La Nina is Spanish for “the little girl”. It’s the counterpart of El Nino (“the little boy”). El Niño and La Niña are climate patterns in the Pacific Ocean that can affect weather worldwide.
Trade winds blow toward the west along the equator, taking water from South America towards Asia. To replace that warm water, cold water rises from the depths — a process called upwelling. El Niño and La Niña are two opposing climate patterns that break these normal conditions. Scientists call these phenomena the El Niño-Southern Oscillation (ENSO) cycle. El Niño and La Niña both have global impacts on weather, wildfires, ecosystems, and economies. Episodes of El Niño and La Niña typically last nine to 12 months, but can sometimes last for years. We are now in the 2nd year of the current La Nina.
The top map shows sea surface water temperature anomaly – or difference from average. Blue indicates where the water is cooler than average and yellow/orange indicate where the water is water than average.
You can see the blue along the Equator west of South America. This is the trademark look of La Nina. We also have colder than average currents along the west coasts of both North and South America.
Just looking at this map…I see the colder than average water west of the Pacific NW. They have a prevailing westerly wind, so it would suggest that it might be a cool pattern for cities like Seattle. So, I go and look up Seattle’s climate summaries. I see that April was 4.2° cooler than average and May 1-8 was 5.1° cooler than average. Fits the pattern.
I also see that the Gulf of Mexico is warmer than average. I checked – it’s about 1 to 3° warmer than average. So, I call up the climate data from Pensacola FL. I see that April was 2.2° warmer than average and May 1-8 was 4.6° warmer than average. Air temperatures often correlate to the water temps. of nearby bodies of water (oceans) when the prevailing wind comes off that body of water.
All that warm water in the Gulf and along the East Coast is fuel for a significant hurricane season this summer/fall. That’s often the case during La Nina.
Also, if the Gulf States are warmer than average and the northern U.S. is colder than average – it makes a bigger contrast of temperatures and that can fuel thunderstorms in the spring and summer.
Here’s the severe weather reports from Monday. Minnesota got clobbered…115 reports of severe criteria hail and 12 of those were hail 2 to 3 inches in diameter. Stewartville MN had a gust to 76 mph. There was one report of wind damage in the U.P. near the town of Rumely.
Fortunately for us, the severe weather has pretty much bypassed Michigan so far this year – but I bet we’ll have our turn at some point this spring/summer.