ATL: IRMA - Models

[txwatcher91]

I've lost track of how many times this season the GFS has fooled me showing a Tropical Atlantic hurricane many runs in a row only to drop it suddenly in just 1 run. The takeaway is despite the season peak just being less than 2 weeks away the Tropical Atlantic remains EXTREMELY unfavorable for whatever reasons.

No, the new GFS just does not handle TC formation very well. Once a storm forms, it does pretty well with track and intensity but it does not do well with picking up on formation. Other models like the Euro, CMC and UK along with their ensembles are much more useful for developing storms. 93L almost has a closed LLC and very well may be a TD/TS within 12-24 hours if current trends continue.

[jlauderdal]

Just for giggles...here is the 12z Canadian slowly moving WNW at the end of the run approaching the southern Bahamas lol




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with that ridge setup in the model we can see where its headed

[chaser1]

I've lost track of how many times this season the GFS has fooled me showing a Tropical Atlantic hurricane many runs in a row only to drop it suddenly in just 1 run. The takeaway is despite the season peak just being less than 2 weeks away the Tropical Atlantic remains EXTREMELY unfavorable for whatever reasons.

Huh????

The GFS has cried wolf far more times than I can keep track.

How in the world does a potentially faulty and inconsistent global model have anything to do with the rest of your statement???????

".....The takeaway is despite the season peak just being less than 2 weeks away the Tropical Atlantic remains EXTREMELY unfavorable for whatever reasons."

So..... because you believe that a particular model sucks causing you to have little or no faith in its modeling, means conditions over the tropical Atlantic are "Extremely unfavorable"??

[KWT]

Well the GFS is doing a classic GFS and totally dropping the system, I seem to recall it did the same with both Gert and Harvey and that didn't turn out like the GFS expected on both fronts...

Track wise, if something forms there is something begin to resemble agreement on that WSW bend and that is bad news.

[Langinbang187]

Man the GFS really is terrible.

[BensonTCwatcher]

12z GFS - whatever its level of development of 93L, is showing the vort. coming east of Cuba and impacting S FL. CMC and Euro are not really that different considering it's 240+ hours out . I think the thing to watch is the overall trend in globals is for significant ridging getting in place at the system ( if it survives) makes it approach to the islands. Always worries me for mid September high pressures in the basin. I would prefer to see all kinds of troughs depicted.

[KWT]

GFS doesn't seem to have a very good intia hold in terms of strong the vorticity actually is at the moment, looks a good deal stronger in reality than the GFS has it currently.

It then pinches off a upper low and sits it right in 93L's path which impinges shear onto it, nothing too major but enough to cause some issues.

It also wraps around it some dry air, which combined with the moderate shear and under-developed start simply choke the system off totally.

Ironically the CMC is much closer to the truth of the vorticity of 93L in its initial estimation which supports the idea it does develop and handles the upper low very differently as well.

[NDG]

Surprise surprise, the GFS is trending toward the Euro of stronger Atlantic ridging.

http://i.imgur.com/jlrS6W3.gif

But what really shows is little to basically no development through the run.

If the GFS shows no development then it means development

The point here is that we most likely see a strong Atlantic ridge to keep the system from curving out to sea before the 50th longitude, development or no development.

Edit: Funny how the GFS ends with yet another ghost storm in the EPAC just west of C.A. for like the 300th time in its long range forecast.

[forecasterjack]

Remember that time the GFS didn't develop a TS that already existed? Yeah I don't have a lot of faith in that model for TC anything. Let's see what ensembles show. The pattern is locked and loaded. Will either be a hit or a close call IMO.

[chaser1]

Well the GFS is doing a classic GFS and totally dropping the system, I seem to recall it did the same with both Gert and Harvey and that didn't turn out like the GFS expected on both fronts...

Track wise, if something forms there is something begin to resemble agreement on that WSW bend and that is bad news.

YES, exactly. This is what the basic take-away and general benefit (limited as it may be) that the GFS is contributing here. Not to say that the EURO won't come in a little (or a lot weaker).... I don't really know.

For the folks out in the Leeward Islands, Virgin Islands, and Puerto Rico I sure DO hope there may be disruptive upper level conditions that will temper a well organized system from barreling into them. Beyond that, the last thing that the Bahamas, Florida, Gulf Coast, or E. Seaboard want to see, is a strong tropical wave to fly under the radar only to find far more hospitable conditions further west - a la Harvey. It's NOT about the parts of the Atlantic where atmospheric conditions ARE hostile that cause hurricanes to destroy property and kill people, it's those regions within the Atlantic that ARE conducive for development that cause devastation of the likes of Hugo, Andrew, Charlie, Katrina, Harvey (and MANY MANY others throughout history).

[sma10]

I've lost track of how many times this season the GFS has fooled me showing a Tropical Atlantic hurricane many runs in a row only to drop it suddenly in just 1 run. The takeaway is despite the season peak just being less than 2 weeks away the Tropical Atlantic remains EXTREMELY unfavorable for whatever reasons.

Not sure how this is relevant to 93L (unless you are making this claim based on 1 run from 1 model) but neither here nor there; what DOES seem to be apparent is that conditions in the Western Atlantic and Gulf of Mexico are at least fairly favorable, and that's where all the people live, so that kind of trumps the importance of an "EXTREMELY unfavorable Tropical Atlantic".

[ace]

YES, exactly. This is what the basic take-away and general benefit (limited as it may be) that the GFS is contributing here. Not to say that the EURO won't come in a little (or a lot weaker).... I don't really know.

For the folks out in the Leeward Islands, Virgin Islands, and Puerto Rico I sure DO hope there may be disruptive upper level conditions that will temper a well organized system from barreling into them. Beyond that, the last thing that the Bahamas, Florida, Gulf Coast, or E. Seaboard want to see, is a strong tropical wave to fly under the radar only to find far more hospitable conditions further west - a la Harvey. It's NOT about the parts of the Atlantic where atmospheric conditions ARE hostile that cause hurricanes to destroy property and kill people, it's those regions within the Atlantic that ARE conducive for development that cause devastation of the likes of Hugo, Andrew, Charlie, Katrina, Harvey (and MANY MANY others throughout history).

Folks here in the Gulf are watching 93L...but we'd REALLY love to know where to find more information about a spin up in the BOC this weekend or next week.

[SouthFLTropics]

I'm seeing quite a bit of GFS bashing here now that it shows 93L coming in much weaker than previous runs. Keep in mind that the GFS very accurately predicted the demise of 92L as it was approaching the Bahamas. I wouldn't discount the possibility that the MDR and a good portion of the Atlantic basin, save for a few very specific areas, continues to be unfavorable for tropical development.

[AxaltaRacing24]

I'm seeing quite a bit of GFS bashing here now that it shows 93L coming in much weaker than previous runs. Keep in mind that the GFS very accurately predicted the demise of 92L as it was approaching the Bahamas. I wouldn't discount the possibility that the MDR and a good portion of the Atlantic basin, save for a few very specific areas, continues to be unfavorable for tropical development.

The problem is that it drops the system. If you look at it now it literally has a 95% chance of become Irma before next Monday. It might be weak at first but it's most likely going to develop. Conditions are going to be a lot more favorable than when 92L was around.

[KWT]

I'm seeing quite a bit of GFS bashing here now that it shows 93L coming in much weaker than previous runs. Keep in mind that the GFS very accurately predicted the demise of 92L as it was approaching the Bahamas. I wouldn't discount the possibility that the MDR and a good portion of the Atlantic basin, save for a few very specific areas, continues to be unfavorable for tropical development.

I can't disagree, however the main thing I do notice with the GFS 12z is it has a BAD representation of the strength of 93L right now, and since it never relaly builds 93L beyond that initial strength, it does make it a suspect run for that reason alone. Of course who knows the worse downstream conditions the 12z has shown will or will not happen, I think conditions aren't going to be all that great before 50W but we will see.

Hard to trust a models forecast when it hasn't even got 00hrs all that well represented.

12z ECM analysis is also a little on the weak side, but it is closer to the mark than the GFS for sure.

[chaser1]

YES, exactly. This is what the basic take-away and general benefit (limited as it may be) that the GFS is contributing here. Not to say that the EURO won't come in a little (or a lot weaker).... I don't really know.

For the folks out in the Leeward Islands, Virgin Islands, and Puerto Rico I sure DO hope there may be disruptive upper level conditions that will temper a well organized system from barreling into them. Beyond that, the last thing that the Bahamas, Florida, Gulf Coast, or E. Seaboard want to see, is a strong tropical wave to fly under the radar only to find far more hospitable conditions further west - a la Harvey. It's NOT about the parts of the Atlantic where atmospheric conditions ARE hostile that cause hurricanes to destroy property and kill people, it's those regions within the Atlantic that ARE conducive for development that cause devastation of the likes of Hugo, Andrew, Charlie, Katrina, Harvey (and MANY MANY others throughout history).

Folks here in the Gulf are watching 93L...but we'd REALLY love to know where to find more information about a spin up in the BOC this weekend or next week.

Heres a link to the GFS from this a.m.
www.tropicaltidbits.com/analysis/models/

There looks to a new surge of energy entering the BOC in about 72 hr's. At 110 hrs pressures appear to drop throughout the W. Gulf. Somewhere around 210 hr.s was where I noticed a tropical system beginning to take shape. Remember.... it's the GFS so don't overly focus on the details as much as the potential trend

[AutoPenalti]

GFS since the update has had a bad measure of the upper atomosphere.

[ColdMiser123]

New Euro is further NE and stronger compared to the 0z run. GFS completely on its own.

[Blown Away]

12z Euro way N & E of 00z through 72 hours, likely OTS...

[SouthFLTropics]

It's about 1.5 degrees further north than the 00z. Definitely further NE than yesterday's 12z.