Tidal Currents Trip planner App

Jul 1, 2010
972
Catalina 350 Port Huron
Yeah, I've never noticed their effects on current, as I've only noticed the effect when docked. We were on fixed docks on one trip through Lake Erie, and I noticed around a 3' drop in about 20 minutes. A scramble of checking dock lines that day for those not used to the issue.
 
Jan 11, 2014
12,195
Sabre 362 113 Fair Haven, NY
Seiches usually occur with a frontal passage. Strong winds push water across the lake causing the lake level to rise in the east and drop in the west. Then the high water levels in the east slosh back west. If the seiche is strong enough the water continues sloshing back and forth for a day or two. This is sometimes called a bathtub effect.

There were a few real time water level monitors that clearly showed the effect. Lake Erie often has the most dramatic seiches probably due to being both shallow and having a long east-west axis. I've seen 3-4 foot seiches on Lake Ontario. It's and interesting phenomena.
 
Jan 7, 2011
5,194
Oday 322 East Chicago, IN
Yeah, I've never noticed their effects on current, as I've only noticed the effect when docked. We were on fixed docks on one trip through Lake Erie, and I noticed around a 3' drop in about 20 minutes. A scramble of checking dock lines that day for those not used to the issue.
I have heard our floating dock moan and groan for sure.

3’ in 20 minutes is a lot! I haven‘t seen that before.

Not sure how the different lakes are affected. Lake Michigan is a large body of water (not the largest by volume, but maybe by surface area). Erie is shallow, Superior is big and deep, Huron is also large but I don’t know the typical depth,.
 
Jan 11, 2014
12,195
Sabre 362 113 Fair Haven, NY
Lake Michigan is large, however it long and relatively narrow at about 100 miles, Erie and Ontario are both much longer, Erie is about 240 mile long and Ontario is about 190 miles. The longer fetches which align with the prevailing winds result in much larger seiches.
 
Jan 7, 2011
5,194
Oday 322 East Chicago, IN
Lake Michigan is large, however it long and relatively narrow at about 100 miles, Erie and Ontario are both much longer, Erie is about 240 mile long and Ontario is about 190 miles. The longer fetches which align with the prevailing winds result in much larger seiches.
Yep…but 300+ miles N-S.

I imagine a strong, prolonged north wind would stack water in my sailing grounds on the south end of the lake. I know it can drive big @ss waves!

Greg
 
Jul 1, 2010
972
Catalina 350 Port Huron
It doesn't actually take prolonged winds, but you'll rarely notice it on floating docks. Just fronts and t-storms will pull water out and send it back in. We've noticed it on Lake Huron, but not the extremes we've seen on Erie. Last fall we got held up by weather for a couple of days . I believe it may have been at Port Austin, but not sure. I watched the boat go up by 8" to a foot and then back down several times one morning as the weather came through. Don't remember the period of the slosh that was happening but it seemed like around a half hour of so from peak to valley.

Of course, on Erie, it's not unusual during a prolonged blow to have the western part of the lake down by 6' and the eastern end at Buffalo flooding with an extra 6' of water there. Just one of many reasons we're much happier being permantly relocated to Huron. Never bonded with Lake Erie in my several seasons there.

And on Lake Michigan, never say never...history tends to repeat.


Of course, none of this is remotely related to the OP's question, other than when the fronts are causing squall lines and t-storms, you probably don't want to be navigating out on the lake anyway, so you might as well watch your boat go up and down with the "tides". :biggrin:
 
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