Marine Weather and Tide Forecast for Spring Lake, MI

DISCUSSION
Issued at 329 AM EDT Mon May 12 2025

- Warm with scattered showers/storms tonight through Wednesday

We will start today off just like the weekend with plenty of sunshine and mild temperatures. Except today, clouds will be on the increase this afternoon on the northern periphery of the upper low that has been affecting the SE U.S. over the weekend. Better low and mid level moisture will arrive this evening from the south, providing for increasing chances of rain showers tonight. These showers look rather light as the dry air in place will eat away at the incoming pcpn, and as the low will be weakening and moving away from its moisture source. Thunder does not look likely tonight as model CAPE progs show that we stay too stable for thunder through 12z Tuesday.

Tuesday will see a transition from the showers along the weakening occluded front tonight to more of a diurnal afternoon/evening pop up shower/storm nature that will continue into Wednesday. This transition occurs as the weakening occluded front moves north of the area, and we become under more direct influence of the actual upper low and "cold" pool aloft associated with it. Sfc dew points approaching 60F combined with sfc temps in the 70s will help touch off showers/storms. One focus for showers/storms will be a potential lake breeze off of Lake Michigan. Outflow boundaries from any individual cells inland will also cause additional development as shear will be quite weak and cells will be of the pulse variety. The lack of shear will really limit the potential of strong to severe storms for Tuesday and Wednesday.

- Strong to severe storms possible late Thursday

We will see a break in most of the convective activity then from Wednesday night through much of Thursday, with only a small chance of an isolated shower/storm possible. We will see the upper low pull away from the area to the east, and short wave ridging will build in for a period before the next system moves in later Thursday. The small chance of a shower/storm will remain due to the lingering low level moisture that hangs on as it never gets swept out.

The Thursday system will be supported by a strong closed upper low that lifts into the Upper Midwest late in the day. This will bring a cold front/occluding front toward the area late in the day.
Instability does not build significantly during the heating of the day. This is likely due to the fact that the cold pool aloft does not arrive until later. In addition, there is not much of a trigger earlier even with some instability.

This event is looking more and more likely to be an evening event for our area. The arrival of the cold pool aloft, a short wave, and resultant instability developing will all likely fire convection near the area. Models have been persistent in showing limited deep layer shear (around 30+ knots), but enough to help the cause for strong to severe storms. The short wave moving in is likely to try to form a line ahead of it. Wind looks to be the biggest threat with dry mid levels leading to DCAPEs of 1000+ J/kg present. Also, can not rule out a tornado as the triple point will be near the southern portion of our area. Forecast soundings show some good directional shear as a result. This will all move out by the early overnight hours.

- Cooler next weekend with a chance of showers

We will see the dry slot move over the area on Friday in the wake of the frontal passage. This would support with still mild temperatures with mainly dry conditions.

There remains some uncertainty with regards to next weekend depending on the exact track of the upper low. Some model members are rotating it just north of the area, while others are bringing this far south with some showers. Too uncertain at this time to say one way or another, so we will have some small rain chances with cooler temperatures present.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
Issued at 718 AM EDT Mon May 12 2025

We are starting off this forecast period with more VFR conditions like the last couple of days. This forecast period will however see conditions deteriorate in the last 6-9 hours as we will see rain, fog, and low clouds all move in from South to North late in this forecast period.

Some thin high clouds based around 25k ft agl can be seen already starting to move over from the south. This will be the case most of the day, with winds from the East around 7-10 knots. We will see lower end VFR clouds move in starting just after 00z tonight, and so too will be a few rain showers.

It may take a few hours, but as the front approaches, rain chances will go up, and ceilings will drop significantly. We expect that ceilings will drop to IFR in the last few hours of this forecast period from South to North.

MARINE
Issued at 329 AM EDT Mon May 12 2025

No marine wind/wave headlines are likely to be needed through Wednesday night. The system coming up later today and lingering over the area will have a weak pressure gradient, and fairly light winds.
The only impact that could result from these weak winds could be some marine fog with the moist air moving over the cool waters of Lake Michigan.

The stronger winds that arrive on Thursday will be in advance of the next stronger storm system that will approach the area. Small Craft Advisories are looking likely for that time frame, but we still have some time yet to monitor the trends.

GRR WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...None.