textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Isolated storms are possible early to mid-morning today, with large hail a possibility if storms form. Confidence is on the low end with this storm potential.

- Dense fog is possible in the east towards Lake Michigan into mid-morning today. Marine Dense Fog is expected over the lake.

- A High Swim Risk is in effect mid afternoon today into the evening. High waves and dangerous currents will be likely, and swimming is not advised at Sheboygan and Ozaukee beaches.

- Multiple rounds of storms are expected today and Thursday. Severe thunderstorms are likely at times. An Enhanced Risk for Severe Weather exists both Wednesday and Thursday.

- Warm and humid conditions expected Wednesday and Thursday.

SHORT TERM

Issued 110 AM CDT Wed Jun 10 2026

Today through Thursday:

Areas of fog are expected in the east overnight into early today given the high dewpoints and relatively chilly waters of Lake Michigan. A Dense Fog Advisory may be needed.

Showers keep trying to form tonight just to the west and southwest as an area of warm advection aloft and higher precipitable water advect into the area. There are still a couple models that try to pop a few storms as this airmass moves in. Plenty of elevated instability tonight along with modest shear and steep mid-level lapse rates would lead to a potential for large hail if storms do fire.

Still watching the potential for a round of thunderstorms after daybreak this morning. The activity over Iowa and into the Dakotas early is expected to largely lift northeast through the top of the upper ridge, staying more closely tied to the shortwave. These storms could clip the northern forecast area roughly between 7 am and 11 am, though latest short term models continue to largely keep this activity to the north.

The main concern for storms today seems to be trending towards the afternoon hours. Latest guidance has latched onto a wave and vort max exiting the OK/TX panhandle area. Any morning storms and associated clouds should largely be out of the area for a decent recovery period late morning into early afternoon. Plenty of instability is expected to go along with modest shear, so severe storms will be possible as the forcing moves into southern Wisconsin. The storms could form into a line relatively quickly, with damaging winds the primary concern. Large hail would also be possible, especially as the activity is getting going. 0-3 km shear isn't particularly strong (25-30 kt), but looks largely perpendicular to the expected line of storms, so a QLCS tornado or two is also possible.

The main round of storms is currently expected to exit the east by 6 pm, while the main trough will swing through during the mid to late evening. This will keep the door open for storms through the evening, though the severe potential would likely be somewhat less if the afternoon round of storms rolls through as expected.

Given the multiple rounds of storms and clouds likely today, not expecting enough sunshine to push heat indices up towards 100 degrees as previously thought possible. While it will be quite warm and humid, widespread Heat Advisory conditions are not anticipated.

There should be a lull in storms tonight into early Thursday between shortwaves. The trough Thursday is expected to be stronger, with an associated surface low and cold front also swing through by mid-evening. The timing of this system is such that there should be plenty of time to destabilize during the day before the stronger forcing moves through. Models are hinting at some warm air advection aloft lifting through by late morning which could muddy things up a little. Overall though, shear and instability should be plenty as this system pushes through for another round of potentially severe storms in the afternoon and early evening. Models continue to suggest that the south half of the forecast area would have the best chance for severe storms based on instability fields, though things have shifted a bit northward compared to 24 hours ago. Given current expected timing, storms should wind down by mid-evening, with a drier airmass moving in overnight behind the cold front.

DDV

LONG TERM

Issued 110 AM CDT Wed Jun 10 2026

Friday through Tuesday:

Dry weather is expected Friday behind the departed low and front, with high temps back towards normal values. Dewpoints will be lower as well, likely settling into the 50s most places.

It is still looking like a shortwave and cold front will drop through the area later Saturday into Saturday night, bring shower/storm chances back to southern Wisconsin. Temps should warm to at least 80 ahead of the front during the day Saturday, with dewpoints creeping back up into the low 60s. Seeing enough shear and instability in the 00Z models to think that a few strong to severe storms will be possible as this system moves through.

Mainly dry weather and cooler conditions are then expected Sunday and Monday as high pressure moves in behind the departing system. Could see shower/storm chances return Tuesday as a shortwave moves through the region.

DDV

AVIATION

Issued 110 AM CDT Wed Jun 10 2026

Low ceilings and areas of fog, dense at times, will continue through the early morning hours across the eastern forecast area.

Will continue to watch for isolated storms that may develop through early this morning, with the ongoing storms to the west possibly clipping areas north of I-94 after daybreak through mid to late morning. This latter activity may stay north of the forecast area, though.

Attention then turns to the main round of storms today, with the timing trending towards the afternoon hours. If storms develop as currently expected, 18Z-23Z would be the most likely window for potential severe weather. The main shortwave won't move through until mid to late evening though, so additional storms chances would linger through the late evening hours.

Light and variable winds early this morning will become south to southwest and breezy by late morning ahead of an approaching shortwave.

DDV

MARINE

Issued 110 AM CDT Wed Jun 10 2026

Marine dense fog is expected to continue, with an advisory in effect across the lake until mid-morning today.

Generally light northerly winds will become southerly and southeasterly early this morning. Winds will then remain southerly through the day today as low pressure of 29.3 inches approaches from the northern plains. The winds may become moderately breezy late this afternoon into the evening. Thunderstorms are expected over the lake at times today, with some strong storms favored this afternoon and evening.

Winds come around to southwesterly tonight into Thursday, with winds then returning to southeasterly ahead of an approaching cold front on Thursday, with additional storms possible.

DDV

MKX WATCHES/WARNINGS/ADVISORIES

WI...Beach Hazards Statement...WIZ052-WIZ060...4 PM Wednesday to 4 AM Thursday.

LM...Dense Fog Advisory...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563- LMZ565-LMZ567-LMZ643-LMZ644-LMZ645-LMZ646-LMZ669-LMZ671- LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874- LMZ876-LMZ878 until 10 AM Wednesday.

Small Craft Advisory...LMZ643-LMZ644...4 PM Wednesday to 1 AM Thursday.