“Tropical” Storm #Odette, other disturbances

Here’s the morning surface analysis from TAFB (the Tropical Analysis and Forecast Branch, within the National Hurricane Center) over the GOES IR satellite image …

click to embiggen.

The two features of interest are “Tropical” storm Odette, and the disturbance approaching the Leeward Islands(lower right, above the word “Surface” in the label). I put Odette’s title in quotes because Odette isn’t really very tropical – and despite having some areas of tropical storm force winds, it’s really more like a nor’easter in structure and impact. It will be bringing wind and rain to the Canadian Maritime Provinces, especially Newfoundland (more properly, Vinland). To quote from the Environment Canada forecast

This storm is expected to behave more like a strong fall storm with northerly winds and heavy rain. A cold front moving over Newfoundland on Sunday will interact with Odette's moisture to enhance the rainfall over southeastern Newfoundland later in the day Sunday and Sunday night. A special weather statement is in effect for eastern Newfoundland for Sunday into Monday. There will be some minor influence in Nova Scotia's weather with gusty northerly winds on Sunday. Gusts could be near 70 km/h or so in Cape Breton which may cause some minor issues. Some enhanced rainfall is likely over eastern Nova Scotia Sunday morning as Odette interacts with the cold front.

Odette is another example of a storm that needs advisories, but doesn’t quite fit our current system of “tropical gets one kind of advisories, other storms get something different.” Why does this matter? It’s inconsistent for one thing, and confusing in that a 50 mph wind and coastal flooding from a nor’easter has a different warning structure and, especially in the commercial weather media world, different level of reporting and attention.

On the science side it can cause problems as well, especially in the popular mindset. As data has become better, and marginal storms are tracked and named, there is an impression that tropical cyclones/hurricanes are more frequent. It is true that storm characteristics seem to be changing (almost certainly due to human driven climate change), but you have to be careful with the numbers game because the metrics haven’t been consistent over time. Simple storm counts and trends aren’t diagnostic when it comes to climate change. That’s not a criticism of NOAA or the Hurricane Center – they are doing their job, which is to issue watches and warnings, and over time they have continued to get better and better at it. But people who use that data for other purposes need to be very careful. Which brings up the insurance world.

At least in the US, how something is named and warned has a direct impact on things like insurance deductibles, and the same damaged roof could cost a homeowner $500 or $5000 depending on how the contract handles the “named storm deductible.” After the huge industry losses in the late 1980’s and early 1990’s due to earthquakes and hurricanes, rather than design a rational system the insurance industry successfully lobbied state regulators to allow them to have separate “catastrophe deductibles” for these major events. So US consumers face a bewildering array of contract conditions depending on the hazard or if a storm is named or not. You get crazy things like if your roof is damaged and water leaks in and damages your carpet, it’s covered by private insurance. But if that same rain backs up because of a drainage problem, enters your house and ruins your carpet, it isn’t covered unless you have separate, Federally sponsored flood insurance from FEMA. Even outside the US things like reinsurance contracts and parametric insurance depend heavily not on the actual impacts or damage a storm produces, but how it is classified and if it is named or not. It’s a dumb system – insurance triggers should NOT be tied to a watch and warning system. That just isn’t what it was designed for. End of rant.

For the US, it looks like the impacts of Odette will be limited to high surf and rip currents; there are no watches or warnings at this time. As for the disturbance off of the Leeward Islands, it may briefly become a tropical system, but isn’t likely to last long once it starts its northward curve. As the Tropical Weather Outlook says, people there should “monitor” until it is safely past …

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