La Nina means "The Little Girl". La Nina causes the Eastern Pacific
to be much colder than usual. This change in the oceans temperature
can then cause changes in the weather due to the changes in the oceans
temperature. The opposite of La Nina is El Nino. El Nino causes the ocean
water temperature to be warmer than usual. El Ninos usually
occur more often than La Nina. A La Nina typically occurs every three to
five years and they usually last from nine to twelve months although some
La Ninas have lasted as long as two years.
The effects on the United States from La Nina
La Nina can cause the Pacific Northwest area to have much wetter than
normal conditions. The South will usually see dryer and warmer weather
than they would usually see in the winter. Temperatures are usually
warmer than usual in the Southeast and colder than normal in the Northwest.
How do we know if a La Nina is present?
Scientists use many tools including water temperature monitoring buoys
and satellites in addition to computer models to help predict and
detect La Ninas.