Thursday, March 30, 2023

How to calculate Trout Lake's ice-out

 Long-time Trout Lake fisherman George Miller provided his technique for figuring ice-out on this big lake northeast of Red Lake. George is always an opening week angler at Booi's Fly-In Lodge.

George had just read on the blog my system for predicting Red Lake's break-up and writes:

"We've been going to Booi's for opener for over 20 years and as you can imagine watching the ice has become a part of that.  After spending far too much time over the years doing all sorts of statistical analysis of far too much data, this spring I finally arrived on an approach that appears to work very well and is - nearly identical to what you suggested.

It appears the only (and not significant) difference for me is the use of the date snow is gone as the start date of keeping track of temperature.  I decided the snow insulates the ice from temp and sun so the day it was gone would be a good trigger date. I then keep a running average daily high temp. The model I came up with for ice out around the island is 1.5 days longer than 'normal' for every degree below average high, and 2.6 days faster for every degree above normal; average ice out is 27 days after snow is gone.  The entire lake typically goes out completely a week after the island area is open."
 
I e-mailed George back and wondered how he knows when the snow is gone.

"We're down in Rochester so I have to rely on what I can find on the Internet.  Red Lake used to have a remote sensing station that provided snow depth but for whatever reason that stopped a few years ago.  Now I use the station in Ear Falls; at ~30 miles away it seems like the snow cover should be the same.  This is a link to it which has a wealth of historical data also.  


One of my favorite tools to see how the ice is doing is from NASA.  Take a look at this link:


The layer under Albedo listed on the left hand sidebar is like magic.  It lets you see through the clouds and it seems to give a sense of the thickness of the ice.  The other layer that I have turned on is the Corrected Reflectance (True Color) which is a clear enough image to get a good idea of ice when it isn't cloudy.  With this you can look at past years and see when the ice has gone out too.  Great way of monitoring remote lakes!  When the color is gone under the Albedo layer it seems like the ice is gone a day or so later.

I found ice out history for Howey Bay at this link and it is consistently within a day or so of when I have the ice going out around the island on Trout.  https://hwy105.ca/wp/wp-content/uploads/2017/12/2016-ice-out-history.pdf  The entire lake is almost always fully ice free about a week after the island area is open.

It's looking like another late ice out this year so far unfortunately.  The average is roughly a month after the snow is gone that things start to open up.  With (possibly quite a bit) more snow on the way and no sign of melting in the 2 week forecast, it could be a while unless a heat wave comes in."
 
Thank you, George, and good luck fishing this season! 

And while we are on the subject of watching the weather, I like the Windy.com app. It not only has a great radar picture and graphic, it also has links to live weather cams all over North America, including a bunch in Northwestern Ontario. And it has a layer that shows snow on the ground. I'll try to link to that here.
Here's a screenshot below from today.


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