Tools for Estimating Ice-Out
It's March & North Shore Steelheading is almost here!
If you're like me, you are getting the itch, but winter has the tributaries locked up under ice & snow. The question everyone begins to ask is, "When do you think the rivers are going to open up?" Fortunately there is a way to tell that it is coming & here's how you do it: Magic 8 Ball...
I'm kidding, it's really: Magic USGS Flow Data!
Take a close look at the following graphic-
If you're like me, you are getting the itch, but winter has the tributaries locked up under ice & snow. The question everyone begins to ask is, "When do you think the rivers are going to open up?" Fortunately there is a way to tell that it is coming & here's how you do it: Magic 8 Ball...
I'm kidding, it's really: Magic USGS Flow Data!
Take a close look at the following graphic-
What you are looking at are the effects of the daily warming cycle on snowmelt & flow. Note that the peaks in gage height (& therefor flow) occur just after mid-day. This is when the air is warmest, the sun at its most intense; & the most melting occurs contributing water to the river. The lows occur just after sunrise which is also typically the coldest part of an average day. At that point, very little if any meltwater is making its way to the river. However when the sun is high, meltwater begins to scour the ice from above & below. The more meltwater, the more ice erosion until the river opens up.
The above is the typical gauge signature of a river about to throw off its winter coat, & it can open up a medium-sized river in as little as a week. When you see a trend similar to this, it's time to get your gear ready!
Regards & Good Fishing!
NMF
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