31 March 2019

Dual Cold Fronts

A cold front came over southeast Australia on Friday afternoon as depicted in this quick animation of mean sea level pressure (MSLP) chart animations.

mslp_loop.gif

Though almost impossible to distinguish, my attempt was to beat the front back to my flat. It was a race on bicycle. I saw that front was due to hit Melbourne airport, given winds changes occuring on the coast of southwestern Victoria, around 5PM (local time). This location is not far from my departure point. So just after 5PM I departed, but alas could not out run the front. Not that I really thought that I could.

https://www.strava.com/activities/2248799893/embed/ab3cb7d66a3f73dea790dfa75c6cd7f51fa89d62

Interestingly enough the front did provide some good weather for Victoria over the weekend. Noticed the dual cold front that was analysed on Friday afternoon. This dual cold front is unforunately not visual in the upper air soundings from Melbourne Airport over the same time period. Though one does observe the stark shift from a very stable air column to one that is very conducive to convection and instability.

skewTlogP_loop.gif

 

Also of interest I thought would be to look at the cloud drift winds for the same period. One can clearly observe a head boundary form on 29 Mar just west of Victoria/Tasmania and then roll over to form a fairly strong and quick moving sub-tropical low. Which is further corroborated in the MSLP chart above.

Since this is such a cool event (ahh! to pun), why not show the cloud drift winds (lower and upper) as well as upper divergence and lower convergence. Unfortunately, it appears that wordpress is not allowing the animated gifs of those cloud drifts.

Oh well, here's a time lapse of the St/Sc rolling by on Saturday. Thank you for whethering the weather with me!

https://youtu.be/EmBMONyxN38

 

No comments: