BATON ROUGE, LA (WAFB) - The 2015 hurricane season started early with the development of Tropical Storm Ana in early May. That storm made landfall in the Carolinas. We are barely two weeks into the official start to hurricane season and now all eyes are on the Yucatan Peninsula in Mexico as Invest 91L has formed.
As of their 2 p.m. advisory, the National Hurricane Center gives 91L a 50% chance of developing into a tropical depression over the next two days and a 70% chance over the next five days.
A broad tropical wave, later named Invest 91L, formed late Friday in the extreme Western Caribbean. This wave moved into Belize and the Yucatan during the day Saturday. Early Saturday morning a majority of the weather models barely even registered 91L as a blip on their proverbial radars.
Saturday afternoon the majority of the weather models began picking up on 91L and are moving it into the Gulf of Mexico. The vast majority of the weather models forecast the wave to move out into the Southern Gulf of Mexico, or Bay of Campeche, Sunday and then move across the South Central Gulf towards Texas.
A 'somewhat' suitable environment for development will exist in this area. But, the things going against 91L are:
- It's current interaction with land. Questions remain on how 91L will progress over the next 12 to 24 hours as it emerges from Mexico and moves back over water. Also just where it will emerge also remains unclear at this time.
- Wind shear is not high, but it's also not low. An upper level low sits just to the NW of the existing tropical wave. This has resulted in shearing westerly winds. The bad news is this upper level low is expected to drift south and out of the way of the tropical wave allowing for a decrease in wind shear over the coming days.
- Dry air is being filtered into the system at this time. The upper level low's position is causing drier air off the U.S. to be streamed into 91L. But like the wind shear the upper level low will move and abundant moisture will be present over the coming days.
The biggest aid to this system will be very warm waters currently in the South Central Gulf of Mexico. Sea surface temperatures are in the mid 80°s which is ample fuel for 91L.
The good news is that 91L is expected to move quickly across the Gulf of Mexico meaning it may not have enough time to develop into something significant. Most of the weather models develop the system only into a weak tropical storm. If it reaches tropical storm status it would be Bill. The intensity forecast is subject to change once the models reinitialize 91L as it moves back over water.
As mentioned earlier the track of 91L appears to be headed for Texas. This is because high pressure is expected to build in the Eastern Gulf of Mexico. This high would block 91L from moving east and push it more west. The concern for us is whether the high develops too late or isn't very strong. That could cause 91L to drift a bit more east of the forecasted track.
The bottom line, however, looks like South East Louisiana will see little if any impacts from 91L.