90L Slowly Organizing in Caribbean

Heavy rains will be heading toward Nicaragua and Honduras from a strong tropical wave in the central Caribbean. Dubbed Invest 90L, the system could become a Gulf of Mexico tropical storm early next week if it doesn't run aground over Central America.

Showers and thunderstorms (convection) blossomed around Invest 90L on Friday night, and satellite imagery showed an increasing amount of spin near the center of the convection, located midway between Jamaica and Colombia. The wave may continue to slowly organize on Saturday as it moves west to west-northwest at about 10 mph. Conditions will be very favorable for 90L to develop further on Sunday into Monday in the northwest Caribbean.

One of the biggest short-term questions is whether 90L will track mainly due west, which could take the wave along the Honduras coast or just inland from it on Sunday. In this case, 90L may never progress beyond tropical-wave status. However, if 90L maintains a distinct low-level center that stays well north of the coast, it could become a tropical depression or tropical storm by the time it reaches Belize and the Yucatan Peninsula of Mexico around Monday. About a third of the European model ensemble members from 0Z Saturday favor this northern trajectory and tropical-storm status. The northern scenario also leaves the door open for further development in the Bay of Campeche, a very favorable location for tropical cyclones because of its warm SSTs and concave topography. Again, roughly a third of the Euro ensemble members from Friday night call for a tropical storm in the Bay of Campeche or just to its north, approaching northeast Mexico or far southern Texas around the middle of next week. In contrast, only about a quarter of GFS ensemble members calls for development, with lower tropical-storm intensities and a track into the far southern Bay of Campeche.

"thunderstorms (convection) blossomed" = Swell-ups

"imagery showed an increasing amount of spin near the center of the convection" Actually not necessarily spin, but cloud coming up from Venezuela on it south, and easterly Caribbean wind on its north. This could start rotation, but it has not as yet. "Spin" is the wrong work, should be "rotate", spin means fast rotation.