ATL: ISAIAS - Post-Tropical - Discussion

[HurricaneEnzo]

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As I figured, not going to be able to sustain it. Convection already falling apart. Getting blasted by shear still.

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[tolakram]

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[Ubuntwo]

Recon isn't even finding any evidence of a sub-1000mb pressure right now.

Recon is also having issues with transmitting data, but it seems like there's enough evidence to justify the 998mb central pressure that the NHC said at 11 am.

It does seem to be taking its time to intensify, which is good news for the Carolinas.

Recon hasn't transmitted in over an hour now, but radar velocities out of KCLX have been on a steady increase. Some 70-75kt bins.

[HurricaneEnzo]

Recon isn't even finding any evidence of a sub-1000mb pressure right now.

Recon is also having issues with transmitting data, but it seems like there's enough evidence to justify the 998mb central pressure that the NHC said at 11 am.

It does seem to be taking its time to intensify, which is good news for the Carolinas.

Recon hasn't transmitted in over an hour now, but radar velocities out of KCLX have been on a steady increase. Some 70-75kt bins.

How high is the beam though? That is going to be way up in the storm. Not indicative of anything near surface.

[Steve]

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https://i.imgur.com/uURFgmn.gif

As I figured, not going to be able to sustain it. Convection already falling apart. Getting blasted by shear still.

Sent from my SM-N975U using Tapatalk

Idk Enzo. Looks like a tightening/strengthening phase to me. Shear is still present, but I think it shows up better on satellite than radar
https://www.tropicaltidbits.com/sat/sat ... product=ir

https://www.tropicaltidbits.com/sat/sat ... roduct=vis

[HurricaneEnzo]

Beam is at about 13k for those higher wind readings. Not anything even close to that getting near the surface.

[Ubuntwo]

Recon is also having issues with transmitting data, but it seems like there's enough evidence to justify the 998mb central pressure that the NHC said at 11 am.

It does seem to be taking its time to intensify, which is good news for the Carolinas.

Recon hasn't transmitted in over an hour now, but radar velocities out of KCLX have been on a steady increase. Some 70-75kt bins.

How high is the beam though? That is going to be way up in the storm. Not indicative of anything near surface.

~10kft beam height, similar to recon flight level. The NHC regularly uses a reduction of radar velocities as a basis for intensity. The fact that velocities are increasing is indicative of intensification in and of itself, even if they are elevated.

[Vdogg]

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https://i.imgur.com/uURFgmn.gif

Trying one more time to close off an eye (an ugly ragged one, but an eye nonetheless). Precip shield looks better than I expected, they're going to have some decent storms on that part of the coast.

[Vdogg]

saved loop
https://i.imgur.com/uURFgmn.gif

As I figured, not going to be able to sustain it. Convection already falling apart. Getting blasted by shear still.

Sent from my SM-N975U using Tapatalk

Satellite presentation has improved markedly over the last hour and convection has increased. It's strengthening.

[emeraldislenc]

Will the strengthening push the landfall more towards NC? Would love to hear some comments.

[Vdogg]

Seems to be heading pretty much NE now. I think it will miss it's forecast points to the east (it's been constantly east of track).

[Vdogg]

Will the strengthening push the landfall more towards NC? Would love to hear some comments.

every time that LLC gets sucked back under the convection, it seems to take a little jog East. Definitely possible.

[NCWeatherChic]

Will the strengthening push the landfall more towards NC? Would love to hear some comments.

This is what stood out to me on the latest NHC discussion.

**After landfall, Isaias is forecast to only slowly weaken due to
interaction with an unusually strong winter-type jetstream that will be possessing winds of 100-120 kt. Expected strong baroclinic forcing will keep Isaias' circulation intact and also produce very strong wind gusts along the Mid-Atlantic states tomorrow.**

[NCWeatherChic]

I was just outside making a last sweep around the house, and I can tell you that the humidity here (just SE of Raleigh 15 miles) is super high. It's also DEAD calm out there. Not a leaf moving.

Yet!

Now that you mention...it is very calm outside. Like eerily calm and quiet. I'm not even seeing birds, hearing any dogs barking or cows moo'ing.

[clambite]

I was just outside making a last sweep around the house, and I can tell you that the humidity here (just SE of Raleigh 15 miles) is super high. It's also DEAD calm out there. Not a leaf moving.

Yet!

Now that you mention...it is very calm outside. Like eerily calm and quiet. I'm not even seeing birds, hearing any dogs barking or cows moo'ing.

And.... Mule Day's ain't gonna happen this year because of covid 19 !

[Craters]

I can't remember where I first heard it, but there's decent rule-of-thumb regarding rainfall totals from tropical systems. It doesn't work all the time, especially for systems that are very asymmetrical or otherwise atypical, or in the cases of a small storm and a big one moving over a spot at the same speed. But overall, I've had pretty good luck with it. Take the motion of the storm in miles per hour, divide that into 100, and the answer will be a rough estimate of the total rainfall in inches. So, for instance, if Isaias were to get itself a little more organized and reasonably symmetrical, at its current speed of 13 mph you could expect a total of around (100/13)" or seven to eight inches of total rainfall. When Harvey paid its visit to SE Texas a few years ago, it was moving between two and three miles per hour; rainfall totals in the area were in the 30" to 50" range, so the approximation worked fairly well then (unfortunately).

Again, it's a rule-of-thumb, not a precise prediction.

[southportwxfan]

Will the strengthening push the landfall more towards NC? Would love to hear some comments.

Looks like if it follows it's current NE heading it will come in somewhere around Ocean Isle to Holden beach

[pgoss11]

Maybe it’s my eyes but there’s seems to be more of an eastern component to the track. Does anyone else see that?

[Steve]

Will the strengthening push the landfall more towards NC? Would love to hear some comments.

It's going to landfall close to NC anyway if not directly in NC. So I'm not sure the strengthening will have much of an impact since it's not going east of the Outer Banks.

Plots are tight. It's one side of Little River or the other as it is.
https://www.sfwmd.gov/weather-radar/hur ... odel-plots

[Bizzles]

Maybe it’s my eyes but there’s seems to be more of an eastern component to the track. Does anyone else see that?

Probably just getting the vort stacked back up.