Nino3.4 SST anomalies moderated to around -0.5C below normal in early July, but an increase in trade wind strength has been restrengthening the event in the last few weeks. Nina conditions will remain in place through fall, with the pattern progression of last year’s event continuing to be a good guide for 2022’s trajectory.
Articles by Ryan Truchelut
WeatherTiger’s initial forecast for the 2022 Atlantic hurricane season offers limited hope of more typical threats in the year ahead. Our seasonal forecasting algorithm projects a most likely outcome of around 155% of average activity.
Nino3.4 SST anomalies are hovering around 1C below normal as weak to moderate La Nina conditions persist into mid-spring. WeatherTiger’s modeling continues to suggest a slow drift towards cool-neutral conditions over the summer, though a continuation of La Nina is now more likely than not through fall.
It’s time for WeatherTiger’s look back on the 2021 hurricane season, which again brought misery to the Gulf Coast, this time while Jeff Bezos took short, pointless trips to space.
El Niño Outlook for September 2021
Two factors have strongest historical relationship with late season tropical activity: Atlantic SSTs, and El Niño/La Niña state in the Pacific. Both Atlantic and Pacific support an extended hurricane season in fall 2021, but are fortunately not as favorable as they were in heading into late 2020.
WeatherTiger’s August Atlantic hurricane season outlook is out now. It continues to call for an active season, with most likely ACE ~50% above normal. Analogs suggest steering may favor elevated U.S. and Florida landfall risks in October. Overall: get ready. Tropical go-time is almost here.
True neutral ENSO conditions are in place in the Pacific, with SST anomalies in the Nino3.4 region drifting around zero in June and early July. Continued neutral or cool-neutral conditions are likely through the summer, and it is now clear that a new La Nina will not develop in time to influence the peak of U.S growing season.
WeatherTiger’s expectations for the 2021 hurricane season shifted higher over the last two months, but remain shy of last spring’s (accurate) prediction for a hyperactive 2020. The most likely outcome is tropical activity around 40% above the average hurricane season.