FXUS63 KMKX 261509

AFDMKX



Area Forecast Discussion

National Weather Service Milwaukee/Sullivan WI

1009 AM CDT Thu Jun 26 2025



.KEY MESSAGES...



- Patchy fog will continue this morning in scattered spots

  inland and along the Lake Michigan shoreline.

 

- A few isolated storms this morning, followed by better chances

  this afternoon and evening. There will be a conditional

  tornado threat with a few storms along a warm front this 

  afternoon, followed by a line of storms with an associated 

  wind threat this evening.



- Rivers are currently rising, with additional rounds of rain

  and storms bringing potential rises to action stage and minor

  flood stage into the weekend.



- A brief warm up for Sunday, with heat indices once again 

  approaching 100 degrees.



&&



.UPDATE...

Issued 1009 AM CDT Thu Jun 26 2025



A quasi-staionary front remains across the central portion of

the forecast area this morning. As low pressure lifts across

Iowa and southern Minnesota this afternoon, the front will begin

to slowly lift north as a warm front. The airmass along and

south of the front will be very unstable, with 2000+ J/KG of

MLCAPE, and over 100 J/KG of low level CAPE. Overall lift along

the front isn't particularly strong, so the extent of

development along the warm front this afternoon is 

questionable. Anything that does develop, however, would have an

associated tornado threat given the presence of the front and 

the low level instability. 



Additional development is then expected across Iowa and

Minnesota this afternoon, along and ahead of a cold front and 

pre-frontal trough. One or more lines of storms are expected to

move into the forecast area from the west late this afternoon 

and this evening, primarily with a threat for strong winds. Some

QLCS-type circulations will also be possible, especially in the

vicinity of the warm front and any remnant outflow boundaries. 

This line should slowly decay with eastward extent, with the 

overall higher severe weather probabilities along and west of 

Highway 26. 



Boxell



&&



.SHORT TERM...

Issued 406 AM CDT Thu Jun 26 2025



Today through Friday:



Scattered thunderstorms and patchy fog, both inland and along 

the Lake Michigan shoreline, will continue this morning as dew

points pool along a stationary front at the surface, and low

level WAA continues at the 925 to 850mb level aloft. Guidance

suggests inland fog will dissipate after dawn, but some

nearshore fog along the Lake Michigan shoreline will remain

through the day.



After dawn and through the remaining morning hours, models 

depict the stationary front lifting north as a warm front to 

about Fond du Lac County through Marquette County, as a weak 

surface low moves into western Iowa. As lift from this surface 

low approaches this afternoon and some PVA from a 500mb trough 

aloft spreads over the region, storms are expected to blossom 

near the surface low and cold front over Iowa, as well as along 

portions of the warm front closer to the surface low. 



This afternoon, CAMs depict storms forming along the warm front

over central Wisconsin to varying degrees of coverage and

timing, but the main consensus seems to focus a potential storm

or two forming along the warm front through Sauk, Marquette,

Green Lake, and Fond du Lac Counties. This would likely occur

somewhere around 2 to 4pm. With partly cloudy skies in the

morning, HRRR soundings show that enough instability should 

build along and south of the warm front to support 2500 J/kg of 

SBCAPE, with some really good 0-3km CAPE around 150 J/kg. In

addition to the enhanced low-level stretching potential, 

the presence warm front will support >200 m2/s2 of effective 

storm relative helicity. Hodographs, while lacking in flow 

aloft, do show streamwise helicity near the surface and 

effective shear will be around 40 knots, supporting a 

supercellular mode. LCLs will be around 500m as well. If a storm

forms in central WI and latches onto the warm front as some 

CAMs suggest, a localized tornado threat may exist this 

afternoon in central WI.



Turning our attention back west, storms along the cold front 

will be ongoing over Iowa and Minnesota during the late 

afternoon and will likely cross the Mississippi as a squall line

around 6pm. This line will approach our far western counties

during the early evening with CAMs showing a weakening trend as

the line moves into our CWA. Even so, soundings remain uncapped

enough west of Madison and a gusty wind threat may occur with 

the line as it moves in, as model soundings show just a bit more

dryness to the low levels in southwest WI. There may also be a 

conditional brief QLCS tornado threat in central WI as the 

squall line moves in, given the lingering presence of the warm 

front before the line gusts out as the boundary layer decouples 

after dusk. Much like this past evening, a then severely 

weakened line of storms will then travel east and exit over Lake

Michigan during the overnight hours.



Friday, the cold front will pass during the morning hours. There

may be a few lingering weak showers for the first half of the 

day as the front passes, but the afternoon hours look mostly dry

at this time.



CMiller



&&



.LONG TERM...

(Issued 343 AM CDT Thu Jun 26 2025)



Saturday through Wednesday:



Weak ridging over southern WI should help us to remain dry through

the day Saturday. The better forcing with warm air advection and

vorticity advection is expected to be over northern MN. Any

lingering frontal boundary from the Friday front should be well

into Illinois. That puts southern WI in the non-eventful sector.

Of course, this can change if any upstream convection tracks into

our area late in the day, but at this time we are not expecting

anything. 



Heat will begin to build back into the area Saturday, with highs

in the upper 80s for inland areas. With dewpoints around 70, heat

indices should be in the lower 90s. The winds look much lighter

than they were this past weekend, which will make it feel more 

muggy.



Sunday will remain warm and muggy until a thunderstorm complex

potentially rolls in during the afternoon or evening. A potent

shortwave within the right entrance region of an upper jet is

expected to initiate a cluster of thunderstorms over central MN

Sunday. This cluster will likely ride the CAPE gradient which

should be over a portion of south central WI. Areas along and west

of I-94 have the higher chance of seeing storms, possibly severe. 



An upper trough will swing across the Upper Great Lakes Monday. A

few showers and thunderstorms may be possible. The upper ridge is

going to strengthen over the Northern Plains from Tuesday through

Thursday. Models start to diverge then, with the GFS trying to

break down the ridge and the ECWMF maintaining its strength.

Either way, a ridge rider or two look possible later in the week,

which would include Independence Day. Still a lot of uncertainty

here. 



Cronce



&&



.AVIATION...

Issued 1009 AM CDT Thu Jun 26 2025



MVFR and IFR ceilings are in place north of a frontal boundary

this morning. This boundary should slowly lift north with time

today, with ceilings improving. South of this front, VFR will

prevail through at least the early afternoon hours. 



Thunderstorms will become more numerous as early as this

afternoon, if development takes place along the front.

Otherwise, look for one or more lines of storms to move in from

the west during the evening hours.  



Once convection clears the area late tonight, areas of lower

clouds will be possible heading into Friday morning. 



Boxell



&&



.MARINE...

Issued 343 AM CDT Thu Jun 26 2025



A stationary front will continue to linger over the center of Lake

Michigan, roughly from Port Washington to Ludington. A few showers

and storms are possible along this front during the afternoon as

low pressure of 29.8 inches approaches from central Wisconsin. A

a weakening line of storms oriented north to south along the

associated cold front over Wisconsin is expected to reach Lake 

Michigan around midnight. 



Winds will gradually become westerly on Friday in the wake of the

front, with gusts remaining below 20 kt. High pressure around 30.0

inches will drift across the Upper Great Lakes on Saturday. A

storm complex may roll across Lake Michigan Sunday evening. Then

the high is expected to sit over the region through the middle of

the week. 



Cronce



&&



.MKX WATCHES/WARNINGS/ADVISORIES...

WI...None.

LM...None.

&&



$$



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