El Niño & La Niña (El Niño-Southern Oscillation)

Vertical perspective map of ocean temperatures across the tropical Pacific Ocean in March 2019 compared to average

El Niño Advisory

A weak El Niño is likely to continue through the Northern Hemisphere summer 2019 (65% chance) and possibly fall (50-55% chance). Weak events can still produce moderate or strong temperature or precipitation impacts in some places, but such impacts are less likely overall during weak events.  

More ENSO status information
Latest official ENSO update
Latest ENSO blog update

(image at left) Difference from average sea surface temperatures at the equator in the tropical Pacific. 

El Niño and La Niña are the warm and cool phases of a recurring climate pattern across the tropical Pacific—the El Niño-Southern Oscillation, or “ENSO” for short.

The pattern can shift back and forth irregularly every two to seven years, and each phase triggers predictable disruptions of temperature, precipitation, and winds.

These changes disrupt the large-scale air movements in the tropics, triggering a cascade of global side effects.

More about El Niño
What is El Niño in a nutshell?
Understanding El Niño (video)
FAQs
ENSO alert system criteria
ENSO essentials
Educational Resources on ENSO

El Niño is anchored in the tropical Pacific, but it affects seasonal climate "downstream" in the United States. This map shows some of the precipitation and temperature impacts we may experience if El Niño develops this winter as predicted, but not all impacts occur during every event, and their strength and exact location can vary. 

Typical U.S La Niña impacts
Winter temperature and precipitation
Hurricane season impacts
Current outlooks
6-10 day outlook
8-14 day outlook
1-month outlook
3-month outlook

El Niño and La Niña have their strongest impact on global climate during the Northern Hemisphere winter.  The map at left shows some of the precipitation and temperature patterns that might occur this coming winter if El Niño develops as predicted. However, not all impacts appear during every El Niño event.  

More information
ENSO's cascade of global impacts
The Walker Circulation
More maps of global impacts of La Niña and El Niño

Map of U.S. and Canada showing the winter temperature anomalies common during positive phases of the PNA

The Pacific-North American Pattern: the stomach sleeper of the atmosphere

April 22, 2019

Stand aside polar vortex!  The PNA may be the most important atmospheric circulation pattern you've never heard of.  

Read more

(left) Temperature anomalies during PNA-positive winters from 1979-80 to 2018-19.