To be notified of news about this storm and others through the season:

For computer model forecasts, visit our charts page.

Clarification of Stan

I understand that last night's comments about the future of Stan are drawing a lof of doubt and criticism. I think a lot of the confusion surrounding the current situation is how we name tropical systems. Last year when NHC decided to resurrect Ivan, they did it because the tracked a distinct vorticity maximum from the Mid-Atlantic back to the Gulf of Mexico. Crazy, I realize. My justification for relating any development in the Pacific to Stan falls under the same line of thought.

Here is the current 500mb vorticity from the UKMET. There is a single vorticity maximum (vort max) in southern Mexico with nothing shown over the nearby Pacific.


By 24 hours, that same vort max is clearly still intact and elongated at an angle to the coast.


Now let's fast-forward to where we can see the development of a new Pacific system in 72 hours.


If you go step-by-step through the model run, that is CLEARLY one continuous vort max. For the exact same reason NHC kept Ivan intact, I think this new development can be related to Stan. For those of you who would like to walk through the development yourself, here is the model loop.

Now, what is out there right now? There a couple convective cells, neither of which have a circulation. If any circulation were to develop, you could definitely make a case that it was induced by the positive vorticity advection from Stan.


Posted by Bryan Woods | Permalink