If you have been keeping up with climate forecasts, heading towards the end of 2020 we were anticipating a La Niña winter. Typically, La Niña winters begin in the late fall and can last through the spring time with warm and dry conditions for Central Texas. This was the case for us up until February when we had record breaking cold in combination with round after round of winter storms. So, is La Niña still ongoing, or has it come to a screeching halt?
March 1st, the National Oceanic and Atmospheric Association (NOAA) released an update on the current La Niña and what we can expect moving into the spring and summer.
La Niña Conditions exist when:
- A one-month negative sea surface temperature anomaly of -0.5° C or less is observed in the Niño-3.4 region of the equatorial Pacific Ocean (5° N – 5° S, 120° W – 170° W) and an expectation that the 3-month Oceanic Niño Index (ONI) threshold will be met , AND
- An atmospheric response typically associated with La Niña is observed over the equatorial Pacific Ocean
According to recent analysis from NOAA, current sea surface temperatures (SSTs) in the equatorial west-central to eastern Pacific Ocean are below normal as of February 2021. This is highly indicative of a La Niña pattern which is why there is a La Niña Advisory in effect.
Scientists at NOAA predict that as we head into spring in the Northern Hemisphere, conditions will move more towards a ENSO-Neutral. This gives us in Central Texas equal chances at receiving normal precipitation and experiencing normal temperature values starting in April and lasting through at least the late summer.
Forecast models continue to show La Niña conditions to persist through springtime before returning to ENSO-Neutral for the remainder of 2021. There’s about a 60% chance of La Niña conditions to continue through the spring.
The IRI/CPC model below shows average SSTs for each three month period for the remainder of 2021. You’ll notice that they are trending more towards the middle 0°C line which is where temperatures that reflect a ENSO-neutral pattern by the summer months of this year.
What can we expect moving into springtime here in Central Texas? Well, not much with absolute certainty. But if model trends continue to show ENSO-neutral conditions, we know we typically are wet in the spring, hot and dry in the summer, and wet and cool towards fall.
For more information, visit NOAA’s El Nino & La Nina information webpage here.