ATL: LAURA - Post-Tropical - Discussion

[3090]

https://i.imgur.com/SIXzQmV.png

NHC forecast track will be moving back and forth within a window between Vermillion bay and the Mississippi gulf coast. She will probably end up making landfall somewhere right in the middle of that window.

[northjaxpro]

https://i.imgur.com/kCRzX5k.jpg

Looks like Hispaniola did exactly what a lot of us expected (unfortunately) helped make Laura a much larger system but without a well defined LLC, which will allow it to survive Cuba.

Yep. Exactly. It will reallly intensify when it traverses to the Florida Straits region.

[txag2005]

https://i.imgur.com/SIXzQmV.png

NHC forecast track will be moving back and forth within a window between Vermillion bay and the Mississippi gulf coast. She will probably end up making landfall somewhere right in the middle of that window.

If you read the forecast, it sounds like they are becoming more confident about a more Western run but are just waiting for a bit more data to confirm.

[Blinhart]

https://i.imgur.com/SIXzQmV.png

NHC forecast track will be moving back and forth within a window between Vermillion bay and the Mississippi gulf coast. She will probably end up making landfall somewhere right in the middle of that window.

If you read the forecast, it sounds like they are becoming more confident about a more Western run but are just waiting for a bit more data to confirm.

I'm afraid it will be somewhere in between Sabine Pass and Morgan City, probably around Cypremort Point or Pecan Island..

[3090]

https://i.imgur.com/SIXzQmV.png

“NHC forecast track will be moving back and forth within a window between Vermillion bay and the Mississippi gulf coast. She will probably end up making landfall somewhere right in the middle of that window.

If you read the forecast, it sounds like they are becoming more confident about a more Western run but are just waiting for a bit more data to confirm.

No where does it mention, or sound like...”waiting for a bit more data to confirm”.



000
WTNT43 KNHC 230859
TCDAT3

Tropical Storm Laura Discussion Number 14
NWS National Hurricane Center Miami FL AL132020
500 AM EDT Sun Aug 23 2020

Laura has maintained an impressive convective pattern despite the
center being located over extreme south-central Dominican Republic.
Numerous cloud tops of -85C to -90C have been noted over the
Barahona peninsula, an indication that extremely heavy rainfall has
been occurring there. The center of Laura passed over or very near
Santo Domingo around 0430Z based on a noticeable wind shift that
was measured at the international airport. Laura's outflow pattern
has also continue to improve in all quadrants. The initial intensity
of 40 kt is based on earlier scatterometer and aircraft data, along
with surface observations along the north coast of the Dominican
Republic.

Laura has continued to move west-northwestward and the initial
motion estimate is now 285/16 kt. There has been a significant
westward shift in the latest NHC model guidance, which appears to be
due to most of the global models taking the center of Laura farther
south over central or southern Hispaniola rather than emerging it
off the north coast of Haiti like the GFS is and has been
forecasting. Given that the most intense convection has persisted
along the southern coast of Hispaniola, that is where the most
likely area that a low-level and/or mid-level circulation is most
probable to develop or persist. As a result, the new NHC track
forecast favors a more southerly and westerly track solution
similar to the preponderance of the track guidance. However, the
new forecast track has not been shifted as far to the left as the
consensus models in the event that the models shift back to the
north. However, the latter scenario is appearing less likely based
observed satellite trends since the previous advisory.

Little if any significant change in strength is expected due to
Laura moving pretty much down the spine of Hispaniola and Cuba
during the the next 36 hours, with the strongest wind likely
remaining over water in the northeast quadrant where the pressure
gradient will be the tightest between the cyclone and the Bermuda
High. By 48 hours and continuing until landfall, Laura is forecast
to remain in a low shear and very favorable upper-level outflow
environment while passing of extremely warm SSTs near 31C. This
should allow for significant strengthening to occur once the cyclone
regains a decent inner core after exiting Cuba. The new NHC
intensity forecast is a blend of the intensity forecasts by the GFS
and ECMWF global models and the corrected consensus models HCCA and
FSSE.

Key Messages:

1. Tropical storm conditions are expected across portions of the
Dominican Republic and Haiti, the Turks and Caicos, the
southeastern Bahamas, and Cuba through Monday. Heavy rainfall is
likely across these areas and could cause mudslides and flash and
urban flooding.

2. Tropical storm conditions are possible the central Bahamas and
Andros Island tonight and Monday, and in the Florida Keys on
Monday.

3. The details of the long-range track and intensity forecasts
remain uncertain since Laura is forecast to move near or over
portions of the Greater Antilles through Monday. However, Laura is
forecast to strengthen over the Gulf of Mexico and could bring storm
surge, rainfall, and wind impacts to portions of the U.S. Gulf Coast
by the middle of next week. This could result in a prolonged period
of hazardous weather for areas that are likely to be affected by
Tropical Storm Marco earlier in the week. Interests there should
monitor the progress of Laura and Marco and updates to the forecast
during the next few days.

[Hurricane Mike]

Sunday Morning Video Update on Laura and Marco
https://www.youtube.com/watch?v=aSIF65eAPZo

[txag2005]

I’m paraphrasing.

“As a result, the new NHC track forecast favors a more southerly and westerly track solution similar to the preponderance of the track guidance. However, the new forecast track has not been shifted as far to the left as the
consensus models in the event that the models shift back to the north. However, the latter scenario is appearing less likely based observed satellite trends since the previous advisory.”

What does that sound like to you?

[Kingarabian]

“NHC forecast track will be moving back and forth within a window between Vermillion bay and the Mississippi gulf coast. She will probably end up making landfall somewhere right in the middle of that window.

If you read the forecast, it sounds like they are becoming more confident about a more Western run but are just waiting for a bit more data to confirm.

No where does it mention, or sound like...”waiting for a bit more data to confirm”.

. However, the
new forecast track has not been shifted as far to the left as the
consensus models in the event that the models shift back to the
north. However, the latter scenario is appearing less likely based
observed satellite trends since the previous advisory.

[Keldeo1997]

Looks like the LLC and MLC might be Stacked or almost stacked. The hot towers looks like they just merged into one

[Hurricane Mike]

Laura does look the best we've ever seen. Like Stewart said. Outflow in all quadrants, strong bursting. Once this thing is away from land, we could see some significant strengthening.

[Kingarabian]

Fresh SSMIS F-18 pass got most of the system. Lots of strong convection all the way down close to the surface.





Hard to tell what is what without recon.

[Nimbus]

North of Jamaica there may be a chance for some consolidation and Laura might hug the southern coast of Cuba rather than go inland. I wouldn't call the track forecast high confidence.

[Keldeo1997]

Possible LLC reformation on just off the SW tip of Haiti?

[Kazmit]

I've never seen a system over Hispaniola with such impressive deep convection and outflow.

[eastcoastFL]

I’m paraphrasing.

“As a result, the new NHC track forecast favors a more southerly and westerly track solution similar to the preponderance of the track guidance. However, the new forecast track has not been shifted as far to the left as the
consensus models in the event that the models shift back to the north. However, the latter scenario is appearing less likely based observed satellite trends since the previous advisory.”

What does that sound like to you?

It sounds just like what you mentioned. Seems like they think the models are onto something but want to wait and see where the center is when it emerges over water.

[eastcoastFL]

I've never seen a system over Hispaniola with such impressive deep convection and outflow.

https://i.imgur.com/2kO6bJ3.png

Hopefully this puts to rest the theory that Hispaniola is “shredder” to every system. Each system and scenario is unique. Nothing is one size fits all in the tropics. Odd things happen too like when We saw Michael defy shear for days and strengthen boggling the minds of geniuses at the nhc.

[eastcoastFL]

Fresh SSMIS F-18 pass got most of the system. Lots of strong convection all the way down close to the surface.

https://i.imgur.com/GobAFLF.jpg

https://i.imgur.com/ntple46.jpg

Hard to tell what is what without recon.

Looks like recon is about to fly into that deep convection to the south. Let’s see what they find down there.

[Nimbus]

I've never seen a system over Hispaniola with such impressive deep convection and outflow.

https://i.imgur.com/2kO6bJ3.png

Hopefully this puts to rest the theory that Hispaniola is “shredder” to every system. Each system and scenario is unique. Nothing is one size fits all in the tropics. Odd things happen too like when We saw Michael defy shear for days and strengthen boggling the minds of geniuses at the nhc.

I explained how the core of larger systems is more vulnerable to the shredder than small systems without an established hurricane circulation a few pages back. LLC can jump around a lot easier without being sheared apart from the established circulation. That is probably what we will see with the southern relocation of the lowest surface pressure near the Macaya mountain range later today.

[Jr0d]

No chance of the Fujiwhara effect pulling Laura north?

Too far apart from Marco and/or Marco being too small for it to happen?

If this does start to happen it would really through of the forecast.

[eastcoastFL]

I've never seen a system over Hispaniola with such impressive deep convection and outflow.

https://i.imgur.com/2kO6bJ3.png

Hopefully this puts to rest the theory that Hispaniola is “shredder” to every system. Each system and scenario is unique. Nothing is one size fits all in the tropics. Odd things happen too like when We saw Michael defy shear for days and strengthen boggling the minds of geniuses at the nhc.

I explained how the core of larger systems is more vulnerable to the shredder than small systems without an established hurricane circulation a few pages back. LLC can jump around a lot easier without being sheared apart from the established circulation. That is probably what we will see with the southern relocation of the lowest surface pressure near the Macaya mountain range later today.

What do you think the reason is for the deep convection we’ve seen all night over land?