TD 26 forming?

The tropical disturbance in the extreme south central Caribbean north of Panama appears to have spun up into a tropical depression this afternoon. A strong circulation has developed near 10.2N 81W, and some solid deep convection has built up on the northwest side of the circulation, near the coast of Nicaragua. Radar out of Panama can only see the east side of the storm, and echoes on this side are very weak. The system has a long ways to go before reaching tropical storm strength.

The computer models, as usual for a developing system, are all over the place. The general consensus is for a slow northwesterly track with a landfall in eastern Nicaragua on Friday. The latest 8am EDT runs of the GFDL and NOGAPS model don't develop the system at all. This is quite a contrast to last night's 8pm EDT run of the GFDL model, which forecasted a Category 2 hurricane hitting Nicaragua Friday. A more plausible solution is the SHIPS intensity model, which brings the system up to a 50-mph tropical storm before landfall on Friday. The wind shear is light--less than 10 knots now--and water temperatures are warm (85 F, 30C), so we should see Tropical Storm Beta here by Thursday night. This system could bring heavy rains of 5 - 10 inches to Nicaragua this weekend, causing life-threatening flash floods and mudslides. Costa Rica and Honduras could also see significant rains from this system.


Figure 1. Early model tracks for developing disturbance north of Panama.

Elsewhere in the tropics
The strong tropical wave approaching the Leeward Islands remains disorganized today. The wave will spread heavy rains to those islands tonight and to Puerto Rico on Thursday. Wind shear levels are about 10 - 15 knots, which is marginal for tropical storm development. There are no signs of a surface circulation at this time. This system looks similar to the tropical wave that spawned Tropical Storm Alpha, so we'll have to watch it as it moves into the Caribbean.

Jeff Masters