An early 2019 hurricane season forecast from suggests this year could see a little less Atlantic tropical storm related activity than normal overall, but the recently begun El Niño events strength and persistence is expected to be a major factor here.
NOAA announced the arrival of an El Nino event back in February and as ever it is expected to be a major factor in how many Atlantic tropical storms or hurricanes form during the coming season.
El Nino is expected to be a little on the weak side through spring, hence it is the influence that El Nino could have later in summer that is likely to have the most bearing on hurricane activity in the Atlantic it seems.
Forecasters recently gave a roughly 80% chance that weak El Nino conditions will persist through the Northern Hemisphere spring, with a 60% chance of El Nino conditions persisting into summer, and a 50% chance of El Nino conditions running beyond the summer months.
El Nino’s are often thought to be a driver of less active Atlantic hurricane years and there’s plenty of research to suggest that hurricane numbers and the intensity of tropical storms is perhaps influenced by the occurrence of El Nino conditions and how strong an El Nino is.
But for insurance, reinsurance, ILS and catastrophe bond interests the number of storms is less important than the direction any tropical storms that do form during the season take and their eventual intensity should they interact with land.
Weatherbell Analytics LLC forecaster Joe Bastardi suggests we are in for a hurricane season with below average levels of activity in 2019, in his early season forecast, this includes on an accumulated cyclone energy (ACE) basis, as well as strictly on numbers of storms that form.
Bastardi forecasts between 10 and 15 named tropical storms will form in the Atlantic basis in 2019, with between 4 and 7 becoming hurricanes, and from 0 to 2 attaining major hurricane status.
In terms of accumulated cyclone energy (ACE), Bastardi’s early seasonal hurricane forecast for 2019 suggests a season al ACE of between 60 and 110.
He cites similarities in sea surface temperature forecast charts for 2019 with other low activity years, particularly where there is an El Nino influence to consider.
With El Nino and what Bastardi terms as a “cool looking” Atlantic multidecadal oscillation (AMO) both expected to persist into summer, Bastardi feels the current forecast conditions are analog with less active years.
The other major factor of note to insurance, reinsurance and insurance-linked securities (ILS) market interests is that there remains significant uncertainty in any forecast due to tropical storm potential to get in-close to the United States as well as to intensify over very warm waters.
As ever, any tropical storm that makes its way close-in to the United States coastline will pose a threat, especially where sea surface temperatures may be very warm (such as the Gulf and southern eastern seaboard including Florida).
But Bastardi says, “This year does not look as bullish for in-close development on the Euro, with high pressure extending over much of North America and in the Main Development region but lower pressure in the northwestern Atlantic.
“This is analogous to years with less activity, especially in the Main Development Region. Like last year fast moving features at low latitudes that get torn up or head into South America seem to be something to watch for, but the pressure pattern of higher than average pressures in the Main Development Region looks like the analogs.”
Bastardi stresses the early nature of this forecast off a forecast, but says that so far it does seem to point towards less tropical storm and hurricane activity in the main development region in 2019, as well as a quieter year further north in the Atlantic as well.
But he cautions, “The caveat is that in-close systems and warm water feedback will lead to the kind of challenges that can make or break the season from an impact perspective. On the high end, if the El Niño isn’t impressive we could see activity in line with last year, hence the relatively broad range.”
Hence El Nino conditions look set to be a driver of 2019 Atlantic hurricane season activity levels, while the usual warnings that it only takes one hurricane to make it to land for significant human and economic impacts to occur, driving losses to insurance, reinsurance and potentially ILS interests.
More forecasts will be available in April and we will collate them all on our dedicated 2019 Atlantic Hurricane Season page.
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