ATL: LAURA - Post-Tropical - Discussion

[Comradez]

I wonder if all of the convection firing on the south side this morning, and the locally ascending air and falling surface pressure that is associated with such strong thunderstorm activity, has been dragging the main low pressure center further to the south than some models expected. I wonder if that is partly why the LLC has been keeping almost due west this morning rather than WNW right into Cuba.

The HWRF, which best predicted where the thunderstorm activity would be this morning, has Laura doing kind of a drunken walk right over Guantanamo Bay, then back to the west over the ocean, then back over the spine of Cuba, then back over the ocean, etc. until Laura re-emerges over the Gulf. (12z 8/23 run). But what if Laura shoots south of most of Cuba?

[gatorcane]

Laura certainly has sustained some impressive convection so far on her treck through Hispaniola.

But she still has the big mountains of Cuba to get through.

As I mentioned yesterday, and as some have mentioned, this land interaction is highly unpredictable as we already have seen. How do you even model this accurately?

12Z guidance outside of the HWRF and HMON have come in significantly weaker. This does not diminish the seriousness of this situation, but at least there is still a chance she doesn’t make it to a major hurricane or even a hurricane at landfall.

Hurricane at landfall still looks likely though but still not a 100% guarantee.

[NDG]

Intensifying quickly and still heading due west..

closed low level eyewall.

https://i.ibb.co/0FQF1qR/ezgif-com-gif-maker-15.gif

Not quiet due west, IMO.

[Cat5James]

Convection to the south headed straight towards Jamaica.

[ConvergenceZone]

Winds down slightly to 45mph. We will see if it can maintain tropical storm status. It's still possible it can weaken to a depression going over the mountains , especially that's only 6 mph or so less than what it is now

Where do you see that?

SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...19.4N 74.3W
ABOUT 55 MI...90 KM S OF THE EASTERN TIP OF CUBA
ABOUT 80 MI...130 KM SE OF GUANTANAMO CUBA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES

then wunderground weather is wrong then (see link below, it says 45 mph)

https://www.wunderground.com/hurricane/ ... torm-laura

[NDG]

Laura certainly has sustained some impressive convection so far on her treck through Hispaniola.

But she still has the big mountains of Cuba to get through.

As I mentioned yesterday, and as some have mentioned, this land interaction is highly unpredictable as we already have seen. How do you even model this accurately?

12Z guidance outside of the HWRF and HMON have come in significantly weaker. This does not diminish the seriousness of this situation, but at least there is still a chance she doesn’t make it to a major hurricane or even a hurricane at landfall.

Hurricane at landfall still looks likely though but still not a 100% guarantee.

Hispaniola's much higher mountains didn't do anything to it, I doubt the Mountains of eastern Cuba will be any worst for it.

[Aric Dunn]

Laura certainly has sustained some impressive convection so far on her treck through Hispaniola.

But she still has the big mountains of Cuba to get through.

As I mentioned yesterday, and as some have mentioned, this land interaction is highly unpredictable as we already have seen. How do you even model this accurately?

12Z guidance outside of the HWRF and HMON have come in significantly weaker. This does not diminish the seriousness of this situation, but at least there is still a chance she doesn’t make it to a major hurricane or even a hurricane at landfall.

Hurricane at landfall still looks likely though but still not a 100% guarantee.

Hispaniola's much higher mountains didn't do anything to it, I doubt the Mountains of eastern Cuba will be any worst for it.

And on its current west motion.. its trek across the mountains look to be short and back over water south of cuba.

[eastcoastFL]

It seems most are focused on next week and not so much what is happening real time.

Laura's LLC is about to run into the mountains of Cuba. This will be a major disruption. The HWRF shows the center staying south and intact but inialized southwest of the actual center. It looks like the GFS makes this an open wave. It looks unlikely a center will reform on the north coast.

The next couple hours will make a big difference on the future track and the impact on the Florida Keys. The south and east trend of models is making it look like the Keys won't get much.

If Hispaniola was not an issue why would Cuba be?

It did not have a well defined center when it went through Hispaniola. Now there is a well defined LLC that is going straight into some mountains.

Laura will be looking ragged soon. That is one thing all the models agree upon.

It will be ragged after Cuba but it will spring back to life rapidly when it hits the gulf. I think you’ll be ok in the keys besides some rain and wind. Hopefully you won’t lose power.

[pcolaman]

Intensifying quickly and still heading due west..

closed low level eyewall.

https://i.ibb.co/0FQF1qR/ezgif-com-gif-maker-15.gif

Not quiet due west, IMO.

Looks almost due west according to Radar.

[eastcoastFL]

Laura certainly has sustained some impressive convection so far on her treck through Hispaniola.

But she still has the big mountains of Cuba to get through.

As I mentioned yesterday, and as some have mentioned, this land interaction is highly unpredictable as we already have seen. How do you even model this accurately?

12Z guidance outside of the HWRF and HMON have come in significantly weaker. This does not diminish the seriousness of this situation, but at least there is still a chance she doesn’t make it to a major hurricane or even a hurricane at landfall.

Hurricane at landfall still looks likely though but still not a 100% guarantee.

Hispaniola's much higher mountains didn't do anything to it, I doubt the Mountains of eastern Cuba will be any worst for it.

And on its current west motion.. its trek across the mountains look to be short and back over water south of cuba.

The HWRF showed it going about half way across Cuba then into the water south of Cuba before tracking across the western tip towards the gulf.

[ConvergenceZone]

Laura certainly has sustained some impressive convection so far on her treck through Hispaniola.

But she still has the big mountains of Cuba to get through.

As I mentioned yesterday, and as some have mentioned, this land interaction is highly unpredictable as we already have seen. How do you even model this accurately?

12Z guidance outside of the HWRF and HMON have come in significantly weaker. This does not diminish the seriousness of this situation, but at least there is still a chance she doesn’t make it to a major hurricane or even a hurricane at landfall.

Hurricane at landfall still looks likely though but still not a 100% guarantee.

Gator, you use to be so bullish on storms in past seasons compared to this season. Are you sure this is the same gator and someone didn't hijack your account? lol.... I notice that sometimes that happens when people go through a bad storm and they try and think positive and wishful think it away.... If you did go through a bad storm. I'm so sorry . While I've never been through a bad storm myself(I'm in California, I know others that have and it's horrible see them lose so much. Again, if that did happen to you, stay strong!!!

[eastcoastFL]

Winds down slightly to 45mph. We will see if it can maintain tropical storm status. It's still possible it can weaken to a depression going over the mountains , especially that's only 6 mph or so less than what it is now

Where do you see that?

SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...19.4N 74.3W
ABOUT 55 MI...90 KM S OF THE EASTERN TIP OF CUBA
ABOUT 80 MI...130 KM SE OF GUANTANAMO CUBA
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES

then wunderground weather is wrong then (see link below, it says 45 mph)

https://www.wunderground.com/hurricane/ ... torm-laura

Maybe they updated it. This is what it says


Tropical Storm Laura
Last Updated: 8/23/2020 2:00:00 PM (EDT)
Location: 19.4 N 74.3 WMovement: WNW at 18 mph Wind: 50mphPressure: 1004 mb

[CyclonicFury]

Laura certainly has sustained some impressive convection so far on her treck through Hispaniola.

But she still has the big mountains of Cuba to get through.

As I mentioned yesterday, and as some have mentioned, this land interaction is highly unpredictable as we already have seen. How do you even model this accurately?

12Z guidance outside of the HWRF and HMON have come in significantly weaker. This does not diminish the seriousness of this situation, but at least there is still a chance she doesn’t make it to a major hurricane or even a hurricane at landfall.

Hurricane at landfall still looks likely though but still not a 100% guarantee.

Gator, you use to be so bullish on storms in past seasons compared to this season. Are you sure this is the same gator and someone didn't hijack your account? lol.... I notice that sometimes that happens when people go through a bad storm and they try and think positive and wishful think it away.... If you did go through a bad storm. I'm so sorry . While I've never been through a bad storm myself(I'm in California, I know others that have and it's horrible see them lose so much. Again, if that did happen to you, stay strong!!!

I'm a little surprised too at how bearish he has been on the Atlantic and how bullish he has been about the EPAC this year. The EPAC hasn't exactly been on fire this season.

[gatorcane]

Looks like finally convection is starting to wane some. Perhaps she is starting to feel some effects of land interaction. Here is a wide shot loop you can use. The Tropical Tidbit loops are very slow:

http://rammb.cira.colostate.edu/ramsdis ... display=24

[ConvergenceZone]

Looks like finally convection is starting to wane some. Perhaps she is starting to feel some effects of land interaction. Here is a wide shot loop you can use. The Tropical Tidbit loops are very slow:

http://rammb.cira.colostate.edu/ramsdis ... display=24

It's bound to lose SOME convection along its journey,all systems usually do, and it's getting ready to move back over water right after its very short 2nd journey across the mountains.

[Shell Mound]

I’m more than a little worried about the situation with heavy rainfall and flash flooding in Haiti and the western Dominican Republic. Any news?

[Comradez]

Laura is losing some of the convection that was dislocated to the south of the LLC, but it is re-building convection near the center just south of Guantanamo Bay.

[tolakram]

saved loop

[gatorcane]

saved loop

https://imgur.com/2wYTn6e

Really nice loop. She has a very vigorous spin. Looks to be headed directly towards some of very tall mountains of eastern Cuba.

[NDG]

Whoever believes 12z Euro's weaker run on Laura as it heads north in the GOM is not using logic, first of all Euro has been really bad with both systems' forecast strength all along, and very inconsistent, secondly Marco is a hurricane despite much higher windshear that it is going through than what Laura will have while in the GOM.