La Niña conditions are expected to strengthen through the winter, according to National Oceanic and Atmospheric Administration weather forecasters. “For the Northern Hemisphere, that’s the headline,” says Jon Gottschalck, three-month forecaster for NOAA’s Climate Prediction Center.
For December through February, that means colder temperatures in the U.S. starting in California, up through the Pacific Northwest and moving east in to the Northern Plains and the Northeastern states. It also will chill the lower portion of the United States from New Mexico to the Southeastern states, Gottschalck notes.
As for total precipitation, the South and Southeast will remain dry, he adds. The odds are good for above average precipitation in the Pacific Northwest, then moving east in to the Rockies and the northern portion of states and the Eastern Great Lakes area.
Given that La Niña is sticking around, it will likely make the already horrific drought in Oklahoma and Texas worse, as well as the dry conditions facing southeastern states, says Jake Crouch, climate scientist with NOAA’s National Climatic Data Center.
Texas and Oklahoma did have a “wetter than normal October” but Crouch adds that the Southern Plains and the Southeast would need 15 inches of rain to end the drought.
In fact, the drought could expand north into Kansas, and even parts of Iowa and Minnesota, although snowfall could help Northern areas. The dry fall, typical of a La Niña, could reduce the prospect of spring flooding following heavy snow melt.
From a globe perspective, Crouch reports October was the eighth warmest since record keeping began in 1880. Arctic sea ice extent was the second smallest extent on record for October at 23.5 percent below average.
Global temperature highlights: Year to date
- The combined global land and ocean average surface temperature for the January – October period was 0.95 F above the 20th century average of 57.4 F, making it the 10th warmest such period on record.
- The January – October worldwide land surface temperature was 1.53 F above the 20th century average, the sixth warmest such period on record. The global ocean surface temperature for the year to date was 0.74 F above the 20th century average and was the 12th warmest such period on record.
Polar sea ice and precipitation highlights
- The average Arctic sea ice extent during October was 23.5 percent below average, ranking as the 2nd smallest October extent since satellite records began in 1979. The extent was 846,000 square miles below average and 127,000 square miles larger than the record low October extent set in 2007.
- On the opposite pole, the October Antarctic monthly average ice extent was 1.2 percent above the 1979–2000 average, the 12th largest on record.
- Despite a record-breaking snowstorm in the U.S. Northeast, Northern Hemisphere snow cover extent during October was below average, and ranked as the 15th smallest October snow cover extent in the 44-year period of record. The North America and Eurasian land areas both had below-average snow cover during the month.