Thoughts on the GOM/CARIB Low

[Anonymous]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

This is a real preliminary look at the data....the models can quickly change their tune since they're just beginning to nail down this progged low.

IWIC Worldwide Tropical Weather Discussion - June 7 2005 - 9:00 UTC

The potential for tropical cyclone development in the southeast Gulf of Mexico or northwest Caribbean Sea between the 10th and 15th of June (previous discussions can be found on this page) has been mentioned since June 1. The true threat is beginning to emerge in this morning's model guidance. The discussion will begin with an overview of today's 00Z model runs.

The 00Z run of the Global Forecast System (GFS) is projecting the rapid formation of a 996MB-1000MB surface low north of Honduras in 48-72 hours. By 84 hours, the surface low will have already entered the southeast Gulf of Mexico based on this run. The northwesterly steering is a result of a weakness of the subtropical ridge over the central Gulf Coast. By 144 hours, the GFS shows a moderate tropical storm making landfall in eastern Louisiana, southern Mississippi or Alabama. The ECMWF shows a similar path through day five, but it does not forecast a surface low nearly as strong as progged by the GFS. The Euro has been fluxing back and forth between little or no surface low formation for the last 48 hours. The UKMET has a slightly different feel of the pattern vs. that of the GFS. Rather than quickly developing a surface low in the northwest Caribbean, it shows a broad area of low pressure moving over the Yucatan Peninsula and eventually moving into the central Gulf of Mexico. By day six, the model shows what appears to be a broad wave axis moving inland near Lake Charles, Louisiana. The appearance of an open low pressure area is most evident on the UKMET forecast precipiation accumulation at the FSU tropical cyclogenesis model page. Nevertheless, this is the first run of the UKMET that even hints at the possibility of surface low development in the Gulf, and the the forecast is indicative of heavy rainfall along portions of the Gulf Coast if it verifies. The Canadian is by far the most aggressive and variant of the global model suite. First, it develops a massive upper level ridge of high pressure over the western Caribbean Sea. Such a ridge would be highly condusive for tropical cyclone formation, but the strength of the high is likely being exaggerated. With that being said, the model is trying to develop a tropical storm or hurricane underneath the progged mid to upper ridge. A tropical system of that magnitude would be steered by mid to upper level weaknesses. In this current patten, a track over the Florida peninsula would be most likely, and that is just what the Canadian is trying to do. The CMC shows a tropical storm or minimal hurricane landfall near Tampa early Sunday morning. But as mentioned, the Canadian is the overwhelming outlier, and there are no other indications that a hurricane developing out of this progged feature is even remotely possible so Floridians need not to worry about such a scenario just yet. A weaker tropical system (such as a broad low, depression, or storm) would be steered more by the low to mid levels (where the troughing is not as prominent), and that is why the majority of global models are more focused on the central Gulf Coast rather than the FL peninsula. For instance, the NOGAPS shows a more westerly track than any of the other global models, and it also happens to be the most conservative in terms of intensity.

The progged surface low already getting so much hype is nowhere to be seen on current satellite imagery. However, the origin of the low is evident in all of the model data. The tropical wave in the eastern Caribbean Sea is being heavily sheared by an upper level low over Hispaniola. Some of the energy associated with the wave will slide westward into the western Caribbean. In addition, a southerly fetch of moisture coming out of Central America will be present over the next several days. A consolidation of the two moisture channels will be necessary in order for tropical cyclogenesis to become possible. Such a scenario does seem logical. A mid to upper level trough is positioned over much of the Gulf of Mexico and southeast this morning. This trough will enhance the divergence and outflow over the Yucatan Channel, and a mid to upper level ridge is progged to form over the area. The ridge would equal less vertical shear and latent heat would become concentrated in this region, prime conditions for tropical development when sea surface temperatures are 86ºF.

The possibility of slow tropical development in the northwest Caribbean or eastern/central Gulf of Mexice over the next five days does exist. The likelyhood of any upcoming tropical entity becoming anything more than a tropical storm is considered highly unlikely. Any significant threat to the Gulf Coast would not solidify until a few more days, and nothing more than an increase in heavy tropical downpours along the Gulf Coast should be anticipated this far out. Nothing more than a close watch on the tropics is being called for.

The potential for tropical development in the central Atlantic still exists. None of the global models have backed off from previous runs, and a surface low is still progged to form north of the Virgin Islands. This low would be no threat to land, and it may not even be fully tropical in nature.

Typhoon Dante (04W) is beginning to acquire extratropical characteristics. The typhoon will likely be degenerate within 24-48 hours. There is no threat to land.

http://www.independentwx.com/discussion.html

[skysummit]

Well, I'm glad to know I'm not the only one up at this hour! Thanks for your very in depth analysis!

[southerngale]

Interesting. Thanks TropicalWxWatcher.

[Brent]

Very interesting.