Another Long Period of No Storms Coming

A powerful storm is moving through the Northwest today and will move into the central Great Basin tomorrow. M posting from Wednesday covered this storm nicely. There will be a couple more of this type of storm in the Northwest that will move southeast next week but not as strong as the current one. And each one will go a little farther east as well. Then a rather large ridge will build the later half of next week.

The impressive cold storm of a couple of days ago, which moved through California then Arizona, then contributed to one of the biggest snow events in years in the central Plains yesterday, is the last storm that has had any great impact in much of California and Arizona. There is one exception to this and that is the current storm in the Northwest. This will bring a few snow showers to northern Arizona tomorrow afternoon. Besides that it looks like California and Arizona will be experiencing another long period of no rain or snow for at least the next seven to nine days.

I was asked in a few media interviews earlier in the week whether the storm occurring then was going to help the snowpack and thus the water situation for California. One storm never makes a season, but I said I believe that the Sierra snowpack will continue to run below normal the rest of the winter into the spring. First of all going into the storm earlier in the week that average water equivalent locked up in the snowpack was only running about 70 percent of normal. We are in historically some of the snowiest times of the winter season, so the storm that came through was not out of the ordinary and ordinary certainly was not going to help the current snowpack. The charts below show snow water content in the Sierra by region by historically driest, wettest, last year, normal and current year as a percent of normal by April 1. The purple line is the current year.

With the likelihood of no snow at least in the next week, the gap between normal and current water equivalent will grow. Given the overall weather conditions with the NAO and La Nina, the chance of getting back to normal is very, very small this snow season. The chance of a bigger gap is higher than a smaller gap between this year and normal as well.