Marine Weather and Tide Forecast for Benton Harbor, MI

DISCUSSION
Issued at 215 PM EDT Fri May 16 2025

A shortwave, 70-80 kt 500 mb jet, and an attendant cold front track through this evening into the early overnight through the base of an Upper Midwest upper low. The associated shot of deeper ascent and some low level moisture return with a developing low level jet should bring a period of scattered showers/storms to most of the area this evening. Still cannot rule out a few strong to severe storms, mainly south of US 24, as shear profiles are favorable for organized convection. Instability is the limiting factor however with MLCIN and dry air to overcome, though incoming height falls/cooling aloft, and some last minute low level theta-e advection, should eventually allow updrafts to break the cap with MLCAPE potentially surging into the 1000-1500 j/kg range (highest southeast of US 24). High DCAPE with steep 0-3km lapse rates favor a downburst wind threat if any multicell clusters/lines emerge. Overall confidence in anything more than isolated strong to severe cells is low, with greater probs for severe storms off to the south near the primary moisture/instability axis.

Cold advection on the southern fringes of a stacked low moving east through the Great Lakes region will provide significantly cooler and breezy conditions post-frontal later tonight into Saturday. Cyclonic flow around the low will also allow stratocu to build in for a time, especially north of US 30 where non zero chances for a rogue sprinkle/shower will exist. Sunday is definitely the preferred weekend day weather-wise as high pressure nudges in from the north with sunshine, lighter winds and slightly warmer temps.

Next week continues to look wet at times as an upper low cuts off and slowly tracks east through the Central US and Great Lakes. The greatest chances for rain are the Tuesday through Thursday periods, with temperatures generally below average for mid-late May.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
Issued at 127 PM EDT Fri May 16 2025

An upper level speed max lifting across downstream portion of upper trough and an accompanying upper level short wave will help to advect some increased low level moisture northward late this afternoon/early this evening. Sfc dew points have mixed out nicely early this afternoon into the upper 40s to lower 50s. The challenging part of this convective forecast is trying to assess extent of moisture return in advance of this short wave tonight and how much destabilization can occur. Strengthening low/mid level wind fields and initial dry profiles do suggest potential of some strong winds with any storms (or showers). Have not made substantial changes to previous timing of main potential threat in the 00Z-03Z window for thunder. Otherwise, southerly gusts to 20 to 25 knots will be maintained in advance of the associated cold front this evening, with post-frontal west winds gusting to 30 to 35 knots by Saturday afternoon. Conditions should remain primarily VFR this period with the exception of any stronger showers and storms.

IWX WATCHES/WARNINGS/ADVISORIES
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory until 5 PM EDT Saturday for LMZ043-046.