ATL: CRISTOBAL - Models

[aspen]

HWRF wants a strong TS or a weak hurricane in the BOC by Thursday.

[Cpv17]

Well through this run of the Euro out the door..

Any reason in particular? It seems like a lot of the models are trending towards a second low forming along the gyre as this one rotates around to the west.

I agree, but would it keep the same name?

[Aric Dunn]

Well through this run of the Euro out the door..

Any reason in particular? It seems like a lot of the models are trending towards a second low forming along the gyre as this one rotates around to the west.

Because Current actual trends are showing less of a GYRE motion it has condensed. the Vorticity on the pacific is much weaker.

and the majority of the EPS have been showing less of a cyclonic loop and staying over the BOC>

[MississippiWx]

The European and GFS seem to be showing a second storm forming near the tip of the Yucatan. Both of them bury 93L into Mexico. Very interesting and plausible idea.

[SoupBone]

The European and GFS seem to be showing a second storm forming near the tip of the Yucatan. Both of them bury 93L into Mexico. Very interesting and plausible idea.

Is that what that is on the Euro at 168 heading almost due west into central Texas?

[MississippiWx]

The European and GFS seem to be showing a second storm forming near the tip of the Yucatan. Both of them bury 93L into Mexico. Very interesting and plausible idea.

Is that what that is on the Euro at 168 heading almost due west into central Texas?

Correct.

[Cpv17]

The European and GFS seem to be showing a second storm forming near the tip of the Yucatan. Both of them bury 93L into Mexico. Very interesting and plausible idea.

Is that what that is on the Euro at 168 heading almost due west into central Texas?

Yes. It probably has a landfall just south of Matagorda. Maybe Port O’Connor.

[stormlover2013]

More like Galveston

[Cpv17]

More like Galveston

Yeah I wasn’t expecting that hard north turn like that. Very strange movement. A hard left turn then a hard north turn. Crazy.

[SoupBone]

The European and GFS seem to be showing a second storm forming near the tip of the Yucatan. Both of them bury 93L into Mexico. Very interesting and plausible idea.

Is that what that is on the Euro at 168 heading almost due west into central Texas?

Yes. It probably has a landfall just south of Matagorda. Maybe Port O’Connor.

Then it turns it due north sending it on top of Houston.

[stormlover2013]

Well hard left then is from ridge building in, doesn’t surprise me

[Cpv17]

Well hard left then is from ridge building in, doesn’t surprise me

Yeah that part doesn’t surprise me either, but the sharp north turn does. I mean I can see why it happens though because it has the ridge breaking down.

[Wx_Warrior]

[stormlover2013]

Yep makes sense no doubt

[Cpv17]

Yep makes sense no doubt

It’s all going to come down to that ridge. Placement and strength. Regardless it’s looking like a Texas landfall as at least a moderate tropical storm is looking more and more likely.

[stormlover2013]

Yep, corpus to lake Charles

[MississippiWx]

The most interesting thing about that run is how the Euro makes the storm stronger over Mississippi after it has been inland for two days.

[Nederlander]

It’ll be interesting to see what the ensemble shows as most members were disregarding the second circulation theory. Maybe hinting at a stronger ridge in the short term?

[USTropics]

https://twitter.com/TropicalTidbits/status/1267520343192862723

So what would cause such a turn back due south into those mountains?

Currently there's a bit of a blocking pattern to the north, which is creating weak steering currents:


With no dominating steering dictator, 93L is inherently attached to the CAG's rotational momentum (or angular momentum). Imagine you have a round tabletop, and it's spinning counter clockwise (CAG). Now drop a fidget spinner or some type of table top spinner (vorticity of 93L), and it will inherently start to follow the tabletop's angular momentum even though its rotation is also independent.

Essentially we have this large scale feature (CAG), and now a small scale feature embedded within. It's typical for the CAG to create numerous areas of low pressure that eventually can form into separate lows. They can become detached, especially when dominant steering currents become present (such as a passing trough). This pattern is typical for May-June, but the current position is anomalous (it's typically more biased towards the Pacific in May/June and biased towards the Atlantic in September/October).

So what will eventually become of these processes? There are (as usual) quite a few possibilities this early on. In the short term, location of consolidation for 93L is important. A more north and eastern location could give it time for steering currents to break down and allow for a more northern component. Reformations due to pressure drops could also impact this. Later in the week, there will be a passing trough to lift this north.

The more likely scenario with the latest runs of the GFS/ECMWF is for 93L's vorticity to get pinwheeled back into Mexico. While the vorticity of 93L is long gone, there's enough consolidation of the broad cyclonic flow of the CAG to lift north, as a passing trough lowers pressure in the central GOM. The 12z GFS forecast shows these processes:

[captainbarbossa19]

The most interesting thing about that run is how the Euro makes the storm stronger over Mississippi after it has been inland for two days.

I wonder if it's land interaction that is causing the vorticity to tighten?