gusts up to 40 mph possible.

A shortwave trough crossing the Central Plains Monday and Monday
night will help us warm briefly. There is a chance of rain with
this feature, although there are model differences in the track of
this associated low and therefore the precip. It looks like the
pattern will change back to warm and unsettled beyond Day 7.

Cronce

&&

.AVIATION...
Issued 1018 AM CDT Wed Apr 17 2024

Slowly falling ceilings with subsidence behind a low pressure
system are expected through the morning, slowly rising again
into the afternoon hours as low pressure lifts northward. Expect
ceilings between 1000 and 2200 ft generally, with a few pockets
of IFR ceilings near showers in southwestern Wisconsin and a
few pockets of clearing in southeastern Wisconsin this morning.
Otherwise, southwesterly winds will slowly shift westerly this
afternoon as the low lifts northward. Expect gusts around 25 kt
across all of southern Wisconsin through the afternoon. A few
gusts near 30 kt are expected near Lake Michigan.

MH

&&

.MARINE...
Issued 422 AM CDT Wed Apr 17 2024

Low pressure of 29.4 inches over southeast Minnesota will track
through central Wisconsin today and across northern Lake Michigan
this evening while weakening to 29.6 inches. Strong easterly
winds will continue across all but the southern third of the lake
until around 7 AM CDT. While winds will diminish across most of
the lake today, the far northern areas should see frequent gale
force gusts through late afternoon. No change to the gale
headlines.

Gusty westerly winds will develop today and gradually diminish
tonight into Thursday as the low departs the area. A Small Craft
Advisory is in effect for the southerly winds this morning and
then westerly winds this afternoon and early evening.

Weakening low pressure around 29.8 inches over Ontario Thursday
night will track into Ontario through Friday night. Westerly
winds will be gusty on Friday near the lakeshore, but not as
much over the lake. Another Small Craft Advisory will be needed.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Gale Warning...LMZ261-LMZ362 until 7 PM Wednesday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 9 PM
     Wednesday.

&&

$$

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