Tuesday, June 3, 2014

What If We're Waiting For the Wrong Kind of El Niño? Colorado State Bumps Up Their Estimate Of The Hurricane Season

First up, Artemis:
Klotzbach & Gray increase 2014 hurricane forecast slightly
The tropical cyclone forecast team from Colorado State University, led by Klotzbach & Gray, has increased its forecast for the 2014 Atlantic tropical storm and hurricane season, citing slower than expected development of El Niño and a warmer Atlantic.

Klotzbach & Gray’s April forecast called for the development of 9 named tropical storms, 3 hurricanes and 1 major hurricane during the 2014 season. The April forecast also called for accumulated cyclone energy (ACE) of 55, a measure of cyclone energy expected during the season.

The latest update to the forecast, which the team published yesterday, has increased the numbers slightly calling for 10 named tropical storm, 4 hurricanes and 1 major hurricane to form in 2014. The forecast for accumulated cyclone energy (ACE) has also been increased to 65.

The slight difference in forecasts could, of course, make a huge difference to the insurance, reinsurance and catastrophe bond industry, as just one landfalling hurricane can erode profits very rapidly. However the forecast remains below the long-term averages, but the increase should be noted as the forecasters say that conditions for storm development are more conducive than they expected to see....MORE
That got me thinking. It's not just that this year's El Niño is slow to develop, we, along with some of the pros have thought the little one would come later in the summer, see for example February's "El Nino Won't Come Quick Enough To Break the California Drought".

Where this gets really interesting is an El Niño variant the Japanese identified and which hit the risk community's consciousness about ten years ago. Here's one of our 2009 posts, "New Type Of El Nino Could Mean More Hurricanes Make Landfall" and here is the JAMSTEC Modoki ENSO page.

Here's Wunderblog referring to that same 2009 paper:
...A new paper published in Science last Friday attempts to explain why some El Niño years see high Atlantic hurricane activity. "Impact of Shifting Patterns of Pacific Ocean Warming on North Atlantic Tropical Cyclones", by Georgia Tech researchers Hye-Mi Kim, Peter Webster, and Judith Curry, theorizes that Atlantic hurricane activity is sensitive to exactly where in the Pacific Ocean El Niño warming occurs. If the warming occurs primarily in the Eastern Pacific, near the coast of South America, the resulting atmospheric circulation pattern creates very high wind shear over the tropical Atlantic, resulting in fewer hurricanes. This pattern, called the Eastern Pacific Warming (EPW) pattern, occurred most recently during the El Niño years of 1997, 1987, and 1982 (Figure 1). In contrast, more warming occurred in the Central Pacific during the El Niño years of 2004, 2002, 1994, and 1991. The scientists showed that these Central Pacific Warming (CPW) years had lower wind shear over the Atlantic, and thus featured higher hurricane activity than is typical for an El Niño year. One of the paper's authors, Professor Peter J. Webster, said the variant Central Pacific Warming (CPW) El Niño pattern was discovered in the 1980s by Japanese and Korean researchers, who dubbed it modiki El Niño. Modiki is the Japanese word for "similar, but different"....
And finally, here are the current Sea Surface Temperature anomalies via Unisys, note the heat in the eastern Pacific off South America:
Current Sea Surface Temperature Anomaly Plot