La Niña and Arctic Oscillation Bring Winter Storms
Extreme winter weather hit 44 states and caused power outages for millions of Americans. Texas reported 10 deaths due to the cold temperatures.
Smith's ESGradings has conducted decades of research on climate change. This year's events are due, in part, to La Nina.
While the current La Niña is expected to be moderate to strong, this winter's forecast is highly variable, according the Smith's Event Risk Research.
Smith's Research has tracked climate changes over the past 30 years and documented how these major environmental factors influence credit quality of municipal bonds. For example, La Niña has undergone significant changes over the past 20 years, which has shifted monsoons in the Southwest and storms in the Northwest.
Moreover, Smith's Research was among the first to show how changes to the mid-ocean current(s) sent moisture up into the atmosphere far out to sea rather than onshore because of global climate change.
Since 1950, the National Weather Service of the National Oceanic and Atmospheric Administration (NOAA) reported there have been 4 moderate (1955-56, 1970-71, 1984-85, and 2010-11) La Niñas. "All of these were among the coldest third of winters," the National Weather Service said.
NOAA's database shows there have been 7 strong (1949-50, 1973-74, 1975-76, 1988-89, 1998-99, 1999-2000, and 2007-08) La Niñas since 1950. Six of these 7 La Niñas were either among the warmest third (3 La Niñas) of winters or had near-normal temperatures (3 La Niñas).
"In addition, there has been no temperature trend for winters during the past 15 years," NOAA said. "There has been nearly an even split between warmer-than-normal and colder-than-normal."
A moderate to strong La Niña is favored to develop during the remainder of the Northern Hemisphere autumn and peak out in either December or January. Due to this, the CPC winter temperature and precipitation outlooks are consistent with typical La Niña impacts.
The last time that there was a La Niña winter was 2017-18 (weak).
Arctic Oscillation (AO)
Besides La Niña, this winter will also be affected by Arctic Oscillation (AO) and North Atlantic Oscillation (NAO). These oscillations can influence the number of Arctic air masses that penetrate into the Southern United States and nor'easters on the East Coast.
Eastern Pacific Oscillation (EPO) — This can affect the location of where the cold air masses will be located in the northern United States.
Madden-Julian Oscillation (MJO) — This can affect both temperatures and precipitation in the weekly time scale.
Texas Hit Hardest
Over 2 million people were without power in Texas due to the cold weather. The Electric Reliability Council of Texas (ERCOT)—an agency that oversees the state's power grid—introduced rolling outages as "extreme winter weather" forced generating units offline. According to the group about 10,500 MW of customer load was shed at the highest point. This is enough power to serve approximately two million homes. Frozen wind turbines and limited gas supply prompted the rolling outages.
Elsewhere in the U.S., outages hit more than 290,000 and 146,000 customers in Oregon and Virginia respectively. North Carolina, Louisiana and Kentucky are also reporting significant outages, with around 35,000, 18,000 and 12,000 customers without power.
Top Areas by Outages
Last Updated 2/16/2021, 10:22:28 AM
On Sunday evening, President Joe Biden declared an emergency in Texas, enabling the Department of Homeland Security and the Federal Emergency Management Agency to coordinate disaster relief efforts and provide assistance to people affected by winter storms.