Reminder: the information and illustrations on this site are NOT INTENDED to protect property and people from cyclonic risks. For this, you must follow the information and recommendations of your prefecture for France and the competent authorities for other territories.
This article is no longer up to date. A news on the situation in the Atlantic is available HERE.
The situation is getting a little more complicated in the Atlantic. There are the 2 waves monitored by the nhc since yesterday and a third disturbed zone which is inserted between the 3 and which did not make much talk about it. Today it is this one (2) which has developed a somewhat structured deep convection while the 2 followed by the nhc are a little more loose. We will take stock and take them one by one, in order.
Tropical wave number 1
It is currently close to 10 / 12N by 50W even if its convection is displayed a little further north. It is moving west at around 25 km / h which should get it to the arc on Sunday. The nhc established a weak risk of reinforcement at 48 hours (evening before the West Indies) at 20% The risk for the following 3 days is a little higher but reasonable at 30%. It does not give any sign of improvement in its organization with a very elongated vorticity on a NE / SW axis but it remains quite strong. It is located in an area of shear quite weak and hot water, but it is literally surrounded by dry air and sand. The shear is expected to remain fairly weak around it for the next 48 hours.
No global model develops it into a short-term cyclone, only the model Icon, whose cyclonic development is not the specialty, sees it getting organized a little but without reinforcement. The Arôme model from Météo France sees it pass Sunday over the center and south of the arc with thunderstorms.
In the end, there is nothing to worry about for this wave on the West Indies because of its proximity, which does not prevent you from keeping an eye on it.
The disturbed zone number 2
It's a bit of the surprise guest of the day. It is located just east of the first and a little further north, around 15N by 35W. It is quite difficult to estimate if it is linked with the 3rd or not since there are 3 zones of vorticity east of 40W. We had to be fairly quickly fixed since this disturbed area is almost static while the wave behind moves west between 15 and 20 kt.
Tropical wave number 3
It is located in the south of Cape Verde and therefore very far from the West Indies. She stayed a little static that night and this morning and started moving through the day. Its vorticity seems quite southerly, around 10 / 12N which protects it a little from the dry air and sand. The shear is strong enough to its immediate south and should prevent it from strengthening in the short term.
It is still fed by a lot of moisture coming out of Africa and the bulk of that moisture has not yet arrived. As long as it was static, this permanent arrival of convective cells could give it a little vigor. This was, moreover, what the GFS and other global models until this morning. Low displacement and constant supply of humidity and convection over the next few hours. But the latter totally changed his forecast in his 18H run and is no longer developing anything on the Atlantic at 7 days, just like all of his comrades. It is likely that the fact that it is now moving a little faster towards the west, when it should be a little static, is the reason for this very marked turnaround.
Le nhc increased its risk of strengthening at 5 days to 40%, a bit off-beat of the models. But the turnaround of GFS could change their view on tonight's bulletin.
Conclusion
To be informed live of new articles, you can subscribe to the Facebook group or to the account Twitter.
Image credits; Tropical tidbits, NHC / Noaa, UW-CIMSS
