92L Still Struggling

The tropical wave that has moved across the Atlantic has struggled to develop when it has seemed poised to become a tropical depression. Cool sea surface temperatures, dry air and dust, and moderate wind shear have ultimately suppressed development thus far. However, satellite images show that the wave has undergone a burst of convection today and may slowly be showing signs of organization. Still, wind shear is a bit high on the west side of the wave and is currently preventing any outflow associated with the deep convection. This wind shear is forecast to decrease over the next 24 hours and should promote better outflow as the wave approaches the Lesser Antilles. Additionally, SSTs should warm about 2 C in the next 24 hours and should provide more potential for develop. The cool SSTs that wave has encountered thus far can be attributed to a prolonged period of dust from the Saharan Air Layer. This increase in dust that has been observed has prevented good heating of the waters and has resulted in lower than normal temperatures.

The main inhibiting factor still appears to be the dry ambient air associated with the SAL. This has periodically prevented sustained deep convection near the center. Until the environment is able to moisten around the wave, it's possible that this could significantly hinder development. This is likely to occur in the next few days.

It's tough to discuss the track of the wave at this time since a true center has not formed. However, computer models are generally unanimous on moving the wave just north of Puerto Rico, Hispanoila, and Cuba. Regardless, the tropical wave should move around the southern periphery of a strong subtropical high pressure center. It's even possible the wave could even flirt with the islands and this could further disrupt the strengthening and development. The ultimate destination could place the U.S. in danger of a landfall next week. Using teleconnections, a strong ridge is in place in Eastern Asia and is what really worries me about a U.S. landfall. It's too early to pinpoint a definitive track, but I'll discuss this when the wave develops a true center.

To sum up, I think the tropical wave will finally begin to develop tomorrow, but significant strengthening will likely be hampered until the weekend. Residents of South Florida need to pay very close attention to this wave over the next few days.