ATL : TROPICAL DEPRESSION ERIKA (06L)

[Orrie]

That was uncalled for.

[Derek Ortt]

the convection appears as if it is starting to weaken. Starting to wonder if my 30-40% chance of development is too high now

[cycloneye]

Note=-Edited above posts that had giant text in quotes to resize them.

[artist]

Note=-Edited above posts that had giant text to resize them.

thanks cycloneye

[Sanibel]

I'd wait for another d-max later today before lowering the expectation.

[SapphireSea]

After a long time of being away and lurking, I will have to agree with the pros on this one. In the event that this gets it's act together, according to the focast height map posted by wxman before, this is a likely path for an intact 500mb steered system, in my opinion. I'm sure since i'm not an expert that my path may be a tad east than what would actually happen.

[Lurker]

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Thank you. I have seen forecast discussions mention that if a well defined center is not establish model runs can be misleading. The next time I see a discussion I'll link to it so the pros can review it and tell us what they're referring to.

[artist]

After a long time of being away and lurking, I will have to agree with the pros on this one. In the event that this gets it's act together, according to the focast height map posted by wxman before, this is a likely path for an intact 500mb steered system, in my opinion. I'm sure since i'm not an expert that my path may be a tad east than what would actually happen.

thanks for that depiction SapphireSea. It helps to see what could be steering this.

[curtadams]

That Quickscat shows a really bizarre windfield. This is a weird one.

Looks like a classic open wave, which it probably is based on that center fix provided by WxMan57.

Gale-force WSW winds blowing *away* from a surface trough don't fit my concept of "classic open wave".

[dolebot_Broward_NW]

Quick question - outflow boundaries on Plains thunderstorms are often indicators of a collapsing storm. How do they feature in the organization of a developing TD?

I.e. is this a signature of increasing or decreasing organization of 94L?

This is one area where I do know a bit, but I am not a pro or even a student met, so take my words with a disclaimer.

Convection is something critical to the development of a tropical system. Its sort of the fire in the combustion chamber so to speak. Without convection, you have no continuing storm, no engine, no way to keep the LLC going and develop winds. Without the heat exchange that occurs and develops into a continuous process, the storm will not survive.

An outflow boundary is literally where convection has stopped or weakened, and there is not enough lift to support the mass of moist air that has been lifted. Literally the mass of air collapses on itself and since the air has nowhere to go it shoots out radially from where the convection has collapsed. The visible component is an arc of clouds shooting quickly from the CDO.

If you see an outflow boundary coming from a developing system, it is a sign that the system is not developing. If you see them on an established system, expect weakening. You may also see them during land interaction which is caused more by terrain than by convection collapsing.

[cycloneye]

Latest image shows clearly the LLC.

[Stormhunter27]

Thanks Derek - much appreciated.

What amazes me about 94L is the fact that you can get such a nice looking presentation on what is, essentially, an open wave. Something new everyday...

[curtadams]

2nd cycloneye. That quickscat is from last night. You can't miss the circ today on RGB.

[Nimbus]

If a center does not form under the CDO the storm will remain weak and track with the shallower steering. A strong storm with a structure that is more symmetric would have a better chance of developing into a hurricane that would respond to deeper steering. A major hurricane can actually change the steering environment by pumping up the ridge it is traveling in. Troughs often seem to dig deeper for stronger storms.

SIZE MATTERS!

[cycloneye]

RGB image.

[Blown Away]

Allan Huffman's (RaleighWeather) take on 94L this morning for those who are interested. http://www.examiner.com/examiner/x-4053-Raleigh-Weather-Examiner~y2009m9d1-Invest-94-has-plenty-of-question-marks

That was a good read, nice when it's broken down for us amateur's to understand. My take on 94L is, if 94L survives, it should continue WNW for the next 72-96 hours and be east of the SE Bahamas. The trough that moves in early next week is forecasted to be minor so if 94L does not gain enough latitude that trough may not be deep enough to pick up 94L and allow 94L more west towards Cuba or SFL. If 94L is far enough N that trough may pick up 94L and move towards the Carolinas or out to sea. It's very early but it seems that minor trough early next week will decide if the CONUS get's affected by 94L. JMHO

[SapphireSea]

I always thought, if the atmosphere is condusive enough, there can be all sorts of impressive convection that has nothing to do with a TC or a forming TC. Infact, this wave looks similar to 1996 Bertha as it left the African coast. Infact, time after time again; we see impressive blobs of convection over africa and are not necessarily TDs or TSes for the sole reason of: Lacking a closed LLC.

The fact that outflow is spewing out is definately a sign of weakening. If the pro mets are right, then the atmosphere should have stabilized enough and this should be the end for this in the shortrun.

[vbhoutex]

After looking at several different loops including those posted here I am officially in ????? mode!!!
Possibilities, imo, are Luis is right and there is a LLCC as he has pointed out or we still have 2 or 3 vortexes rotating around the still elongated CC. With all the outflow boundaries 94L has been spitting out I lean towards the latter, but officially stay ?????????
I think that we all are going to learn something from this one in the end.

[Blown Away]

RGB image.

Give me that lat/long where you see that LLC.

[tolakram]

There is a circulation feature at 18, 56. You can see it on both loops.

I have no idea if it's an llc forming, or just another swirl, but I see it.