La Nina Officially Arrives – What Does This Mean for Winter?
It has been talked about for months and now it is officially here – La Nina has arrived. According to the National Weather Service’s Climate Prediction Center Diagnostic Discussion, the arrival of La Nina was declared yesterday, November 10th. NOAA says it is weak and may only last a few months.
La Nina occurs when the waters of the Pacific Ocean show a general trend of cooling, the opposite of an El Nino. During La Nina periods, the Jet Stream is less active in the Southern U.S. This usually leads to less storms systems and below average precipitation. Cooler than normal weather typically occurs across the northern tier of the country and occasionally wetter periods as well. The trends of an El Nino or La Nina often take some time to establish, so it is likely to see its effects felt in the coming months. Imagery from NASA’s Jet Propulsion Laboratory has started to show the cooler water temperatures, although the cooling is not nearly as strong as it was during the intense La Nina from the Winter of 1997-1998.
— NOAA Climate.gov (@NOAAClimate) November 10, 2016
La Nina was discussed and forecast previously by the Climate Prediction Center in the November and Fall/Winter long range forecasts. The next seasonal outlook will be issued next week on November 17th.
For WeatherNation: Meteorologist Mace Michaels