Marine Weather and Tide Forecast for Dune Acres, IN

DISCUSSION
Issued at 307 PM CDT Fri Apr 25 2025

Through Sunday:

Showers and isolated storms ending late this afternoon over northwest IN and east central IL as the shortwave trough and wave of low pressure move east of the area. Increasing nly winds are then expected as low pressure deepens across the lower Great Lakes while a 1030 mb high builds into ern MN and nw WI. Nly wind gusts of 30-35 mph will be possible near the lake.
Temps will fall into the 40s by Saturday morning.

High pressure will then move across nrn IL and nrn IN Saturday afternoon and night. Sly winds and warm advection will then begin on Sunday. High temps Saturday will range from near 60F toward central IL to around 50F at the lake followed by mid to upper 60s away from the lake for Sunday.

MG

Sunday Night through Friday:

High pressure will hang on for one more day as temperatures begin to moderate Sunday. This moderation will be courtesy of southerly winds and rising heights aloft as a ridge starts to build into the upper Midwest. Humidity and warmth then increase Monday as a low pressure system approaches the western end of Lake Superior. Thunderstorms are expected over the northwestern half of the CWA Monday morning as a waning LLJ leans over east into the region. MUCAPE and effective shear appears weak on the GFS, so any storms look to be sub-severe at this time. The morning storm potential will be followed by a late morning and afternoon lull with some potential scattering of the clouds. A line of storms then looks to form over Iowa and translate east with time Monday night. GFS soundings support some severe threat with 1500 to 2000 J/kg of MLCAPE, effective shear of 40 knots and modest low to mid lapse rates ranging from 6 to 7 C/km.
0-6km shear boundary parallel shear seems to suggest a linear storm threat with some QLCS potential given cyclonic hodograph curvature and 0-3km shear around 40 knots. Trends will be monitored through the weekend to pin down more accurate timing and threats for Monday. A second threat window also looks possible Tuesday pending how quickly a boundary clears us Tuesday morning and afternoon.

Beyond, high pressure moves in mid week, keeping conditions quiet, before a warm front approaches bringing rain chances toward the end of the extended period.

CM

AVIATION /00Z TAFS THROUGH 06Z SATURDAY/
Issued at 620 PM CDT Fri Apr 25 2025

Aviation forecast concerns for the 00Z TAFs:

- Blustery N to NE winds into Saturday, with gusts 25 kts or slightly higher tonight gradually easing tomorrow.

- Period of MVFR ceilings likely from mid-evening into late morning/midday Saturday.

Surface low pressure was over south-central lower Michigan early this evening, with a cold front trailing southwest across IN/southern IL. Blustery north winds gusting 25-30 kt were occurring on the back side of this departing low, and will persist tonight before gradually easing through the day Saturday. Wind direction is currently NNE for ORD/MDW, but may back to 350-ish for a time later tonight before shifting more NNE and NE Saturday. Northeast winds should diminish quickly Saturday evening as surface high pressure approaches.

Cloud wise, an extensive area was upstream across WI, and should spread back into the terminals through early-mid evening. Bases may initially be below 1500 ft, but will likely gradually rise late tonight into Saturday morning before eventually scattering to VFR by midday/early afternoon. Can't rule out some brief IFR bases along/over Lake Michigan which could affect KGYY later this evening. Also may be a few isolated sprinkles along/north of about the I-90 corridor from KRFD to KORD this evening, though nothing which should be of any significance.

Ratzer

LOT WATCHES/WARNINGS/ADVISORIES
IL...None.
IN...None.
LM...Small Craft Advisory until 7 PM CDT Saturday for the IL and IN nearshore waters.