Marine Weather and Tide Forecast for Milwaukee, WI

UPDATE
Issued 1030 AM CDT Tue May 13 2025

The inland progression of fog exceeded expectations earlier this morning, remaining a bit dense east of the Kettle Moraine.
Despite the continued southeast winds and clouds, the sun has managed to erode the fog, leaving it mainly over the waters of Lake Michigan only. Seeing similar expectations for late Tonight into early Wednesday, where the fog (possibly dense) could drift inland once again before burning off a few hours after sunrise.

Inland from Lake Michigan, sunlight is piercing through the scattered clouds along and south of the WI/IL border, with some broad cyclonic flow aloft evident on regional GOES satellite pushing westward (currently centered over Columbia County), with the southeasterly surface winds advecting some of the solar destabilized air into it. As such, we are expecting widely scattered showers and weak thunderstorms into this afternoon inland from the lake.

The first of said showers (which may eventually obtain thunder)
is evident in northern Dane county at the moment, tracking west-northwest with the column-averaged flow.

Sheppard

SHORT TERM
Issued 403 AM CDT Tue May 13 2025

Today through Wednesday:

An upper level low and weak surface low will gradually lift towards the Great Lakes today and tomorrow. Showers will be possible at times due to increasing moisture and and weak lift with the low. Though overnight showers are possible, the best chance will be during the afternoons today and tomorrow, as daytime heating will likely kick off a few showers and isolated thunderstorms. Onshore winds are expected to keep things stable in the east, so kept higher precip chances (30-50%) across the west. Showers/storms should largely wind down by early to mid-evening as daytime heating is lost.

Models still suggest low clouds will be possible at times through tomorrow, especially near the lake due to increasing moisture over the cool lake waters. May see reduced visibilities for a period as well. Will continue to monitor observations to see if the lower visibilities may develop this morning.

Above normal temps will persist today and tomorrow. Highs will likely range from the mid 70s to low 80s away from Lake Michigan, depending on the extent of cloud cover. Cooler temps will continue near the lake.

DDV

LONG TERM
Issued 403 AM CDT Tue May 13 2025

Wednesday night through Monday:

Ensembles continue to suggest that the warm period of temperatures linger through Thursday across the area, as an anomalous 500 mb ridge shifts east of the Great Lakes region.
Highs should reach into the middle 80s inland and perhaps upper 80s with enough sunshine. The record high for Madison Thursday is 86 degrees, so this may be reached or exceeded. Milwaukee and other areas near the lake will have steady southeast winds, which will keep those areas in the 60s to lower or middle 70s for highs. Humid conditions with dewpoints into the lower to middle 60s will linger with increasing south to southeast winds.

There may be some low clouds and fog over and near the lake at times into Thursday, with the higher dewpoints over the cool lake waters. Depending on how far inland any of these low clouds and fog move in, instability and temperatures may be limited and will be something to watch.

A closed and deepening 500 mb low should shift east northeastward across the northern Plains into Lake Superior or southwest Ontario Thursday into Friday. There is uncertainty with this low track.
Still, there looks to be a negatively tiled shortwave trough associated with this 500 mb low that shifts northeast across the region Thursday afternoon and evening. This should help bring a cold front northeast through the region Thursday afternoon and evening. There remains uncertainty in the timing of the cold frontal passage, which would affect thunderstorm and severe weather potential across the area.

This should bring a better chance (40 to 70 percent, highest toward central Wisconsin) for more organized showers and thunderstorms, as supported by ensemble members. There should be more robust mean layer CAPE and bulk shear values as well ahead of the front, so there continues to be severe storm potential.
Again, any low clouds/fog off the lake may be a limiting factor with instability and severe potential.

Machine learning models continue to indicate severe potential during this period across the region with the frontal passage.
SPC continues to have the area in 15 percent severe probabilities for Thursday into Thursday night, so will need to monitor this period for impacts and continue to message the potential and what is still uncertain.

Gusty southwest winds may occur after the front moves through Thursday night and linger into Friday. A secondary cold front may pass through the region Friday or Friday night/Saturday, with continued chances (20 to 30 percent) for showers and perhaps a few thunderstorms. Trends in this period continue to be more uncertain, but ensembles are still showing some members with measurable precipitation. Temperatures look to drop to more seasonable values Friday into next weekend per ensemble trends.

Wood

AVIATION
Issued 1030 AM CDT Tue May 13 2025

Fog is eroding and ceilings are gradually lifting at eastern WI terminals, though the cooling influence of Lake MI could easily allow LIFR ceilings to persist through the early afternoon. Dry weather is likely.

For terminals inland from the lake, diurnal cumulus looking to maintain scattered to broken coverage around 2,500 to 4,500 ft (occasional MVFR), with widely scattered showers and weak thunderstorms though this afternoon. Activity subsides into this evening.

For late tonight, fog and low ceilings are looking likely to enter eastern WI terminals in a similar manner (IFR/LIFR looking likely along the shoreline), gradually improving several hours after sunrise Wednesday.

Light east to southeast winds through the TAF period. Light northeasterlies mix in along the Lake MI shoreline late tonight.

Sheppard

MARINE
Issued 403 AM CDT Tue May 13 2025

High pressure around 30.3 inches well to the east of the region will maintain light east to southeast winds into this morning, becoming northeast this afternoon. Areas of fog may develop or continue into today, especially across the southern half of the lake, where moisture is increasing. Some dense fog is possible at times.

A few isolated thunderstorms are also possible in this same area this afternoon, as low pressure around 29.9 inches progresses into the western Ohio River Valley, and a second area of low pressure around 29.2 inches develops over the northern High Plains. Expect generally light easterly winds tonight, with areas of fog possible or lingering across the entire lake. Some dense fog will continue to be possible.

As low pressure in the northern Plains intensifies Wednesday into Wednesday night, expect east southeast winds and isolated to widely scattered shower and thunderstorm chances across all of the open waters. Low pressure will then move into the Upper Mississippi Valley on Thursday, dragging a cold front across Lake Michigan during the late afternoon and evening hours. This cold front will produce widespread thunderstorms, with some strong to severe storms possible. Gusty southeast to south winds ahead of the front are expected, with Small Craft Advisory conditions possible for the nearshore waters.

Winds shift to west southwest behind this front Thursday night, remaining gusty Friday into Saturday. A few thunderstorms are possible again on Friday afternoon and evening. It is too early to tell if gales are possible during this period, but Small Craft Advisory conditions may occur for the nearshore waters.

Wood

MKX WATCHES/WARNINGS/ADVISORIES
WI...None.
LM
Dense Fog Advisory
LMZ080-LMZ366-LMZ565-LMZ567-LMZ643-LMZ644- LMZ645-LMZ646-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 1 PM Wednesday.