The National Oceanic and Atmospheric Administration declared that La Niña conditions are now present in the East Tropical Pacific as of Sept. 10, 2020 and will likely remain in place through winter. So what does this mean for Colorado?
If you’re not familiar with La Niña, it is a phase of the El Niño Southern Oscillation Cycle. This measures ocean and atmospheric temperatures over the East Central Equatorial Pacific. When conditions are warmer than normal we are in an El Niño phase. When conditions are cooler than normal we are in a La Niña phase. Each of these phases has impacts on the climate of the U.S. and the world.
El Niño years typically bring a wetter winter to Colorado:
La Niña years typically lead to a drier winter in Colorado:
According to the NOAA the current La Niña has a 75% chance of lasting through the winter. That would likely lead to increased drought conditions and poor snow-pack going into Spring.