Marine Weather and Tide Forecast for La Valle, WI

UPDATE
Issued 1209 PM CDT Tue Apr 14 2026

Morning mesoanalysis and surface observations depict excellent southerly return flow over the Upper MS Valley. Surface level warming and moistening ahead of an approaching surface low near Omaha has led to dew points in the upper 60s to 70 degrees amid air temperatures in the upper 70s over eastern IA and NW IL.
This warming and moistening is expected to prime our severe environment this afternoon as the air mass advects northward.
Additionally, lingering cloud cover has dampened any mixing and drying of the boundary layer, which will further aid our low level instability.

12Z runs of the CAMs have depicted storms forming perhaps a bit farther west than previously forecast, with storms now forming along and just west of the Mississippi Valley and then tracking east into southern WI this afternoon. There also seems to be a dampening of the signal for storms along the lake breeze this afternoon. Otherwise, the environment these storms will move into remains relatively unchanged from previous runs. The ingredients will be marked by moderate to high instability of >3000 J/kg SBCAPE amid effective shear of 50 knots, with mid level lapse rates >7 C/km. Initial storms will be discrete supercells and will be explosive. Low level 0-3km CAPE will be in excess of 100 J/kg with low level turning in the hodographs. These supercells will support all severe hazards and sig tor threat from initiation during the mid afternoon into the early evening as they track over southern WI. As the evening progresses, there may be some tendency for storms to conglomerate into a line and sink southeast, mainly between 7PM and 10PM, but a strengthening LLJ will support larger hodograph curvature and the tornado threat may transition from supercellular to QLCS.

The SPC maintained an enhanced risk for this afternoon with their 1630Z update, but have gone ahead and broadened the CIG 2 contour over pretty much all of our CWA for both its tornado and hail categories. This delinates a 30% chance for a tornado of EF2 or greater today, and a 25% chance of seeing hail greater than or equal 2 inches in diameter within 25 miles of any point over southern Wisconsin.

CMiller

SHORT TERM
Issued 1220 AM CDT Tue Apr 14 2026

Tonight through Tuesday night:

A line of thunderstorms will roll through the forecast area over the next few hours, as low pressure approaches along a stalled frontal boundary. The main threat through 2-4 am will be damaging winds, though an isolated tornado will be possible.
Given sustained instability overnight along with WSW 0-3 km shear around 40 knots, any storm line segments that become more north/south oriented could bow out increasing the wind threat and also producing a QLCS tornado threat. The flooding concern remains overnight as well, as the line of storms across the northern forecast area slowly sags southward tonight, with some back building currently evident over southeast MN and northeast IA.

Storms may linger in the southeast forecast area towards around daybreak, with dry weather then likely through the morning hours. Attention then turns to another severe storm threat during the afternoon and evening hours. The stalled frontal boundary will be set up around the far northern forecast area in the afternoon, as another weak surface low and shortwave approach from the west. Plenty of instability is expected across at least the south half of the forecast area, with surface based CAPE of at least 3000 J/KG. Additionally, wind profiles look more than sufficient for severe storms as a 45 kt LLJ noses from the south by late afternoon. All severe hazards will be possible as storms initialize between 3 and 6 pm, with a decent chance for supercell development. Storms will likely eventually organize into line or two, with the severe threat leaning more towards wind and QLCS tornado at that point.
Locally heavy rainfall and flooding will be a concern as well, especially if storms roll through the same areas that received the heavier rainfall the last couple days. Adding to this concern as that some of the latest models do show that a line of storms may set up west to east across the southern half of the forecast area tomorrow night, with some training possible.

DDV

LONG TERM
Issued 1220 AM CDT Tue Apr 14 2026

Wednesday through Sunday:

It is still looking like the frontal boundary could remain far enough north on Wednesday for another severe storm threat. This will somewhat depend on what happens Tuesday/Tuesday night and where the effective front ends up because of that round of storms. Overall though, there is enough confidence to continue to message a severe threat, with locally heavy rainfall also a concern again.

Storms may linger Wednesday night into early Thursday, with a break in activity then likely Thu afternoon into at least Friday morning. Yet another round of storms is then possible Friday evening into Saturday morning as a cold front finally pushes through the region. The later timing of this front may somewhat diminish the severe threat, due to the better interaction with peak daytime heating Friday remaining to the west. Plenty of time though for timing to change, so this period remains worth keeping an eye on.

Much cooler conditions are expected to settle into the area this weekend behind the departing low and cold front. Highs will likely struggle to get out of the 40s by Sunday. It looks mainly dry Sat afternoon through Sunday, though not out of the question for a few snowflakes in the north Sat night as a shortwave rolls through.

DDV

AVIATION
Issued 710 AM CDT Tue Apr 14 2026

VFR flight categories continue through this morning, with strong to severe storm development this afternoon. Reduced CIGs and VIS readings will accompany the storms.

Quigley

MARINE
Issued 1220 AM CDT Tue Apr 14 2026

Shower and thunderstorm activity is expected across lake Michigan late into tonight as low pressure of 29.6 inches over southeast Minnesota continues to head northeast. Winds will be easterly north of a frontal boundary across roughly the northern half of the lake, with southerly winds expected in the south.
Then expecting another a couple passing low pressure system to develop in the Plains and track across Lake Michigan again on Tuesday and Wednesday. Each system will bring a chance for showers and thunderstorms through the middle of the week. Areas of dense fog will likely occur at times due to a relatively mild and humid airmass over the cold waters paired with lighter winds.

DDV

MKX WATCHES/WARNINGS/ADVISORIES
WI...None.
LM
Dense Fog Advisory
LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ643-LMZ644-LMZ669-LMZ671-LMZ868-LMZ870-LMZ872 until 7 AM Wednesday.