Good Morning,

Two days ago Invest 97 looked like it was well on its way to becoming a tropical depression by this point in time, but the convection associated with it weakened and for most of the day yesterday we were wondering if Invest 97 would survive the night. However, late yesterday afternoon it sparked off new convection which has maintained itself overnight. A gulfstream aircraft confirmed that strong wind shear is impacting the system, but its a good sign to see convection tonight. Right now the convection is displaced from the circulation of the system, thus as it may look impressive, in all reality Invest 97 is still quite disorganized.


Wind Shear

The graphics shows above are a depiction of the current wind shear over Invest 97 and the rest of the Atlantic. Right now wind shear is exceeding 45 knots over the invest, which for a tropical system of any strength is very significant and very inhibitive to development.Looking at the rest of the gulf the wind shear relaxes somewhat, but never goes away. However, the atmosphere is not a stationary object and the wind shear will begin to outrun Invest 97 by Friday and by the weekend the shear should be relaxing considerably, which would help the invest begin to develop.

The Gulf of Mexico, with the exception of the most southwestern portions, have been calm for several weeks, thus the SST’s (Sea Surface Temperatures) are in excess of 29C which favors tropical cyclone development.

06Z Early Model Runs - DO NOT USE AS A FORECAST

Now the fun part begins. Even if Invest 97 does not develop past its current state, the moisture associated with the system will eventually reach the United States. Thus the track of the system is important, as some areas may not be able to handle the amount of moisture this system brings inland. The models have been shifting west for the past three runs now and continued to do so as the graphic above shows. The track of this system is fairly difficult in the long term, but equally important in the short term. If Invest 97 rides the Cuban coast it will be subjected to the high terrain and the circulation will have difficulty developing and will likely not be able to do so easily. If the system takes a more northern path and crosses South Florida it will not be as affected as it would have been over Cuba, but development will not likely occur due to the crossing of a land mass. BUT If 97 can shoot through the straights it will have a higher chance of developing as it will remain over water. At this hour there is difficulty determining where the ‘center’ of the invest is located. In weak stages these systems can reform their COC (Center of Circulation) under the strongest convection, thus its possible to have rather dramatic shifts in the location of the storm. At this point of the game its useless trying to pin down a landfall location because of the state of the storm and because of a possible heat ridge developing over the southeastern US by this weekend. Some models indicate a weakness develops in the ridge, allowing the invest to be pulled north/northeastward towards the Mississippi/Alabama coast. While that was the general thought on Tuesday, the models are now indicating the ridge will hold thus pushing Invest 97 (or what it develops into) west/northwest in the gulf. Like I said above the track is very uncertain but the further west it goes, the longer over water it will have.

Based on the current model projections of a landfall over West Louisiana or the Texas Coast it would appear whatever Invest 97 is will make landfall Sunday or Monday. The timing is just as uncertain as everything else. Right now not many models actually develop Invest 97 at all, keeping it an open wave across the Gulf of Mexico. While this is possible I’m not buying that just yet. Convection has flared up tonight and has attempted to form closer to the center. Considering the amount of shear over the system at the moment that is quite an impressive feat. Depending on what happens today that will help increase confidence in one solution, but based off its attempts at organization tonight I would say this will likely become at least a Tropical Depression, if not Tropical Storm Bonnie in the Gulf of Mexico. I will say based on current projections and the state of the system I don’t believe the Gulf Coast will be facing a major hurricane, but nothing is certain in the tropics and neither should that assumption. Whatever happens though, the system will likely help spread in oil inland somewhat and possibly push it westward, but I refuse to get into that area. I’ll leave that to the scientists in the appropriate field.


I plan on posting one discussion a night. Should Invest 97 develop then the discussion frequency may increase. I’ve already made preliminary plans to intercept any sort of system making landfall and should Invest 97 develop into a Moderate TS+ then Connor and I will likely head down to the coast to intercept.

Please be advised that this post is not a forecast, merely a discussion based on many different factors. Please base any decisions on offical forecasts coming from the National Hurricane Center or your National Weather Service office.

David Reimer