Ivan moving slightly Right (N) of NHC path now... 285 or so

[calidoug]

Measuring the coordinates carefully from a blow-up of the 1915Z visible image from RAMDIS, I get:

47.14W, 10.36N

Blowing up the 1PM path graph, 47.14W should correspond to 10.22N.

A small difference, to be sure, but small angles matter a lot down the road, should they continue.

Could mean PR vs. Hispanola.

The motion on the Ramdis loop looks like west 4, up 1, or 285 degree motion, not 280.

We'll see how this plays out over the next several hours....

[CourierPR]

Could the subtle difference be due to the strengthening process?

[B-Bear]

Also, could your plot be skewed by the angle of the sat image you're looking at, or are you basing it off of reported positions? That also can make a difference.

[calidoug]

The RAMDIS images are pretty good, I think. Obviously, if they are putting the lat/long lines down incorrectly, the absolute numbers could be off, but the relative (285) movement would still be correct.

It doesn't look like a wobble to me.

Look for yourself:

http://www.cira.colostate.edu/ramm/rmsd ... PICAL.html

(Under GOES E, click the right Vis/IR floater box on the globe, with "visible" and "loop" selected from the menu above it)

[MBryant]

Keep in mind that lattitude does not equal longitude in distance and will affect direction accordingly.

[calidoug]

Sure, but down around 10 degrees the effect is very small indeed.

[BUD]

Ivan moving wnw

[ROCK]

looks west to me...

[Derek Ortt]

was a WNW wobble, now is moving 270 (and that may be giving it too much northward heading)