464
FXUS63 KMKX 120912
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
412 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.

&&

.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 412 AM CDT Wed Jun 12 2024

Light southwest winds are expected today into tonight, with
gusty southwest to west winds on Thursday. There may be low
level wind shear conditions between 04Z and 12Z Thursday across
area terminals, as 2000 foot AGL southwest winds are expected
to be around 40 knots. Any southeast lake breeze should be
confined to near the lakeshore and east of the lakeshore
terminals.

Chances for showers and storms are still quite uncertain for
later today into Thursday afternoon. For now, will refrain from
mentioning thunder in TAFs until more confidence can be found in
the forecast. Cold front moving through the area later Thursday
will bring a wind shift to northwest by early Thursday evening.

Wood

&&

.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