Marine Weather and Tide Forecast for Oostburg, WI

SHORT TERM
Issued 248 PM CDT Sun Jun 7 2026

Tonight through Monday night:

Surface high pressure will slowly begin to retreat east overnight, allowing for a broad moist axis ahead of a large lee trough over the High Plains to shift east into our area. As the moist axis shifts into our area, surface dew points will rise into the low 70s and PWATs will rise to between 1.7 to 2 inches.

Overnight, convection to our south will generally see a downward turn in coverage as instability wanes after sunset, but some showers may begin to move into southwest and south central WI between midnight and dawn on Monday as the moisture surges northward.

Tomorrow, instability is expected to increase after sunrise and 1500 to 2000 J/kg of CAPE will be realized from the late morning into the early afternoon. Shower and storm coverage will increase, and scattered storms capable of locally heavy rain will occur. Given the high PWATs, very efficient rainfall is expected. Generally 0.5 to 1.5 inches of rainfall is expected over the area, but with the ample moisture, any locations that get stuck beneath the expected slow moving, training storms tomorrow may see locally higher amounts that could eclipse 2-3 inches. SPC HRRR 3 HR PMM corroborates this, showing potential for rainfall in the 2-3 inch range in scattered pockets over central WI during the afternoon.

Another added layer to tomorrow's storms will be the presence of an MCV left over from today's convection. This MCV is likely to be located over NE IA tomorrow, and may cause some local enhancements to shear over southwest and south central WI. This localized shear enhancement, coupled with very good low level stretching potential (3CAPE >150 J/kg) and low LCLs around 400m may allow for a short window for an isolated, brief spin-up tornado tomorrow afternoon, similar to what was seen in Illinois earlier today.

Showers and storms will continue into Monday evening until instability wanes again after sunset, with some widely scattered rain lingering overnight.

CMiller

LONG TERM
Issued 255 PM CDT Sun Jun 7 2026

Tuesday through Sunday:

Hot, humid and mostly quiet on Tuesday as subsidence takes hold behind a departing upper trough. Highs will be in the mid to upper 80s, with head indices in the low 90s. There will be chances (~20 to 30 %) for a lake breeze driven shower or storm Tuesday afternoon, though these may not materialize owing a sturdy cap aloft of 13 C at 700mb that will build in behind a push of warm advection during the morning into the afternoon.

Warmth builds Wednesday with highs pushing 90. The combination of the heat and humidity may cause heat indices near 100. We'll have to monitor Wednesday in particular for a Heat Advisory.
Wednesday afternoon and evening strong trough is expected to kick off convection over northern WI which will then track southeast Wednesday night into our area. Still a bit too early to pin down the particulars but GFS soundings suggest a highly unstable environment with 4000 j/kg of SBCAPE, appreciable low level turning in the hodographs, and effective shear around 25 knots which would support all modes of severe weather.

Another wave may propagate northeast along a baroclinic zone on Thursday, causing another chance for severe weather on Thursday before a cold front comes crashing through Thursday night.

Temperatures and humidity briefly moderate on Friday, with additional shower and storm chances Saturday and Sunday.

CMiller

AVIATION
Issued 221 PM CDT Sun Jun 7 2026

VFR conditions are expected to persist this afternoon and into tonight, save for Far SW WI, where rain may cause lower flight categories. Overnight, VFR conditions slowly give way to MVFR and IFR conditions from west to east around dawn on Monday as a more humid airmass and rain showers/storms move into southern WI. Scattered rain showers/storms will then continue through Monday, with a mixture of flight categories through the day.

Southeast winds will persist through the TAF period with moderate gusts from 15 to 20 knots tomorrow.

CMiller

MARINE
Issued 254 PM CDT Sun Jun 7 2026

High pressure over the Upper Great Lakes will gradually begin to shift east through the rest of today and into Monday morning.
Warm and humid air lingering over the relatively cool waters of Lake Michigan has caused marine dense fog over the northern half of the lake into the early part of the afternoon. Recent satellite trends have shown this area of fog dissipating, so the Marine Dense Fog Advisory may be cancelled before 7PM CDT this evening.

Otherwise, broad low pressure over the Great Plains and high pressure over the northeastern states will lead to moderate southeast winds over the lake into Tuesday morning. Winds then become southerly during the day on Tuesday as a warm front lifts north over the lake.

Occasional chances for showers and thunderstorms are in the forecast, particularly late Monday through Monday night.
Additional chances later in the week.

CMiller

MKX WATCHES/WARNINGS/ADVISORIES
WI
Beach Hazards Statement
WIZ052-WIZ060-WIZ066- WIZ071...midnight Monday to 7 PM Monday.

LM
Dense Fog Advisory
LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ643-LMZ868 until 7 PM Sunday.

Small Craft Advisory...LMZ643-LMZ644...4 AM Monday to 4 PM Monday.