TS Bertha

[kayman]

I do wonder if the low-level circulation is reforming further south near the mid-level circulation in Bertha.

[Chinook]

what a weird tropical storm

surface low by Louisiana

convective storm far south

 

 

 

 

[vortex95]

6 hours ago, Chinook said:

what a weird tropical storm

surface low by Louisiana

convective storm far south

 

 

 

 

You can see the mid-level center spin on radar near CRP currently.  Talk about a tilted vortex sfc to mid-levels!  This one of the most "disconnected" TCs I think I have ever seen.  Great case study.

The ECWMF handled this evolution very well.  Compare its 925 mb RH/streamlines to its 500 mb RH streamlines, and the disconnect was fcst very well.

This is about as far as you can get from a classic TC structure, but they exist on a *spectrum*.  You can't use textbook examples all the time for what actually occurs in the real world.

So both Arthur and Bertha  were odd ducks, and even for sheared TC, more atypical for this variant of a TC.  It also shows how the models still struggle w/ initial TC genesis for systems like this.  Pre-Bertha was a non-tropical low that appeared it would remain broad and cold core, and strong shear was factor.  Not that the models can't handle non-tropical to tropical transition, but the overall environment was not favorable, so that likely influenced the models.  Yet the system still managed to form a large, solid LLCC in the mid 990s.