Tag: models

Categories
Tropical Weather

Invest 91L and ex-Gaston

Ex-Gaston who seems to have been around forever has lost most of it’s cyclonic spin is now just under Puerto Rico and the last satellite imagery of Gaston was showing the best convection it has had in a long time. The only problem with Gaston is that he will soon be headed right into Hispaniola. The mountain range there can be very high and has many a time either disrupted a storm or killed it. If Gaston only clips the mountains, Gaston may survive and possibly may develop while in the the western Caribbean.

Satellite image of ex-Gaston

A tropical wave that has just come off Africa has been designated as Invest 91L. This tropical wave does have some decent cyclonic turning but there is some wind shear of about 20-30 knots just north and northwest of it. The shear will relax within the next 24-48 hours. Some on the models have just been initialized thus there may be errors or bias within them. Several models are suggesting this will be our next tropical cyclone.

IR Satellite image of Invest 91L
Early Models for Invest 91L
Categories
Tropical Weather

Tropical Storm Hermine

What was Invest 90L then updated to TD Ten has now been upgraded to Tropical Storm Hermine. Overnight, TS Hermine started to head N which did give it a little more breathing space to develop. It is still forecast to make the turn toward the NW but when that turn will happen is still unclear. The track for Hermine has shifted right from the previous one and this places TS Hermine right again the Mexico/Texas border. TS Hermine has a very ragged CDO(Central Dense Overcast), but unless it start to make the turn to the NW, the CDO should begin to have a better overall appearance. Additional strengthening is forecast but I don’t think it will have enough time to become a minimal hurricane even though the SST’s are in the 30°C-31C° range. I do believe the forecast track will need to be adjusted slightly to the right again as the ridging over the northern Gulf has been slow in coming.

Visible Satellite image of TS Hermine
IR Satellite image of TS Hermine
Water Vapor Satellite imagery
Models for TS Hermine
Categories
Tropical Weather

Tropical Depression Ten

Invest 90L has now been upgraded to a depression this evening with the 11PM advisory. TD Ten is favorable for some intensification till land interaction will restrict further development. At the moment TD Ten in headed NW to NNW. There is some disagreement between the models as to when the left turn will occur. A ridging will be developing over the northern Gulf of Mexico. All models are in agreement on this scenario.

Satellite image of TD-10
Visible Satellite image of TD-Ten
Models for TD-Ten
Categories
Tropical Weather

Tropical Storm Gaston

What a day! This morning the wave that was designated as Invest 98L then later in the morning it was then upgraded to Tropical Depression Nine has now been upgraded to Tropical Storm Gaston. I still believe that there will not be too much more intensification because of the the dry air to the north and west though there is little shear – it may but very little. See my previous post about TD Nine.

Satellite image of TS Gaston
Satellite image of Gaston
AVN Satellite image of Gaston
Models for Gaston
Categories
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.

Models

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
Categories
Tropical Weather

TD Five reborn?

The remnants of Tropical Depression Five and had crossed into LA and moved across the Gulf states, now has a chance to redevelop as a depression again. The storm is headed south/south-westward and may develop as soon as Tuesday. Both satellite and Radar is showing a band of very intense thunderstorms.

Radar image of ex-TD Five
Satellite image of ex-TD Five

A few models are forecasting that the remnants of ex-TD Five will approach the Gulf coast and begin to develop to at least a tropical depression. If the storm is far enough into the warm waters, and enough time, it may have a chance to develop into a weak tropical storm. Shear is very low 5-15 knots and the regeneration of the storm should occur and if so landfall somewhere around Southeast Louisiana between late Tuesday or Wednesday.

Models of Ex-TD Five