AZ Winter Predictions: Drought Likely To Continue Due To La Niña

PHOENIX, AZ — Winter in the Phoenix and Tucson areas is shaping up to be warmer and drier than usual, due to a second year in a row of La Niña.

The National Oceanic and Atmospheric Administration's Climate Prediction Center released its 2021 Winter Outlook Wednesday, with broad predictions for December through February. The NOAA is a division of the National Weather Service.

“The Southwest will certainly remain a region of concern as we anticipate below-normal precipitation where drought conditions continue in most areas,” said Jon Gottschalck chief of the Operational Prediction Branch of NOAA’s Climate Prediction Center.

The prediction center is seeing modest odds of a drier-than-usual winter across the southern three-quarters of Arizona as well as modest odds of a warmer-than-usual winter for the entire state.

In contrast, below-normal temperatures are expected across the northern United States, with wetter-than-usual conditions in some parts of the northern U.S., including the Pacific Northwest, northern Rockies, Great Lakes, Ohio Valley and western Alaska. These patterns are typical in a La Niña year. La Niña is a phenomenon with persistent colder-than-normal sea surface temperatures across the central and eastern Pacific, according to the National Weather Service.

While Phoenix and Tucson typically receive pretty sparse rainfall during the season anyway, winter rainfall can have an impact on the ongoing drought and a drier-than-usual winter could make for worsening drought conditions, Gottschalck said in a phone interview.

Even with an active Monsoon this year, drought conditions still persist across much of Arizona. And a dry winter could mean more fires in the coming spring and summer, Gottschalck said.

The prediction center's Winter 2021 drought outlook map calls for worsening or developing drought conditions across Arizona.

As of Tuesday, all of southern Arizona was facing abnormally dry or moderate drought conditions, according to NOAA.

NOAA updates its seasonal predictions each month, with the next update set for Nov. 19.