Tropical Weather Discussion...As mentioned in the regular forecast discussion, there are 2 main areas of concern tonight. First, close to home, a very small circulation is trying to get better organized as it parallels the Louisiana coast. This low has been tracked since late last week when it formed off the coast of the Panhandle of Florida near Apalachicola. It has been moving Westward since the weekend, and has been struggling to organize as it separated itself from a decaying frontal boundary. This system has behaved as it was expected to as far as where it would move. However, its tenacity as far as intensity has been interesting to say the least. It is a very small circulation, and most of the rain associated with it is confined to right around the center of circulation. There has been much deliberation since Monday afternoon on whether or not Invest 95L has intensified enough to be classified a Tropical Depression or a weak Tropical Storm. There were some observations just south of the coast between Houma and Morgan City that supported the potential upgrade to at least a tropical depression. However, the small circulation is very near land at this time, in fact it is paralleling the Louisiana coast in the vicinity of Marsh Island tonight. The center has been skirting the coast, with part of it moving inland Monday evening in Terrebonne Parish, but after heading on a WNW to NW motion for much of the last 24 hours, the small system is heading nearly due West tonight. This is keeping it over water, and it actually shows a continued strengthening trend. No matter what this system does, it will remain very weak, and only be a rain producer across the area for the next couple of days.
The close proximity of the circulation center to the coast will likely inhibit much develop, but if this system remains offshore overnight into Tuesday morning then it very well be like the little system that could and obtain tropical depression or tropical storm status. It won't make much difference what the intensity ends up being. As far as a landfall location, it seems likely that this will occur on the west side of Vermilion Bay near Intracoastal City early Tuesday. However, a more due westward motion would delay landfall until later in the day on Tuesday, and it could occur around Sabine Pass. TX. All model guidance for Invest 95L is clustered between Vermilion Bay and Sabine Pass, so this certainly seems to be right on track. It is conceivable that the low will pass right over or very near Lake Charles on Tuesday. Heavy rain and wind gusts over 30 mph are to be expected particularly in coastal areas. Rainfall will become likely for everyone during the day on Tuesday as the moist axis on the East side of the circulation overtakes the forecast area. Areas further West into SE Texas will remain in the subsident zone for another 24 hours or so. My initial thinking based on satellite and radar representation is that this system is a tropical depression, and continues to strengthen despite virtually hugging the coast. However, the National Hurricane Center is the one who makes the official forecast for these tropical systems, so we'll leave it at that. Again, it is not really that important with this type of system whether it is classified or not because the weather associated with it. A motion of W to WNW will continue through Tuesday, and this small system will move into SE Texas by Tuesday night. I believe there will be much speculation as to whether or not this system should have been upgraded or not. Sometimes, it takes a post-storm analysis to garner such an upgrade. It isn't totally certain where landfall will be at this point, but as I said a moment ago it will more than likely be in the aforementioned region. I believe it will track right over Lake Charles during the day Tuesday. No matter what happens with Invest 95L between now and the time it finally moves inland, it has surely been entertaining to watch. Before I move on to Invest 96L, a satellite and radar image link are included along with the forecast models.
Radar Image of 95L
Invest 96L is the area of disturbed weather off of the coast of the Yucatan Peninsula. It is in nearly the same area where Alex formed about 10 days ago. This system is still fairly poorly organized, however, it is forecast to move into a favorable environment over the Southern Gulf of Mexico Tuesday afternoon. It will cross over a small portion of Mexico's Yucatan Peninsula late tonight and early Tuesday, and even if it shows better signs of organization, additional development will be inhibited during this time. Model guidance suggests that development will occur over the next 48 hours as the storm heads into the favorable environment in place over the Gulf of Mexico. A general NW motion at around 10-15 mph is expected to continue for the next couple of days. Models suggest strengthening to a tropical storm of varying intensities. The system will be steered around the SW periphery of a strong ridge to the North of the tropical wave. This will keep it on the NW heading, and the general consensus of the models (illustrated below) is for this system to make landfall somewhere on the Texas coast likely between Galveston and Corpus Christi Thursday. Some Eastern outliers of the model suite suggests a landfall in Louisiana, but the Western outliers suggests a track similar to that of Alex last week and show landfall in Mexico. It is hard to pinpoint exactly where landfall will occur when there is no established fixed point. So, until there is, we will just continue to watch model trends to help us understand the synoptic set up in the projected path environment. The majority of the models suggest that this system will indeed organize and become the season's second named storm, Bonnie within the next day or two.
This is a large area of tropical moisture, and this system itself remains disorganized tonight. If signs of consolidation are shown, then that will certainly be a sign of strengthening. I do note here that regardless of what becomes of Invest 96L a large influx of tropical moisture will envelop much of the Gulf Coast states by mid-week. The actual center of circulation will likely track towards the NW Gulf, and therefore, SW Louisiana would be in the right-front quadrant (NE side) of the circulation. This will keep us in the axis for deep tropical moisture to be pumped into the area from the Yucatan, thus high rain chances are expected for the rest of the week in response to the influence of these two systems. If Invest 96L, does as models suggest and gets its act together, then a noticeable increase in winds, tides, and seas along the coast will occur. Breezy conditions will develop inland as well. Models offer up different solutions on a time for landfall. Some suggests a very quick forward motion of this system with landfall as early as Wednesday night in Texas, while some hold off on landfall until sometime Friday. The consensus would have Thursday pegged for landfall. An Air Force Hurricane Hunter may investigate the system on Tuesday if the National Hurricane Center deems it necessary. For a system that has yet to be classified, I would say that the model output is extraordinarily consistent. Each model run since this weekend has shifted further to the right (NE), and with a ridge building across the SE U.S. It is the forward speed of Invest 96L that will likely be one of the most important factors in determining where landfall will occur. This system will continue to be steered by the upper level winds on the edge of the SE U.S. ridge. A landfall on the Western Gulf coast continues to be increasingly likely. I also believe that this will indeed become Tropical Storm Bonnie by mid-week, but due to the relatively fast forward motion of the system, rapid development should be impeded. I believe landfall will be between Corpus Christi and Galveston maybe as far North as Sabine Pass, but either way we're on the right side of the circulation meaning our weather will be very wet and a bit breezy. I urge everyone from Northern Mexico to New Orleans to be very vigilant of the latest forecasts throughout the week. A stronger system will certainly create more significant weather conditions along the Gulf coast. We will know a lot more once this system emerges into the Southern Gulf and pulls away from the Yucatan Peninsula. All interests along the Gulf coast should continue to monitor the progress of this system. Graphics follow.
That is all for this update. You can see the tropics are busy. I will have my next update Tuesday before noon. The tropical update will continue to be a separate post from the regular forecast discussion until further notice.
Good night & God bless!
-DM-
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