Gustav Moving Past Jamaica, Primed For Explosive Development

Interaction with Jamaica and dry air were the only two negative factors inhibiting Gustav from rapidly intensifying yesterday. Jamaica had very little impact on Tropical Storm Gustav's inner core and only weakened the storm a small amount. Gustav is moving away from the island so that will not be any hindrance to strengthening. Also, the vast expanse of dry air to the north of Gustav yesterday is completely gone this morning. That's ominous news with the environment that Gustav is about to traverse. Noting the satellite presentation of Gustav this morning, it looks like the storm is already beginning to intensify and this may be the initial stages of a rapid intensification phase that will soon commence.



Gustav is very slowly inching its way back into the very warm Caribbean waters, and radar mosaics along with satellite images show that an eye-like feature appears to be developing just west of Jamaica. As of the last reconnaissance data, I note that the pressure has now dropped to 988 mb. This may be the onset of a rapid intensification phase that will likely take place given the low shear (5 knots), the highest oceanic heat content anywhere in Atlantic (SSTs 86-88 F and TCHP 90-130 kJ cm-2), and moist air surrounding Gustav. With the expected environmental conditions favoring rapid intensification, I wouldn't be surprised if Gustav reaches near Category 4 and possibly Category 5 intensity before moving into the Gulf of Mexico early Sunday morning.

The models are split once again on the track of Gustav. Some take Gustav northward to Louisiana while others build the ridge strong and push it back toward Texas. At this point, there is considerable uncertainty in the models, but a NOAA G-IV mission is scheduled later today and this should improve the model divergence tonight. I'm not changing my forecast ideas of a landfall near Sabine Pass, TX. I'll have more later this afternoon.