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005
FXUS63 KMKX 201633
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1133 AM CDT Fri Sep 20 2024

.KEY MESSAGES...

- Summer-like Temps continue today and Saturday, but
  cooler/near normal temps are expected into next week behind a
  weekend cold front.

- Additional shower and thunderstorms return Saturday night into
  early next week.


&&

.UPDATE...
-- Changed Discussion --
Issued 1133 AM CDT Fri Sep 20 2024

Wly winds and drier air will continue to gradual move into srn
WI this afternoon. High temps in the lower 80s for east central
WI and middle 80s elsewhere still looks good. Weak high pressure
over IA will then shift across srn WI tnt-Sat AM with low temps
mainly from 55-60F. Sly winds and warm, moist advection will
then begin Sat afternoon as a n-s sfc trough/cold front
approaches from the west. This front extends swd from a strong
upper wave and well developed sfc low over Manitoba and Ontario.
High 850 mb dewpoints will surge back into the area from the sw
with negative showalter indices developing along with marginal
MLCAPE. South central WI may see initial shower and storm
development by mid to late afternoon, but with increasing
chances through the evening and overnight for all of srn WI as
the cold front passes.


Gehring
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&&

.SHORT TERM...
Issued 418 AM CDT Fri Sep 20 2024

Today through Saturday:

As the upper-level trough pushes eastward, the last of the
overnight showers and storms will follow suit and push east out
over the Lake Michigan by daybreak. The weak cold front will not
be far behind the precip and will slide through southern WI
this morning. Expect westerly winds and drier airmass to push in
behind the front as surface high pressure briefly builds across
the area. However, southern WI will still see above
normal/summer like temps today given the deeper mixing of warmer
air aloft and ample sunshine. Still looking at highs to top off
in the low to mid 80s this afternoon. As the high shifts east
overnight, winds are progged to become light/calm and paired
with mostly clear skies, will see temps drop into the mid 50s to
low 60s. High pressure will push east for Saturday and
southerly flow will return to southern WI. Once again will see
above normal/summer-like temps in the mid to upper 80s.

Wagner

&&

.LONG TERM...
Issued 418 AM CDT Fri Sep 20 2024

Saturday night through Thursday:

As southern WI "enjoys" the summer-like pattern, another upper-
level trough is progged to dig across the northern Plains and
skirt the Upper-Midwest overnight Saturday and Sunday. The
associated surface low is progged to track across
Manitoba/Ontario toward Hudson Bay, which will drag another cold
front across WI Saturday night into Sunday. Expect moisture to
advect into the warm sector ahead of the front and bring another
bout of precipitation to southern WI. Thinking there will be
better potential to see a bit more coverage of rainfall/storms
with this weekend system given the frontal forcing paired with
mid-level dCVA ejecting out ahead of another upper-level trough
working its way from the the Desert Southwest into the Central
Plains. Both the EPS and GEFS along with the NBM all prog a
50-70% chance of southern WI seeing a half an inch or more of
rainfall across southern half of the CWA (generally south of
I-94) within the 24hr period ending Sunday evening. Higher
amounts approaching 1 inch will be possible, especially for
areas along the Cheddar Curtain into IL, but chances remain less
than 40% for southern WI at this times.

Additional shower and storm chances will continue through early
next week as a series of shortwave trough traverse across the
region. However, as we head into next week models differ in
timing and track of these features. Thus uncertainty remains,
but nevertheless the pattern looks more active through at least
Tuesday. Otherwise, the return of more seasonal/near normal
temps are expected behind Sunday`s cold front and this trend
continues through next week. Looking at daily highs in the 70s
with overnight lows in 40s/50s.

Wagner

&&

.AVIATION...
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Issued 1133 AM CDT Fri Sep 20 2024

Areas of MVFR Cigs ending early this afternoon north of MKE.
Otherwise VFR conditions this afternoon through Sat other than
a brief period of fog at sunrise Sat in the lower WI River
Valley and other low lying areas.

Gehring
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&&

.MARINE...
Issued 418 AM CDT Fri Sep 20 2024

Low pressure centered over Manitoba will gradually lift into
the Hudson Bay today. This low to the north will drag a weak
cold front across Lake Michigan through this evening where
southerly winds today will turn more westerly overnight into
Saturday. Will see a broad area of high pressure build in behind
the front for Saturday before winds turn back to the south and
pick up ahead of another low pressure. Expect this low to lift
across Manitoba/Ontario and deepen overnight Saturday into
Sunday dragging another cold front across Lake Michigan. Will
once again see southerly winds turn more west-northwesterly
behind the front during the day Sunday. Northerly winds will
continue into the the start of next week as high pressure builds
across the Upper Great Lakes region.

Wagner

&&

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

$$

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