A La Nina winter seems a sure thing
COLLEGE PARK, MARYLAND
November 9, 2017
• New forecast gives it up to a 75 percent chance
• More precipitation in northern tier of states, less in southern
The weather condition called “La Niña” is given a 65 percent to 75 percent chance of influencing California and West Coast weather this winter, according to the latest forecast, released Thursday morning by the Climate Prediction Center of the National Centers for Environmental Prediction.
During October, weak La Niña conditions emerged as reflected by below-average sea surface temperatures across most of the central and eastern equatorial Pacific Ocean, the report days.
The weekly Niño indices were variable during the month, with sub-surface temperatures remaining below average during October, “reflecting the anomalously shallow depth of the thermocline across the central and eastern Pacific,” it says.
“Overall, the ocean and atmosphere system reflects the onset of La Niña conditions,” the report says.
For the remainder of the Northern Hemisphere fall and winter 2017-18, a weak La Niña is favored in computer modeling. The consensus of forecasters is for the event to continue through approximately February-April 2018.
La Niña is likely to affect temperature and precipitation across the United States during the upcoming months. The outlooks generally favor above-average temperatures and below-median precipitation across the southern tier of the United States, and below-average temperatures and above-median precipitation across the northern tier of the United States.