wi discuss
Office: MKX
FXUS63 KMKX 120245
AFDMKX
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
945 PM CDT Fri Jul 11 2025
.KEY MESSAGES...
- The cloud to ground lightning risk will continue into the
overnight hours. Rain will gradually taper off overnight.
- Scattered thunderstorms expected Saturday afternoon and early
evening.
- Dry weather expected Sunday into early Tuesday, then turning
warmer and more active mid week.
&&
.UPDATE...
Issued 945 PM CDT Fri Jul 11 2025
Active evening with a pesky supercell and a robust line of
storms. The remnants of the line are now moving over the open
waters of Lake Michigan, though a rather expansive area of
stratiform rain remains. There is a sneaky lightning risk in
this area of rain and will continue to mention the chance for
thunder into the overnight hours.
The shield of rain will gradually shift to the east and north,
though with a trial of upper level vort maxes and boundaries
around, redevelopment of scattered showers remains possible
through daybreak.
The forecast for Saturday is largely on track. A cold front will
enter from the northwest and scattered showers and storms are
expected during the afternoon into early evening hours. This
round looks more hit or miss compared to the current widespread
rainfall.
Gagan
&&
.SHORT TERM...
Issued 314 PM CDT Fri Jul 11 2025
Rest of this Afternoon through Saturday night:
Showers and thunderstorms have developed early this afternoon
along an elevated frontal boundary, which is stretching from
west to east across the central portion of the forecast area.
Stronger activity so far has been across Iowa and far western
Wisconsin, where instability and lift are stronger.
More substantial, surface based activity is developing across
central and east central Iowa, and this will progress eastward
over the next few hours as well. The severe threat associated
with this activity will largely be tied to the location of the
surface front, which while somewhat defuse, appears to be
located generally just north of the Wisconsin/Illinois state
line. As low pressure over Iowa strengthens and lifts
northeastward, this surface front should end up a little south
of the I-94 corridor by early evening. Mid level lapse rates
across this area will be weak, but substantial low level CAPE
and sufficient 0-3 KM will present a wind and QLCS tornado
threat with any organized, eastward surging line segments. This
threat looks to reach the lakeshore area between 8 and 10 PM,
before pushing east.
In addition to the severe threat, heavy rain remains a concern.
PWATs near 2 inches and a deep sub-freezing cloud layer will
favor very efficient rainfall rates. Individual storms will be
moving, but flooding concerns will ramp up for any areas that
see multiple rounds of convection in a short time.
The strongest convection looks to end by around 10 PM, though
some storms may linger across central Wisconsin, tied to the
location of the meso-low and shortwave. Other scattered showers
may persist overnight.
A few additional scattered thunderstorms are then possible on
Saturday along an advancing cold front. Weak convergence along
the front and poor upper level support suggest scattered
coverage at best, with slightly higher potential (30%) over
central Wisconsin. The front will clear the area by Saturday
evening, with cooler and drier air building into the area.
Boxell
&&
.LONG TERM...
Issued 314 PM CDT Fri Jul 11 2025
Sunday through Friday:
Sunday looks to be a rather pleasant day, with highs in the low
80s and lower dewpoints. Warmer and more humid conditions return
for Monday, with highs in the mid 80s. Couldn't rule out a brief
shower or two on Monday as a frontal boundary stalls out to our
north, but most locations will remain dry.
Temperatures will be back into the upper 80s on Tuesday, with
dewpoints in the low to mid 70s, as stronger warm advection
overspreads the region. Thunderstorms are then expected to
develop later Tuesday to our north along the aforementioned
front, with periods of showers and storms across the region
Tuesday night and Wednesday, and potentially into Thursday, as
the front wiggles around the area. As is usually the case with
this type of set-up, the timing and location of individual
rounds of showers and storms will be predicated on how earlier
convection evolves, so predictability more than a day or so in
advance is low.
A stronger shortwave will push a more substantial front through
the region late in the week, with cooler and drier high pressure
looking to be favored as we head into next weekend.
Boxell
&&
.AVIATION...
Issued 945 PM CDT Fri Jul 11 2025
Primary concern for the rest of the night will be lingering
rainfall and occasional embedded lightning strikes and the risk
for MVFR/IFR ceilings.
The main line of storms has pushed over the lake, and an
expansive stratiform area of rainfall is left in its wake.
Overall rainfall is generally on the lighter side with pockets
of MVFR visibility and IFR ceilings (though at this point not
widespread). In general, guidance lowers ceilings into the IFR
range at most locations during the overnight hours and showers
gradually taper off and winds shift to the southwest.
Heading into the daylight hours of Saturday, IFR/MVFR stratus
will gradually lift/break up. There are signals for scattered
showers and storms Saturday afternoon into the evening, though
confidence is not high enough to include in the TAFs at this
time. Looks like these storms will be a bit more hit or miss.
Quieter weather finally settles over the region into Saturday
night as the cold front passes and winds shift to the northwest.
Gagan
&&
.MARINE...
Issued 314 PM CDT Fri Jul 11 2025
A broad trough of low pressure averaging 29.7 inches will lift
from Iowa into the northern Great Lakes tonight into Saturday.
Thunderstorms are expected across the lake tonight, some of which
may have strong winds. Winds will be from the south over the
southern half of the lake and from the northeast over the northern
half of the lake through early evening, becoming southerly over
the entire lake overnight. A cold front will then pass through the
lake Saturday afternoon and evening, with winds turning westerly
Saturday night.
High pressure of 30.0 inches will move across the southern tip of
Lake Michigan on Sunday, with winds turning southerly and
southwesterly as the high moves east. Southerly flow is then
expected into at least Monday, before a front becomes stationary
over the central portion of the lake through mid week.
Boxell
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&
$$
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Office: ARX
FXUS63 KARX 112331
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
631 PM CDT Fri Jul 11 2025
.KEY MESSAGES...
- Heavy rain and storms progress northeast through northeast
Iowa, southwest Wisconsin, and central Wisconsin through the
daytime hours. Highest rainfall amounts expected along
southern peripheral counties where 1"+ of rainfall is possible.
- Low confidence in limited precipitation chances through start
of new week, eventually increasing Tuesday, lasting through
Wednesday.
&&
.DISCUSSION...
Issued at 209 PM CDT Fri Jul 11 2025
Tonight: Strong Storms and Heavy Rain Possible
Elevated convection behind a warm front/baroclinic boundary is
starting to pop up across portions of northeastern Iowa early this
afternoon. Many of these storms are meager at best with better
instability residing much further south into central and
southern Iowa where SBCAPE is greater than 1500 J/kg. A surface
low is currently located across far southeastern Nebraska with a
convectively reinforced upper level shortwave present across
Iowa in 18Z 500 mb analysis. As we are north of the warm front
and quasi baroclinic boundary, the severe threat overall looks
pretty marginal but there is a minor threat for large hail with
these initial storms, becoming more of a damaging wind threat
later on (especially across far southwestern Wisconsin with
DCAPEs greater than 500 J/kg) as they will likely grow upscale
into more of a MCS/QLCS type feature with time. Vertical shear
overall is marginal at 20-30 kts with some pockets of 35 kts
across our far southern counties, being aided/enhanced by the
shortwave trough. The severe threat will continue through the
afternoon and into the evening, likely waining after 00Z.
While the severe threat isn't looking overly impressive for our
area, the threat for heavy rain looks much better. Areal pWats sit
at 1.5-1.8 inches and warm cloud depths are approaching 3 kft. Any
storms will likely be efficient rainfall producers so if we see any
training activity, this could lead to signficiant ponding or
localized flooding. 11.12Z HREF mean precip totals look to be in the
.5 to 1.25 inch range for Northeastern Iowa and Southwestern
Wisconsin with lower totals to the north. Due to the convective
nature of the storms, there remains some pretty significant
differences in the 75th-25th percentiles with the 75th around 1.5-2
inches and the 25th percentile less than .25 inches. Unless we start
to see some excessive training, the mean HREF totals look
reasonable. Recent (last 24 hours) rainfall across Grant/Clayton
counties were generally less than 1.25 inches with the heaviest
rains staying south of our area more towards Dubuque, Delaware, and
Buchanan counties. Soils and rivers across the area should be able
to handle the rain, keeping widespread flooding concerns at bay for
the time being. A "cold front" associated with a surface low across
Western Ontario will push unto our area later tonight which could
bring some additional low end rain chances through the overnight
hours before exiting our area through the day Saturday. Rain chances
should generally be over by 12Z for areas west of the Mississippi
with low chances (20-30%) lingering into the afternoon before moving
off to the east.
Sunday - Monday: Likely Dry, Warming Temperatures
A weak surface high is expected to build into the Mid-Mississippi
River Valley behind the cold front, likely keeping conditions dry
for Sunday into Monday. We'll see more abundant sunshine across the
area, which will allow for temperatures to start climbing back into
the mid to upper 80s by Monday with a few places maybe even reaching
the 90 degree threshold. With a broad upper level ridge building
across the southern CONUS, our area will be in northwest to weakly
zonal flow through the start of next week. A stray shower cannot be
ruled out Sunday night, especially across north-central Wisconsin,
but the general trend should remain dry.
Tuesday and Beyond: Wet Mid-week with Cooler Temperatures
WPC cluster analysis and mid range models are hinting at a weak
trough axis developing across the Northern Rockies and subsequently
moving east into our area Tuesday into Wednesday. These features are
not well resolved in the mid/long range models but moisture will be
reinforced by then with south to southwesterly surface flow helping
to deepen areal moisture. As the cold front moves through, PoPs
increase to likely (50-70%), especially during the day on Wednesday.
How the upper level pattern evolves beyond mid-next week is still
uncertain but will leave the slight chance PoPs of the NBM for
the late week timeframe. Temperatures will be much more pleasant
behind the cold front Wednesday into the weekend with highs in
the 70s to low 80s.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 631 PM CDT Fri Jul 11 2025
Rain and maybe an isolated storm will continue at the KLSE TAF
through 12.02z. With the low levels of the atmosphere saturated
and light winds, there will be IFR/MVFR deck of clouds from
tonight through mid-morning Saturday. Once these low clouds
dissipate, it will be VFR for the remainder of the day.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Barendse
AVIATION...Boyne
Office: GRB
FXUS63 KGRB 120359
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
1059 PM CDT Fri Jul 11 2025
Updated aviation portion for 06Z TAF issuance
and new information added to update section
.UPDATE...
Issued at 1041 PM CDT Fri Jul 11 2025
Precipitation trends are tough to pinpoint, as showers in NC/C WI
have been more persistent than previously thought, and the area of
rain associated with the MCV and surface meso-low is not as
widespread as expected. Heaviest rains have occurred in C WI,
where a few spots in western Marathon County received 2+ inches
earlier. Not as confident in heavy rainfall chances farther east
due to recent radar trends and a lack of instability (leading to
somewhat lower rainfall rates).
Made some changes earler to add some smoke to the grids in the
wake of the cold frontal passage tomorrow afternoon, and again
during the day on Sunday. WDNR issued an Air Quality Alert to
address this potential.
&&
.KEY MESSAGES...
- Periods of rain and isolated embedded thunderstorms are
expected overnight. Pockets of heavy rainfall will remain
possible, but do not expect additional amounts to exceed 1 inch
through daybreak.
- A few strong to severe storms will be possible on Saturday
afternoon. Gusty winds, isolated large hail, and heavy
downpours will be the main hazards with any stronger storms.
- Next round of active weather arrives during the middle of next week.
&&
.DISCUSSION...
Issued at 438 PM CDT Fri Jul 11 2025
Precipitation/Thunderstorm Chances...This afternoon's water vapor
imagery was showing two features of interest. A developing MCS
was located over eastern IA/southwestern WI/northwestern IL, while
a line of convection developed along a cold front in northern MN.
In the near term, the attention is focused with the developing MCS
as models have trended with a slightly further north track. While
the higher potential for severe weather will remain well to the
south of the forecast area, a threat for a narrow corridor of heavy
rainfall is seeming more apparent as models indicate the deformation
zone of the system will set up somewhere over the area tonight.
There seems to be a general consensus the narrow band will occur
east of a Stevens Point to Iron Mountain line. Within this band, 1
to 2+ inches of rainfall and localized flooding is possible. Even
higher, very localized, rainfall amounts cannot be ruled out given
the abnormal PWATs of 1.75 to 2.10 inches (175-200% of normal for
this time of year). Locations in north-central WI will see the
lowest rainfall amounts (0.50 inches or less). The precip associated
with this system will come to an end Saturday morning as it exits to
the northeast of the region.
The aforementioned cold front in northern MN will be the feature
of concern for Saturday as it tracks across the forecast area.
There is good consensus that a broken line of showers and
thunderstorms will develop along the front sometime midday
Saturday or Saturday afternoon over the area. The front and
convection will exit by Saturday evening. A tongue of 1000-1500
J/kg of MUCAPE, deep-layer shear of 35-45 kts, and steep mid-level
lapse rates will support a marginal severe threat for any of the
storms that develop along the front. However, if there is too much
cloud debris Saturday morning from the overnight precipitation,
this may hinder some of the instability for the afternoon. If
strong or severe thunderstorms develop, damaging winds, large
hail, and brief heavy downpours will all be possible.
Following the cold front, models continue to show subtle indications
of a weak boundary sweeping across the area late Sunday or Monday,
which could bring light precip and thunderstorm chances. Otherwise,
sometime midweek will be the next chance for widespread
precipitation and thunderstorms.
Smoke...An area of smoke from Canadian wildfires was observed on
visible satellite imagery this afternoon entering far northwest MN,
following the previously mentioned cold front. Smoke models indicate
a concentrated area of near-surface smoke sweeping across the
forecast area following the front for Saturday and continuing into
Sunday. As a result, coordination with the WI DNR has led to the
issuance of an Air Quality Advisory for the entire state through
noon Monday, with the PM2.5 AQI reaching the Unhealthy for Sensitive
Groups to Unhealthy level.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1041 PM CDT Fri Jul 11 2025
Areas of light to moderate rainfall and a rare rumble of thunder
were reported across the forecast area late this evening. While
most of the area still had VFR conditions, sporadic MVFR
conditions were observed in the western and southern parts of the
forecast area.
Light to moderate rain will continue overnight, with ceilings and
vsbys gradually dropping to MVFR/IFR. locally heavy rainfall may
occur, along with IFR vsbys. Expect the rain to pull out late
tonight into early Saturday, with gradually improving flight
conditions during the mid to late morning. A cold front will move
through the region on Saturday, reaching NC/C WI late morning and
exiting eastern WI by evening. Kept the Prob30's for thunderstorms
at the eastern TAF sites for the 18z-22z time frame, as the front
moves through during peak heating. Locally strong storms are
possible. Gusty west winds will develop in the wake of the front
on Saturday.
Clearing skies and decreasing winds are expected by sunset.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.........Kieckbusch
DISCUSSION.....Kruk
AVIATION.......Kieckbusch
