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042
FXUS63 KMKX 181004
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
504 AM CDT Tue Jun 18 2024

.KEY MESSAGES...

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- Slight chances (15 to 20%) for scattered storms in southeast
  Wisconsin this morning and afternoon, then better chances for
  storms overnight over central Wisconsin spreading east with
  time tomorrow.

- Heat index values will be between 95 and 100 this afternoon.
  Hydration and frequent breaks are advised if working outdoors.

- Dangerous swim conditions are likely this morning into tonight
  at Lake Michigan beaches in Sheboygan and Ozaukee Counties.
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&&

.SHORT TERM...
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Issued 459 AM CDT Tue Jun 18 2024

Today through Wednesday:

This morning, a week wave over the southern end of Lake
Michigan is expected to bring some low clouds to southeastern
WI, along with slight chances for rain (~15%). Any rain that
happens is expected to be widely scattered. Skies should clear
mid morning and the heat should build, with highs in the low
90s, amid dew points in the low 70s. Resulting heat indices will
be between 95 and 100 this afternoon.

In addition to the heat, southerly winds will gust between 25
and 30 mph. At local beaches in Sheboygan and Ozaukee counties,
this will drive a High Swim Risk from high waves and dangerous
rip currents this morning into tonight. A Moderate Swim Risk
will exist in Milwaukee and Racine Counties. Even with the high
heat outside, swimming is not advised.

Overnight, the large ridge over the eastern United States will
lean more latitudinally, allowing for a cold front to make an
approach at Wisconsin from the northwest before washing out.
This cold front will drag showers and storms over central WI
overnight. Through the day on Wednesday, the cold front will
become more of a southwest to northeast oriented stationary
front from Iowa into lower Michigan. Convergence along this
baroclinic zone will drive on and off scattered shower and storm
chances through Wednesday into Thursday. Heat will still linger
south of the baroclinic zone on Wednesday, and much of southern
WI will see highs in the upper 80s to low 90s again.

CMiller
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&&

.LONG TERM...
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Issued 448 AM CDT Tue Jun 18 2024

Wednesday night through Monday:

Lee troughing over the front range of the Colorado Rockies will
allow for an increase in southerly flow over the plains
Wednesday night into Thursday morning. Sfc WAA will allow
moisture to surge back north and the stationary front should
lift north as a warm front. Through the day on Thursday, sfc
flow along the sfc trough/warm front will allow for east flow
off of the lake, driving a lake modified air mass inland. As a
result, much of southern WI should see a break from the heat,
although conditions will still remain humid with dewpoints
remaining in the mid to upper 60s. Weak scattered shower and
storm activity may occur along the warm front as well.

The WAA will bring another surge of warmth north for Friday and
Saturday with daytime highs on both days in the upper 80s.
Relief may not finally come until a cold front comes through
Saturday night. The NBM paints great PoPs at 70%, suggesting a
line of showers and storms along with the front Saturday night.
Temperatures then cool for Sunday and Monday.

CMiller
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&&

.AVIATION...
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Issued 429 AM CDT Tue Jun 18 2024

Some low MVFR to low VFR ceilings are expected to spread into
southeast Wisconsin this morning with an area of light scattered
showers. These showers should largely miss TAF sites in
southeast Wisconsin. These ceilings should clear and FEW250 to
SCT250 is expected for much of southern WI during the late
morning and into the afternoon. There are low chances for pop-up
thunderstorms in the afternoon, but confidence in occurrence is
low.

Winds will be elevated today out of the south-southwest, with
gusts from 20 to 25kts.

CMiller
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&&

.MARINE...
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Issued 421 AM CDT Tue Jun 18 2024

Modest southerly winds will prevail through the rest of this
morning. Low pressure around 29.5 inches lifting from the
northern Plains into northwestern Ontario today will then
produce gusty southerly winds during the post dawn hours this
morning and will continue into tonight. Locally, this will cause
small craft advisory conditions. Winds will then gradually ease
early Wednesday morning, and lighter southwesterly winds are
then expected through Wednesday as the low continues to lift
into the Hudson Bay.

A cold front will slowly push southward across the lake Wednesday
night into Thursday, shifting winds northeasterly.

CMiller
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&&

.MKX WATCHES/WARNINGS/ADVISORIES...
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WI...Beach Hazards Statement...WIZ052-WIZ060...10 AM Tuesday to 4
     AM Wednesday.

LM...Small Craft Advisory...LMZ643...10 AM Tuesday to 1 AM
     Wednesday.

     Small Craft Advisory...LMZ644-LMZ645-LMZ646...10 AM Tuesday to
     10 PM Tuesday.
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&&

$$

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