#79 Postby ouragans » Sat Sep 22, 2018 9:00 am
wxman57 wrote:I pulled up the GFS and high-res Euro (3-hr intervals) and put together a track for 99L. I plotted mslp in the GFS at 0.25mb intervals and the Euro at 0.5mb intervals. Starting at 15Z (10am CDT this morning), the result is the track below. Both move it at 20-21 kts for the first 3 days, losing the LLC by 24 hours. As it nears the Caribbean by 96 hrs, both indicate slowing to 15-16 kts. Slowing = increased low-level convergence, and both re-find the LLC, but with a pressure of 1006-1008 mb. It moves through the southern islands Thursday morning (5 days) then dissipates north of Venezuela. Looks quite reasonable to me, given the hostile environment in its path.
By the way, the graphic below (and speed calculations) was made using an Excel program developed by my former coworker. He is a whiz at Excel. We set the initial time on the first line then type in an hour interval and lat/lons and it plots each point and calculates forward speed between the points.
http://wxman57.com/images/99L.JPG
Very intesting method
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This post is a personal point of view, not an information. Please refer to official statements for life-threatening decisions.
David '79, Frederic '79, Hugo '89, Iris, Luis & Marilyn '95, Georges '98, Lenny '99, Dean '07, Irma '17, Maria '17, Fiona '22, Philippe '23, Tammy '23
16°13'33.3,"6N -61°36'39.5"W