ATL: ISAIAS - Post-Tropical - Discussion

[Nuno]

Been busy with the Isaias advisory for the past 6 hours, did I miss anything here? Looks like the plane found a 50kt open wave. That's no well-defined LLC south of the DR. However the center will reform under the convection soon. With the models now focusing on the northern part of the wave, they will do a better job. It's quite possible that the center tracks far enough off the coast of Florida such that TS winds miss the coast. It still looks like the storm will be experiencing SW wind shear and dry air then, so heaviest squalls should be east of the track. After Florida, it moves with the upper flow, allowing it to strengthen. Could well be a hurricane when it passes the OBX on Monday. Beyond then, it runs into the SW-NE jet stream and begins a transition to a larger ET storm. Look for NHC track to shift a bit farther east of FL on future advisories, though they may elect not to move it so residents don't stop preparing. On to next advisory...

Isaias seems to be holding its own for now in regard with dry air. With it's large envelope I'm not so sure it'll be as big of a problem closer to the coast.

[NDG]

No respect for the Euro out there at all, after nailing Hanna's & Don's track 2-3 days ahead.

[jlauderdal]

Been busy with the Isaias advisory for the past 6 hours, did I miss anything here? Looks like the plane found a 50kt open wave. That's no well-defined LLC south of the DR. However the center will reform under the convection soon. With the models now focusing on the northern part of the wave, they will do a better job. It's quite possible that the center tracks far enough off the coast of Florida such that TS winds miss the coast. It still looks like the storm will be experiencing SW wind shear and dry air then, so heaviest squalls should be east of the track. After Florida, it moves with the upper flow, allowing it to strengthen. Could well be a hurricane when it passes the OBX on Monday. Beyond then, it runs into the SW-NE jet stream and begins a transition to a larger ET storm. Look for NHC track to shift a bit farther east of FL on future advisories, though they may elect not to move it so residents don't stop preparing. On to next advisory...

Thx..so far the only florida preps are hitting refresh on this forum

[Nuno]

No respect for the Euro out there at all, after nailing Hanna's & Don's track 2-3 days ahead.

After weeks of everyone slating the GFS as useless now suddenly it's the end all go-to model.

We'll see what Euro says soon enough. Though with the issues locating a proper center, all of these models should be taken with a grain of salt.

[Hypercane_Kyle]

Been busy with the Isaias advisory for the past 6 hours, did I miss anything here? Looks like the plane found a 50kt open wave. That's no well-defined LLC south of the DR. However the center will reform under the convection soon. With the models now focusing on the northern part of the wave, they will do a better job. It's quite possible that the center tracks far enough off the coast of Florida such that TS winds miss the coast. It still looks like the storm will be experiencing SW wind shear and dry air then, so heaviest squalls should be east of the track. After Florida, it moves with the upper flow, allowing it to strengthen. Could well be a hurricane when it passes the OBX on Monday. Beyond then, it runs into the SW-NE jet stream and begins a transition to a larger ET storm. Look for NHC track to shift a bit farther east of FL on future advisories, though they may elect not to move it so residents don't stop preparing. On to next advisory...

I mean, we're 66 hours out from a potential landfall and none of the models are showing a FL landfall anymore, sans the ECMWF which is struggling by keeping the storm too weak in the short term.

[wxman57]

https://tropicaltidbits.com/sat/images/goes16_vis_09L_202007301625_lat17.7-lon291.5.jpg

Something something comma shape, something something about to take off.

Looks like the larger version of Dorian in the same area.

https://img.techpowerup.org/200730/aa26a433-650e-44d6-a13c-511f58810efd.jpg

So that's an open wave....

Look at the recon data. No well-defined closed circulation. I.E., a wave axis. That big blob of convection does not have a surface center, yet. It's developing one now.

[CourierPR]

Been busy with the Isaias advisory for the past 6 hours, did I miss anything here? Looks like the plane found a 50kt open wave. That's no well-defined LLC south of the DR. However the center will reform under the convection soon. With the models now focusing on the northern part of the wave, they will do a better job. It's quite possible that the center tracks far enough off the coast of Florida such that TS winds miss the coast. It still looks like the storm will be experiencing SW wind shear and dry air then, so heaviest squalls should be east of the track. After Florida, it moves with the upper flow, allowing it to strengthen. Could well be a hurricane when it passes the OBX on Monday. Beyond then, it runs into the SW-NE jet stream and begins a transition to a larger ET storm. Look for NHC track to shift a bit farther east of FL on future advisories, though they may elect not to move it so residents don't stop preparing. On to next advisory...

You heard it here, wxman57 has given the all clear for us here in FL.

Read it again. He did not give the all clear for Florida, NDG. "It's quite possible that the center tracks far enough off the coast of Florida such that TS winds miss the coast."

[wxman57]

Been busy with the Isaias advisory for the past 6 hours, did I miss anything here? Looks like the plane found a 50kt open wave. That's no well-defined LLC south of the DR. However the center will reform under the convection soon. With the models now focusing on the northern part of the wave, they will do a better job. It's quite possible that the center tracks far enough off the coast of Florida such that TS winds miss the coast. It still looks like the storm will be experiencing SW wind shear and dry air then, so heaviest squalls should be east of the track. After Florida, it moves with the upper flow, allowing it to strengthen. Could well be a hurricane when it passes the OBX on Monday. Beyond then, it runs into the SW-NE jet stream and begins a transition to a larger ET storm. Look for NHC track to shift a bit farther east of FL on future advisories, though they may elect not to move it so residents don't stop preparing. On to next advisory...

You heard it here, wxman57 has given the all clear for us here in FL.

I know you're joking, NDG. We advised all our clients from south Florida to Boston to activate their hurricane response plans. However, if the center does track east of Florida by 75-100 miles, then strongest winds will pass offshore.

[AutoPenalti]

Wow you guys sure like to twist a promet’s words around. We still have 72 hours until this passes SFL.

[DestinHurricane]

Why would the NHC shift east while the latest models are shifting west?

[crimi481]

Ala Andrew - the ridge may be strong and devours the weakening trough. Possibly sending storm trough keys and s.e Gulf.
I know nothing... just remembering John Hope (TWC) forecast change for Andrew. Ridge usually strong in summer

[NDG]

Been busy with the Isaias advisory for the past 6 hours, did I miss anything here? Looks like the plane found a 50kt open wave. That's no well-defined LLC south of the DR. However the center will reform under the convection soon. With the models now focusing on the northern part of the wave, they will do a better job. It's quite possible that the center tracks far enough off the coast of Florida such that TS winds miss the coast. It still looks like the storm will be experiencing SW wind shear and dry air then, so heaviest squalls should be east of the track. After Florida, it moves with the upper flow, allowing it to strengthen. Could well be a hurricane when it passes the OBX on Monday. Beyond then, it runs into the SW-NE jet stream and begins a transition to a larger ET storm. Look for NHC track to shift a bit farther east of FL on future advisories, though they may elect not to move it so residents don't stop preparing. On to next advisory...

You heard it here, wxman57 has given the all clear for us here in FL.

I know you're joking, NDG. We advised all our clients from south Florida to Boston to activate their hurricane response plans. However, if the center does track east of Florida by 75-100 miles, then strongest winds will pass offshore.

Of course I was, I know you are smarter than that in giving the all clear this early on

[MississippiWx]

Looks like the larger version of Dorian in the same area.

https://img.techpowerup.org/200730/aa26a433-650e-44d6-a13c-511f58810efd.jpg

So that's an open wave....

Look at the recon data. No well-defined closed circulation. I.E., a wave axis. That big blob of convection does not have a surface center, yet. It's developing one now.

With all due respect, recon didn’t even go far enough west to sample the area where the center should be now.

[cycloneye]

 https://twitter.com/TropicalTidbits/status/1288887767502598145

[wxman57]

Why would the NHC shift east while the latest models are shifting west?

When the models initialize the newly-formed center farther northeast of the current "center", they should shift east with the track. It would help if this storm would have a single, coherent center.

[AutoPenalti]

Huh...

[stormhunter7]

Surface center appears its now to the north... no sign on the side side of the Island.

https://weather.cod.edu/satrad/?parms=local-Hispaniola-truecolor-96-1-100-1&checked=map&colorbar=undefined

[SFLcane]

Why would the NHC shift east while the latest models are shifting west?

When the models initialize the newly-formed center farther northeast of the current "center", they should shift east with the track. It would help if this storm would have a single, coherent center.

Yes indeed 57 and probably quite a bit ways of the Florida coast. Look for that in tonights models.

[tolakram]

Why would the NHC shift east while the latest models are shifting west?

They're professionals and have access to more tools and more blended models than we do. They strive to make objective decisions, not subjective.

My guess, and it's just a guess, is that the super ensemble is showing that an easterly track is more likely.

[ScottNAtlanta]

I've been following our local NWS discussion the last couple of days on the evolution of the troff. They state that the axis of the troff will be in the Mississippi valley. I'm not sure that is going to be close enough to push shear over Isaias. I know we here in GA are expecting southwesterly flow, but we are a good ways away.