Météo France plans a passage from the center of Isaac, Thursday and Friday, between Guadeloupe and Martinique, placed on red alert. But nothing comparable with Hurricane Irma, says a forecaster interviewed by Franceinfo.
Red alert in Guadeloupe and Martinique. Heavy rains are expected in the wake of the storm Isaac, which must pass between the two Caribbean islands Thursday 13 and Friday 14 September. The passage of this tropical storm brings back the specter of the devastating passage of Category 5 hurricane Irma almost a year ago. Eleven people had died in St. Martin.
This time, what should we expect? Franceinfo asked Emmanuel Demaël, forecaster at Météo France.
Franceinfo: Can we compare the storm Isaac to hurricane Irma?
Emmanuel Demaël: No. These two phenomena are incomparable. They do not have the same severity, nor the same size and geographical amplitude. This time, we are only on a tropical storm. Irma was a hurricane, and category 5: the highest level that exists. Isaac will weaken gradually, but will retain the characteristics of tropical storm during his trajectory on the Lesser Antilles. Martinique, the north of Dominica and especially Guadeloupe will be concerned. Then he will not go back to other lands in a trained way. The islands of St. Martin and St. Barth will be spared.
Why trigger the red alert for Martinique and Guadeloupe?
Be careful, red is not the same kind. For Martinique, it is a vigilance red rain and thunderstorms. An alert for a dangerous phenomenon related to intense rainfall and thunderstorms, as it could be the case in mainland France, especially in the South-East during the Cevennes or Mediterranean episodes.
Infos: https://t.co/2qQnReB4b8 pic.twitter.com/WhRNuySxbd
– Weather-France (@meteofrance) September 13, 2018
For Guadeloupe, it is a cyclonic red alert directly related to the passage of Isaac. The color is related to the time of the cyclone. From 48 hours to 72 hours before, it's yellow, 48 hours before, it's orange and from 6 to 8 hours, it's red. The passage to the violet is only done in case of hurricane, 3 to 6 hours preceding the impact. For cyclonic alerts, colors are therefore related to delays, not to intensity.
What can the inhabitants expect?
The two overseas territories have in common rain and thunderstorms. A total of 100 to 200 mm of rain is expected in Martinique and Guadeloupe, especially on the relief of Basse-Terre. In Guadeloupe, gusts of 100 km / h are also expected, as well as a swell height of 4 to 6 meters. The waves will be high locally, up to 6 meters. But not in Martinique, where there will be nothing significant at this level.
With 100 mm of rain in two hours, there may be floods, with a significant material and human toll. But the consequences are difficult to apprehend, because it is related to the development of the territory. In any case, we must remain vigilant.