ATL: HERMINE - Post-Tropical - Discussion

[Chris_in_Tampa]

First part of mission.

12:34am EDT through 5:35am EDT on August 29th, 2016. Plane position at 5:28am EDT.

Credit: NOAA-AOC



Link: https://youtu.be/5_IJ7DncHwA

[NDG]

TD 9 looks like crap this morning. The consensus this morning is that TD 9 will never reach hurricane strength before reaching FL, even though later today and tomorrow it will start having less northerly shear it will be fighting dry mid level air and only a slow strengthening is expected.
The FL hurricane free streak has a good chance of continuing unless global models start trending the other way once again. The GFS may indeed have the last laugh.

[chaser1]

I don't think 99L warranted the designation of depression when it did. I don't think we're seeing any level of organization at this point that would better make the case for it being a depression than we've seen at at least one or two previous junctures during this systems life-span. Thats not to say that things will not change, but thus far the shear and/or dry air have not.

One reason why it is now TD #9. A LLC.

Thank you for making my point. "An LLC". Like the one a full day ago when west winds closed off a LLC north of the Cuban coastline as determined by surface obs and ships reports. No more broad than what we have right now, and with no lett co-located convection than what we're seeing right now. I could be mistaken here, but I believe surface obs then, also indicated a 1007mb pressure.

[HurriGuy]

These recon fixes are useless. The storm is too weak for that.

I do say though, I do think the llc will tighten up more to the west this morning than what people think.

[Chris_in_Tampa]

Through 6:08am EDT:

[SouthDadeFish]

Recon is finding that the circulation is still closed, with plenty of westerly winds. Actually, it is arguably better defined now than it was yesterday afternoon. However, the convective pattern is still pretty ragged. I find it interesting that the center has seemed to temporarily slow down, likely part of an organization process. The 06Z GFS shows a pretty favorable upper-level pattern developing later today, with shear dropping off as an upper-level anticyclone builds over the top of TD 9. Should that occur, there is a chance the convective pattern could become more organized before dry air begins to affect the system.

[SouthDadeFish]

These recon fixes are useless. The storm is too weak for that.

I do say though, I do think the llc will tighten up more to the west this morning than what people think.

I highly disagree. These recon fixes are quite valuable, particularly at night time when cloud motions are not as clear. Additionally, these are NOAA flights, which typically have specialized instrumentation on board for new research projects. It is likely the data collected from TD 9 from these NOAA flights will be helpful in advancing our understanding of the TC genesis process, which is something we really need to understand better as a community.

[HurriGuy]

These recon fixes are useless. The storm is too weak for that.

I do say though, I do think the llc will tighten up more to the west this morning than what people think.

I highly disagree. These recon fixes are quite valuable, particularly at night time when cloud motions are not as clear. Additionally, these are NOAA flights, which typically have specialized instrumentation on board for new research projects. It is likely the data collected from TD 9 from these NOAA flights will be helpful in advancing our understanding of the TC genesis process, which is something we really need to understand better as a community.

Good point

[HurriGuy]

Right on cue for the morning hours. Big convective bursts near the center

[jlauderdal]

Right on cue for the morning hours. Big convective bursts near the center

this system has went from a night owl last week to a rooster this week

[HurriGuy]

https://www.ssec.wisc.edu/data/1min/

First visible shots can be seen here. Not too far off

[jlauderdal]

These recon fixes are useless. The storm is too weak for that.

I do say though, I do think the llc will tighten up more to the west this morning than what people think.

recon fixes are highly accurate in almost all cases and when they arent they will flag it...whether the system is intense or ragged really doesn't matter..they go take their measurements and report back..its a rather simple process actually..this is the usaf we are talking about, they know exactly what they are doing and there is a plan before take off

[GCANE]

The ULL off Savannah looks to be filling in with mid-layer moisture.
http://www.atmos.washington.edu/~ovens/ ... nhanced+24

Checking GFS, 300mb winds, it looks like the forecast is that the ULL will be breaking up or at least weakening in about 24 to 36 hrs.
The other ULL will then be north of Hispaniola.
IMHO, that is the one to watch; it will be perfectly positioned to ventilate TD9 if it starts to ramp up.

[GCANE]

Very high rain-rate cell over Cuba with very cold top.
Looks like it is trying to draw the vort back toward it.

[Blinhart]

Very high rain-rate cell over Cuba with very cold top.
Looks like it is trying to draw the vort back toward it.

that is what I was thinking, drawing the vort further South.

[GCANE]

Seeing a warm core again.
0.5C, 9 km altitude, and about 160 km from CoC.

[GCANE]

It is defintely sucking in moisture. Getting real juicy ahead of it in the GOM.
http://tropic.ssec.wisc.edu/real-time/m ... /main.html

24 to 36 hrs should be interesting.

[ronjon]

Convective mass expanding...shear dropping...UL anticyclone just to its west. Moisture surging off the east coast of Florida from the leftover wave-trough axis will move over the peninsula enriching environment. I think all systems are go for further development now as it moves away from Cuba.

[wxman57]

Looks on track today. Models in excellent agreement on the NE turn early Wednesday with landfall north of Tampa a bit earlier - mid morning Thursday. Could be near hurricane strength then. Out to sea once it passes Jacksonville Thursday evening. Not much impact on the Carolinas. I predict that I may finally get a day off next weekend, maybe even Friday!

[canefan]

Convective mass expanding...shear dropping...UL anticyclone just to its west. Moisture surging off the east coast of Florida from the leftover wave-trough axis will move over the peninsula enriching environment. I think all systems are go for further development now as it moves away from Cuba.

I agree. I think we see a more rapid intensification than what is forecasted. I also think the forecast is greatly underestimating the potential of this system. There is a LOT of warm gulf water ahead of it and a lot of time to tap into it.