Wednesday, March 25, 2020

Questions America Wants Answered: "Will La Niña Develop and Boost the 2020 Atlantic Hurricane Season?"

From Weather Underground's Category 6 blog:

Will La Niña Develop and Boost the 2020 Atlantic Hurricane Season?
Above: A strong La Niña event spread cooler-than-average waters across the eastern tropical Pacific in 2010–11, as shown by this graphic of departure from seasonal sea surface temperatures on Dec. 15, 2010. The 2010 Atlantic season is tied for the second largest number of hurricanes on record (12) and for the third largest number of named storms (19). (NASA Earth Observatory)

It’s too early to make a confident forecast of how the upcoming hurricane season will evolve, but the tea leaves now on the table suggest that 2020 could be the Atlantic’s fifth season in a row with above-average activity. The latest harbinger is a shift in seasonal computer forecast guidance, heralding the possibility that a La Niña event could emerge later this year.

The mid-month model summary from the International Research Institute for Climate and Society (IRI) and the NOAA/NWS Climate Prediction Center (CPC), released on February 19, shows the odds of a La Niña event pushing above climatology by late summer. By the August-to-October period, the IRI/CPC probabilities include roughly a 35% chance of La Niña, a 20% chance of El Niño, and a 45% chance of neutral conditions. The long-term averages are about 25%, 25%, and 50%, respectively....

We usually start posting IRI/Columbia's model runs in mid-April and CPC's ENSO discussion in  June.