ATL: ALBERTO - Post-Tropical

[Aric Dunn]

Models shifting east ?

it will all depend on the placement of the upper trough and if it closes off. so far the models have gone back and forth on this upper trough. if it stays open and a sharp trough than we will see more easterly trends do to the shear and a weaker system. if the trough cuts off then more west and a stronger system... only time will tell.

[Evil Jeremy]

That Ukmet is eye-grabbing. Can''t stay up for ECMWF but eager to see it in the morning. The trend appears to remain east.

Any possibility this system could warrant pre-tropical cyclone advisories?

[Aric Dunn]

That Ukmet is eye-grabbing. Can''t stay up for ECMWF but eager to see it in the morning. The trend appears to remain east.

Any possibility this system could warrant pre-tropical cyclone advisories?

not likely . since things will likely shift back west.

[Aric Dunn]

Things are looking good for this area developing just east of belize. combination of things are playing out. upper winds are beginning to switch to a more sw direction and becoming divergent. low level convergence is increasing in this area. and some clear signs of a larger low level circ are developing. tomorrow morning we should be looking at a organizing TD/TS or Sub trop.
http://rammb-slider.cira.colostate.edu/ ... mmb-slider

http://weather.cod.edu/satrad/exper/?pa ... colorbars=



earlier..



compared to now

[Aric Dunn]

hmmm. looking at the upper levels. that upper low/trough is a good deal farther south than the models have been showing for this timeframe.. I mean quite a bit.. that will change things..
http://rammb-slider.cira.colostate.edu/ ... mmb-slider

[FLpanhandle91]

hmmm. looking at the upper levels. that upper low/trough is a good deal farther south than the models have been showing for this timeframe.. I mean quite a bit.. that will change things..
http://rammb-slider.cira.colostate.edu/ ... mmb-slider

Almost appears as though the trough is tilted negatively already no? Why aren't models picking up on this and strengthening 90L? It seems so obvious?

[Aric Dunn]

hmmm. looking at the upper levels. that upper low/trough is a good deal farther south than the models have been showing for this timeframe.. I mean quite a bit.. that will change things..
http://rammb-slider.cira.colostate.edu/ ... mmb-slider

Almost appears as though the trough is tilted negatively already no? Why aren't models picking up on this and strengthening 90L? It seems so obvious?

yes ahead of time and also slightly filling in a little ? but for sure farther south ..

[FLpanhandle91]

hmmm. looking at the upper levels. that upper low/trough is a good deal farther south than the models have been showing for this timeframe.. I mean quite a bit.. that will change things..
http://rammb-slider.cira.colostate.edu/ ... mmb-slider

Almost appears as though the trough is tilted negatively already no? Why aren't models picking up on this and strengthening 90L? It seems so obvious?

yes ahead of time and also slightly filling in a little ? but for sure farther south ..

I'm not sure on the specifics of how data like this is inputted into the models, but I expect the Euro to pick up on this early tilt and southern trend in the trough and come in with a stronger, more westerly storm on the 00z run. All indicators point to that in my opinion. Unless the trough magically positively tilts again, or the dominant LLC manifests itself near the tip of Cuba, I don't see how the best track low could possible stay east, or in line with the current guidance.

[Aric Dunn]

Almost appears as though the trough is tilted negatively already no? Why aren't models picking up on this and strengthening 90L? It seems so obvious?

yes ahead of time and also slightly filling in a little ? but for sure farther south ..

I'm not sure on the specifics of how data like this is inputted into the models, but I expect the Euro to pick up on this early tilt and southern trend in the trough and come in with a stronger, more westerly storm on the 00z run. All indicators point to that in my opinion. Unless the trough magically positively tilts again, or the dominant LLC manifests itself near the tip of Cuba, I don't see how the best track low could possible stay east, or in line with the current guidance.

haha well we dont want the Euro coming in any stronger than the 12z !

[FLpanhandle91]

00z Euro initializing further east than 12z run. Dominant LLC is off the coast of Belize this run.

[USTropics]

Most of the GEFS members of the 00z run make a WNW turn along the coast line:

[FLpanhandle91]

Trend:

[MississippiWx]

Trend:

Stronger/slower this run initially.

So far the ICON, HWRF, NAM, GEFS, JMA are west on the 0z run while CMC, GFS, UKMET are east. Euro will be interesting to see which camp has more credibility.

[Dylan]

0z European has 90L approaching hurricane strength as it approaches the north-central gulf coast on Sunday night.

[AtlanticWind]

Shift to the east on this Euro run.

[MississippiWx]

Shift to the east on this Euro run.

You mean west? Landfall is Mississippi/Alabama border where it continues moving northwestward instead of northeast.

Euro also brings it down to 983mb before landfall...

[Dylan]

0z European sends 90L into the MS/AL border as a category one hurricane on Monday. Wind gusts over 80mph from Pascagoula to Pensacola!

[bamajammer4eva]

Monday night 7 CT



https://weather.us/model-charts/euro/fl ... 0000z.html

[LarryWx]

But climo is not always right. No one thought we would have so many cat 5 hurricanes last year but we did... when the Euro and Nam both show a period of steady to quick deepening it catches my eye. GFS is rolling let’s see what it does.

We are talking about MAY climo. Not SEPTEMBER clomp. Gigantic difference.

It doesn’t matter, September climo doesn’t favor multiple cat 5s but it happened. Point is the models are tools and to be used as such. The Euro and NAM showing a storm that deepens quickly up until landfall, possibly sub 980mb, is worth considering as a possibility. The shear charts show an anticyclone developing providing nice outflow and reducing shear dramatically. The loop current is plenty warm at 27-29C as well. May climo says there should be 50kts of shear to rip this apart but if modeling is correct it will be very low and favor steady intensification...

From my perspective, climo doesn't say what will definitely happen or not happen. Instead, it is a tool that suggests probabilities. So, in those cases where climo didn't/did favor something and it still happened/didn't happen, I don't look at that as saying climo was "wrong" per se. Rather, I'd think of climo as not helping in those cases. Regardless, climo will, of course, be helpful in most cases if used correctly.

Sometimes climo based suggestions are stronger than others. That there won't be a 0Z 3K NAM type major H (955 mb) in late May in the Gulf is an EXTREMELY strong suggestion by climo because there has not been one on record back to 1851. Heck, there has been only one H of any strength in the Gulf on record since 1851 and even that was over 150 years ago! That there won't be a major H is something I'd bet heavily on and feel very comfortable about my chances.

[Hammy]

Things are looking good for this area developing just east of belize. combination of things are playing out. upper winds are beginning to switch to a more sw direction and becoming divergent. low level convergence is increasing in this area. and some clear signs of a larger low level circ are developing. tomorrow morning we should be looking at a organizing TD/TS or Sub trop.
http://rammb-slider.cira.colostate.edu/ ... mmb-slider

http://weather.cod.edu/satrad/exper/?pa ... colorbars=

It looks like a definitive LLC is starting to form in the last hour to the west of the convective burst near the circled area.