Clark
Meteorologist
Reged:
Posts: 1710
Loc:
|
|
Tropical Storm Harvey has become much better organized as a tropical cyclone during the course of the day today, with a nice -feature near and just to the north of the center of circulation. Maximum sustained winds were near 65mph as it passed Bermuda and remain at that level now. As it begins to be caught by a midlatitude trough currently to its north, the system should continue moving generally towards the east and northeast, perhaps slowing down in the 1-2 day time frame before accelerating once again. Shear will become an increasingly large factor as the system moves away, though the acceleration will help negate some of its effects; water temperatures should remain favorable to about 40N or 45W, whichever the storm passes first. Short-term, some minor strengthening is possible with the storm having an outside shot at hurricane intensity, with gradual weakening beginning in about a day to day and a half. transition is possible beginning in about 4 days.
As Harvey accelerates to the northeast, it should leave behind a narrow trough of low pressure to the SE. I'm not buying another area of low pressure forming along it like some of the models are calling for, however, as an approaching upper-low from the central Atlantic should begin to erode the southern extent of this trough and not allow for anything to become organized. This upper-low is retreating to the west-southwest at a good clip (now through the northern Lesser Antilles) in advance of the soon-to-be Irene, currently located near 13N and 34W. This system (95L) has continued to become better organized through the day, with an area of convection now consolidating over the center of circulation. It is still being sheared slightly by an upper-low to its north, but the shear has been weakening (this upper-low "swallowed" another weaker feature from the SE recently) and should continue to do so as the system moves west, an upper-ridge builds in, and the upper-low gradually fills and moves out to the northeast.
Slow and gradual strengthening is likely with this disturbance/depression over the next day or so, with the potential for more substantial strengthening once it gets to about 40-45W. Models are calling for an upper-level ridge to build westward with the storm, something I do not disagree with as the signs of this occurring are already in place With Harvey unlikely to leave behind anything to help capture this storm -- it's just too far north and too far in advance of this storm -- a gradual stair-stepping track for the future Irene is likely through 5 days, potentially bringing it to a position east of the northern islands at that time. Intensity at that point is up in the air, but I see no reason to disagree with the statistical guidance at this time, which brings it to minimal hurricane strength. If anything, I'd trend a little stronger. Only thing really impeding it is a bit of dry air, which should become less of a concern through time.
Beyond that, it still remains to be seen whether or not the storm is captured by a trough and recurves out to sea. A developing low along the northern Gulf coast will help to maintain the current weather pattern across the east -- ridge to the north, weakness in the south -- through the weekend, with some hints at a building ridge after that. Of course, that would tend to build a trough to the east over the open waters...but how strong, where it is, and where the storm is at that point are all up in the air. Any US impact is 10 days away, meaning it's just something to watch for now.
Other features of interest include the aforementioned low along the northern Gulf coast and another wave about to exit the coast of Africa. The low along the northern Gulf coast is more of a mid to upper-level feature at this time but, given the warm waters offshore, stands a chance at potentially spinning up a weak system late in the weekend. Wouldn't give it a big shot, though, but it'll likely keep the Florida Panhandle and deep south rather wet for the next few days. The wave emerging off of the coast of Africa is small but has a nice signature on satellite imagery...it's being sheared by a trough along the west coast of Africa right now, though, and needs to keep far enough back off of the developing Irene to have a shot. There's some model support for it, however, notably from the ...so it too should be watched. The has done a bit better with genesis this year, for what it's worth, due to some improvements made in the model. It's still several days from doing anything of note, however.
More as events warrant...
--------------------
Current Tropical Model Output Plots
(or view them on the main page for any active Atlantic storms!)
|
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
