The tropical wave I spoke about yesterday appears to be falling apart due to the influence of the dry, Saharan air to the north. Convection around the center of low pressure has waned throughout the day today. It appears that the dry air will keep this tropical wave from becoming a depression, as shear values are expected to increase in the next 48 hours. None of the global models have yet picked up on the wave, either, which is not a good sign for development.

Figure 1. Infrared satellite image of Invest 99L. Convection is poorly organized due to the influx of dry air.

However, the global models are picking up on a development about 3 days from now. A tropical wave that will move off the African coast tomorrow is forecast by the GFS, Canadian, and Navy models to become a tropical storm shortly after moving past the Cape Verde Islands. This will definitely be something to monitor in the early part of next week.

Figure 2. 84-hour forecast from this morning's run of the GFS model. The green area to the southwest of the Cape Verde Islands indicates an area of low pressure, i.e. a tropical storm.