abajan wrote:ThetaE wrote:Hey all! This is my first post here! I've been reading here as a guest since Hermine, but 97L has convinced me to post some as well.
I actually have a question regarding future conditions for 97L: What's going to cause all this shear in the Caribbean to clear out?
http://tropic.ssec.wisc.edu/real-time/a ... wg8shr.GIF
It clearly doesn't seem to be an issue on any of the models, per their rapid development, but I can't help but wonder what may cause such a drastic switch over the next few days.
Welcome aboard, ThetaE!
As to your question about the shear, I'll leave that to those more knowledgeable about it than me to answer.
The top of the troposphere (aka tropopause) is forecast to increase in altitude the same time as 97L enter the Carib.
GFS shows this as 355K PV.
You can find it here:
http://www.tropicaltidbits.com/analysis ... 0&ypos=560
The darker the blue, the higher the tropopause and the calmer the UL winds.
A higher tropopause also causes the total vort column to expand vertically and stack which allows it to spin up (spinning skater pulling in arms analogy).