ATL: MARCO - Remnants - Discussion

[CrazyC83]

With a center at around 14.1N, this could very well make landfall in Honduras or Nicaragua first.

[Craters]

So the potential vorticity streamers break up the Rossby wave and helps the storm to strengthen? Or if a Rossby wave is not occurring then they weaken the storm? Thanks....

Would love to answer your question but it's out of my pay grade. Maybe GCANE can answer.

Might want to PM him because he keeps different hours than lots of people, and you never know when he's going to pop up (usually 4:30 or 5:00 am to drop some charts and maps).

I think that "different" is putting it mildly, Steve. I'm starting to think that his clock starts at Dmax and he starts shutting down for the day around Dmin...

But if you do PM him, lrak, let us know what his answer is, okay?

[Kazmit]

NHC adjusted their forecast down a bit to a 55kt peak.

[northjaxpro]

It has been a long time since I remember seeing at least a TD with such a great looking structure in the middle of the Caribbean this time of the year without being shredded apart l]

Yeah, no kidding. It has been awhile since we have seen this in the middle of the Caribbean no less.

It really looks like it is pulling together late this afternoon.

[MississippiWx]

The outflow is perfect. A few strong bursts of convection near the center will help it tighten up. It should continue to slow its forward momentum which will only help the tightening process as well. This is in a much better environment than TD13.

Once the low levels are tightened up, the Yucatán is the only thing stopping this for a couple of days.

[FixySLN]

Friendly reminder of two things:

1) It's 2020

2) This system is headed to the gulf...where nearly anything will thrive in its current state.

The models haven't reached a consensus, the mets have their arms up in the air...it's a fairly unique situation that doesn't have an answer yet. The models are...also likely confused. It's likely they're having trouble with the possible interaction, the changes in speed, and the increase in a positive environment over time. There's a LOT to take into account.

[wxman57]

If it is lacking a low-level circulation center, then it may not be as strong as predicted over the next 48-72 hours, and it may not be picked up by the trof as easily. May still track into Mexico. It does appear to have a vigorous mid=level circulation. Perhaps a LLC will eventually develop beneath it.

[tolakram]

[aspen]

The NHC put the center far lower than in the previous advisory, but given how loose the circulation is, I’m expecting more jumps to the north (and possibly south again) before a definitive, stacked CoC forms. It now seems like the best opportunity for intensification will be between 30 and 66 hours, after scraping Central America and before making landfall in the Yucatán Peninsula.

[supercane4867]

Kimberlain is bullish on TD14

 https://twitter.com/toddkimberlain/status/1296489719891730434

[Kingarabian]

The 12z GFS's "peak" for this system was in about 24-30 hours @ 999mb. So we still have some waiting to do. After it peaks anything is possible. We know that stronger systems react to less than ideal environments differently than something we're currently looking at.

[EquusStorm]

The further south it tracks the worse the flood and mudslide risk for Honduras becomes; that's an area that seems quite prone to those issues. So either track scenario is bad news for someone

[MarioProtVI]

Not buying the center they fixed onto at 5. Real center appears to be farther north, and as such I still think this may become a hurricane before reaching the Yucatan.

[tolakram]

Not buying the center they fixed onto at 5. Real center appears to be farther north, and as such I still think this may become a hurricane before reaching the Yucatan.

If it's at the surface it's pretty weak and or small. Look at the winds out of the east that recon found.

[hurricanehunter69]

What a gorgeous storm. This thing is coming together beautifully! 2 days over the NW Caribbean...…..Good Luck! https://www.star.nesdis.noaa.gov/GOES/s ... &length=24

[wxman57]

Remember, the models that accelerate it northwestward are relying on a stronger tropical storm (that's farther north to start with). I expect big changes with this forecast over the next day or two.

[shiny-pebble]

If more convection fires in the center of the storm where there's that sort of convectionless area I would not be surprised if there's a center reformation under that

Sent from my SM-G970U using Tapatalk

[GCANE]

Potential vorticity streamers
http://www.atmos.albany.edu/student/ppa ... ch_phd.php

So the potential vorticity streamers break up the Rossby wave and helps the storm to strengthen? Or if a Rossby wave is not occurring then they weaken the storm? Thanks....

Would love to answer your question but it's out of my pay grade. Maybe GCANE can answer.

PVS's are basically small elongated upper level vorts in about the 300mb to 200 mb level. That is the about the top of the troposphere. Because they are so high, they don't have updraft. Its actually the opposite, they create downdraft, sinking air, subsidence. So if there is a LL vort and a PVS gets over it, the PVS pushes down on the vort column and the vort spins less. Its the opposite of an anticyclone which allows the vort column to stretch vertically and spin faster.

PVS's come from many features such as TUTTs, Rossby Waves, UL Eddy's, etc. Sometimes its hard to figure out where they come from and how they evolve. The air is very thin up there, so they are very volatile. Many things can quickly effect them, especially strong convection. For a strong PVS and weak convection, the PVS wins. For a weak PVS and strong hot tower, the hot tower wins.

[lrak]

So the potential vorticity streamers break up the Rossby wave and helps the storm to strengthen? Or if a Rossby wave is not occurring then they weaken the storm? Thanks....

Would love to answer your question but it's out of my pay grade. Maybe GCANE can answer.

PVS's are basically small elongated upper level vorts in about the 300mb to 200 mb level. That is the about the top of the troposphere. Because they are so high, they don't have updraft. Its actually the opposite, they create downdraft, sinking air, subsidence. So if there is a LL vort and a PVS gets over it, the PVS pushes down on the vort column and the vort spins less. Its the opposite of an anticyclone which allows the vort column to stretch vertically and spin faster.

PVS's come from many features such as TUTTs, Rossby Waves, UL Eddy's, etc. Sometimes its hard to figure out where they come from and how they evolve. The air is very thin up there, so they are very volatile. Many things can quickly effect them, especially strong convection. For a strong PVS and weak convection, the PVS wins. For a weak PVS and strong hot tower, the hot tower wins.

TY Sir!!!

[xironman]

I could definitely see the coc migrating northward to the best convection.