Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Atlantic Tropical Action 2012 - Part II


Recommended Posts

The 0z Euro and 0z/06z GFS demonstrates some of the points outlined. 0z GFS is too far south, and it opens back into a TW. 0z Euro is too far north and crashes with Hispaniola and is kept very weak because is under the influence of the TUTT. Finally, 06z treks over Barbados, a bit north of the 0z run, and fares a lot better, keeping a distinct circulation until it reaches the W Caribbean, where it restrengthens before visiting Chetumal.

sun.gif

P.S. Split the difference between the 00Z Euro and the GFS, and you have a nice track. cool.png

Link to comment
Share on other sites

  • Replies 1.4k
  • Created
  • Last Reply

Given what I've seen on visible imagery and the recent microwave passes, its likely that 99L already has a surface circulation, and whether or not this system gets upgraded to a TD will likely be due to how its convective organization progresses over the next 12-18 hours.

That convective organization is not a given yet. We are still in the middle of a battle for synoptic pattern dominance. In one corner, we have a strong upper level trough thats still inducing significant westerly shear over the Atlantic basin, especially between 40-60W 15N and above. On the other, we have a significant convectively coupled kevin wave (CCKW) which should enhance upper level easterlies after its passage. As many people have already mentioned this morning, the track of 99L is becoming critically important. A track further south will likely keep it away from the strongest shear of the TUTT, while allowing it to take advantage of the easterly flow and upper level divergence of the CCKW. However, this might make its track across the Caribbean more difficult hugging the South American coastline where the low-level easterly flow is strongest. On the flip side, if the storm goes too far north, the upper level westerlies will almost certainly rip it apart and decouple the low/mid level circulation centers. However, it might have a chance to better survive in the Caribbean and re-develop in the Western Caribbean.

These two scenarios are highlighted by the ECMWF and the GFS models. The GFS takes the storm further south, and thus, it survives longer than the ECMWF under more favorable upper level conditions. However, the storm struggles when it gets in the Caribbean. The ECMWF is much faster and further north, resulting in less influence of the CCKW (its influence decreases with latitude). In addition, the vertical wind shear is higher which leads to center decoupling from the mid-level center and the system falls apart well before reaching the Lesser Antilles.

28atg87.gif

Looking at the short term trends on visible today, the center is around 12N, 47.5W. This is slightly further south than the ECMWF and slightly faster than the GFS. Thus its really tricky to figure out at this time which model is right. However, if the storm remains further south today, I would lean toward the GFS solution, which should result in the system not accelerating since the synoptic low-level flow should actually slow down after the kelvin wave passage.

Link to comment
Share on other sites

AN AREA OF LOW PRESSURE LOCATED ABOUT 850 MILES EAST OF THE WINDWARD

ISLANDS HAS BECOME BETTER DEFINED. ENVIRONMENTAL CONDITIONS ARE

CONDUCIVE FOR TROPICAL CYCLONE FORMATION...AND THE LOW COULD BECOME

A TROPICAL DEPRESSION LATER TODAY OR TONIGHT. THIS SYSTEM HAS A

HIGH CHANCE...70 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING

THE NEXT 48 HOURS AS IT MOVES WEST-NORTHWESTWARD AT NEAR 20 MPH.

INTERESTS IN THE WINDWARD ISLANDS SHOULD MONITOR THE PROGRESS OF

THIS SYSTEM.

IR looks ghastly, but oh well.

GOES171520122145nBrTK.jpg

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...