Tropical Weather

Invest 92L, TS Igor

A wave in the eastern Caribbean, just south-southeast of the Windward Islands has become better organized and has been designated as Invest 92L. Once Invest 92L can move away from the South American coast, 92L will be in a position to strengthen and develop into a tropical cyclone. Most models are in agreement of 92L developing into a hurricane and the flow will be a W to WNW movement. An outlier model (the Canadian CMC) model has it closer to Cuba and possibly Florida. Shear will be very light and the environment will be conducive for further development. The pattern for this system will be for 92L to have landfall toward the Yucatan and if it follows a more WNW-NW flow it will get into the southern GOM and this might be another threat to Texas if it holds together.

IR Satellite image if 92L
Visible Satellite image of Invest 92L
Wind Shear West Atlantic/Caribbean
Models for Invest 92L

Tropical Storm Igor overnight and this morning was being assaulted by moderate easterly shear but as the day progressed the shear began to relax a little and this allowed deep convection within the center to form along with an expanding convective field. There was a weak low to the northeast of Igor but that has been absorbed by Igor. The shear will be relaxing over the next few days along with warm SST’s and a very moist envelope, Igor will be in an environment conducive for steady intensification. Both Statistical and Dynamical models are in agreement for Igor to be a hurricane with 2-3 days. Further intensification is also forecast. There is a mid-level ridge to the north of Igor and this will keep Igor on a W to WNW track along with a gradual increase of forward speed. On day 4 Igor will be be in the Central Atlantic and will be near a trough which should cause Igor to turn toward the NW. Exactly how much of a turn and when has caused the different models to slightly disagree. Some models tend to believe that Igor will follow a path similar to Danielle and therefore the will not affect Bermuda where as other models are taking a slower track and taking a path similar to Earl being between the coast of the SE U.S. and Bermuda.

IR Satellite image of TS Igor
Visible Satellite image of TS Igor
Shear Map of the Eastern Atlantic
Models for TS Igor
Tropical Weather

Invest 95L

A wave that rolled off Africa a few day ago has been designated as Invest 95L. This is a system that has a very good chance to be a tropical depression within 48 hours. Invest 95L has very good cyclonic turning and it has a very moisture envelope.

(ADDENDUM – as of 5:00pm 8/21 Invest 95L developed enough to be classified and designated as Tropical Depression Six)

Satellite image of Invest 95L
LSU satellite image of Invest 95L
Water Vapor satellite image of 95L

In the water vapor image above, you can see there is some dry air to the north of Invest 95L. The forward motion of 95L is W-WNW and this should allow the system to not be hindered by the dry air. Below is an image of Wind Shear analysis. The wind shear at the moment is not to bad for the system, but it is not allowing any development. The environment for 95L is going to be changing and the wind shear will be very low. Forecast is for better conditions overall.

Wind Shear

The forecast for 95L is that it will develop into a tropical depression by sometime Monday. All models do want the system to turn NW then N and eventually curve out to the sea and away from any land masses. The problem is exactly when it will do so.


The intensity in the models seem to keep 95L in the yet to tropical storm range (at least for 48 -72 hours) for when it does develop. An outlier does want to have 95L into a hurricane but that is will have to be shown later on. Until the system fully develops, I would take the model intensity with a grain of salt.

Early intensity forecast