Since early Thursday morning the situation in the Gulf has changed si9gnificantly in that now the track for Hurricane Rita includes a high degree of uncertainty as to where landfall might take place in the next day and half. The tracking graphic includes a large ciruclar area which shows this degree of uncertainty with an enclosed cone of probability showing the most probable track which ccontinues to shift eastward towards Louisiana. The situtation is consistent with that predicted early in the week by the GFDL computer model, which at that time was predicting a strike in Louisiana to the west of New Orleans.
for a look at this predicted GFDL track see the page
The computer models now display a degree of confusion as to where Rita might turn next, with one model even predicting a sudden turn south into Mexico, and at another extreme, a second model is predicting a strike to the West of New Orleans, with three other models predicting strikes close to Houston and Galveston.
The reason for this uncertainty can be seen in the pressure graphic. The High pressure ridge has continued to move Eastward as predicted earlier in the week by GFDL model. This ridge prevents Rita from tracking northward, and as consequence Rita has been following a path around this ridge. Similarly, an area of high pressure sits over Mexico, which keeps Rita tracking to the North. However there is no clear guidance for the storm along the Texas and Louisiana coasts, thus resulting in the uncertainty in the track. As well there is some shear evident in the South East corner of Rita, which has resulted in Rita weakening from a catagory four to a catagory five storm during Thursday, although this area of sheer has been shrinking over the course of the day, and looks like it might become absorbed into the storm, thus allowing Rita to strengthen once again, since it does not look like there is any other prospect for sheer in the area, since the low pressure area in the Pacific is being blocked by the High Pressure in Mexico. This could become a concern if Rita begins to wander or loop, thus giving the shearing effect time to disappear before Rita makes landfall.
The low pressure area over Texas has now been pulled North and is being absorbed into a trough over Eastern Canada, and depending on how fast this occurs, and whether Rita does some of that looping or wandering, could give the High pressure ridge over the Mid West a chance to move East, thus steering Rita towards the East, and resulting in a hit near New Orleans.or Mississippi, since as you can see this is currently the Eastern boundary of the high pressure Ridge over the South East which marks the boundary for where Rita can track to the East.
Currently Rita is projected to plow through an area densely packed with off shore rigs, and also refineries which are resonsible for one quarter of America's petroleum. However, it is worth considering that America, with 5 percent of the world's population, consumes 25 per cent of the pertroleum used in the world, so even such a loss as one quarter one would think should be manageable, and might even spur a growing consciousness of conservation and result in changing habits to bring American consumption more in line with that typical of places such as Europe (and America could even approach energy self sufficiency, but this would require an analysis of why it is that Americans are so profligate in their consumption of fuel.