99L intensifying, 90L forms, 91L coming? Plus my August forecast.

We have A LOT to talk about today in the tropics, as they are really heating up. We have 2 invests, plus a near-invest, and I'll talk about my August tropical forecast.

99L: Invest 99L has regained a lot of its convection due to diurnal max. It is in a moister environment with low wind shear, and it still has a well-defined surface low pressure center. Its T# is 1.5, enough for a weak T.D., but the NHC wants to see if it keeps the convection through the day. If it does, then expect a T.D. to be declared at 11:00 pm tonight. If it doesn't, then expect the NHC to play this system conservative until they're certain it can maintain its convection.
My forecast for 99L calls for it to be an invest for a little longer, then gradually strengthen into a nice tropical storm. The track is hard to forecast because a trough is coming down in a few days. Half the models take it out to sea, the other half point it towards the East Coast. Right now my cone offers both options, with the latter being the more likely for now.
















90L: Our new invest does not have a low-level circulation yet, but I expect it to gain one soon due to the favorable conditions surrounding it. Convection has held up very nicely since Thursday, and that is not very typical for a wave this far off Africa this early in the season. The factor that may inhibit 90L from getting the low-level circulation is a surge of African dust coming off the coast right now. This why I keep it an invest for a few more days. But after that, it's go time. Expect moderate intensification from 90L due to very favorable conditions at it approaches the Caribbean. My forecast even has it as a category 1 hurricane in 5 days. The islands really must watch this for further intensification as it continues to move WNW.

















Future 91L: A low pressure system is emerging into the bathtub known as the Gulf of Mexico. This thing is a sleeping giant in my opinion and will surprise everyone. The GFS develops this and takes it towards TX/LA. I predict this to strengthen into a tropical storm, a little stronger than Erin was when she made landfall in Texas last year. Everything is favorable, the proximity to land will limit development into a hurricane.

My August forecast: Well, August has gotten off to a busy start, with 2 invests strengthening, and another system about to become an invest. This action is all coming with a downward pulse of the MJO, which is not extremely favorable for development. But just about everything else is going our way - low wind shear, high SSTs, low surface pressures, etc. When we get into an upward phase of the MJO, in about 1 1/2 weeks, watch the action in the Atlantic crank up big-time. The African wave train looks to be getting very active as indicated by the long-range GFS, and that is likely with the new MJO phase. A 2005-like August is certainly not out of the question.
The biggest land threats in August are the Southeast states and northern islands, with the Bermuda High building more westward.

So here is my forecast for August:
6 named storms
3 hurricanes
1 major hurricane (landfall likely)


-Mitch