Weather outlook for winter and 2021

Weather forecast: La Nina is here, may last through winter
Posted at 1:23 PM, Dec 28, 2020

TUCSON, Ariz. (KGUN) — On top of everything else in 2020, it was one of the hottest and driest years on record for our area. Another warmer than normal year looks likely in 2021, but the Climate Prediction Center leaves at least some room to hope for a little more rain.

2020 brought us the two hottest months ever recorded in Tucson. July set the record first and then was replaced by August. 2020 also had the most 100-degree days in a year. The second driest monsoon on record upgraded our area into an exceptional drought.

“2019 was a dry monsoon and everyone was calling it a ‘nonsoon’ and then 2020 came around and we really found out what a ‘nonsoon’ really is,’ said National Weather Service Warning Coordination Meteorologist Ken Drozd. “Two consecutive dry monsoons will really put you in a deficit of precipitation.”

Drozd says the warmer and drier than normal pattern will likely continue for winter thanks to La Nina.

“That tends to steer storm systems generally to our north.”

La Nina is part of the El Nino-Southern Oscillation in the Pacific Ocean. In La Nina, cooler water pools up near South America. This affects high-level winds and often means our area must watch winter systems passing us by to the north.

“We can every once in a while, have one that will dip a little farther south and bring us some precipitation, and that’s bound to happen a few times. It’s just not as likely to happen as many times if we weren’t in a La Nina pattern.”

La Nina is projected to last into the spring. Right now, it’s a toss-up how wet or dry monsoon 2021 will be.

“El Nino or La Nina, neither one has a high correlation with monsoon precipitation, monsoon is a lot harder to predict in the long term.”

As far as temperatures go, warmer than normal seems to be a safe bet for 2021. The Tucson area hasn’t had a cooler than normal year since 1998.

“Seem to be maintaining at least warmer than average and the last several years have been top five or at least close to it.”

On the bright side, Warmer temps don’t necessarily mean dry weather. Drozd says hoping for more rain next monsoon and winter won't hurt our chances one bit.

“We can hope for more monsoon precipitation right off the bat that is something we’d like to see.”