NY NJ PA Weather Forecasts

More trouble is brewing in the Tropical Atlantic!

Tropical depression Eight has developed roughly 355 miles east-northeast of the northern Leeward Islands. Tropical depression Eight is still under some weak northerly shear from a departing upper low, which is forcing the majority of the convection onto the southern side of the low level circulation. However, the shear is expected to end as high pressure builds over top of tropical depression eight. In fact, over the past few hours, convection is beginning to develop over the center of circulation and out flow is also rapidly improving. Model guidance projects the depression to develop into Tropical Storm Hanna in the next 24 hours. High pressure is expected to continue to build over and to the north of the tropical depression through the next 5 days, which will send the tropical system to the west. There is potential for this depression to intensify into a strong hurricane by the end of Labor Day.

Tropical Storm Gustav has redeveloped to the south of Haiti and to the east of Jamaica, under some very deep convection.  Gustav will be under a building ridge of high pressure ridge over the next 66 hours, which will allow the tropical storm to intensify back to hurricane strength and beyond.  

It is interesting to note how the center of circulation jumped south from the western tip of Haiti to east of Jamaica over the past 8 hours under the convection, which is rapidly building.  Clouds tops are dramatically cooling to -80°C this morning, which suggest a tremendous amount of rising motion and the outflow signature this morning is also rapidly improving.  I think we’ll see Gustav return to hurricane strength by later this afternoon or evening.  So what is the future of Gustav?

The ridge that is building over the Bahamas will weaken slightly over the central Gulf of Mexico, which will produce a weak southern wind at 850 to 500 MB.  The receding ridge will send Gustav into the central Gulf of Mexico by Sunday night and towards the central Gulf Coast by Tuesday morning.  It is striking how almost every model guidance this morning shows this outcome in one form or another.  Shear will be weak through the period and the sea surface temperatures are plenty warm enough with some areas in the Gulf of Mexico approaching 90° F!  That’s a lot of high octane fuel for a hurricane!  I expect Gustav to continue to gradually intensify through the weekend and become a major hurricane by the end of Saturday at the latest.  Gustav has the potential to reach category 4 strength by the beginning of next week.