"Isaac" Remnants Heading for the Gulf of Mexico; "Leslie" - Large Circulation; ..."Michael" (Not Buresh) in E. Atlantic...........
***** A moderate to high rip current risk at First Coast beaches due to easterly swells from "Leslie" through at least Thu. *****
The mid & upper level disturbance that was "Isaac" will soon be into the Northern Gulf of Mexico & is accompanied by a persistent cluster of showers & t'storms. "Ivan" made a somewhat similar loop in 2004 (see 4th & 5th images below). Forecast models have now pretty unanimously jumped onboard in developing a weak surface low over the North Central Gulf of Mexico the next couple of days as the disturbance returns to the warm water. Based on history ("Ivan" in 2004), if another tropical cyclone were to develop & could be traced to what was "Isaac", it would again be named "Isaac". Models do not develop a strong low, but this is something to watch as there should be eventual interaction with a strong upper level trough that will move into the Eastern U.S. this weekend. There is a good deal of shear over the Eastern Gulf which could limit sustained strong redevelopment, at least the next couple days. Something to watch is the trough this weekend that could enhance the low in the Gulf & should also pull the low northeast. The combination of the tropical disturbance + the strong upper trough could lead to the potential for heavy rain for the First Coast (& much of the Southeast U.S. & Gulf Coast) by the weekend. In fact, heavy rain is already occurring -- & will continue -- along the Gulf Coast. Click here
for updated storm summaries on 'Isaac" from the Hydrometeorological Prediction Center.
IMAGE FROM LAST THU., AUG. 30TH:
IVAN'S TRACK IN 2004:
has been putting up a good fight against moderate to strong shear & is a very broad circulation
. Shear will relax the next few days which could allow for significant strengthening into the weekend & development into a hurricane. The upper level trough in the NW Atlantic will not entirely pick up the cyclone leaving "Leslie" in a weak steering flow which will cause the storm to stall at or just north of Jacksonville's latitude in the Central Atlantic. There could be some jog west but indications are that "Leslie" will still get steered north then northeast in time. If we look at the W. Pacific last week, the 2nd typhoon moved to the China coast west & southwest of Japan, so we'll have to beware of a farther west track in the long run than forecast models are currently indicating. All will hinge on the timing & intensity of what will be a strong upper level trough that will dig into the Eastern U.S. late this week into the weekend. "Leslie" should start to increase its forward speed to the north or north/northwest as the trough approaches. This move north could be helped by an upper low near Florida as the upper low moves east/northeast. In the long run, however, the expansive "Leslie" circulation could end up absorbing the upper low. Very rough surf will likely affect New England this weekend & parts of Nova Scotia &/or Newfoundland could be directly impacted late in the weekend into early next week.
In any case... "Leslie" will be strong enough & large enough to send an easterly swell to First Coast beaches this week increasing the rip current risk.
"Michael" (not Buresh!) in the E. Atlantic has become quite a bit stronger with much better structure. The storm is likely to only move very slowly to the north then turn northwest & is no immediate threat to any land areas. There may be some eventual interaction with much bigger "Leslie" in the N. Atlantic next week. On a historical note....only 2005 & 2011 had the 13th tropical storm before Sept. 4th.
A wave in the far E. Atlantic well south of "Michael" & southeast of "Leslie" at a much lower latitude has recently flared up. This wave will move just about due west the next few days. Other waves will start to come off Africa with renewed vigor by the weekend into next week. There is the potential for long term development.