Brookfield, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

145
FXUS63 KMKX 110913
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
413 AM CDT Wed Jun 11 2025

.KEY MESSAGES...

- Periodic shower and thunderstorm chances are forecast from
  Wednesday evening through Saturday, though there will be some
  dry periods. Cannot rule out a few stronger storms during
  this period.

- Conditions look a bit drier by later this weekend.

&&

.SHORT TERM...
Issued 413 AM CDT Wed Jun 11 2025

Today and Tonight:

WAA is underway across southwestern Wisconsin and will expand
across the entire forecast area through this morning.
Temperatures have maintained or increased with many locations
having temps in the mid to upper 60s. Despite clear skies early
this morning, the overnight lows will remain warm due to this
WAA. The pressure gradient will also tighten slightly across
the state which will lead to some breezy southwest winds.

Aloft there is mostly zonal flow across the Great Lakes Region
with a trough to our northeast in the Hudson Bay area and a weak
ridge to our west. There will be multiple little upper level
disturbances moving through this zonal flow, but many will be
largely uneventful until moisture increases. Which thanks to
the WAA kicking in this morning, moisture will gradually be
climbing throughout the day. Dewpoints are lower this morning,
so we can largely expect cloud cover to increase and maybe a
shower or two. Chances for any showers are much better to the
west, but that`s still not saying a lot with a 10 to 15% chance
POPs to our west. Therefore dry conditions should win out here.
Heading into this afternoon dewpoints are likely to climb into
the 60s with highs in the 80s leading to a more typical hot,
humid summer day.

This evening, a cold front will move south down the state and
eventually stall out along the WI/IL border Thursday. As this
cold front moves south, a shortwave will move through bringing
some upper level support. With both upper level and sfc
lift/forcing, showers and storms will be likely (60-70%)
especially for southwest and west central Wisconsin. Portions
of far southeastern Wisconsin may see little in the way of rain
until Thursday. This is in part due to a lack of instability and
the low level jet will be to our west which leaves us with
mostly decaying showers/storms. That being said, the best of our
instability will be across our far southern counties and shear
is good around 40 kts. Therefore a stronger storm or two can`t
be ruled out. The main hazards with any stronger storm will be
brief gusty winds and hail. Instability will fall off quickly as
the cold front passes so timing will be limited to the early
evening hours.

Shower and storm chances continue into Thursday across the
forecast area. Chances for rain and storms fluctuates wildly
from model to model and run to run. A lot of this is dependent
on just where the frontal boundary will stall and if it wiggles
slightly north or south at any given time. What we can be sure
of is that showers/storms are likely to linger into the morning
hours from the day prior. There will be periods of dry weather
throughout the day. Now moving onto the big ifs here, there does
look to be more movement of the mid level frontal boundary than
the sfc. Guidance is trying to push the mid level boundary
further north out our area with help from a LLJ and shortwave.
There are two scenarios here that would play out depending on
the movement of this mid level boundary. One is if the mid level
front stays put, it will likely be overhead leading to more
rain and storms developing through the afternoon and evening.
The second is the mid level front moves north and with it the
better forcing and lift does too. This leads to more dry
conditions for southern Wisconsin and more rain for central
Wisconsin. Currently among guidance there is more support for a
northward shift of the mid level frontal boundary and drier
conditions. Its not enough to erase POPs but kept them lower in
the 30s to 40s. Stay up to date with the forecast through
Thursday.

Patterson

&&

.LONG TERM...
Issued 413 AM CDT Wed Jun 11 2025

Thursday night through Tuesday:

There is a lot of uncertainty with how showers and thunderstorms
will trend Thursday night into Saturday. Operational models have
been trending northward with the focused 850 mb warm air
advection and subsequent showers and storms for Thursday night
into Friday. Ensembles have trended north of the area as well
with the highest probabilities for at least 0.50 inches of
rainfall. However, the warm/stationary front remains over or near
the area, so cannot totally rule out some shower and thunderstorm
activity occurring.

There may be a better chance for showers and storms Friday night,
as the weakening low pressure system slides southeast through the
area and may be accompanied by some differential CVA aloft. If the
area can get into the warm sector and see some sunshine, then it
can get more unstable and lead to better chances for
thunderstorms.

Ensembles are generally showing around 40 to 60 percent chances
for at least 0.10 inches of rainfall Friday night, but are much
lower (less than 30 percent) with at least 0.50 inches of rainfall
occurring. So, this may indicate lighter showers and weaker storms
during this time.

It will all depend on what happens Thursday night into Friday for
any impacts on Friday night shower and storm chances. There may
be a few showers or storms that linger into Saturday, though
anything here will be behind the exiting system and be scattered
and weaker.

For now, will leave NBM PoPs in place through Saturday, perhaps
with some adjustments, given the large amount of uncertainty with
what may occur during this time. Temperatures will also be
impacted by the amount of cloud cover and showers and storms that
occur, so will leave those from the NBM as well.

High pressure to the northeast Saturday night into Monday morning
may keep the area dry with cooler temperatures. There is more
uncertainty later Monday into next week with shower and storm
potential, so kept PoPs and temperatures from the NBM. Ensembles
suggest a warmup may occur into next week, which may be reflected
in NBM temperatures during this time.

Wood

&&

.AVIATION...
Issued 413 AM CDT Wed Jun 11 2025

Southwest winds are expected to increase as warm air advection
kicks in this morning. Some gusts to around 20 knots are
possible. LLWS remain possible through this morning until
roughly 15z. If LLWS does occur it should be brief and near the
top of the column around 2000 feet AGL around 45 kts.

WAA ahead of an approaching cold front will lead to some
increased cloud cover and maybe a showers or two this morning.
Shower chances are very low. The cold front should move south
into the area and stall in southern portions of the area by
this evening. There may be weakening showers and storms that
move east into the area during this time. Winds will weaken as
the front moves in. Since showers and storms are weakening as
they move in, kept mentions of thunder limited in the TAFs.
Ceilings through out the day should largely stay VFR. The best
chance for a few MVFR ceilings to move in with any storms will
be across west central Wisconsin and should stay north and west
of MSN. Periods of showers and storms will continue through
Wednesday night.

Patterson

&&

.MARINE...
Issued 413 AM CDT Wed Jun 11 2025

Low pressure in Ontario will slowly move out of the northern
Great Lakes Region to the east, while high pressure in the Ohio
Valley region is near stagnant. Light to moderate southwest to
west winds are expected across the lake between these two
systems today. Moderate winds will approach Small Craft Criteria
late this morning into the afternoon. Winds should stay below
with gusts of 21 kts possible.

This evening, a cold front will drop south down the lake and
become stationary across the far southern end Thursday. This
frontal boundary will remain draped across the far southern lake
until Friday, when a low pressure system moves into central
Wisconsin from the Rockies. Multiple rounds of showers and
thunderstorms will be possible from Wednesday evening through
Friday, with better chances remaining to the west.

Light north to northeast winds are expected behind the cold front
this evening. When the front stalls, areas north of the boundary
will have light northeast winds and areas to the south will have
light southeast winds. While winds remain light, waves will
slowly build into the weekend. Winds across the lake will
increase slightly Thursday night into Friday and become
easterly, as the low approaches. No gales expected at this time.

Patterson

&&

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

$$

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