In week 1 (top), the CFS v2 is indicating extremely warm temperatures to be present across all of North America- an uncommon feat. The only exception is Alaska, which is forecasted to be much below normal. The unusually warm spring theory looks to be off to a great start per these CFS v2 forecasts.
Week 2 (bottom) still has a huge area of much above normal temperatures, but as the forecast period increases, so does the uncertainty, thus the lessened intensity of the temperature forecasts. However, Alaska still remains much below normal.
In week 3 (top), a large swath of above normal temperatures still exists over the North America, but here's the thing- notice how Alaska is no longer cold. This could very well mean that the infamous Alaskan Vortex could be replaced by a ridge, thus lower temperatures in the US. But this is not reflected in the US, meaning that some other indices may be influencing the pattern to disprove the possible below normal temps and keep them above normal.
The same situation exists in week 4.
Week 2 (bottom) still has a huge area of much above normal temperatures, but as the forecast period increases, so does the uncertainty, thus the lessened intensity of the temperature forecasts. However, Alaska still remains much below normal.
In week 3 (top), a large swath of above normal temperatures still exists over the North America, but here's the thing- notice how Alaska is no longer cold. This could very well mean that the infamous Alaskan Vortex could be replaced by a ridge, thus lower temperatures in the US. But this is not reflected in the US, meaning that some other indices may be influencing the pattern to disprove the possible below normal temps and keep them above normal.
The same situation exists in week 4.