TD INGRID: Discussions & Images - Last Advisory

[cycloneye]

Derek,is there a center down at 9.7n?

[Derek Ortt]

I didn;t see anything there

[Chris_in_Tampa]

Visible loop:
http://www.meteo.psu.edu/~gadomski/SATA ... m8vis.html

[cpdaman]

just out of curiousity why is there a 60-70 percent chance this wont develop

[hcane27]

Question for the "pro mets"
could the wave immediately following 91L be influencing it's development rate ???
The global models do point to development there as well ....

[x-y-no]

just out of curiousity why is there a 60-70 percent chance this wont develop

As tropical disturbances go, a 30 to 40 percent chance of development is quite high.

[CalmBeforeStorm]

has not organized overnight

still at least 24-36 hours away from ebcoming a TD, if it develops at all. Chances of development remain in the 30-40 percent range

For a strong tropical wave at that location and with conditions forecast to be good and at the peak of hurricane season I would say the percentages are much higher then 30-40 percent.

[Gustywind]

http://www.wunderground.com/tropical/at ... ml#a_topad
Latest of weatherwunderground
12 GMT 09/11/07 11.0N 42.2W 25 1010 Invest

[Sanibel]

It has slowed down to a crawl because it has hit the Atlantic airmass bending down in front of it. I assume this is the ridge (or a part of it). This slow down has slowed development. This wave could bust still like I said last night. The only thing to do is watch and see how it handles the synoptic block in front of it. Look at the visible loop and you'll see the Atlantic airmass bending towards South America in front of 91L keeping it from moving along like Dean. This is now no longer like Dean or Felix. Don't ask me if it will do some crazy poleward move like GFDL in response. I just don't know.

[Gustywind]

has not organized overnight

still at least 24-36 hours away from ebcoming a TD, if it develops at all. Chances of development remain in the 30-40 percent range

For a strong tropical wave at that location and with conditions forecast to be good and at the peak of hurricane season I would say the percentages are much higher then 30-40 percent.

Absolutely....i dont' see why not, shear is good , sufficient amout of moisture better environnement than the previous Dean and Felix only Dean had a better deeper moisture, but given the current conditions and the peak of the season....after the early stages, this could devellop faster than expected......wait and see

[miamicanes177]

just out of curiousity why is there a 60-70 percent chance this wont develop

As tropical disturbances go, a 30 to 40 percent chance of development is quite high.

Not with the environment this finds itself in at the peak of hurricane season. I'm not sure how someone comes to the conclusion that this has a 70% chance of dissipating. I guess if this were fighting off extreme dry air and shear then you could go with a 70% chance of nothing happening, but I do not see that this time.

[skysummit]

12z:

[Sanibel]

I suggest you read what I wrote in my last post. It's hitting a brick wall in the form of the Atlantic airmass in front of it. This is inhibiting development for now. Why do you think it slowed down?

[Derek Ortt]

now why would its slowing inhibit development. That post made no sense at all, Sanibel. It would only make sense if it was being caught by SAL or if there were strong upper level easterlies

[Frank2]

This does seem very similar to the strong wave that was behind Felix, and, likely had some serious potential, but, was blocked by a bending (or a lobe) of the subtropical high (also see topic "Cape Verde Season's Early End?")...

viewtopic.php?f=31&t=97680

Derek, is this similar to the post-Felix event mentioned above?

Frank

[otowntiger]

12z:

Is it really moving that much north? If so and if these models are anywhere near correct, is it possible that this "thing" if it ever develops, would become a fish? Kinda looks that way to me. But I"m no expert and this is not a forcast of any sort.

[Blown Away]

Posted by: JeffMasters, 9:17 AM EDT on September 11, 2007

A strong tropical wave near 11N 43W, halfway between Africa and the Lesser Antilles Islands, is headed west-northwest at 10-15 mph. This system (91L) has the potential to develop into a tropical depression later this week. This morning's QuikSCAT pass continued to showed a broad, elongated circulation and top winds of 25 mph. Satellite loops show no improvement in organization has occurred since yesterday--91L consists of some disorganized clumps of heavy thunderstorm activity. The disturbance is under about 10-15 knots of wind shear. Shear is forecast to remain near 15 knots today and Wednesday, then drop below 5 knots on Thursday. I expect this will allow 91L to develop into a tropical depression on Thursday. The HWRF brings it to a Category 3 hurricane by Sunday, at a position near 19N 58W, about 500 miles east-northeast of Puerto Rico. This is too aggressive an intensification rate, but I expect 91L will be at least a strong tropical storm by Sunday. The 06Z run of the GFDL model is more believable, making 91L a 55 mph tropical storm about 800 miles east of Puerto Rico on Sunday. This storm is definitely a threat to the Lesser Antilles Islands. It is too early to say if the northern islands are more at risk, as the current model runs are indicating. The system may represent a threat to the U.S. East Coast ten or more days from now, but there is no way to judge the likelihood of this.

I guess it's hard to tell w/o a defined LLC, but I don't see the circulation moving NW still looks like it is moving slowly N of due W.

[Sanibel]

Ask the storm Derek. The storm is the best measure. Currently 91L has stalled in development. With a ridge guiding it along the storm is kept under the gradient forcing of the difference between the ridge and the low pressure. When the ridge airmass bends downward in front of it, like what is happening here, it sort of hampers that forcing, making the system slowdown and enter a sort of development limbo (as we are seeing, by the way). With more stable air in front of it, the instability is limited. Furthermore, the SST's it is sitting over don't warm as it hurries west. Just look at the storm. You tell me why it isn't developing in the same area that has already developed two category 5 hurricanes?

You didn't answer my question Derek: "Why do you think it slowed down?"

[CalmBeforeStorm]

http://www.ssd.noaa.gov/goes/east/catl/loop-wv.html
~~~~~~~~~~~~~``````

I think 91L forms further north around 13n maybe at 45 w. This is pretty much what the GFDL has been showing in what could be interpreted as a jog to the NW. If you look at the WV loop the center of the moisture envelope is up around 12.5 to 13.

[Sanibel]

Well at least with an elongated surface feature, anyway, in a forming wave. If what Master's says is correct the wave is under shear AND hitting a blocking feature. That is why it isn't moving along under a strong guiding ridge like Dean and Felix.

They seem to take it west ala GFDL after this works out in a WNW-NW track.