Charley vs Ivan

[stormwatcher]

Overlay Ivan's path on Charley's. VERY little difference. Very little. Including the westward movement when approaching Jamiaca.

[chris_fit]

And forecast.

Too far north and west.

[PurdueWx80]

That's great and all, and could have some slight validity to it, but the synoptic, large-scale pattern is nothing like it was for Charley. There is no full-latitude, record breaking trough in the central US, nor is there one forecast in the next 3-10 days. That is what turned Charley north and then NE into Punta Gorda a month ago. People keep starting posts on this, and I think it only serves to scare people that Ivan will take the exact same path as Charley in the end, even though the two are nothing alike.

[chris_fit]

That's great and all, and could have some slight validity to it, but the synoptic, large-scale pattern is nothing like it was for Charley. There is no full-latitude, record breaking trough in the central US, nor is there one forecast in the next 3-10 days. That is what turned Charley north and then NE into Punta Gorda a month ago. People keep starting posts on this, and I think it only serves to scare people that Ivan will take the exact same path as Charley in the end, even though the two are nothing alike.

http://www.ssd.noaa.gov/PS/TROP/DATA/RT ... -loop.html

Seems like thats enough of a trough to me. I doubt this is going to the panhandle.

[stormwatcher]

You are absolutley correct that you cannot predict a storm's path on the path of a previous one; however, everybody is talking about the west movment like it was unexpected and it was it sort of a way. But studying these storms all over the world shows a history that when these large storms approach a land mass they seem to move left prior to landfall. By the way people should be scare in a healthy way. IF you have never been though a cane you will never fully understand.

[Weatherboy1]

Purdue -- you are absolutely correct, there is not as strong a trough involved with Ivan as there was with Charley. But it sure looks to me on WV that the trough that is there is digging fairly far S and E. The brightest area on WV is now all the way into the FL Panhandle, and some energy appears to be diving SE into the base of this thing in the W GOMEX. Meanwhile, the ridging over FL appears to be collapsing due to the digging US trough and the massive ULL approaching the Bahamas. Shouldn't this -- at the very least -- lead to an almost complete stall ... and possibly a northerly turn earlier than forecast? I believe we're safe here in SE FL now, but I'm not so sure about this thing making it as far west as Panama City Beach, or even the Tallahassee area.

[chris_fit]

exactly my thinking weatherboy1.

Way to go Avila for adjusting the track even more west at the 11am

[PurdueWx80]

The only trough in the GOM is a small upper level low in the Bay of Campeche. The dry feature you see in the NW Gulf is a ridge.

http://www.rap.ucar.edu/weather/upper/upaCNTR_300.gif.

Notice the broad clockwise flow centered over Mexico - this is indicative of an upper ridge and not a trough.

The trough forecast to back down into the Gulf is still in the central US, and only the southern part will pinch off. Some models don't even take this into the Gulf, so it isn't a sure bet either way. With a gi-normous piece of energy digging into the Pac NW now, and much more to come in a couple of days (try a jet max w/ speeds above 120 kt), that means large height falls in the west, acting to carve out the trough in the west and a ridge in the east. There will still be this ambient upper trough I'm talking about to fudge things up, but it should be along the western Gulf and up into the TN valley. That means broad and weak SW flow over the Gulf, that will weaken over time. The longer Ivan takes to get to the Gulf, the less chance he'll have feeling the effects of this. In fact, if anything, it would help ventilate the storm.