According to National Geographic, La Nina is formed "by a build-up of cooler-than-normal waters in the tropical Pacific, the area of the Pacific Ocean between the Tropic of Cancer and the Tropic of Capricorn. Unusually strong, eastward-moving trade winds and ocean currents bring this cold water to the surface, a process known as "upwelling."
What does “La Nina” mean?
- La Nina means "the little girl"
- La Nina's full name is El Nino-Southern Oscillation (ENSO)
- It is the counterpart of El Nino – a pattern that warms waters in the Pacific
What happens in La Nina years?
- During periods of La Nina, sea-surface temperatures across the equatorial eastern central Pacific Ocean will be lower by 3 to 5 degrees centigrade.
- La Nina brings warmer-than-normal sea-surface temperatures to the southern Pacific Ocean around northern Australia, New Guinea and the islands of Indonesia.
- The pattern generally lasts around five months.
- La Nina causes above-average precipitation across the northern Midwest, the northern Rockies, Northern California, and the southern and eastern parts of the Pacific Northwest.
- It will be dryer in the Southwest and Southeast.
- It triggers stronger-than-average hurricanes in the Atlantic and fewer hurricanes in the Pacific.
- The Southeast and Mid-Atlantic will see warmer-than-average temperatures during a La Nina winter.
- In Canada, La Nina brings more cold and more snow.
- This is the second consecutive La Nina winter.
- Last year's episode lasted only from November to February which was unusual.
- Texas A&M University agricultural economist Bruce McCarl told USA Today that La Nina years are often bad for agriculture in Texas. The same goes for other parts of the United States during a La Nina year.