The remnants of Isaac (90L) have begun to consolidate some over the extreme northern gulf coast, under favorable water temperatures and a favorable upper level environment, being enhanced by an upper level low pressure area just east of Florida, which will also ventilate Leslie. Generally, this system may become a tropical cyclone and could cause a few headaches along the western coast of Florida. The steering pattern over the area of interest is generally towards the southeast, but as the trough of low pressure currently over the upper level midwest moves eastward and captures this system, it should move northeast, and could cause some stormy weather over areas of the southeast, especially Florida. If it gets named it is likely to be named Nadine, not Isaac, because it is a separate area of low pressure, but that decision to name it as such is up to the NHC.
Also of note, the global models (which are available on Allan Huffman’s Weather Model and Data Page), including the GFS and ECMWF have been fairly consistent on showing the tropical wave currently over western africa developing into a significant tropical cyclone, and being a problem for landmasses farther west as we get later into September. The models are currently strengthening the potential storm rather quickly and steering it out to sea. That solution seems somewhat unrealistic given the usual poleward model bias we have seen this year, and the fact that every system has struggled to get its act together over the deep tropics due to the above normal dry air and wind shear that has been hampering tropical development this year. It is too early to speculate what will become of this system and who will be affected, but we do know that some tropical system will try to get its act together from the tropical wave a few days from the coast of Africa. It is likely this tropical system will face some of the same issues as many of the storms before it, with dry air issues in the tropics and with a downward pulse of the MJO, convection will be suppressed overall across the atlantic and conditions as a whole will be less favorable than normal for this time of the hurricane season. However, as we have seen with almost every storm that tries to develop in the tropics this year, it will probably wait until it gets father west, and closer to land to develop where the atmosphere is more moist and where water temps and TCHP values are higher. This is a problem for the United States, the Caribbean islands, the Canadian Maritimes, and Bermuda, as the chances for a landfall are greatly increased under this kind of pattern. Any threat from this system is VERY far away and we have plenty of time to wait and see how this all unfolds over the next few weeks.
2 comments
Jason
September 6, 2012 at 7:35 am (UTC -4) Link to this comment
Eric
September 6, 2012 at 4:30 pm (UTC -4) Link to this comment