Latest El Nino forecast provides warm winter outlook for NW
Oct 21, 2015, 6:03 PM | Updated: Oct 22, 2015, 5:06 pm
El Nino is proving weather predictions correct, maintaining its rank among the three warmest on record, which means the Northwest won't likely get any relief from its current drought. (National Weather Service)
(National Weather Service)
El Nino is proving weather predictions correct, maintaining its rank among the three warmest on record, which means the Northwest won’t likely get any relief from its current drought.
The latest winter weather outlook from the National Weather Service’s Climate Prediction Center (CPC) was recently released and included what is anticipated for this winter in the Pacific Northwest. The CPC monitors El Nino and its sibling La Nina, as well as neutral conditions that play a significant role in the CPC seasonal weather outlooks.
El Nino conditions in the eastern Pacific tropical waters remain quite warm – among the warmest three on record going back to 1950. Sea-surface temperatures in these tropical waters continue to be more than 2.0 degrees Celsius above average. Other such warm El Ninos include the winters of 1982-83 and 1997-98. These similar warm El Nino conditions are expected to continue through this winter season.
What does that mean?
For Western Washington, the CPC winter seasonal outlook maintains a strong likelihood of warmer than average temperatures. For precipitation, the latest outlook indicates near average, or tips the odds toward below average precipitation through this winter.
This combination is not good news for the mountain snowpack. The warmer than average temperatures will likely result in a higher average mountain snow level. This trend translates into an increased likelihood of a below average mountain snowpack, particularly at lower elevations. Yet, a repeat of last winter’s meager mountain snowpack is not anticipated.
Related: Washington is still in a drought
The history of El Nino for Pacific Northwest winter seasons has a good correlation with warmer than average temperatures. Yet for precipitation, it is important to note that there is no clear trend. For instance, the El Nino of 1982-83 was wetter than average while 1997-98 was drier.
Of additional interest, September was the first month that Sea-Tac Airport had a below average monthly temperature since February 2014. Sea-Tac was 0.8 degrees F below average last month.
NOAA highlighted today that nationally, September was the second warmest on record, second only to September 1998. Last month was 3.7 degrees Fahrenheit above the 20th century September average temperature. Worldwide, September was the warmest month on record.
The winter seasonal weather outlook will continue to be fine-tuned this fall. For the latest seasonal outlooks, click here.
