Western U.S. Snowpack Update – March 8, 2018

The current snowpack across the Western U.S. is much different across northern areas than across central and southern areas.  Overall, February was a more active month across the entire Western U.S. with most areas experiencing gains in the snowpack.  However, March has turned more “divisive” again so far with some areas experiencing above average snowfall, and others (such as Colorado) experiencing much drier conditions.




As of March 8th, snowpack in Colorado is 75-90% of average across the northern half of the state, and 50-60% of average across the southern half of the state.  The state is projected to experience below average precipitation in March, which unfortunately means it will be very difficult for areas to come anywhere close to experiencing average snowpack, even if April and May turn out to be wetter. 

A good portion of the state, excluding the northern/central Continental Divide region, is now experiencing drought conditions, with severe to extreme drought now occurring across southern parts of the state.  If these areas do not experience above average precipitation this spring, then drought conditions would likely worsen heading into the summer, and the wildfire risk would also increase for many areas, such as the San Juan Mountains.



Elsewhere across the Western U.S., Utah and California are also experiencing well below average snowpack.  The late winter pattern is now turning more favorable for California with March expected to have above average precipitation, but it will likely be too little too late for building up the snowpack.  If above average precipitation were to continue into the spring for California, then that would certainly help from a drought and wildfire perspective, but that remains to be seen as the long range pattern does not offer any clear signals for the Golden State.  Utah is more likely to struggle making up ground in the snowpack and moisture department in this spring, and could end up with worsening drought conditions heading into the summer.

The best snowpack relative to average is across the Northern Rockies, including Wyoming, Montana, and Northern Idaho.  Snowpack in Western Montana is 125-165% of average, and local skiers at places like Big Sky are reporting their best skiing conditions in years.  More importantly, the increase in snowpack and moisture with a favorable moisture outlook for the spring should result in lower wildfire potential this summer compared to last summer, which was a bad fire year for Montana.  

For the Pacific Northwest, the Washington Cascades are near average in snowpack, while the far northern Cascades near the Canadian border are above average.  Farther south, the snowpack in Oregon is in much worse shape compared to Washington.  In general, the Pacific Northwest looks to be more favored for precipitation this spring, and at this point Oregon could use the moisture more than Washington.

It will be interesting to see how things play out this spring, but there is a significant difference in snowpack health between the northern states and the southern states across the Western U.S., and this could have a major impact on water supply, drought, and fire danger this summer.

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