Marine Weather and Tide Forecast for Michigan City, IN

DISCUSSION
Issued at 1225 PM EDT Sat May 9 2026

A cold front already arriving in our northwest by 18z means better chances for storms along and east of I-69. Mid level vorticity moves more eastward as opposed to southeastward, but some 700 mb vorticity exists in the 21z window caught up behind the front and that paired with the moisture convergence along the thermal gradient should be enough to erupt showers and storms. The main limiting factor for these storms appears to be moisture, which with sfc dew points and 850 mb dew points in the mid to upper single digits is just below threshold for better flooding potential. Given 500 to 1000 J/kg of CAPE and strong low level lapse rates alluding to somewhat of an inverted-v profile, wind damage and perhaps a hail threat appear to be the most likely storm hazards. Effective shear is right around 30 kts, but low level turning appears to be weaker and, along with a drier profile, the tornado threat should also be limited. Either because it vacates the area or the instability wanes, an initial guess at severe weather coming to an end is around 00z this evening.
However, there is a post-frontal thermal gradient that moves west to east in conjunction with some more 700 mb vorticity and this may keep showers and perhaps some thunderstorms going in a training environment south of US-24. It is possible that we see some ponding or flooding there as long as storms continue to fire along that stalled front.

Surface high pressure begins to poke into the area on Sunday behind the cold front leading to a dry day. That dry weather continues into Tuesday morning. As the relatively cooler air swings through the area during this period, we'll have to watch for some front potential. For Monday morning, the better 850 mb temperatures, least cloudy threat, and weakest low level pressure gradient exists between Monday and Tuesday mornings. Tuesday, the theta-e plume is on our doorstep around 12z and this may be enough to protect the area. However, we'll have to see if temps drop quickly just after sunset and if we can form frost earlier in the overnight. Both of these mornings look like along and north of the Toll Road could see frost.

The theta-e plume is into the area during the daytime on Tuesday in conjunction with the low pressure system arriving. As such, there is a good area of large scale ascent. It is interesting to see the large scale ascent weakens by the time we get to the afternoon. The instability axis waits until after 00z to get into the area, though, and that may affect the overall intensity of storms. Overnight, the low continues to deepen and develops into an upper low pressure system over the Great Lakes region and cold air spills in for Wednesday. There is some question about moisture content for Wednesday, but there could be some isolated to scattered showers.
Given what appears to be a lake shadow removing low level lapse rates through the day, am skeptical of thunderstorm potential, especially given weaker CAPE values. A 40 kt LLJ will probably make it easy to get breezy winds between 25 and 35 mph during the daytime, especially ahead of the rain.

High pressure and mid level ridging follow for Thursday and at least the first half of Friday. The theta-e plume probably waits until Saturday (the GFS is probably too fast), but am not confident enough to remove PoPs entirely from Friday yet.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/
Issued at 657 PM EDT Sat May 9 2026

A few remaining scattered showers and thunderstorms are currently moving eastward out of the area and chances will decrease through the evening. Winds will begin to diurnally weaken after 00z Sun
Otherwise
VFR conditions are expected to continue through this TAF period with diurnal gusty northwesterly winds increasing again after 18z Sun for both sites. Gusts will approach 20 kts.

IWX WATCHES/WARNINGS/ADVISORIES
IN...None.
OH...None.
MI...None.
MARINE...None.