In January, nearly all states west of the Rocky Mountains, west US, saw wind speeds at least 20% below their long-term monthly average. Some areas experienced wind speeds nearly 50% below usual in January.
Texas, California, and parts of the Midwest were particularly hard hit given their large concentration of operating wind assets.
Project owner Pattern Energy said the low wind speeds meant it lost 5% of its annual expected production in the first quarter in the western US and Texas.
Vaisala blamed a cycle of warm air, caused by the El Niño weather pattern over the Pacific Ocean, and above-average winter temperatures due to the polar jet stream being unusually far north.
In contrast, wind speeds at 100 metres in central Canada and some US border states were as much as 20% higher than average during Q1. Weather is expected to return to near normal in the second quarter.