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A new more recent article on the situation in the Atlantic is HERE.
Hurricane Laura is preparing to bring a hellish night to residents of the western part of the Louisiana coast and the eastern part of the Texas coast. It is now a Category 4 hurricane (and very close to the Cat.5 according to the last passage of the Hunter, it can evolve again). Beyond the wind, which should greatly exceed 250 km / h, the concern will be the rising waters with a cyclonic tide of more than 5 meters which is expected in these flat and marshy areas. The city of 78.000 residents of Lake Charles in Louisiana could be partially submerged. The authorities of the two states are extremely concerned and nhc published extremely alarmist bulletins, which is not at ALL in their habits.
But as the expression goes, “the show goes on”, and the spectacle is this hurricane season that is starting to wear down everyone.
And it will continue to be exhausting since the nhc monitors a wave coming out of Africa and which they believe could develop as they approach the West Indies early next week.
Those who have followed me for a long time know that I am quite allergic to long-range forecasts, or at least to their use in public without them being analyzed. In this case we are on a 120h forecast to be more or less close to the longitude of the arc, which indicates that we can start to look at the trends resulting from the crossing of the models.
On the last available runs (12 p.m. or 18 p.m.), a vast majority of global models clearly see something strengthening a little on the ocean, but a majority do not develop it into a cyclone and make it pass north of the West Indies. It is currently the only thing some concrete that can be said on this system. The nhc for its part, it sees nothing happening at 48 hours and establishes a reinforcement risk at 20% at 5 days. Given that the wave is passing from land to the ocean, it is too early to draw conclusions or even any forecast. I actually a little hard to understand why the nhc advances on this ground whereas a few days before they already anticipated an exit from Africa which gave absolutely nothing in spite of a risk which had however gone up to 30% in 5 days. This kind of prediction does not contribute to the security of the territories and especially risk to discredit a little body. Forecasting is a scientific approach, but it must leave a little room for the psychological component. In short, I do not see the point. And all the less since the map below does not even indicate the reality which is that the envisaged system is not even yet on the Atlantic while the zone of reinforcement risk is on the opposite side of the ocean. It led everyone astray.
For the rest, if we look a little bit environment on the eastern half of the ocean may be noted the presence of dry air area and sand very wide and very dense and a shear strong. The conditions are therefore very hostile to cyclonic development for the next 2 days. Beyond that improves a bit but forecasting shear beyond 72 hours is very uncertain.
As for the pressure on the Atlantic, the vigorous ridge that led Laura to the Gulf of Mexico is predicted to weaken in the coming days, which partly explains the model predictions for a passage north of the 'West Indies.
Finally, we recall that the 5-day forecast is extremely complicated and rarely relevant. On his run of August 21 at 18 p.m., the GFS saw a wave which passed over Florida and was going to disappear in the Gulf of Mexico… whereas 5 days later there is Laura attacking the American coasts with winds at 250 km / h!
Image credits; Tropical tidbits, NHC / Noaa, UW-CIMSS
