No worries. Gpm is geopotential metres
Thanks for that observation re the stationary temp',anomaly at 50hpa. How curious.Didjman wrote: ↑Wed Jul 17, 2019 11:43 am Again, the tropopause has dropped, albeit approx half a klm in last 12 hrs. That makes a dropping trend for at least the last 36hrs for Hobart, Melbourne and Sydney. Adelaides latest chart is incomplete.
Also, the below link shows the warming anomoly has become stationary between Africa and OZ (prolonging the effects of stratospheric warming):
https://www.cpc.ncep.noaa.gov/products/ ... 50anim.gif
And the Tropopause appears to be on a lowering trend! What will the Polar Vortex do? We should know in a week. If I have taken on board what JS has taught me (many thx JS!), it could split again, then real winter returns around end of the month!
On the 1100Z 17 July melbourne sounding, the tropopause had dropped to 7klm or 23000ft - down from 10.5klm/34000ft -12hrs earlier.
Hi Didjman, IMO, another crucial piece of the puzzle is the Rossby wave or commonly known as the long wave trough. It needs to propagate at the right time into SE OZ to deliver the cold snap. If the timing doesn't line up, it peaks east or west. The crucial level to look at is 500 hPa on the charts. Weatherzone have free polar charts they produce everyday which is a nice a quick way to see what might be in the pipeline
Is 50hpathe lower stratospher?JasmineStorm wrote: ↑Thu Jul 18, 2019 6:48 am
Hi Criky, what is your definition of a vortex split? The 2002 event was a full vortex split. As posted at the beginning of the thread, this was a lower stratopsheric vortex split/separation as seen on the observations of 2 spinning vortices at 50 hPa, which lowered the tropopause and was the behind 3 foot snow dump into the Alps. A similar event triggered the once in 20 year snow event at the end of May.
@Didjman, I'm still reviewing this next event. Not all the pieces have come into place yet.
050 to 100 hPa is mid to lower strat. Strat heights varies between Poles and equator as well. Don't have a nullschool shot but here is the disturbance at 050 hPa from 11th May caught on GEFS ensemble. Flushed out in late May into the mid latitudes for the biggest Alps May snowfall since the year 2000.crikey wrote: ↑Thu Jul 18, 2019 9:04 amIs 50hpathe lower stratospher?JasmineStorm wrote: ↑Thu Jul 18, 2019 6:48 am
Hi Criky, what is your definition of a vortex split? The 2002 event was a full vortex split. As posted at the beginning of the thread, this was a lower stratopsheric vortex split/separation as seen on the observations of 2 spinning vortices at 50 hPa, which lowered the tropopause and was the behind 3 foot snow dump into the Alps. A similar event triggered the once in 20 year snow event at the end of May.
@Didjman, I'm still reviewing this next event. Not all the pieces have come into place yet.
My definition of a vortex split is the same as yours l,suspect.,The formation of 2 vortices. We saw that on the null,school wind streams
I have been documenting this event since your first observations Here
https://weathercycles.wordpress.com/201 ... nd-onward/
The research l read on the 2002 event Esler et al 2006 ,described a split at the uppers, if l remember.But would newe to read more widely l suspect to get a better handle on what went on back in 2002.
My take' or observations show evidence of split from top to bottom with a sort of bottle neck shape at around 200hpa
....
re.. " A similar event triggered the once in 20 year snow event at the end of May'
Was there.. another PV split...at 50hpa back in May 2019 as seen on null school windstreams?
Thx for the update JSJasmineStorm wrote: ↑Thu Jul 18, 2019 5:04 pmThe scientist who runs the site is aware but is currently writing a paper and won't be able to fix the feed for a few more days.