Effects of El Nino and La Nina

El Niño

Warmer than normal Pacific Ocean temperature.

La Niña

Cooler than normal Pacific Ocean temperature.

Trade Winds

Weaken during El Niño and strengthen during La Niña.

Upwelling off South America

Decreases (fewer nutrients) during El Niño and increases (more nutrients) during La Niña.

Australia - El Niño Effects

Drought, wildfires.

Australia - La Niña Effects

Heavy rain, major flooding.

Southeast Asia / Indonesia - El Niño Effects

Strong drought, fires.

Southeast Asia / Indonesia - La Niña Effects

Wet conditions, flooding.

West Coast of South America (Peru, Ecuador) - El Niño Effects

Heavy rain, flooding.

West Coast of South America (Peru, Ecuador) - La Niña Effects

Dry conditions.

Southern U.S. - El Niño Effects

Wetter winter.

Southern U.S. - La Niña Effects

Drier winter.

Southwestern U.S. - El Niño Effects

Drier, warmer.

Southwestern U.S. - La Niña Effects

Drought + wildfire risk.

India / Monsoon - El Niño Effects

Weaker monsoon.

India / Monsoon - La Niña Effects

Stronger monsoon.

Atlantic Hurricanes - El Niño Effects

Fewer storms.

Atlantic Hurricanes - La Niña Effects

More & stronger storms.

Pacific Hurricanes - El Niño Effects

More storms.

Pacific Hurricanes - La Niña Effects

Fewer storms.

Western Pacific (Typhoons) - El Niño Effects

Storm tracks shift east.

Western Pacific (Typhoons) - La Niña Effects

More storms near SE Asia.

Australia - Drought & Fire Risk - El Niño Effects

High wildfire risk.

Australia - Drought & Fire Risk - La Niña Effects

Less wildfire risk.

Indonesia - Drought & Fire Risk - El Niño Effects

Extreme fires.

Indonesia - Drought & Fire Risk - La Niña Effects

Low fire risk.

Amazon - Drought & Fire Risk - El Niño Effects

Drought + fires.

Amazon - Drought & Fire Risk - La Niña Effects

Flooding, fewer fires.

Coral Reefs - El Niño Effects

Coral bleaching from heat.

Coral Reefs - La Niña Effects

Less bleaching.

Ocean Nutrients - El Niño Effects

Drop (less upwelling).

Ocean Nutrients - La Niña Effects

Rise (more upwelling).

Fish Populations (Peru/Chile) - El Niño Effects

Poor fishing.

Fish Populations (Peru/Chile) - La Niña Effects

Better fishing.

Wildlife Migration - El Niño Effects

Fish & birds move away from warm waters.

Wildlife Migration - La Niña Effects

Species return to nutrient-rich areas.

Agriculture - El Niño Effects

Drought losses in many regions.

Agriculture - La Niña Effects

Flood damage in others; better monsoons.

General - El Niño

Warm Pacific.

General - La Niña

Cool Pacific.

Global Climate - El Niño

More floods in Americas, more drought elsewhere.

Global Climate - La Niña

More rain in Asia/Australia, more drought in Africa/US Southwest.

Hurricanes - El Niño

Fewer (Atlantic).

Hurricanes - La Niña

More (Atlantic).

Fishing - El Niño

Bad (low nutrients).

Fishing - La Niña

Good (high nutrients).

What are the jet streams?

Fast-flowing, river-like air currents high in the atmosphere that steer weather systems.

How does El Niño influence winter weather in the U.S.?

It shifts the atmosphere's storm-generating air eastward, affecting jet stream patterns.

What happens to the subtropical jet stream during El Niño?

It becomes stronger and extends farther east across the Southern U.S., bringing more moisture.

What weather conditions are associated with El Niño in the Southern U.S.?

Wetter-than-average and cooler-than-average conditions.

How does the polar jet stream behave during El Niño?

It is pushed farther north into Canada, resulting in warmer and drier conditions in the Northern U.S.

What is La Niña's effect on the Pacific pattern?

It reinforces the normal cool-east, warm-west pattern but with stronger winds.

How does the polar jet stream change during La Niña?

It dips farther south over the Northwest and is often more erratic across the continent.

What weather conditions does the Northern U.S. experience during La Niña?

Cooler-than-average and wetter-than-average conditions, with increased storminess.

What are the typical conditions in the Southern U.S. during La Niña?

Warmer-than-average and drier-than-average, increasing the risk of drought and wildfires.

What months are primarily affected by El Niño and La Niña in North America?

December to February (winter months).

What is the primary mechanism through which El Niño and La Niña affect weather?

Their impact on the jet streams.

What is the typical impact of El Niño on the Gulf Coast?

Increased moisture leading to wetter conditions.

What regions of the U.S. are typically affected by La Niña's cooler and wetter conditions?

The Northwest and Northern Plains.

What is a significant consequence of La Niña in the Southern Tier of the U.S.?

Increased risk of drought and wildfires.