Weather Report – October 2022

The water year ahead

Hydrologists use the term ‘water year’ to describe the water supply year from October 1 – September 30. In this way of viewing it, the year begins with the development of the snowpack, increasing through the winter until freshet, followed by the irrigation season which mostly wraps up in September. It’s a particularly good way of thinking about the year in the Okanagan, because so much of our supplies depend on the snowpack.

One of the biggest factors is the El Niño/Southern oscillation (ENSO). The forecast this year is for La Niña conditions to continue through the autumn, decreasing to a 54% chance of La Niña in January – March 2023. This will be the third La Niña winter, and it is unusual for La Niña conditions to continue for this extended length of time.

La Niña winters in the Okanagan are typically associated with greater-than normal amounts of precipitation and below normal temperatures.

The following is an excellent post from the U.S. government Climate.gov website about the potential (or not!) affect of climate change on ENSO: https://www.climate.gov/news-features/blogs/enso/enso-and-climate-change-what-does- new-ipcc-report-say .