Snowpack, Streamflow, and Summer Fishing Forecast – April 30 2022 Update

Posted on April 30th, 2022 in Season Forecasts, Weather & Water Conditions

Introduction, Current Conditions, and Long-Range Outlooks

Here in Yellowstone Country, winter snowpack and how this snowpack melts from late April through June play the most important roles in summer water supply for both fish and agriculture from early June through mid-September. June through mid-September temperatures and rainfall play a secondary role. Only after mid-September does day-to-day weather play the largest role in overall water levels and water quality. Winter weather is thus very helpful in planning summer fishing trips to the region.

On the heels of low snowpack in 2020-2021 followed by a record warm, dry summer that came early, we are currently in severe to extreme drought throughout the YCFF operations area. Most areas are in extreme drought, the second-worst category overall. Montana is in worse shape as far as drought than any other regions in the West except for Oregon east of the Cascade Range and southern Nevada. Unfortunately, we had a very dry winter. Thankfully, substantial rain and snowfall occurred through most of April, and the weather has been substantially colder than normal. This has significantly improved our outlooks for the core summer season from our early April outlook, when we basically thought the sky was falling and expected absolutely terrible water conditions this year.

We still don’t expect a high or even normal water year, but instead of the record-low water we were facing a month ago, we now generally anticipate somewhat low flows. We’ll take it, assuming that’s what we get.

April 30 snowpack detail image

YCFF operations area is circled in red.

As of right now, snowpack within our operations area is at 85% to 99% of normal. This is a huge increase from the end of March, when things were at 68% to 80% of normal. The most important basins–the Yellowstone River Basin in WY and Yellowstone Park and the Yellowstone River Basin in Montana–are at 95% and 96% of average, respectively. While on paper these numbers suggest near-normal water levels, they don’t take the drought into consideration. A lot of our snow will disappear straight into the ground during the spring melt, rather than actually contributing to streamflow.

8-14 NOAA outlook through mid-May 2022

We have enjoyed a cold and wet April. Current NOAA outlooks generally predict below-normal temps and above-normal precip through about the middle of May. This is great news. We now anticipate a late start to the spring snowmelt (rivers have only recently risen from winter-low flows, three weeks late). The longer the snow stays in the mountains, the longer water stays in the rivers in mid-late summer.

Long-range outlooks through May are also friendly: an equal chance of above/below-normal weather in the southern part of our operations area (though we are closer to the “cold” side of this map), a greater chance of below-normal temps in the northern part of our ops area, and increased chances of above-normal precip throughout our ops area.

May 2022 NOAA outlooks

If the 8-14 and monthly outlooks are correct, we will have a very late start to the spring melt. Very good news for summer weather and water conditions. Worse news is our long-range outlooks for summer. This graphic for the June-August period is not what we want to see. If these forecast hot and dry conditions dominate through summer, it will undo a lot of the good we’ve had this April and have forecast in May.

Visit NOAA’s Climate Prediction Center for the full range of long-term outlooks as well as lots of information on ENSO, assorted oscillations, and other weather and climate info that goes right over my head.

Summary of Anticipated Water & Fishing Conditions

In a general sense, here’s what we expect for June through mid-September streamflow and fishing conditions. This is based on current conditions and the longer-range outlooks. Think of the following as something like a weather forecast from a week out: it’s too early for specifics, but the general outline is probably accurate. We anticipate low streamflow conditions for the June-September core season. Water temperatures may also be warm, but this depends on summer weather.

Here’s what this means for anticipated water and fishing conditions. In general, the following assumes a somewhat accurate weather outlook for the next couple weeks and summer weather that tracks roughly with the NOAA long-range outlooks.

  • The fishing and guiding seasons began in mid-March. Early fishing was good. Of late it has been poor, since we have still had winter water conditions when we should have had warmer, higher water, more insect hatches, and good streamer fishing.
  • Warmer spring weather is on the horizon, but not the kind of heat that prompts spring runoff to begin. We therefore expect spring runoff to occur late on all waters. On the Yellowstone River, it is unlikely to begin in earnest for at least another ten days, and possibly as much as three weeks. There may also be “runoff breaks” when spells of cold weather interrupt spells in the 60s-70s. At the moment we do not expect 80 degree temps for the foreseeable future, which is wonderful.
  • After the heavy melt hits and then recedes, the best fishing is likely to occur between about June 25 and early August. Thereafter, cloudy days and rougher water will be best at least until the weather deteriorates in September. We do not anticipate widespread 2:00PM drought/heat closures on our prime waters barring extreme summer heat. This is a profound improvement. We were almost certain of such closures a month ago.
  • Below-normal snowpack and resulting summer streamflows are now certain. How low we go depends on how much moisture we get through mid-May and how the snow melts from now through mid-June. Record-low water in late summer is very unlikely and will only occur if we have another awful heat dome in June-July as we did last year.
  • We anticipate a light snowmelt but a near-normal end to the snowmelt cycle, with the melt generally ending between June 20 and July 4 depending on the water in question. This discrepancy reflects the fact we are in drought and have a somewhat low snowpack, but that this snow is melting late.
  • July is almost certain to offer the year’s most-consistent water conditions when the area is taken as a whole. Conditions will be good in late June in many areas and into early August on some of the colder, rougher waters.
  • The fish are likely to be spooky and difficult from sometime in early August through mid-September in many areas. In August and September, steeper, faster, deeper water will fish much better than the flat, shallow stuff.
  • 2:00PM fishing closures will occur in late July and August on a few low-elevation waters, but will be rare if we have normal weather in summer. These closures are unlikely to impact the “core” fisheries (YNP, upper Madison, Stillwater River, Yellowstone River above Livingston) that are most popular at this time. That said, late afternoon and early evening fishing is likely to be poor from late July through August. More widespread 2:00 closures are possible if we have an early extreme warmup in late May-June and/or extended record heat in June and July as we did in 2021.
  • Complete 24hr closures are extremely unlikely even if we have a brutal heatwave like we had in 2021. This is another huge improvement and relief. A month ago we thought there was a 1 in 3 chance of such closures.
  • Due to tinderbox conditions throughout most of the West, fires and smoke from both local and distant fires are likely to be very bad this year beginning in late July.
  • Due to the winding-down of COVID (we hope) prompting high tourism, as well as the rapidly increasing population in the region, fishing pressure will be intense from the end of runoff through early October, assuming fires and stream closures allow for it. The quality of the fishing will not play any role in how many people are on the water. We are already seeing much more fishing pressure than used to be typical, including record-high bookings for March and April.

Detailed Fishing Conditions by Water

There have been substantial changes to the following forecasts due to the abundant snow and cold weather we’ve enjoyed in April. In particular, we no longer expect 2:00PM closures in late summer unless we have an extreme heat wave save on rivers that almost always have them, such as the lower Madison River.

Runoff is starting at a normal or late date. Our next update in mid-May will bring the following date ranges into much sharper focus.

Montana Fisheries

  • Yellowstone River: Runoff will end between June 20 and the end of June, with June 25 most likely. The Salmonfly hatch will occur for about a week immediately after runoff recedes. It is possible the earliest days of the hatch will see conditions too high and muddy to fish. The fishing will be best on slower, shallower sections of river upstream from Livingston as well as all water east of Livingston prior to early August. Faster, deeper water upstream from Livingston should produce acceptably well all summer unless we see exceptional heat as we did last year, though midafternoon onward will probably be slow in August except on cloudy days. 2:00 fishing closures will depend on weather. Absent extended extreme heat, such closures are unlikely upstream from Livingston.
  • Madison River: The Lower Madison will not experience any appreciable runoff and will be best prior to June 20. After June 20 it will generally run too warm after noon depending on day-to-day weather. The Upper Madison (really outside my ops area) will likewise probably not experience much of a runoff. It will be best from mid-June through late July. 2:00 closures are certain on the Lower Madison beginning no later than early July and possible but much less likely on the upper Madison beginning in late July.
  • Boulder River: Runoff will end late due to intense recent snow. June 20 to July 4 is a reasonable window for the end of the melt, with June 25 most likely. The river will get too low to float by July 25, and perhaps sooner. High water temps and low flows will almost certainly be a problem even for wade-fishing in August due to this small river’s intense irrigation drawdowns. The Boulder seldom sees any fishing restrictions due to water levels or temperature, but in all honesty I expect areas downstream of Natural Bridge should be closed 24 hours a day in August, due as much to irrigation drawdowns as water temps.
  • Stillwater River: Runoff will end between June 20 and July 4, with June 25 to July 1 most likely. Upper sections will be too low to float around July 15-25. Lower portions downstream of the Rosebud confluence will be high enough to float through sometime between August 20 and September 10. Late summer rains will be required for float-fishing to remain an option after that. The best fishing will occur in July and early August. 2:00 closures are possible in late July and August only if we see extreme heat in June and early July. Intense late season snow over the past few weeks will REALLY help the Stillwater this season and I encourage visitors coming in late July and August to fish it.
  • Missouri River: No appreciable runoff will occur. The carp/walleye/pike water upstream from Canyon Ferry Reservoir will as always fish best from late July through early September. Head-hunting carp here will be our preferred option for early August trips if we have a hot/dry summer. The trout water downstream of Canyon Ferry (including “Land of Giants”) will fish best from now through June. Both the trout water and the “other” water are less likely to have closures than any other water we fish.
  • Private Lakes: Day-to-day weather is more important on the lakes than snowmelt. These lakes should fish well from early April through at least mid-June, with hot/bright weather thereafter the determining factor on when things get slow.
  • Paradise Valley Spring Creeks: Fishing is always best on the creeks from early March through April, then again from about June 20 through July 20. Unfortunately, radically-increasing pressure on the creeks now means that many prime dates in June-July 2023 are now booked solid. We’re basically done guiding on these creeks except in March-April because of this.
  • Other Waters: The Gallatin River will likely drop out of runoff around June 20-25 and possibly get too warm by late July. The Jefferson River will drop from runoff by June 15-20 and probably be too warm the instant it does. We will not be offering floats on this river anymore, odds are. The fish populations are too low and too stressed by heat in the lower stretches of river close enough to Livingston. Mountain small streams in Montana will generally fish best from July 10 or so through about August 20, but may hang on into early September if summer is not too hot and dry. Public lakes in Montana will be best in May and June except for carp, which rise to hoppers on some lakes in late July and August.

Yellowstone Park Fisheries

  • Yellowstone River: The Lake-Falls stretch always opens July 15. It will be best over the remainder of July thereafter. The Grand Canyon from the Falls to the Lamar confluence may not experience an unfishably-high runoff, though it probably will for ten days or so in early June. Given the likelihood of a late runoff and a forecast for below-normal temps until mid-May, it is possible runoff will not yet be fully underway during the first few days of the season. Can you say Mother’s Day Caddis? Conditions suitable for nymph and streamer fishing may be present throughout the first three weeks of the season, though more likely the river will begin coming into shape between June 10 and June 20. More consistent conditions will begin after that. While Salmonflies may pop anytime after June 20 sporadically, they will be heaviest in the first ten days of July. Good conditions should continue throughout the summer unless we experience an extreme heat wave that prompts the park to close all flowing waters at 2:00. The Black Canyon generally tracks similarly to the Yellowstone downstream in Montana, though the first half of July should still see Salmonflies at least in the upstream areas between the Lamar River and Hellroaring Creek confluences.
  • Gardner River: The lower Gardner downstream of Boiling River will be fishable on a day-to-day basis from the opening of the park season, joined by the stretch from Sheepeater Canyon to Boiling River around June 10-15. Consistent fishing will begin by June 20 and continue in both stretches through about July 20 and above Boiling River until early October. Below Boiling River will be too warm and weedy at the end of July and on through mid-September. The headwaters above Osprey Falls will come in between June 20 and July 4 depending on weather and remain good until at least early August.
  • Lamar River & Tributaries: Runoff will end between June 20 and July 4 depending on the water involved and the weather. The best fishing will occur in July and perhaps very early August. The water will be low and slow and the fish heavily-pressured and spooky thereafter.
  • Firehole River: The Firehole will not experience an appreciable runoff and will fish best between the park opener and June 15. The first hot/dry spell after June 15 will shut down fishing until after Labor Day. While conditions have improved in the Firehole drainage over the past few weeks, they’re still not ideal. In fact, snowpack is lower in this basin than anywhere else in the area. We did not guide on the Firehole in 2021 and almost certainly will not in 2022, either. If current climate models continue, the Firehole will cease to be a relevant fishery downstream of Old Faithful by 2030 due to repeated fish kills associated with high water temperatures.
  • Gibbon River: The Gibbon upstream of Norris Geyser Basin will be fishable sometime between the park opener and June 10 and will be best before mid-July. Areas downstream of Norris Geyser Basin are unlikely to experience an appreciable runoff and will be best between the season opener and June 20. After June 20, the first hot spell will shut the fishing off until September 1.
  • Upper Madison River: Generally similar to the Firehole but will hang on for a few days after the first hot spell.
  • Lakes in YNP: Ice-out will depend on day-to-day weather but should occur before or right around Opening Day. Travel to the lakes before mid-June might be a wet, sloppy mess due to mud and snowmelt, though all except high-elevation lakes and those in snowy areas (Lewis Lake, I’m looking at you) should be snow-free by the opener. All will fish best from ice-out (or Opening Day, whichever comes second) through June, then trail off through early July.
  • Creeks in YNP: Meadow-type streams will become fishable between June 10 and the end of June, with those draining lakes becoming fishable towards the earlier end and those draining mountains falling into shape later. All will be best for the first month after they come in. Rough, mountain creeks will come into shape around the beginning of July and be best for a month to six weeks starting about a week after they fall into shape.