La Ni帽a: less likely than expected?
After the "El Ni帽o" effect died out earlier this year, meteorologists all over the country predicted that "La Ni帽a" would be hard on its heels in the coming winter.
But recent NASA satellite data has led the聽National Oceanic and Atmospheric Administration (NOAA) to reevaluate the initial prediction. The organization is now saying that a standard winter is more likely in the months ahead.
El Ni帽o and La Ni帽a ("The Boy" and "The Girl," respectively), are names given to meteorological phenomena tied to the surface temperature of waters in the Pacific Ocean. During El Ni帽o, those temperatures are unusually high, leading to changing weather patterns across the globe. La Ni帽a will often follow an El Ni帽o pattern, creating mostly opposite effects from its warmer brother.
As recently as June,聽climatologists had projected a this spring that Ni帽o-to-Ni帽a cycle would play out. But the cool waters that started bubbling to the surface in May from the equatorial Pacific are not shaping up to be as cool as initially expected.
In a La Ni帽a cycle, the cool equatorial Pacific waters interact with cooler air, which sinks down to lower altitudes. Meanwhile, the always-warm waters in Indonesia buoy warm air to higher altitudes, where they interact with the equatorial air. This causes increased convection in the atmosphere, creating wind that blows strongly from east to west near the ground and west to east higher in the atmosphere. This phenomenon, known as Walker Circulation, is key to producing the La Ni帽a weather patterns across the planet. According to NOAA, the , but the equatorial ocean is expected to warm to normal temperatures by the time winter begins, so the Walker Circulation pattern will probably not be strong enough to kick off La Ni帽a in time.
While La Ni帽as have often followed El Ni帽os, history provides plenty of counterexamples, too. Neutral conditions like the one currently predicted followed the El Ni帽os聽of , according to The Weather Channel.
NOAA currently holds the chances of a La Ni帽a event聽occurring聽this winter at 40 percent, based on data provided by .
"We're really trying to bring as much NASA observational data as possible into these systems," said Steven Pawson, chief of the Global Modeling and Assimilation Office, as NASA data is vital to globally.
Scientists hope that such data will help them better understand the impact of climate change on the El Ni帽o/La Ni帽a cycle as well. NOAA scientists report that , making it difficult to accurately predict global climate trends.聽While many scientists think that global warming may make El Ni帽o cycles more likely, more research is needed.
With La Ni帽a less likely, the forecast for the winter is likely to be , predict NOAA scientists. In North America, this means Canada, the upper Midwest, and the Northeast will be colder than normal, while the southeast will likely have a wet winter.
