Fishing water, when and how much

Every year about this time I make a fool of myself by trying to forecast fishing water conditions for the season. It is not smart to continue to violate the maximum “it is better to remain silent and seem stupid than vocalizing your opinion and erasing all doubt,” but I am eternally hopeful that one of these years my forecast will be right. Looking at the winter on a macro scale, weather experts say we are still under the influence of La Nina, a weather pattern created by cooler ocean temperatures in the eastern Pacific, which usually brings more moisture and cooler temperatures to our part of the country. Traversing a quarter-mile of two-track road to get to my home without plowing snow during January through March tells me we did not get a significant increase in moisture from La Nina.

There were some areas that received good snowfall this winter. The Yellowstone and eastern Wyoming snowtels recorded good snow packs with high water equivalents. In the Upper Green River drainage, the Kendall and New Fork snowtels held up reasonably well. It seems that the moisture traveled in bandwidths, delivering significant moisture to one area and missing others. There is another weather phenomenon called the "arctic oscillation" that may account for this streaky moisture pattern. When the arctic surface air pressure is strong it traps the moist air produced by La Nina near the Arctic Circle. When the arctic oscillation pressure weakens, it allows moist air to escape southward, which is carried by the jet stream and delivers snow to our mountains. This on-and-off arctic pressure switch interacting with the jet stream could account for the moisture variance in different locales.

At the end of April our local moisture situation did not look too promising with the basin snowpack hovering around 79 percent of average and the water equivalent standing at 69 percent. Particularly concerning was the total lack of low snow below the 9,000-foot level, which left desert grazing allotments and winter meadows bone dry. The moisture level is below what we would like, but we could survive with it if the weather cooperates in the next 30 to 60 days. We still have a chance to add to our snowpack since, historically, our highest average moisture month is May. Some weather experts believe the arctic oscillation will moderate this spring, allowing La Nina to deliver an increased moisture flow into our area. The resent moisture-producing events in early May could be evidence of a favorable shift to a more favorable moisture pattern. We need moderate increases in daytime temperatures and chilly nights to promote a gradual thaw of the snowpack above 9,000 feet, where most of it seems to be this year. If this materializes, it would bode well for our fishing water. We have very little snow piled up in the low-lying valleys, so as the temperatures increase we will have less murky water emptying into the stream basins early in the spring which could lead to some good fishable water in the May/June timeframe. If we have gradual rises in temperature this spring the high snowmelt will be moderated, setting up a slow release of water into the many drainages we have in this area. Since many of the streams emanating from the Wind River Mountains have granite gravel beds, we may get high, clear water in the early part of the summer, which can present good fishing opportunities and give us decent water flows well into late summer. This would be the best-case scenario, but we need to look at some potential impediments.

I have concerns with the composition of the snowpack, which seems to have a low water yield. Yes, there have been some good wet snows, but more have had the characteristic of being dry. It has been my experience that this drier snow melts pretty fast even with moderate temperature increases, something like sugar melting in a hot cup of coffee. If our high snowpack has this characteristic we might get a quicker-than-normal runoff with all the water spilling out of the mountains in a short period of time creating flood conditions, which has adverse impacts on recreation and agriculture. The parched countryside I mentioned earlier could have a detrimental effect on stream flows in that much of the snow melt will be absorbed directly into the ground to replenish the depleted groundwater table and will not reach the stream beds. We need the large groundwater sponges to be filled with water early in the spring so they can gradually release water back into the streams over the course of the summer. The continuation of good stream flows into late summer is dependent on the maintenance of good ground water table.

I have discussed the possible up and down sides of future weather events. Now, what is my real fishing water projected guess? I preface my best guess with the fact that we are very fortunate to live at the headwaters of many streams that originate in the Wind River Mountains to our east and the Wyoming Range to our west. The unique glacier system we have in the Wind River Mountains contributes to a good supply of fishing water under most weather conditions. I have been chasing trout in our local streams for well over a half-century and have found there has always been enough water to maintain a good trout population in most of our streams. If the projected weather patterns hold for the next 60 days we should see good fishing opportunities in May and early June. After a traditional runoff in late June, we will have some fine fishing beginning in early July and continuing through early September in most of the streams. The recent report from the local WG&F fishery biologist indicates there are plenty of big fish in some of our streams so fish catching should be good as well.