Sunday, July 2, 2017 3:02 PM

Tropics Brewing!!

Christopher Nunley

Firsthand Weather is still monitoring the strong tropical wave in the eastern Atlantic (see Firsthand Weather’s first article regarding the wave and explanation of what an African Easterly Wave is HERE!). The National Hurricane Center (NHC) has now given this wave a 50% chance of development into a tropical cyclone (tropical depression or tropical storm) within the next five days.

NHC Monitoring Area For Tropical Development

Firsthand Weather is not concerned about rapid development, but a more gradual development over the next several days is plausible. The wave still does not have the best presence on satellite, and lacks deep, organized convection.

Current Satellite View

This will likely change beyond 48-72 hours since the wave is in an environment conducive for convection to slowly organize and deepen. This environment is characterized by relatively low environmental shear and above normal moisture.

GFS Shear Map (Current)

GFS Moisture Map (Current)

The favorable environmental conditions should persist as the wave moves towards the west over the next few days. This will increase the chances of tropical cyclone development by late in the week. By Saturday, the system will begin more of a west-northwest motion as it approaches the Lesser Antilles. Beyond this upcoming weekend is when the numerical guidance begins differing, and shows slightly different synoptic patterns. It is too early to determine the synoptic pattern, which will influence the track of this wave (or tropical cyclone at this point if it develops); and, the numerical guidance is not of much help with the synoptic pattern this far out.

GFS 500mb Map (Wednesday; July 12th)

Canadian 500mb Map (Wednesday; July 12th)

European 500mb Map (Tuesday; July 11th)

It appears a trough will dig into the central/eastern United States around this time-frame (mid-next week–not this upcoming week). Depending on the exact placement and strength of this trough, the strength of the potential tropical cyclone, and the placement of the Bermuda high will play large factors in the movement of this system. Again, the numerical guidance is handling these features differently, which is why they’re forecasting different tracks. It is too early to say if the United States is in the all clear or if there will be impacts. Firsthand Weather will continue to keep an eye on this wave, so keep checking back frequently for updates as confidence begins to increase.