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Forecast Blog

Part 2 CoSig

By March 19, 20216 Comments

This year we have two main storm systems that I call co-signature storms. They are 13 days apart and have hit every cycle. Part two of the cosignature storm begins on March 26 for Colorado. Below is the two day snowfall total valid for Sunday the 28th. This kicks off the second active part of the pattern towards the end of cycle 4.

The next sequence of photos represent the energy and vorticity of the 500mb chart. Noticed the similarities and differences. Where the ridges are as well as the troughs. Teleconnections and the values that those teleconnections, positive or negative, affect the shape and energy.

Below is the projected GFS for the 27th. Again, look at the similarities and differences. Most of the teleconnections this cycle are positive, the AO, AAO, NAO, and we are still in a moderate La Niña. The jetstream is beginning to weaken and will eventually recede north.

I was hopeful the storm would be strong enough to include the Tahoe region, but it’s not looking good. The weakening jetstream looks like it’s going to keep the storm north, like it did in cycle 1.
Thanks for spending a few minutes reading the blog and as always if you have any questions submit them in the comment section or shoot me an email to


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