495
FXUS63 KMKX 131443
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
943 AM CDT Thu Jun 13 2024

.KEY MESSAGES...

- Thunderstorms developing near the state line this afternoon,
  with storms quickly becoming severe as they move south.

- Brief cool down Friday and Saturday, but hotter temps build in
  for Sunday into early next week

&&

.UPDATE...
Issued 944 AM CDT Thu Jun 13 2024

Focus remains on severe weather potential this afternoon. The
cold front remains to our north, with a weak prefrontal trough
south of the boundary. The front will accelerate southward later
this morning as a weak shortwave over southern Minnesota moves
eastward. There is fairly high confidence that convection will
develop along and head of the front between about 1 and 3 PM,
quickly turning severe as it moves south. The front is expected
to be very close to the state line during this time frame, hence
the uncertainty as to whether the severe risk will occur over
our far southern CWA, or just to our south. Additional showers
are expected behind the front later this afternoon, ending early
this evening.

Boxell

&&

.SHORT TERM...
Issued 405 AM CDT Thu Jun 13 2024

Today through Friday:

Showers and storms will move through at least the northern
portions of the forecast area this morning, particularly north
of I-94. Could be a few stronger storms with some hail this
morning given elevated instability in place.

There remains uncertainty with storm chances the rest of the
day. Latest runs of the HRRR continue to be the most aggressive
solutions with storm development early to mid afternoon, with
the HRRR keeping the effective boundary farther north than other
models. If the boundary is farther south as many models are
showing, much of the activity might wind up south of the WI/IL
border. Any storms that do fire in the forecast area this
afternoon will have the potential to become severe, given plenty
of instability and gradually increasing shear. Large hail and
damaging winds would the main concerns. Best chance for storms
will likely be roughly from Port Washington to Monroe and
southeastward. Should be enough sun between rounds of convection
for temps into the 80s today.

Dry weather is likely to return by early evening, with the
front/boundary south of the state by then. High pressure will
then build in on Friday, brining mostly sunny skies and cooler
temps to the area.

DDV

&&

.LONG TERM...
Issued 405 AM CDT Thu Jun 13 2024

Friday night through Wednesday:

High pressure is expected to gradually shift eastward Friday night
and Saturday. Onshore flow will continue to bring mild
temperatures and lower humidity to the area.

The 500 mb ridge axis shifts eastward over the area on Saturday,
and may bring a shortwave trough northeastward along with it.
Another shortwave trough may shift northeast through the area
Saturday night or Sunday. This may combine with some focused 850
mb warm air advection to bring some elevated showers and
thunderstorms at times later Saturday into Sunday. The best focus
for this activity appears to be to the northwest of the area
during this period, so there may be some uncertainty with how far
southeast into the area any of this activity may reach.

South to southwest winds in the low levels will continue to bring
warm air advection into the area Sunday into next week, with the
area likely to be firmly in the warm sector airmass by Monday and
lingering into at least the middle of next week. Ensembles and NBM
are still confident with general 25th to 75th percentile ranges
for high temperatures of upper 80s to lower 90s for Sunday into
most of next week.

Went in this general range for highs during this period, and
could go a little higher if stronger southerly flow develops. Heat
index values in the lower to middle 90s appears likely at this
time for most of this period. Areas toward Port Washington and
Sheboygan, along with locations right along the lakeshore, may get
a little onshore flow and some relief from the very warm and
humid conditions.

The cold front and next decent chances for showers and storms may
not push into the region until later in the week. Kept some PoPs
for showers and storms in the forecast into next week, though if
the warm sector remains in place, any precipitation may be limited
to peak daytime heating with popcorn showers and storms developing
from reaching convective temperatures.

Wood

&&

.AVIATION...
Issued 944 AM CDT Thu Jun 13 2024

VFR conditions are expected this morning, with thunderstorms
then rapidly developing along a cold front this afternoon. That
front is expected to be south of the I-94 corridor when storms
develop, with convection then moving southward into Illinois.
Impacts to the terminals should be short, but a period of
IFR/LIFR and strong gusty winds is certainly possible with any
storms.

Winds today will initially be from the southwest, turning
northwesterly behind the front.

Boxell

&&

.MARINE...
Issued 405 AM CDT Thu Jun 13 2024

Southwest winds this morning will become west to northwest this
afternoon into the evening as a cold front drops through the
area. There will be a chance for thunderstorms along and ahead
of the front. Winds will be northerly on Friday behind departing
low pressure and ahead of an approaching high. Winds will be
lighter on Saturday, picking back up out of the south on Sunday
as the high pushes east of the area.

DDV

&&

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

$$

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