ATL: IRMA - Post-Tropical - Discussion

[Blinhart]

A wobble is expected through out the life of a cyclone. So saying that it has stopped a certain direction for a short amount of time doesn't mean that is the direction it will be going for a long time.

[Blown Away]

Irma's a wobbling...

[Frank2]

Current northward influence could be due to the ULL. Not the cleanest environment ahead of it right now (ULL, TUTT, Trough)...

http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

[Hurricane Andrew]

Like I said, I have my doubts on current intensity. Irma looks to be struggling to me. promets...?

[Aric Dunn]

the Eye is definitely wobbling around. however, to get too excited the ridging is only getting stronger and we going to see this strair stepping motion.

Also looks like we have yet another ERC.. though I need some microwave data to confirm.

[LarryWx]

The 11AM NHC coordinates are 17.7N, 48.4W. That means that she is located to the south of all 50 0Z EPS members!! ALL of them are between 18N and 20.5N when at 48.4W. This is a very significant indicator and, therefore, I'm fully expecting further SW adjustments in the EPS mean and probably also in the more volatile Euro operational as well as general model consensus as we move forward. That means increased risks for the Leeward Islands, Virgin Islands, PR, and the entire NE Caribbean. This also means the risk for FL, Bahamas, Hispaniola (especially Dominican Republic), Cuba (especially eastern), and the US GOM coast is continuing to increase as the SW trends continue.

First of all, this likely belongs in the model thread, but regardless, I don't think this is correct. According to Brian Tang's page, verification looks to be well within the plume of 00Z ensembles. What information did you use to make this analysis?

1. I think this thread is appropriate for my post because it isn't just a post about a modeled position. It is an analysis about a recent actual position in relation to a modeled position and what that may portend for trends going forward.

2.Link to 50 EPS member tracks:

http://www.weathernerds.org/tc_guidance ... g?93489127

Look at the 50 or so lines of the members and where they cross 48.4 W. All but one member are essentially within the 18.5 to 20.5 N corridor at the intersection of 48.4 W. I see only one member below that (near 18.0 N). So, the mean is somewhere within 19.0-19.5 N when at 48.4 W. Therefore, the 11AM NHC position of 17.7 N, 48.4 W, is south of where all members were at 48.4 W and a good 1.5 degrees/110 statute miles or so south of the mean at 48.4 W.

I'm not at all bailing on this. However, I will note the recent Irma motion that is more westerly, wobble or not. If that isn't just a wobble, then the future motion would bring her back closer, if not all of the way, to the EPS mean as she moves further west since the EPS members all show a WSW motion all of the way to near 52-53 W.

[LarryWx]

^I'm embarrassed to say that I erred badly. I thought the latitude boxes were at 5 degree intervals. But I see they are at 3 degree intervals. So, my posts are wrong. I apologize. This is definitely embarrassing. I thought the top of the box was at 20N. But it is at 18N.

[KWT]

Current northward influence could be due to the ULL. Not the cleanest environment ahead of it right now (ULL, TUTT, Trough)...

http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

Little wobbles like that could be VITAL for the Ne Caribbean islands, lets hope that continues for as long as possible. Whilst unlikely, there is obviously a small chance it already has bottomed out. As I said unlikely, but well worth keeping an eye on!

[Aric Dunn]

Current northward influence could be due to the ULL. Not the cleanest environment ahead of it right now (ULL, TUTT, Trough)...

http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

Little wobbles like that could be VITAL for the Ne Caribbean islands, lets hope that continues for as long as possible. Whilst unlikely, there is obviously a small chance it already has bottomed out. As I said unlikely, but well worth keeping an eye on!

unfortunately the ridge has not even fully begun to build in. another 24 hours it will be at its strongest then slowly slide/weaken .. this is likely just IRMA bumping into it and stair stepping. but yes all the wobbles need to be watched

[LarryWx]

^Further to my previous post, this means that Irma's 11 AM position was, as SouthDadeFish, thought, very much near the mean 0Z EPS position and not 110 miles south of it as I thought. Again, I'm sorry for my error. I think I need to take a break for a bit.

[Aric Dunn]

so right now as of the 06z gfs members the farthest south member is right at 16n and 55W and it brings the center pretty much landfall on PR. so lets go with that as a lowest point to watch out for. in imera's motion for the next 24 hours.

[Jimsot]

so right now as of the 06z gfs members the farthest south member is right at 16n and 55W and it brings the center pretty much landfall on PR. so lets go with that as a lowest point to watch out for. in imera's motion for the next 24 hours.

Would that bring it closer to Anguilla as well?

[Aric Dunn]

so right now as of the 06z gfs members the farthest south member is right at 16n and 55W and it brings the center pretty much landfall on PR. so lets go with that as a lowest point to watch out for. in imera's motion for the next 24 hours.

Would that bring it closer to Anguilla as well?

yes farther south means farther west.

[Aric Dunn]

Current northward influence could be due to the ULL. Not the cleanest environment ahead of it right now (ULL, TUTT, Trough)...

http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

Little wobbles like that could be VITAL for the Ne Caribbean islands, lets hope that continues for as long as possible. Whilst unlikely, there is obviously a small chance it already has bottomed out. As I said unlikely, but well worth keeping an eye on!

unfortunately the ridge has not even fully begun to build in. another 24 hours it will be at its strongest then slowly slide/weaken .. this is likely just IRMA bumping into it and stair stepping. but yes all the wobbles need to be watched

You can see the Ridge just starting to really build in looking at the steering animation.

should see the wsw motion resume shortly.

http://tropic.ssec.wisc.edu/real-time/a ... 3java.html

[jlauderdal]

^Further to my previous post, this means that Irma's 11 AM position was, as SouthDadeFish, thought, very much near the mean 0Z EPS position and not 110 miles south of it as I thought. Again, I'm sorry for my error. I think I need to take a break for a bit.

You owned it, its all good, your post had good intentions with a math issue

[msbee]

so right now as of the 06z gfs members the farthest south member is right at 16n and 55W and it brings the center pretty much landfall on PR. so lets go with that as a lowest point to watch out for. in imera's motion for the next 24 hours.

Would that bring it closer to Anguilla as well?

yes farther south means farther west.

each forecast is bringing it closer to Anguilla and St Maarten!

[Alyono]

this has made a turn to the WNW. It was decidedly WSW earlier, but has made a turn. Will need to monitor to see if this is a trend, or a short term wobble

[AutoPenalti]

this has made a turn to the WNW. It was decidedly WSW earlier, but has made a turn. Will need to monitor to see if this is a trend, or a short term wobble

Maybe the ridge isn't as strong as models forecast?

[SouthDadeFish]

Over the past 4-6 hours, it looks like there has been a temporary break from the earlier WSW motion, and Irma has been on a more W course. I'm intrigued to see how long this W motion lasts before a turn back to the WSW again. This could have big impacts on how close Irma gets to the Leeward islands/Puerto Rico.

[Macrocane]

Like I said, I have my doubts on current intensity. Irma looks to be struggling to me. promets...?

Well, it kind of struggled earlier this morning but it is making a comeback again.
That's Irma, she struggles for a couple of hours than gets its act together for another couple of hours and goes on and on like that