ATL: LAURA - Post-Tropical - Discussion

[AutoPenalti]

Damn, it's crazy how quickly people forget that even the more bullish models don't show strengthening until north of the Islands. This was never suppose to intensify today.

[EquusStorm]

I still wonder if it wouldn't have been better to tag both depressions as PTCs until recon, or a very consistent vigorous LLC took hold, just to make sure it didn't go between a wave and a closed depression briefly over and over. I'm sure the general public doesn't care until they have a name to call them by though. Just makes sense to use that designation when watches are required but it seems like a marginal case for a little while.

[SFLcane]

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...

Usually TDR makes HWRF weaker So we shall see this evening. Great post.

[toad strangler]

 http://twitter.com/johnmoralesnbc6/status/1296533585068007425

[Kazmit]

Isn't it near D Min right now anyway? Seems a bit premature to bring out bones when it doesn't look great for a few hours.

[chris_fit]

So what happens when our little naked swirl runs into all that bubbling convection to the west?

[TheStormExpert]

I still wonder if it wouldn't have been better to tag both depressions as PTCs until recon, or a very consistent vigorous LLC took hold, just to make sure it didn't go between a wave and a closed depression briefly over and over. I'm sure the general public doesn't care until they have a name to call them by though. Just makes sense to use that designation when watches are required but it seems like a marginal case for a little while.

I personally think the NHC should’ve waited until this morning to make the call on an upgrade. At that point they probably would’ve just called it PTC #13.

[stormwatcher95]

Not saying this is the same situation overall, especially being a green enthusiast, I could be way off base...but you could delete all of these posts and replace it with the first 15+ pages of the Dorian thread from last year and you"d be hard pressed to see a difference. Satellite appearance, location, similar SAL/Dry air and shear. Even the immediate track. Only real difference was Dorians microwave presentation seemed much better at this point.

[chaser1]

Isn't it near D Min right now anyway? Seems a bit premature to bring out bones when it doesn't look great for a few hours.

No bones about it (lol), just looking malnourished and a bit dehydrated. Give her a little time and perhaps a 5-hour Energy drink and all that could change.

[BobHarlem]

 https://twitter.com/watkinstrack/status/1296531407792230402

[eastcoastFL]

Damn, it's crazy how quickly people forget that even the more bullish models don't show strengthening until north of the Islands. This was never suppose to intensify today.

This needs to be repeated every half hour

[eastcoastFL]

https://twitter.com/watkinstrack/status/1296531407792230402

That’s gonna drive the “degrading” pack nuts

[Aric Dunn]

So what happens when our little naked swirl runs into all that bubbling convection to the west?

https://i.imgur.com/7Z6x9hI.gif

typically more convection builds

[chaser1]

Not saying this is the same situation overall, especially being a green enthusiast, I could be way off base...but you could delete all of these posts and replace it with the first 15+ pages of the Dorian thread from last year and you"d be hard pressed to see a difference. Satellite appearance, location, similar SAL/Dry air and shear. Even the immediate track. Only real difference was Dorians microwave presentation seemed much better at this point.

I don't think you're way off but that same argument could probably be made by doing the same with Isaias' thread. Look how that slop turned out. Just goes to show how tricky forecasting is

[Blown Away]

2:00 PM AST Thu Aug 20
Location: 16.0°N 52.8°W
Moving: WNW at 21 mph
Min pressure: 1008 mb
Max sustained: 35 mph

I believe the circled area is the LLC @17.8N/54.1W, however the NHC 2pm position was 16.0N/52.8W... I know TD13 is flying, but not enough to cover 2 degrees N in 2.5 hours? Math doesn't seem right, unless my circled area is not the LLC?

[DestinHurricane]

Not saying this is the same situation overall, especially being a green enthusiast, I could be way off base...but you could delete all of these posts and replace it with the first 15+ pages of the Dorian thread from last year and you"d be hard pressed to see a difference. Satellite appearance, location, similar SAL/Dry air and shear. Even the immediate track. Only real difference was Dorians microwave presentation seemed much better at this point.

I don't think you're way off but that same argument could probably be made by doing the same with Isaias' thread. Look how that slop turned out. Just goes to show how tricky forecasting is

Conditions past the Islands will be much more similar to Dorian than Isaias conditions.

[northjaxpro]

TD 13 is yet another classic example of a large, monsoonal gyre whi h takes its time to coalesce into well stacked tropical cyclone. It can take days for this process to complete, and this is no different here.

By Saturday, when this entity emerges just north of PR and Hispanoola into a much more conducive environment, the story will become much more concerning heading into Monday-Wednesday period in the medium term!!

[TheStormExpert]

https://twitter.com/watkinstrack/status/1296531407792230402

Upgrade to storm!?

[IsabelaWeather]

Not really any models predicted a fast, severe intensification of 13, so not sure why current appearance comes as such a surprise. What would come as a surprise to me is if in 48 hours we’re not looking at something more significant when it’s closer to the north of the islands. Meanwhile, I can’t stress enough how almost ALL models are remarkably consistent on path out to 3.5/4 days. Very tight cluster pointing in general direction of SE FL/Keys. Will it be a Cat 2 hurricane? Or a TD/minimal TS at the time? Those seem to be the only questions. So definitely need to pay very close attention

The 12z HWRF doesn't even have it doing anything until 9pm Friday EST. Until then it's a raggy mess. But from ~9PM on it gets it's act together in a hurry. Has it passing about 200 miles north of my house in the low 990's deepening rapidly.

[AutoPenalti]

NOAA flying into TD 13, kinda wish G-IV was there as well.