What impacts do El Niño and La Niña have on tornadic activity across the country?
• Since a strong jet stream is an important ingredient for severe weather, the position of the jet stream determines the regions more likely to experience tornadoes. More Info! Tornado information from the National Weather Service Contrasting El Niño and La Niña winters, the jet stream over the United States is considerably different. During El Niño the jet stream is oriented from west to east over the northern Gulf of Mexico and northern Florida. Thus this region is most susceptible to severe weather. During La Niña the jet stream extends from the central Rockies east- northeastward to the eastern Great Lakes. Thus severe weather is likely to be further north and west during La Niña than El Niño.
