Marine Weather and Tide Forecast for Garden, MI

SHORT TERM /THROUGH TONIGHT/
Issued at 204 PM EDT Tue Jul 15 2025

Afternoon RAP analysis and GOES satellite imagery reveal a "calm before the storm" as morning convection has cleared the UP and sunny skies have allowed for surface based instability to build upwards of 3000 j/kg atop 60-70 degree dewpoints. Upstream, a slow moving cold frontal boundary has begun to redevelop convection in far western Lake Superior. This boundary will be the focal point for strong to severe storms this afternoon and evening as they progress eastward across the UP. While CAM guidance doesn't have much of a handle on the ongoing convection in the western arm of the lake, current thinking is this line will continue developing into the western shorelines over the next several hours before diving south-east into the central UP counties this evening. With increasing bulk-shear upwards of 35-45 kts, organized convection and embedded supercell features with the upscale growth will bring all severe weather hazards to the table, including damaging winds and hail. Cannot rule out a brief spin up since model soundings showing some modest curvature in the 1-3 km range, especially in the west, though the probability is still quite low (<2%). Guidance suggests this line will peter out as it pushing into the central third with the loss of diurnal instability. While not the main hazard concern, training thunderstorms along the slow moving boundary may produce several inches of rain under the strongest convection. This is highlighted by both the HRRR and REFS ensembles, where 6 hrly PMM shows 1-3" across much of the west and Keweenaw by midnight. Give then more anafrontal structure, additional showers and non-severe thunderstorms will linger overnight.

LONG TERM /WEDNESDAY THROUGH TUESDAY/
Issued at 320 PM EDT Tue Jul 15 2025

By Wednesday morning, the cold front will have pushed south out of the UP, ushering in a much cooler airmass. Daytime highs will be noticeably cooler than the previous couple as northerly flow helps cool the western half to the upper 50s and low 60s. Elsewhere across the s-central and eastern third, temps are expected to peak close to 70. Lingering anafrontal showers and sub-severe storms will be the rule for much of Wednesday into Thursday. 12z HRRR and latest NBM guidance suggest a 50-70% chance for an additional 0.5" through Thursday morning across the west-central UP and Keweenaw, with higher probabilities for at least 0.25" for the entire Upper Peninsula. Thursday will remain on the cool side as well with this reaching the upper 60s to low 70s, coolest in the west-central.

As the parent trough and embedded shortwaves passing through the western Great Lakes depart east Thursday afternoon dry weather will finally return to the region, keeping things quiet and seasonable through Friday. A transient shortwave within the broad zonal flow aloft may touch off some showers on Saturday before quiet/dry conditions return Sunday into early next week. From there, deterministic guidance varies on the timing and strength of additional shortwaves traversing the Upper Midwest. Long range ensembles point towards positive height anomalies building in the eastern CONUS while slightly negative anoms fall in the PNW / northern Rockies, leaving the Upper Great Lakes in a favored position for passing shortwaves and active weather through mid-late July.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
Issued at 204 PM EDT Tue Jul 15 2025

Showers and thunderstorms progressing through far western Lake Superior ahead of a cold front will continue east this evening, impacting IWD first ~18-19z, then CMX ~21z, and eventually SAW closer to 00z. Some storms could be strong to severe. Behind the frontal passage, additional showers and non-severe thunderstorms are expected to develop and linger into Wednesday. With an already moist low-level airmass overhead, additional expected rainfall, and cooling temperatures behind the front, cigs will lower at all sites overnight to IFR or potentially LIFR.

MARINE
Issued at 320 PM EDT Tue Jul 15 2025

Winds will shift northerly tonight as the cold front pushes south over Lake Superior and stalls over northern Wisconsin. With the stalled front in place periods of showers and thunderstorms are expected through early Thursday morning over Lake Superior. Some of the thunderstorms this afternoon and tonight could produce damaging winds and large hail. Northeast winds gusting to 25kts will develop over western Lake Superior tonight, with gusts to 20kts central and east. Areas of fog are possible this evening and overnight with rain falling into a moist marine airmass. Any fog that forms should diminish on Wednesday as drier air filters into the Upper Great Lakes. The northerly flow should help clear out much of the wildfire smoke tonight and Wednesday. Winds will become light Wednesday night through the weekend.

MQT WATCHES/WARNINGS/ADVISORIES
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.