ATL: IRMA - Post-Tropical - Discussion

[txwatcher91]

Any system that is nearing 20N 40W is usually a recurve (fish) system. I was trying to explain that yesterday but many put too much on the models, and not enough on basic meteorology. The further east and north a system forms, the more likely it will recurve.

This morning a local OCM (who worked at TWC) said the same, that a system in it's current location usually does not pose a threat to South Florida, but he would monitor it, just in case.

Frank

The problem is that storms which pass through the Herbert Box rarely recurve, and this storm is forecast to move through that. Using the current location is a bit misleading IMO, and when looking at the Euro ensembles, almost every member takes this through the Herbert Box at which point the odds of a US landfall increase to around 80% and only 20% chance of a recurve...

[BucMan2]

Good morning to all- Please remember that as quickly as some models changed in 24 hours they can change right back in 24 hours. My point
is that no scenario is set in stone 9-10 days away no less 3 days away. All it takes is one trough that is not as strong or as weak as predicted .
Stronger high then predicted building back or pulling away- so stay tuned and see if we have a Floyd , Donna , Hugo, Sandy scenario-Have a safe
holiday weekend-

Craig

[NDG]

[Aric Dunn]

I see the ERC is still going on.. though it looks like its nearly done.. it fooled me last night with the lack of microwave and decent satellite images.. but it is what it is.

from 4 plus hours ago.. its likely nearly complete next few hours should see a return of deep convection and a slowly clearing larger eye



also notice the euro made a big shift to the right. good new for everyone

[Frank2]

Living in South Florida for most of my life, it's common knowledge that any storm at that far east and north usually (of course nothing is 100%, but usually) does not pose a threat, and why the local OCM (who is a meteorologist) made the comment.

P.S. Hope all is well in Poughkeepsie...

Frank

[txwatcher91]

Living in South Florida for most of my life, it's common knowledge that any storm at that far east and north usually (of course nothing is 100%, but usually) does not pose a threat, and why the local OCM (who is a meteorologist) made the comment.

P.S. Hope all is well in Poughkeepsie...

Frank

Frank, any reason why you don't think a storm passing through the Herbert Box is a threat when climo argues for 80% odds that it will impact the US? Just curious since the current location is a bit misleading to use climo with.

[Blown Away]

[WeatherGuesser]

Living in South Florida for most of my life, it's common knowledge that any storm at that far east and north usually (of course nothing is 100%, but usually) does not pose a threat, and why the local OCM (who is a meteorologist) made the comment.

I guess we'll know in a week or so, but until then the back and forth really isn't all that productive.

[Frank2]

The problem is that storms which pass through the Herbert Box rarely recurve, and this storm is forecast to move through that. Using the current location is a bit misleading IMO, and when looking at the Euro ensembles, almost every member takes this through the Herbert Box at which point the odds of a US landfall increase to around 80% and only 20% chance of a recurve...

It's funny people mention the Hebert (not Herbert) Box because I worked for Mr. Hebert many years ago. From what I was told, the box was based on a lower-latitude system moving west-northwest - that would not be the present high-latitude system...

Frank

[hohnywx]

The problem is that storms which pass through the Herbert Box rarely recurve, and this storm is forecast to move through that. Using the current location is a bit misleading IMO, and when looking at the Euro ensembles, almost every member takes this through the Herbert Box at which point the odds of a US landfall increase to around 80% and only 20% chance of a recurve...

It's funny people mention the Hebert (not Herbert) Box because I worked for Mr. Hebert many years ago. From what I was told, the box was based on a lower-latitude system moving west-northwest - that would not be the present high-latitude system...

Frank

Frank, the system will be at a lower-latitude and will be going WNW through the box. Perhaps an illustration of the NHC track will help?

http://www.nhc.noaa.gov/refresh/graphics_at1+shtml/085120.shtml?cone#contents

[eastcoastFL]

has the NHC put the forecast points up on the floater yet? If so does anyone have a link?

Edit: Nevermind. i found one http://www.ssd.noaa.gov/goes/east/catl/h5-loop-vis.html

[txwatcher91]

The problem is that storms which pass through the Herbert Box rarely recurve, and this storm is forecast to move through that. Using the current location is a bit misleading IMO, and when looking at the Euro ensembles, almost every member takes this through the Herbert Box at which point the odds of a US landfall increase to around 80% and only 20% chance of a recurve...

It's funny people mention the Hebert (not Herbert) Box because I worked for Mr. Hebert many years ago. From what I was told, the box was based on a lower-latitude system moving west-northwest - that would not be the present high-latitude system...

Frank

Sorry, my auto-correct also changes it from "Hebert" to "Herbert" lol. If this does indeed pass through it though, I do believe the odds go up significantly based on what we've seen with past storms. It's pretty rare for a storm at this latitude to pass through it so there isn't much to compare it to other than previous storms that did pass through it from lower latitudes. I think the end result will ultimately be the same, if there is ridging strong enough to promote a high latitude storm going WSW or SW enough to pass through it, then IMO chances are good that it impacts the CONUS. With the Euro ensembles largely indicating a FL or NC threat, I think it's safe to say these are the two areas that need to watch this the closest. We will find out in a few days when we see how far SW Irma ends up.

[Frank2]

The NHC discussion has mentioned their southern bias the past few advisories, but I'll guess they will steer away from that very soon, and that will put the forecast track outside the area.

The forecasters base a lot on persistence, and Irma has been very persistent to the WNW and the reason the models are trending right, versus yesterday's more southern route...

Frank

[eastcoastFL]

According to this http://www.ssd.noaa.gov/goes/east/tatl/h5-loop-rb.html
the SST's really start to heat up as Irma hits her SW forecast points. Looks like she is currently in 27degree waters and will be approaching 29-30 as she dips south

[eastcoastFL]

 https://twitter.com/ClimateChaosBot/status/903610007316557824

[JPmia]

Woah with 1 model run ECMWF out to sea this place is dead lol.

Yep, it's just us dead-enders, the diehards.

[txwatcher91]

The NHC discussion has mentioned their southern bias the past few advisories, but I'll guess they will steer away from that very soon, and that will put the forecast track outside the area.

The forecasters base a lot on persistence, and Irma has been very persistent to the WNW and the reason the models are trending right, versus yesterday's more southern route...

Frank

The Euro has this going WNW through tonight before starting the W then WSW/SW dive. We probably won't have a good idea if the Euro or GFS will be right as to how far SW this gets until Monday or Tuesday. Considering the strong EPS/Euro agreement and the south trends we saw in the short term with the GFS, I imagine the NHC will probably keep things the same. Who knows though, part of hurricane tracking is the unpredictability of certain elements and figuring out which solution is most plausible

[Aric Dunn]

The NHC discussion has mentioned their southern bias the past few advisories, but I'll guess they will steer away from that very soon, and that will put the forecast track outside the area.

The forecasters base a lot on persistence, and Irma has been very persistent to the WNW and the reason the models are trending right, versus yesterday's more southern route...

Frank

I dont think they are going to change their thinking much. they know that tracks and set ups like this typically lead to longer more prononced westerly motion after the wsw to sw dive. There are a number of physical atributes that point to a southern route. Also dont forget that as this systems bottoms out of the sw dive it will be hitting peak intensity and likely will be pumping of that ridge to its north somewhat and models do not do well with that. It is still quite likely we see a shift south in models the next few runs expecially once it begins that turn to the WSW to SW.

[Weatherboy1]

Morning all! Yesterday, I said it would all be about "watchful waiting" with Irma and nothing has changed for me 24 hours later. The model trend overnight is certainly a bit more encouraging here in South Florida. But we're still a few days from the more reliable "5-7 days to potential landfall" window. I figure by the midday Sunday model cycle, we'll know a LOT more about whether this is a FL/NC/NE or nowhere threat.

[northjaxpro]

I agree Aric. I mentioned the pumping the ridge possibility last night in the Models thread.