ATL: IGOR - Ex Hurricane - Discussion

[OuterBanker]

Ahhh, I feel better now. JB is now for the recurve. Even the JMA has switched to a recurve, it was the last model to switch. He said west of Bermuda. Great waves for the surfers though.

[artist]

i believe that a motion N of 265-270 has started in the 90 minutes.

just from viewing this http://rammb.cira.colostate.edu/ramsdis ... _floater_1 in conjunction with the forecast.

probably around 280....which may technically still be "west" ....but this would be better news for islander's.

again this won't jump out at you on this loop...but i think it is something subtle yet slightly changed (the movement direction in the last 3 frames)

It's starting to wobble toward the north, the long term motion could still be 265-270 though. I islander's were in no danger whatsoever even if Igor were to keep heading west all the way to 55W, the trough would eventually pick him up well to the NE of the islands. The only island in danger is Bermuda although now it appears that the models are trending further east and recurving Igor in the same position where Danielle recurved, keeping Bermuda relatively safe. Of course they should closely monitor Igor just in case.

you really need to add the disclaimer when making such a bold statement.

[canes101]

Yes I agree.. Thats why I posted earlier that he may very well be stair stepping north to hit the next forecast point

[theregulator]

Floating between blogs and forums around the net, I found this interesting post on WUnderground:

"From Dr. Masters, regarding the topic of a Hurricane Pumping the Ridge:

"Hi StormW,

Not sure I'll find time to discuss this, but here are some possibly helpful studies:

An interesting study of this problem was performed by Ross and Kurihara (MWR, 1995)
for Hurricane Gloria. They ran the GFDL model with and without the hurricane
included and looked at the differences in the model fields. The differences were
pretty large and spread far from the storm, especially in the upper levels. This
paper provides some evidence for the influence of a hurricane on its environment.

Bob Merrill (1984) did an observational comparison of small and large storms.

There are cases such as Georges (1998) where the mid- tropospheric ridging north of
the TC is relatively weak, yet the TC maintains a general westward heading for some
time. Another example might be Hurricane Donna (1960), when forecasters remarked
out at the long westerly track of the TC even though there were westerly winds at
mid- to upper-levels ahead of it over the Florida peninsula.

A June 2009 JAS study, based on idealized simulations might be of interest:

http://www.atmos.ucla.edu/~fovell/fovel ... o-2009.pdf

Jeff"


Here is a link to the paper on Hurricane Gloria:
http://www.gfdl.noaa.gov/bibliography/r ... 852e8fa2dc 54efeb

One of my favorites on hurricane-environment interaction."

[Battlebrick]

I really don't see this wobble at all.

Edit: Ok now I see it, but its nothing like the SW one we had yesterday. We'll wait to see if it continues like that.

[KWT]

Looks to me like its right on for the NHC track and moving probably about 275-280 right now, I did think the slowdown earlier on was the start of the turn more towards a WNW/NW heading and I think we are starting to see that occur...

If it follows the NHC track Bermuda could be in real trouble.

[Aric Dunn]

Looks to me like its right on for the NHC track and moving probably about 275-280 right now, I did think the slowdown earlier on was the start of the turn more towards a WNW/NW heading and I think we are starting to see that occur...

If it follows the NHC track Bermuda could be in real trouble.

there is not 280 motion or 275.. its 270 at best.. and it has not slowed down today.. still 9 kts..and was south of the NHC track. they had to adjust it again..

[FLpanhandle91]

Slight turn north of west now. Very slight so far. I'm still undecided if this is a wobble or a definite turn.

[mufasa157]

5 PM Advisory is out:

5:00 PM AST Mon Sep 13
Location: 17.7°N 50.5°W
Max sustained: 150 mph
Moving: W at 10 mph
Min pressure: 933 mb

[FLpanhandle91]

5 PM Advisory is out:

5:00 PM AST Mon Sep 13
Location: 17.7°N 50.5°W
Max sustained: 150 mph
Moving: W at 10 mph
Min pressure: 933 mb

What's keeping this storm from reaching cat 5 status? Lack of high cloud tops?

[KWT]

there is not 280 motion or 275.. its 270 at best.. and it has not slowed down today.. still 9 kts..and was south of the NHC track. they had to adjust it again..

Look at the IR loop in the last 2hrs, I think its quite obvious its moved a little north of west, nothing too much but its not due west anymore I'm certain.

[cpdaman]

5 PM Advisory is out:

5:00 PM AST Mon Sep 13
Location: 17.7°N 50.5°W
Max sustained: 150 mph
Moving: W at 10 mph
Min pressure: 933 mb

so it climbed .1 latitude N....(which would fit in w a 3hr ....275-280 motion) which is still W ...WNW is 281.25-303.75....again very subtle but i think...it's days of 270 (3hr motion is over)....based on the forecast and what i am seeing

[wxman57]

5 PM Advisory is out:

5:00 PM AST Mon Sep 13
Location: 17.7°N 50.5°W
Max sustained: 150 mph
Moving: W at 10 mph
Min pressure: 933 mb

What's keeping this storm from reaching cat 5 status? Lack of high cloud tops?

It takes nearly perfect conditions at all levels for a hurricane to reach Cat 5. Currently, microwave imagery indicates that the eyewall may be a bit weak in some areas. And cloud tops are just a tad "warm". NHC doesn't easily give a Cat 5 upgrade for a system out to sea. There needs to be a better Dvorak representation for Cat 5.

[plasticup]

I don't understand what people are so worked up about. Yes, it traveled west all day, but it wasn't supposed to turn until tonight. The synoptics are verifying and the storm is on track.

[Aquawind]

Wow! What a big ugly beast getting even bigger and stronger!! That is an amazing visable loop... ACE Daddy for 2010!

[artist]

what was the previous best track position?

Here are the last two 06z and 12z.Still waiting for 18z.

AL, 11, 2010091306, , BEST, 0, 177N, 484W, 130, 935, HU,

AL, 11, 2010091312, , BEST, 0, 176N, 492W, 130, 933, HU

and the newest-

5 PM Advisory is out:

5:00 PM AST Mon Sep 13
Location: 17.7°N 50.5°W
Max sustained: 150 mph
Moving: W at 10 mph
Min pressure: 933 mb

[Aric Dunn]

there is not 280 motion or 275.. its 270 at best.. and it has not slowed down today.. still 9 kts..and was south of the NHC track. they had to adjust it again..

Look at the IR loop in the last 2hrs, I think its quite obvious its moved a little north of west, nothing too much but its not due west anymore I'm certain.

the NHC literally just released the advisory 15min ago. the position was still 17.7N ( same as the best track) if it moved north of west in the last 2 hours they would have adjusted the lat position. you dont track the EYE.. since the LLC is always off set from the MLC and up. the "wobble" was and is a illusion of eye expanding and contracting. now if over the next few hours it can at least get to 18N ( which is does not seem like it wants to right ) then we can say its just north of west. it should eventually start wnw but has not yet.

[cpdaman]

there is not 280 motion or 275.. its 270 at best.. and it has not slowed down today.. still 9 kts..and was south of the NHC track. they had to adjust it again..

Look at the IR loop in the last 2hrs, I think its quite obvious its moved a little north of west, nothing too much but its not due west anymore I'm certain.

i was echoing the same...but i do see a slight wobble back just S of due west on the last frame or so here

and now a wobble just south of west (puts foot in mouth) at 445

http://rammb.cira.colostate.edu/ramsdis ... _floater_1

gonna watch how this plays out over at least another hour before re-negging on the 275-280 motion.

[artist]

from the advisory at 5-
HOWEVER...DUE TO THE
INITIAL POSITION AND MOTION...THE OFFICIAL FORECAST HAS AGAIN BEEN
ADJUSTED A LITTLE TO THE LEFT OF THE PREVIOUS ADVISORY THROUGH 48
HOURS.

[WeatherLovingDoc]

Ah, my first wobble! Generally I'm more the big picture type.