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Jamaica Issuing a Tropical Storm Warning Before It Had Formed

Yesterday I was quoted by Capital Weather Gang‘s Jason Samenow and Brian McNoldy in regards to the unusual step by the Met Service of Jamaica to issue a Tropical Storm Warning before the system had even been classified as one by the National Hurricane Center (NHC).

The issuance of watches and warnings is within the purview of each country’s government, but it often involves lengthy coordination with NHC in Miami. This is the first time in my 32 years of Caribbean forecasting that I’ve seen a Tropical Storm Warning issued before a system was classified.

Here is the statement from the new director of the Jamaican meteorological office, Evan Thompson, courtesy of RJR Jamaica:

“The meteorologists, in just observing the signature of the satellite imagery, would have realized that the system [had] developed well past a tropical wave. Now there are some constraints under which the National Hurricane Center operates in that unless there is a confirmed closed circulation of the wind in the lower levels of the atmosphere it cannot be classified as a tropical cyclone. Hence they [continued] to refer to it as a tropical wave. This is something that is being addressed by the U.S. authorities but currently the law still indicates that they cannot issue actual advisories on the tropical systems or indicate track guidance on these systems when it does not have a closed circulation. And that is one of the constraints we’ve been operating under. So, although our understanding .. [pulled] us in the direction of indicating that this [was] at least a tropical storm moving through the central Caribbean, the information that [had] been passed on to us [had] only been able to confirm it as a strong tropical wave. However the hurricane specialists [did] indicate that with their best knowledge it also [appeared] to be a tropical storm.”

NHC did nothing wrong. If it’s not a storm yet, then it’s just not a storm yet. Advisories could not be initiated under the current rules. But the Jamaican government did everything right by using common sense, and not allowing a technicality from getting in the way of warning their population and saving lives.

A similar warning in the Dominican Republic may have saved some of the nine lives lost due to tropical storm conditions experienced in that country. Happily, the National Hurricane Center beginning as early as 2017 may change the ground rules and allow for the issuance of advisories, watches and warnings before a system is officially classified as a tropical cyclone.

But maverick Evan Thompson of the Jamaican Met Service had the courage to do so before the rule change.

So, “Irie, Jamaica” — one way of saying good job!