FOX31 Denver

How La Niña impacts the winter jet stream

DENVER (KDVR) — The Pacific Ocean along the equator is cool off the west coast of South America, meaning La Niña is still in effect. La Niña or El Niño pertains to the sea surface temperatures along the equator in the Pacific Ocean, with warmer temperatures being El Niño and cooler being La Niña. 

This difference in water temperature impacts where and how much rain falls and how the winds blow around the equator. This change has an impact on other global weather patterns. We know that in a La Niña phase certain types of weather are more prevalent across the U.S.

During La Niña, the Polar Jet Stream tends to arch above the Pacific Northwest and dip below the Great Lakes. This brings wetter weather to the Northwest and cooler temperatures to Montana and the Dakotas. Extra moisture is also pushed across the Ohio River Valley and the Upper Mississippi River Valley, meaning a wetter forecast. 

The southern half of the country, from California to the Carolinas, tends to be drier. With warmer conditions stretching from Texas through the Southeast U.S. 

This leaves Colorado with a somewhat average winter. Drier conditions can push in from the south and cold shots sliding in from the north can be expected throughout the winter. La Niña looks to come to an end as the spring, hopefully bringing extra moisture back to the Front Range.