Separate names with a comma.
Discussion in 'Daily & Chat' started by crikey, Jul 6, 2019.
Stratospheric Polar Vortex.
GFS (super-Long Range) showing an early wobble @10mb for the PV.
Same High positioning as last winter (IO region), so potentially similar forcing.
Something to keep an eye on IMO:
SAM is about to hit a brick wall post 12th July.
Is this a good thing or a bad thing. Obviously high SAM is bad, but what does a wobble mean for us?
Maybe an early sign of something good for later in the season. Probably nothing.
We saw a wobble on the models late-July/early-Aug last year and reverbs saw it wind up as one of the biggest anoms climate scientists had ever seen. Early speculation is that it's 'climate change' driven.
Not suggesting much for the snow season, but it's an anom to monitor.
This ties in with this reply I received a week or so back - I wrote to Eun-Pa Lim at the BoM asking about the changes around the 10hpa level:
Hi, I assume you are concerning about +ve/-ve SAM & yes, the forecast increase of the polar night jet around Antarctica may couple down & promote +ve SAM sometime in weekly timescale
But such change in the upper stratosphere may be favorable for spring polar vortex weakening if it is followed by substantially increased wave activity in the lower atmosphere, which may result in -ve SAM in late spring like that of 2019
So it’s good time to start monitoring the condition of the upper strato winds & surface conditions. Thanks 4 drawing my attention to this.
Great to get her reply, and love the great leveller that social media can be, where you can contact someone specific at the BoM and they get back to you. Once again the SAM is going to be one to watch. No IOD, Pacific not looking certain and the SAM offside as well? Going to be interesting late winter.
I posted this in Tassie & deep South thread fwiw.
Evidence of some decent warming in lower strat of IO polar region (26th-3th Jul)
Not a SSW event by any stretch but I'd be guessing the polar night jet will be humming with a nice kink in it this time next month.
Heat flux @ 10MB looking strong in the forecast!
Definitely could be a sign of something. Not significant as of yet for tropospheric effects, but it can become so.