92L Update

After taking a beating by cool waters, high wind shear, and dry air, 92L has survived and is beginning to look much more organized. In fact, satellite estimates and presentation show that 92L is on the verge of becoming the sixth tropical depression of the season. A healthy area of thunderstorms remains clustered near the center, and it even appears that deeper convection is trying to develop near the center this morning. Additionally, the wave's outflow has vastly improved as wind shear has relaxed over the past 18-24 hours. Still, about 20 knots of shear remains on the far western periphery of the wave, and this is forecast to decrease throughout today and tomorrow. By this time tomorrow, the tropical wave should reside in an environment of weak shear (~10 knots).



The main impetus for development seems to be dry air that still surrounds the wave. However, the wave has managed to prevent infiltration of dry air into its center and disrupt the strong convective activity. If this continues to be the case, there is virtually nothing that can hinder 92L from becoming a tropical depression later today or tomorrow. SSTs are near 82 F but should increase to 84 F by tomorrow. Combined with tropical cyclone heat potential values near 50 kJ cm-2, modest strengthening of this system is likely once the wind shear relaxes and as long as dry air remains away from the center. Another potential caveat to strengthening would be any interaction with the higher terrain of Hispaniola. The mountains could act to tear up the circulation and prevent intensification.

I still prefer not to speculate on the exact track of this wave until a true center is formed and confirmed by the Hurricane Hunters. However, model guidance suggests that the wave should move to the WNW as it begins to feel the effects of a trough off the U.S. East Coast. Given the presence of this trough, I think the wave will move north of the Caribbean islands and be approaching the Bahamas by Saturday night. By the end of the weekend, the trough will also beging to lift out and be replaced by a ridge. This ridge may ultimately drive the system into Florida early next week.


Using the trough/ridge pattern in Japan back on Monday, this would suggest that a ridge should be located in the Eastern U.S. by Tuesday or Wednesday next week. This logic would suggest more of a left track than what the current models are currently forecasting. Again, I don't want to get specific with model tracks at this point, but I still feel strongly that Florida is at great risk of a landfalling hurricane early next week. I'll have another update when 92L becomes a depression.