Marine Weather and Tide Forecast for Oconto, WI

DISCUSSION
Issued at 204 PM CDT Mon May 12 2025

Fire weather conditions remain the focus through tomorrow with a day airmass in place. A Red Flag Warning remains in effect through mid-evening across north-central Wisconsin where conditions are most favorable for fires to easily start and spread quickly. There is some improvement tomorrow, but conditions remain elevated across north-central WI where fuels are the most dry and minimum RHs are in the 30-40% range. See Fire Weather section for more details.

Skies will remain sunny through the rest of the afternoon. Then, outer clouds from a system across the southeast U.S. will start to rotate into the area this evening and overnight, bringing partly sunny to mostly cloudy skies across the area the next couple days.
Some patchy fog is possible across east-central WI early Tuesday morning. A few rain showers and isolated storms are also possible during the late mornings and afternoon as daytime heating develops. Instability is around 200-600 J/kg Tuesday, and 200-800 J/kg on Wednesday. Therefore, expect any storms to be isolated and non- severe. CAMs would also support this.

As the eastern U.S. system continues to depart, this allows flow to become more progressive with a stronger system and cold front approaching and moving through Thursday into Friday. Periods of rain are likely (50-80% chance) with this system, and strong or severe thunderstorms are a possibility Thursday afternoon and evening as MUCAPES building to 1000-3000 J/kg depending on the model/guidance. Deep shear is around 40 kts and mid- level lapses rates of around 7.0-7.5 C/km.

Dry slot moves through late Thursday night/Friday morning, with additional on/off rain chances on Friday afternoon into Saturday on the back side of the system. However, instability will be limited by this point. Cannot rule out some isolated thunder, but mainly looking at rain.

Temperatures will be mild tonight in the upper 40s to middle 50s, and then rise into the middle 70s to low 80s tomorrow away from Lake Michigan. Temps cool down behind the late week front with readings AOB normal for mid-May.

AVIATION
for 00Z TAF Issuance Issued at 723 PM CDT Mon May 12 2025

VFR conditions are expected through this evening and tonight before low clouds, mainly with MVFR cigs, spread into east- central WI around daybreak Tuesday, and improve during the afternoon. Lower cigs of IFR/LIFR and patchy fog will also spread to the MTW TAF site Tuesday morning and continue through much of Tuesday afternoon. Clouds will move into the central and north- central WI TAF sites late Tuesday morning and afternoon, but remain VFR.

FIRE WEATHER
Issued at 204 PM CDT Mon May 12 2025

Red Flag Warning continues for counties in northern Wisconsin through 9:00 PM. Relative humidity values have ranged from 12 to 22% for counties in this area, with southerly winds around 12 mph and gusts to 20 mph. Temperatures were also in the low 80s.
Farther south, maintain SPS for elevated fire weather conditions where RHs were a little higher.

Fire weather conditions are elevated across north-central Wisconsin on Tuesday with minimum RHs in the 30-40% range. Winds will be a little lighter around 5-10 mph with gusts to around 17 mph, and high temps in the low 80s. Farther south across the rest of the GRB forecast area RHs are in the 40-60% range and clouds will make for slightly cooler temps in the 70s.

GRB WATCHES/WARNINGS/ADVISORIES
Red Flag Warning until 9 PM CDT this evening for WIZ005-010>013- 018-019.