Idaho Museum of Mining & Geology – Water Snowpack and Drought Update

Mid-March heat dome is melting Idaho’s snow way too earlier. Even the higher elevations are starting to melt and rivers are rising. Here’s an update of how we got here and the 3-D Drought that put us in this unique position. Winter 2026 will be remembered as a winter with near normal water year to date precipitation, elevation distributed snowpacks, warm temps and now a spring heat dome that is melting the snow and pushing rivers up, except in the Owyhee because there is very little snow to melt. Let’s hope cooler weather returns by month’s end and a few cool wet storms in Aril arrive to save our remaining higher elevation snow to melt later this spring. A wet spring is needed this year. Another record dry Apr-May-Jun like last year, would not be good. Spring rain are needed now while the snow is melting to increase runoff. Even a late spring rain event like the one that occurred June 1, 1963 pushing the Owyhee River up to 5000 cfs, would be sweet. 1963 is an analog year for this year which also had very low snow runoff in the Owyhee. Lessoned learned from watching Owyhee River runoff – it often sets the stage for runoff trends seen elsewhere in southern Idaho.

2025 Summary & 2026 Outlook

Here’s a summary of what happened to last year’s runoff because of near record dry spring. Summer is over and Fall precip is moving with a huge Atmospheric River tail that stretches over 1000 miles to SE Asia. Winter Outlooks for 2025-26 with analog years based on similar ocean conditions; we’ll watch and updated as we progress into winter. For now enjoy the wet weather as we start the new water by building our mountain snowpack.

April Fool’s Day Storm

Wow – what just hit us? Here’s a summary of the key indicators I was watching leading up to this storm. Never stop learning and watching the weather to better understand what’s happening here, around us and why.

The PNA started hinting at weather system brewing back on Mar 13 with sharp decrease and biggest drop since last Nov storm. A Buoy Pop was also marked on my calendar from around same time. Always nice to see in agreement of indicators two weeks out.

Here’s current PNA which shows the Apr 1 drop, then going positive which means return to high pressure in early April.

Severe Weather Europe from Mar 31 provides a good explanation, just need to read between the Ads. They summarize the springtime battle between winter and summer patterns fighting for the lead. This probably led to the isolated weather pattern and intense storm with 10” falling at Brundage and a couple at Bogus Monday morning followed 24 hours later with 10” at Bogus while Tamarack & Brundage received a little Tuesday morning. OpenSnow forecast weather radar nailed storm hitting Bogus early Tuesday morning and not pushing north. I should have been watching the radar loop for Brundage storm. https://www.severe-weather.eu/global-weather/april-2025-forecast-stratospheric-polar-vortex-impact-cold-air-united-states-canada-fa/

Severe Weather also provides a good summary of early April weather and why we’re gonna be warm & dry in the West and the East needs to prepare for colder and wet. Many other models are picking up intensity of this event now. Stay safe.

Spring skiing returns this weekend to Idaho’s southern resorts with freezing night temps and warm day temps. Enjoy while the nights are still freezing in the mountains.

This also means the rivers will rebound with the warmer temps. Be safe out there – a friend is on a solo trip down the Main Salmon this week.

March Snow Depths

February brought snow measured in feet. A summary of snow depths at many ski locations across the state follows. Here are some quick facts about February’s snowfall at Bogus Basin. March 1 Bogus Basin snow depth of 83″ is the 11th deepest since 1944. SWE increase of 8.7″ during February was the 8th highest since measurements start in 1944. The snow depth on Feb 1 was 50″ and increased to 83″ by months end; this is tied for 2nd greatest change with 1949. February 2019 was huge with an increase from 36″ to 95″ by the end of February.