ATL: NATE - Post Tropical - Discussion

[Dean4Storms]

Long range radar out of Key West to the ESE is looking interesting this evening.

https://radar.weather.gov/ridge/radar.php?product=N0Z&rid=BYX&loop=yes

[Aric Dunn]

Long range radar out of Key West to the ESE is looking interesting this evening.

https://radar.weather.gov/ridge/radar.php?product=N0Z&rid=BYX&loop=yes

following in talkin tropics thread...

[Big Easy Breeze]

Embarrassing. I have to say, anyone thinking the GFS solution will be close has not been following it very closely this year. This should not happen in 2017.

[im g]https://i.imgur.com/5I1hnBT.gif[/img]

What are you insinuating? You lost me.

[Dean4Storms]

Long range radar out of Key West to the ESE is looking interesting this evening.

https://radar.weather.gov/ridge/radar.php?product=N0Z&rid=BYX&loop=yes

following in talkin tropics thread...

OK wasn't aware. Was just pointing out here where this vort is suppose to close off near Key West tomorrow morning according to the GFS in relation to the future track of TD16 vs the ECM which shows not that much organization with it.

[Aric Dunn]

Long range radar out of Key West to the ESE is looking interesting this evening.

https://radar.weather.gov/ridge/radar.php?product=N0Z&rid=BYX&loop=yes

following in talkin tropics thread...

OK wasn't aware. Was just pointing out here where this vort is suppose to close off near Key West tomorrow morning according to the GFS in relation to the future track of TD16 vs the ECM which shows not that much organization with it.

exactly... though it appears to have a weak closed circ already that started developing few hours ago.. it is very important. the pressure have fallen quite a bit with the system which could affect "Nate"

[NDG]

One thing that the subtropical looking disturbance approaching FL will do is moisten up the atmosphere quite nice as it moves westward across the GOM ahead of TD 16.

Yeah. Yee-haw. We can go from 22 inches over for the year to 30. I can't wait for SWFWMD to tell us that we can only use the sprinklers once a week in January. Boy do I have a reply planned for them.

Is sad how all this rain water just gets drained out to sea and there's no way we can preserve it for dry spells.

[Shell Mound]

A weaker, slower system in the short term might actually be "bad news" over time. Currently, low-level flow is from the southeast and south-southeast, while the mid- to upper-level flow is from the east and northeast. The influence of the mid-level trough to the north is imparting some southwesterly net shear over the low, hence the separation and elongation of low-level and mid-level circulations. However, as the prevailing low-level flow suggests, a weaker, slower system would be more likely to avoid significant land interaction with Central America, tracking instead over extreme eastern Nicaragua and Honduras. Such a track would only briefly make landfall over Cabo Gracias a Dios before moving offshore, while proceeding north-northwestward. In fact, shortwave satellite imagery suggests that the low-level circulation may be reforming closer to the inner band of convection that has recently developed. Recent imagery hints at a slow, north-northwestward turn over the past several hours. So long as the trough over the Straits of Florida remains weak as well, and does not develop a pronounced signature, then Sixteen is likely to make only brief contact with Central America, increasing its opportunity to deepen significantly over the western Caribbean and southern Gulf of Mexico (Loop Current). Shear currently appears too prohibitive for the trough axis to deepen much, if at all, over the Straits of Florida, thereby leaving more room for Sixteen to deepen. Once shear decreases over Sixteen, which should begin within the next twenty-four hours, then expect substantial deepening to happen, given signs of a smaller, inner core attempting to develop. Unfortunately, Sixteen, prospective Nate, may well exceed current expectations, and a major hurricane at some point is a very distinct possibility, should Sixteen avoid significant land interaction, as seems plausible.

[Sciencerocks]

It appears the center is a bit south and east of the advisory position (around 12.4N 82.4W). There is significant tilt between the LLC and MLC.

About where the blow up of convection is...Seems to be slowly moving northward(350 degrees?) these past 6 hours.

[Big Easy Breeze]

It is safe to say, accoding to the way the models are currently projecting, along with the current weather patterns, this system will landfall somewhere between the central La. gulf coast, all the way over to Destin Fl. i am doubting any landfall outside of that window. Things are lining up for that window. Now it is just a matter of where, within that window. By tomorrow evening, a much smaller window will evolve.

[tolakram]

Embarrassing. I have to say, anyone thinking the GFS solution will be close has not been following it very closely this year. This should not happen in 2017.

[i mg]https://i.imgur.com/5I1hnBT.gif[/img]

What are you insinuating? You lost me.

Horrible convective feedback which places multiple vortices all over the map. This pretty much dooms the entire run and makes trusting the model very difficult, especially if it can't get the first 48 hours correct. It's not just with sixteen either, it had the same issue with the disturbance near Florida. Something is terribly wrong.

[NDG]

https://youtu.be/UiJ0KfgQxAA

Just in case you haven't seen this from Levi. Great breakdown of why GFS and Euro see things so differently

Interesting what Levi says will make a big difference in the track of TD 16, if a piece of energy from the area of disturbed wx east of FL stays east of central FL will cause the building ridge just east of FL to say weaker thus a final track towards FL versus LA like the GFS has.
Tomorrow morning we will know which model is correct.

[Aric Dunn]

https://youtu.be/UiJ0KfgQxAA

Just in case you haven't seen this from Levi. Great breakdown of why GFS and Euro see things so differently

Interesting what Levi says will make a big difference in the track of TD 16, if a piece of energy from the area of disturbed wx east of FL stays east of central FL will cause the building ridge just east of FL to say weaker thus a final track towards FL versus LA like the GFS has.
Tomorrow morning we will know which model is correct.

we will know ( though pretty clear already) in the next several hours as it will be approaching closer to the radar sites and wont have to debate if it is mid level or not..

[NDG]

https://youtu.be/UiJ0KfgQxAA

Just in case you haven't seen this from Levi. Great breakdown of why GFS and Euro see things so differently

Interesting what Levi says will make a big difference in the track of TD 16, if a piece of energy from the area of disturbed wx east of FL stays east of central FL will cause the building ridge just east of FL to say weaker thus a final track towards FL versus LA like the GFS has.
Tomorrow morning we will know which model is correct.

we will know ( though pretty clear already) in the next several hours as it will be approaching closer to the radar sites and wont have to debate if it is mid level or not..

Oh boy, you are just not giving up on the mid level vorticity

[Aric Dunn]

Interesting what Levi says will make a big difference in the track of TD 16, if a piece of energy from the area of disturbed wx east of FL stays east of central FL will cause the building ridge just east of FL to say weaker thus a final track towards FL versus LA like the GFS has.
Tomorrow morning we will know which model is correct.

we will know ( though pretty clear already) in the next several hours as it will be approaching closer to the radar sites and wont have to debate if it is mid level or not..

Oh boy, you are just not giving up on the mid level vorticity

lol we all know its not just in the mid levels..hehe

[NDG]

It is safe to say, accoding to the way the models are currently projecting, along with the current weather patterns, this system will landfall somewhere between the central La. gulf coast, all the way over to Destin Fl. i am doubting any landfall outside of that window. Things are lining up for that window. Now it is just a matter of where, within that window. By tomorrow evening, a much smaller window will evolve.

I would say that anybody from LA to as far east as the FL big bend area still need to watch the system, hopefully by tomorrow night there should be a better consensus between the models as we get into the 3-4 day range from landfall and models do much better by then especially since tomorrow they will have data collected from the NOAA G-IV recon.

[AJC3]

It is safe to say, according to the way the models are currently projecting, along with the current weather patterns, this system will landfall somewhere between the central La. gulf coast, all the way over to Destin Fl. i am doubting any landfall outside of that window. Things are lining up for that window. Now it is just a matter of where, within that window. By tomorrow evening, a much smaller window will evolve.

And of course, as I and many others continue to point out..."according to the way the models are currently projecting" is a pretty huge caveat 4 days out, especially given the time of year, lack of strong consensus (i.e. the global/hurricane model and ensemble spread), and some lack of continuity.

This is why any met who has any sort of experience with forecasting in the tropics will avoid using phrase like "will" (all by itself), "definitely", "extremely likely" when it comes to forecasts beyond a couple of days, and instead, use more uncertain terms that express degrees of confidence.

[Alyono]

the TCD tonight seemed very modelologyish. No discussion at all as to the glaring weakness of the GFS and how it affected the consensus

[CrazyC83]

What are the chances that the circulation could actually dissipate over Honduras or Nicaragua if it goes over it? Of course it could (and likely will) regenerate later, but that could change things dramatically in the longer term.

[smithtim]

Embarrassing. I have to say, anyone thinking the GFS solution will be close has not been following it very closely this year. This should not happen in 2017.

[i mg]https://i.imgur.com/5I1hnBT.gif[/img]

What are you insinuating? You lost me.

Horrible convective feedback which places multiple vortices all over the map. This pretty much dooms the entire run and makes trusting the model very difficult, especially if it can't get the first 48 hours correct. It's not just with sixteen either, it had the same issue with the disturbance near Florida. Something is terribly wrong.

"Terribly wrong"

I think the issue goes back to model initialization... gotta remember the majority of equations solved within these models are differential equations which are very very sensitive to slight changed in their initial conditions!

My thought is we really won't have a clear picture until after 12z runs tommorow or maybe even later? As the truth is, before worrying about t>48 interaction with other, we don't know yet how much land interaction which of course is gonna tell story! Currently it's just a td and in theory our potential range of scenarios is from

it staying a td & losing structure due to lots of land interaction tommorow & entering gulf as a big mess

to

it becoming a strong ts ( maybe even cane ) & keeping good structure due to lesser land interaction & then entering gulf as a big problem big concern RI


IMHO just gonna have wait and c... and I think nhc kinda same mindset?

[Steve]

NAM 00Z moves close to the Mouth of the Mississippi then has a hit toward Jackson/Mobile Counties 980s on 12km. Then it moves ENE across Escambia County, FL where the run ends 84 hours or 7pm Sunday local time. This looks like a reasonable solution to me and is similar to the CMC and NAVGEM runs this morning.

https://www.tropicaltidbits.com/analysi ... 0&ypos=190