Keep in mind, Pete’s analog years are based on current Pacific Ocean and atmosphere conditions to generate awareness of current conditions and precipitation and temperatures outlooks based on
analog years. They were never intended to zoom down to a basin level or individual station, but let’s have some fun, give it a try to see how they worked to give us a heads up about the winter snowpack for Twin Lakes SNOTEL, Boise Basin and Bogus Basin SNOTEL.
Recession flows are in full swing which makes it easy to see where they’re coming from and going. Flows range from near record low in northern Idaho, below average in the Salmon, to above average in central and southern Idaho. Even the Owyhee is flowing above average. Enjoy the flow where you can and we’ll see what El Nino brings next winter…
The Teton River is just reaching its snowmelt peak while the Moyie River is flowing near record low. The Owyhee River is just now reaching the tail end of recession flows. Central Idaho’s rivers are receding from their snow driven peaks. May brought warm temps with above freezing nighttime that resulted in 24/7 meting and probably record high SWE loses during the month of May because there was plenty of snow to melt. June’s cooler and wetter weather will help push recession flows out a bit before the normal low flow summer levels arrive. Owyhee and Bruneau recession flows months are a good example of these extended flows. Enjoy the river, know your limits and keep your eye on the weather and those river flow levels.
Update for Owyhee, Weiser, Camas, Salmon Falls, Bruneau, Boise & Big Wood
For complete Snow to Flow Relationships see:
Snow Melt / Peak Streamflow Relationships (PDF; 146 KB) – Report by Kara Ferguson (2017) summarizing the relationship between snowmelt and peak streamflow timing on rivers throughout Idaho.
From https://www.nrcs.usda.gov/wps/portal/wcc/home/quicklinks/states/idaho/watersupply/peak
And NWS peak flow products and forecasts:
Peak Flow and Stage Forecasts from NWS
Know your boating limits as rivers will be high for an extended period.
The Owyhee River at Rome increased to 4600 cfs (mean daily flow) on Mar 16 from melting of valley snow and rain for its first peak since last year. The higher elevation snow is still accumulating, even at Mud Flat SNOTEL site which is only 5730 feet in elevations. March precipitation thru March 27 was 144% of median with another storm to continue building the pack as cold will remain until at least early April. Then, get ready as the cold temps will not last for ever…
With an April-July runoff volume of 150% of median predicted, means we could see volumes similar to the first half of the 2019. The 2nd peak on May 31, 2019 depends if the wet /cool spring weather continues into late spring / early summer.
Here’s a link to today’s natural snow depth for all SNOTEL sites in our region in inches. The Report Generator link below gives full report – you can sort columns high to low or alphabetical.
Lost Lake is the winner with 130” along the NF Clearwater/St Joe divide. Last night’s storm allowed Boise basin’s Trinity Mnt with 127” to pass Schweitzer Basin that only has 126” !
Central Idaho’s has a strong snowpack with Deadwood and Atlanta Summits and Grand Targhee making the top 5!
Usually March’s warmer temps allows the snow depth to start settling down and compacting, but not yet… cold is good ! This map shows month to date precip and March storm track across the the West. Another couple of storms are on the horizon that will keep adding to the pack.
No signs of an early spring in sight yet… so don’t put those skis away.
Here’s an update given at the Idaho Whitewater Association March 1 meeting. We start where we left off last March because 2022 set the stage for this 3rd consecutive La Nina winter. Included is current snowpack and similar (ocean condition analog) years for this winter. Most analog years had a delayed melt like 2022. Keep your eye on the sky as we watch to see what March brings and when warmer temperatures arrive. For now, cold is good to keep the snow in place and allow the mountainous snowpack to keep accumulating.
Here’s an update given Feb 16 at the Idaho Hay & Forage Conference. Includes a summary of last year and 2009 analog year followed by current snow, water supply, soil moisture and weather outlooks for these basins across southern Idaho – Owyhee, Weiser, Payette, Boise, Big Wood, Big Lost, Snake, Salmon Falls Creek & Goose Creek.
Here’s a long PDF talk explaining 2022 snowfall and runoff compared to analog year 2009. This provides the background to better understand Pete Parson’s 2023 analog years. These current analog years are 2000, 2009 (again), & 2012 and runner up years of 1957 & 1972. January 15, marks the half way point of winter. A return to stormier and cooler PNW is predicted next week, which is great and unlike last year! Time will tell if we track one of these analog years or not. And if a late snowmelt as observed in the analog years occurs as winter ends and flows into spring. Spring melts away as rivers increase. Stay tuned and enjoy the ride…
Keep your eye on the horizon and let’s hope the storms continue building snowpacks across Idaho in the 2nd half of winter!!!
Now this is gonna get interesting… who remembers what the meaning of life is – from hitchhikers guide to the galaxy ? 42 and this is also Boise’s Magic temp for snow to be falling at Bogus, for most storms. Let’s Keep It Simple Silly (KISS) so we don’t have to explain the adiabatic temp lapse rate decreasing 3F /1000 ft increase in elevation.
The NWS forecasts for Boise for Tues shows temps pushing 43 F and Bogus at 34 with rain snow mix and snow line / level around 6,600 ft !!! Elevation matters and makes a difference! Stay tuned and let’s hope the snow on ground and frozen soils can keep the temps cooler than the models are predicting and snow keeps falling above 6,000 ft !!!
In Idaho, rain-on-snow runoff events happen below 5,000 ft from mid-Nov to mid-Feb. We’re step-up nicely for rapid runoff if the rain intensity and duration occurs because of valley snow cover and frozen soils. Soils in my backyard are frozen deeper than my shovel can easily dig. What’s happening in your backyard ?
It’s always interesting to watch these storms set up as they cross the Pacific, the ocean swells they produce and becomes an Atmospheric River when they hit the west coast and move inland.
Get ready to enjoy the ride from this AR ! Be safe whether you’re deep in snow on a mountain side as avalanche danger will increase from this heavy snowfall on the colder lighter older snow layers OR if you’re watching the creeks and rivers rise in the valley bottoms! How high the rivers rise depends on duration / intensity of rain and temps above 32F.
The good news from OpenSnow mentions the weather door in PNW may remain open in early Jan to start the New Year !!!
Above NWS hourly temp and precip outlook for my Boise house and for Bogus below.
Ocean swells tracking across Pacific as it brings in next week’s AR.
https://magicseaweed.com/North-Pacific-Surf-Chart/80/?type=swell
7-day total precipitation for Dec 24-31. And OpenSnow outlook for start of the new year. Happy New Year 2023 !!!
Snow Weather and Flow 