2018 Winter Snowpack and Season Fishing and Streamflow Forecast – by Walter

Late February/Early March Snowpack Update and Season Streamflow and Fishing Forecast

Buckle up folks. This is going to be a good year. Unlike points to our south and west (Colorado, Utah, California), we have TONS of snow and will therefore have tons of water this summer. In general, we anticipate excellent conditions on our spring waters (Firehole, Gibbon, Madison) in June and all prime summer waters from some point in July onward. The Missouri River is unlikely to produce good dry fly fishing from April-June, but we anticipate outstanding nymph fishing due to the forecast high flows pushing nymphs, eggs, and crustaceans around.

Snowpack and Winter Weather

Winter started in mid-September with intense high elevation snowfall that did not completely melt. October was likewise cold and wet. November was actually warm and dry, certainly warmer and drier than October overall, and we therefore started our actual winter expecting low snowfall and snowpack. December was near-average. Since then, it is has been consistently wet all winter. Before early February, we had been having a generally warm winter, so much so that it sometimes rained rather than snowed in Gardiner, though it was always cold enough to snow up high. This began to raise concerns that the snowpack, though abundant, would not be cold enough to resist melting with the first warm spell in April. Since early February, it has been both cold and wet. In fact we saw our coldest weather of the season around February 20. One fly shop customer took a picture of his car thermometer in the Lamar Valley: Minus 47 Fahrenheit. Even if this was ten degrees off, that’s cold. This blast of cold was good: it set up the winter snow just like ice in a blast freezer. The snow is now set up and should stay that way until early-mid May.

Snowpack within our area of operations now ranges from 123% of normal in the Madison-Gallatin Drainage within Yellowstone Park to 167% of normal in the Yellowstone Drainages, both within the park and north of it. Other drainage basins that impact some of our waters are somewhere in the middle. For reference, anywhere in the West, only the Shoshone Drainage just east of Yellowstone Park has more snow than the Yellowstone drainage. We’ve got a lot of snow. With the exception of the Madison-Gallatin Drainage, all basins in our operations area are 20-40 points higher than last year at about this time. The Madison-Gallatin is about the same as it was last year, maybe a hair more.

What’s that mean? There is still a lot of winter and spring left to go before we can be sure, but what it probably means is that we’re going to have above average to REALLY HIGH streamflows this year. There is now no chance we will have below-normal snowpack. In fact, some lower elevation snow gauges have already passed their average heights for the year, and March and April are typically our snowiest months at high elevation. If there’s an early warmup in April, we could wind up having near-normal water conditions. It’s much more likely that we will have high water.

So what does this mean for 2018 fishing? Great fishing in the northern part of Yellowstone from the end of runoff all through the season, but the fishing will be delayed slightly. In general, we expect everything to be delayed at least a week. Want to hit the Salmonfly hatch on the Yellowstone? Might not happen this year (blown out by high water). More likely, the Yellowstone will drop into shape July 5-10, with Salmonflies at the same time. The Lamar Drainage will fall into shape a week later. If you’re making plans now, I can’t guarantee that the northern part of the park (Yellowstone/Lamar) will be ready before July 20-25, though it will probably be earlier. More details with the next update. That said, we should have great conditions in late July and August. If we do have enough water, water temps will be ideal all through August, never cracking 65 degrees or so when most Augusts see temperatures nudge 70 on the hottest days.

I should also note that the Missouri River will be a great nymphing option from April-June this year. 2017 saw similar but not quite so high water, and the fishing was outstanding all spring, with lots of fat, healthy fish feeding on eggs and sowbugs all spring. If you’ve contemplated booking a Missouri jet boat trip with me (Walter), 2018 is going to be a good year to do it…

I will go into a lot more detail in later updates. The next will come around April 1. In this update, I’ll cover what the snowpack suggests for important area fisheries. I will say that we’re really happy and excited about having a lot of snow. It hurts our fishing in June, but it dramatically improves it July-September. We’ll trade tough fishing in Yellowstone Park and none at all on the Yellowstone River for spectacular midsummer-fall conditions. I have been guiding since 2001. We currently have the 3rd or 4th highest snowpack of any year since then. Just uess which years have had the best fishing…

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