082
FXUS63 KMKX 121606
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1106 AM CDT Wed Jun 12 2024

.KEY MESSAGES...

- Showers and thunderstorms are possible at times later this
  afternoon into early Thursday evening, with continued
  uncertainty with timing and placement of convection.

- Warmer and more humid conditions today into Thursday.

- A significant warm up still looks likely for Sunday into early
  next week.

&&

.UPDATE...
Issued 1044 AM CDT Wed Jun 12 2024

Previous forecast remains on track with warm air advection
warming things into the 80s today. However upstream showers
across southern MN is bringing a cirrus shield into southern
half of WI and progged to spread eastward through the remainder
of the morning and into the early after. While thin, these
upper-level clouds may limit temps from reaching the higher end
of the probabilities. Otherwise, keeping an eye on the
associated showers and thunderstorms across the same area. 12z
CAMs vary in solutions as the previous forecast and still
difficult to pinpoint the exact evolution as this activity moves
into our CWA. However, given the drier low-level on this
mornings model soundings, think it will be an uphill for these
to maintain its strength. Thus, thinking it will mainly push in
as a decaying line of storms. While the trend favors the
weakening line given the lack of forcing, still cannot rule out
an elevated storm or two to drop some small hail and a sporadic
gust of stronger winds, especially for areas west of I-39
corridor as the deterministic models prog a mid-level ripple of
vorticity working across the area and some meager deep layer
shear.

Otherwise, it looks to weaken the further east. Then
could see some additional showers and storms along the southern
extent of the evening activity move in overnight into Thursday.
Again CAMs vary on handling this activity and it very well could
end up dry, but think will at least some decaying activity
overnight.

Wagner

&&

.SHORT TERM...
Issued 412 AM CDT Wed Jun 12 2024

Today through Thursday:

Steady warm air advection is expected today into Thursday, with
southwest winds developing. Moisture advection will also take
place, pushing dew points into the upper 50s to lower 60s today
and into the middle to perhaps upper 60s on Thursday. Thus, warm
and humid conditions are expected, especially for Thursday.
Highs today should reach into the middle 80s over most of the
area, with a few upper 80s near the Illinois border. Similar
highs are expected on Thursday.

There remains quite a bit of uncertainty with regards to
convection possibilities later this afternoon into Thursday
across the area. CAMs are not in good agreement with what may
occur, though it seems plausible that showers and storms forming
in northwest and west central Minnesota at this time may try to
shift gradually southeastward toward and into the area by later
this afternoon or early this evening. The warm air and moisture
advection may help the showers and storms continue, though they
probably will be more elevated in nature. At worst, they could
bring some gusty winds and small hail if they remain elevated.

More showers and storms could then form in northeast Minnesota
and northwest Wisconsin near the cold front, then shift
southeast overnight tonight toward and into the area. CAMs seem
to suggest a weakening trend with this activity, so again may
just see gusty winds and small hail at worst. Some of the CAMs
are dry or take the convection elsewhere, so it could end up dry
for later this afternoon into later tonight and early Thursday.

So, kept PoPs in the chance category for tonight into early
Thursday morning, until some more clarity in convective trends
can be found.

Thunderstorm chances Thursday afternoon and early evening will
depend on where the effective cold front sets up. Most CAMs
suggest that this would be over northern Illinois, where warm
and unstable air would be more untouched from any overnight and
early morning showers and storms.

If we do not get any storms overnight, then southeast parts of
our area may be more unstable. The cold frontal timing would
then be key for any development in our southern counties. Again,
northern Illinois seems to be favored, so will monitor this
period and see how things evolve overnight and how it affects
our mesoscale environment.

Wood

&&

.LONG TERM...
Issued 412 AM CDT Wed Jun 12 2024

Thursday night through Tuesday:

Cold air advection behind the front should bring less humid air
into the area for Friday and linger into early Saturday. High
pressure moving through the region should bring quiet weather,
with cooler temperatures from onshore winds.

Focused warm air advection develops west of the area Saturday
afternoon and then shifts through the region Saturday night into
Sunday, as south winds increase. This may help bring some
showers and thunderstorms through the region.

As the upper ridge axis builds to the east of the region Sunday
into early next week, very warm and humid conditions are still
likely to move into the region. Ensembles remain fairly
confident with highs into the upper 80s to perhaps lower 90s at
times, near the 25th to 75th percentile thresholds of the NBM.

Kept highs more in the upper 80s, as there may be chances for
showers, storms and clouds at times, which may keep
temperatures limited a bit. May need to adjust these upwards if
the area gets more firmly in the warm sector early next week.

Dew points should rise well into the 60s and perhaps reach 70
or so, and subsequent heat index values may rise into the 90s.
All in all, a very warm and humid period is expected Sunday into
most of next week.

Wood

&&

.AVIATION...
Issued 1054 AM CDT Wed Jun 12 2024

VFR conditions will prevail through the day. While there is a
low end shower and storm chances this afternoon, which may bring
a a brief window for lower visibility and ceilings, generally
thinking the dry air will keep things above the VFR levels.
There will be additional chances for some showers and storms
overnight again as the cold front slides down across the area.

Otherwise, expect light southwest winds today into tonight. May
see a lake breeze develop turning winds more southeasterly, but
looks to mainly be confined to the lake/lakeshore counties.
Then winds pick up overnight into Thursday with gusty southwest
turning west as the cold front pushes through.

Wagner

&&

.MARINE...
Issued 412 AM CDT Wed Jun 12 2024

South winds will continue today into this evening, with
increasing southwest winds later tonight into Thursday. Winds
will shift to the northwest and north behind a passing cold
front later Thursday into Thursday night. There will be chances
for showers and thunderstorms at times tonight into Thursday
evening.

The gusty southwest to west winds on Thursday may approach Small
Craft Advisory levels over the nearshore waters of Lake
Michigan.

North winds will generally remain Friday, as high pressure
around 30.1 inches moves into the region. Winds should gradually
increase and become south by later this weekend, as very warm
and humid air moves into the region. Chances for showers and
thunderstorms will also return.

Wood

&&

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

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/NWSMilwaukee
www.twitter.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee