ATL: LAURA - Post-Tropical - Discussion

[TheStormExpert]

HWRF and HMON are almost undoubtedly wrong.

Can’t trust those two until you have a well developed system, and this is nowhere near that!

Can't trust ANY model until you have a system...

Probably will never be able to because TD #13 looks to be on its death bed. Probably a big coupe for the GFS and Euro if so!

[eastcoastFL]

CLose up of the LLC and the new tower firing over it. should expand as a lot of moisture is being pulled in from the south now.

https://re.ssec.wisc.edu/s/U1wmAi

That’s a great shot. It looks like it will slowly expand in the near term. No signs of degrading. I think people should forget about the nhc downgrading anything.

[supercane4867]

[TheStormExpert]

The environment out ahead of TD #13 might be conducive but if it can’t survive this currently unfavorable environment then chances are nothing much will ever come from this.

Besides this season and the models have been nothing but a BIG HEADACHE so far!

[KimmieLa]

That hazy look is a bad sign...

Headed out now for batteries, water, and to fuel up the car...

Hey Sanibel! Great to see you on here. Whenever you post, I listen and learn. What does the hazy look mean, what does it signal? Thanks!

[DestinHurricane]

Can’t trust those two until you have a well developed system, and this is nowhere near that!

Can't trust ANY model until you have a system...

Probably will never be able to because TD #13 looks to be on its death bed. Probably a big coupe for the GFS and Euro if so!

Stop.

[HeeBGBz]

That hazy look is a bad sign...

Headed out now for batteries, water, and to fuel up the car...

We have kind of a hazy cloud cover for 2 days.Mammatus clouds yesterday. If 13 is delayed trying to form up, how close do they have to get the 2 storms 2 effect each other. Also could it be possible to get hit by both?

[eastcoastFL]

HWRF and HMON are almost undoubtedly wrong.

I hope this ages well

[northjaxpro]

How about lets all agree that the models will continue to bounce around run-to-run for a couple more days, and we won't have a good idea what 13 might mean for Florida until the weekend.

As for whether or not this is a TD, well, I said last night NHC should have gone to PTC, and I still think that should be the designation.

Ahh, the occasional fuss among some of us on the threads. It's the beginning of peak season , in an extremely hyperactive 2020 tropical cyclone season. We have two developing cyclones simultaneously, with a third system coming down the pike now coming off Africa.

Yeah, the trials and tribulations of Storm2K forum.Oh what fun it is for all of of us weather geeks is to help get us through the day now for me 10 years strong!!!

[eastcoastFL]

The environment out ahead of TD #13 might be conducive but if it can’t survive this currently unfavorable environment then chances are nothing much will ever come from this.

Besides this season and the models have been nothing but a BIG HEADACHE so far!

What is so unfavorable about the current environment ?

[Hammy]

CLose up of the LLC and the new tower firing over it. should expand as a lot of moisture is being pulled in from the south now.

https://re.ssec.wisc.edu/s/U1wmAi

Looks like it's racing away from the convection.

[NDG]

I would like to see some more discussion from the NHC on the inhibiting factors for organization. The GFS and Euro are not developing but yet when you read the NHC discussion, no mention of inhibiting factors or why the huge difference between the hurricane models and the GFS and Euro. Yet there is something because no way those two models miss this bad in the timeframe we are talking.

Why put so much stock into both models when both have been so inconsistent and have missed development in their short term forecast for both TD 13 & TD 14.
The majority of both models' ensembles are still further developing it.

[sma10]

Can’t trust those two until you have a well developed system, and this is nowhere near that!

Can't trust ANY model until you have a system...

Probably will never be able to because TD #13 looks to be on its death bed. Probably a big coupe for the GFS and Euro if so!

I'm having trouble following this. All models - HWRF, HMON, GFS, EURO, ICON, CMC - show the system struggling all the way to 65W. The difference in modeling occurs afterwards where Euro shows no development. I think you have to wait a few more days before announcing any "coupes"

[AutoPenalti]

Is that the LLC?

[gatorcane]

I would like to see some more discussion from the NHC on the inhibiting factors for organization. The GFS and Euro are not developing but yet when you read the NHC discussion, no mention of inhibiting factors or why the huge difference between the hurricane models and the GFS and Euro. Yet there is something because no way those two models miss this bad timeframe we are talking.

Normally discussions would include something along the lines of “...it is still uncertain how strong TD13 will be by the time it reaches the Bahamas” or “...it is unclear how favorable the environment will be for TD13”

Yes I am looking for something like this which I just wrote up:

The intensity guidance is highly uncertain. Some dry air as well as mid-level shear may hinder development over the next day or two as the depression moves through an area of dry air from the Saharan Air Layer to the SW of an upper-level trough. By days 3 and 4, an upper-level anticyclone over the Bahamas and stretching north of the Greater Antilles should provide a favorable upper-level environment for strengthening as shown by the HWRF and HMON models as well as the CMC, NAVGEM, and UKMET models. In fact the HWRF and HMON bring the depression to major hurricane status by days 4 and 5. On the other hand, the GFS, and ECMWF models, despite a favorable upper environment, keep the system as a broad low through days 5 possibly because of the aformentioned mid-level shear weakening the structure to allow some dry air in the vicinity of the Bahamas to prevent any significant strengthening. For the now the intensity is a continuation from the previous advisory and not adjusted upward out of respect for the GFS and ECMWF.

[SouthDadeFish]

The next 12–24 h are critically important for the downstream forecast of TD 13. Almost every single model has TD 13 as open wave in this point in time. Yes, even the HWRF and HMON. The 12Z HWRF fires new convection tonight over and, to the east of, the low-level vort max, which causes the center to close off again. We need to see if this convection occurs. Having TDR data into HWRF tonight will be very helpful. The 00Z HWRF should assimilate this data.

Let's closely follow convective trends over the next few hours. Let's see if this new convection actually occurs. But I think writing off TD 13 at this point in time is pure folly. Could TD 13 open up into a wave and stay that way? Yes. Could TD 13 intensify like the HWRF is showing? Yes. We just don't know yet. It's way easier to prepare for the worst and hope for the best, than to get caught with your pants down with a hurricane on your doorstep.

But that's just my opinion...

[TallyTracker]

CLose up of the LLC and the new tower firing over it. should expand as a lot of moisture is being pulled in from the south now.

https://re.ssec.wisc.edu/s/U1wmAi

That view was extremely helpful. It does appear to still be closed. But just barely. Got a long way to go in the organization department.

[TheStormExpert]

The environment out ahead of TD #13 might be conducive but if it can’t survive this currently unfavorable environment then chances are nothing much will ever come from this.

Besides this season and the models have been nothing but a BIG HEADACHE so far!

What is so unfavorable about the current environment ?

http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8shr.GIF

Mid-Level Dry Air which doesn’t seem to going anywhere.

[sma10]

The next 12–24 h are critically important for the downstream forecast of TD 13. Almost every single model has TD 13 as open wave in this point in time. Yes, even the HWRF and HMON. The 12Z HWRF fires new convection tonight over and, to the east of, the low-level vort max, which causes the center to close off again. We need to see if this convection occurs. Having TDR data into HWRF tonight will be very helpful. The 00Z HWRF should assimilate this data.

Let's closely follow convective trends over the next few hours. Let's see if this new convection actually occurs. But I think writing off TD 13 at this point in time is pure folly. Could TD 13 open up into a wave and stay that way? Yes. Could TD 13 intensify like the HWRF is showing? Yes. We just don't know yet. It's way easier to prepare for the worst and hope for the best, than to get caught with your pants down with a hurricane on your doorstep.

But that's just my opinion...

Thank you. Call me crazy, but I've always been a big fan of reasonable responses

[chaser1]

I see no signs of dissipation. There is probably another LLC forming under the convection or at least one will form in the near future.

This system is pulsing causing convection to do the "pop and drop". I'm sure mid level humidity is a factor and one can see what appears as low level shear flying in from the SSW. That doesn't appear to me as "surface convergence ". Having said that, it is an extremely vigorous system whether one wants to call it a TD or open wave (I lean toward the latter). As for the EURO?? I trust my eyes and certainly NHC more then models picking up on genesis this year. We may well have a new LLC forming under new convection; guess we'll know if any semblance of a CDO sticks around for a few hours. I don't see recon finding a TS tonight, but tomorrow is another day. Finally.... I think that as long as TD13 maintains a latitude further north then TD14, then I don't think any downslope outflow from TD14 should have much impact on TD13 from developing. Any impediment to developing will probably be tied to it's own forward speed and moisture of the ambient air.