Vikos

Let’s wait for the warming to begin. I don’t trust gfs with its keen spring ambitions. May to many influences of statistics going into the midterms? warming begins in around 5 days… Because extended range skill is higher when there is a SSW in the forecast initial conditions (Tripathi et al. 2015) then SSW events are a potential source of predictability. From ec hompepage things need to get real, then picked up as a initial condition and then we may see a big flip? Who knows?

per definition the fw is this: *‘…the winds must return to westerly for 20 consecutive days between events, and for at least 10 days prior to April 30.’* source https://csl.noaa.gov/groups/csl8/sswcompendium/majorevents.html

eps goes ssw

I know hahaha. This is the alive version of my avatar have a good one

Carrot on a stick? What do you mean?

I wrote Berlin an email but unfortunately I got no answer. Then I called them but you rather get Joe Biden on the phone to talk about bloons made in China then finding someone to talk about stratospheric charts…

BA, is it possible that the lower trop is trying to connect to the strat, like an upwelling? Seems to me like the winds in strat are also calming down a bit, so would there be a chance?

No downwelling, 30hpa is the limit where it stalls. Dropped to 52% from 90 yesterday. I feel like I’m fooled once again by gfs. If EC doesn’t confirm the (possible) mw with the updated zonal wind chart later today… well gfs is for the

The SSW probability in GEFS is: 90% well... why not

Never have seen a pattern like this before

Not only Greece Weather Warning: Dense snowfalls, stormy winds, frost WWW.KEEPTALKINGGREECE.COM National Meteorological Service warns of cold weather front "Barbara" that will hit Greece with dense snowfalls even in lowland, stormy north

Splat? Splat! Take your magnifying glasses and go for it

The SSW probability in GEFS is: 61% you need to hit that F5-Button repeatedly these days

what ever is left… go to hell!

Was 61% yesterday…

In America.... so mostly ongoing autum over here

In the reanalysis, two large deceleration periods are observed before the SSW onset (12–19 January and 5–15 February). The zonal mean zonal wind is steady at ~30 m/s between the two periods. It is clear that the [U]60°N, 10hPa decelerates most rapidly in the second period. The westerlies begin to reverse to easterlies on 11 February, and the easterlies persist for more than 2 weeks. The easterlies fluctuate below the zero line from 11 to 28 February, and the maximum easterlies reach ~20 m/s on 15 February. It can be seen that the circumpolar westerlies gradually recover after 28 February. Source Just a moment... AGUPUBS.ONLINELIBRARY.WILEY.COM

The link is gold! Thank you! Abstract A major stratospheric sudden warming (SSW) event was observed in February 2018 after a 4-year absence since the winter of 2013/2014. Based on the reanalysis data, the polar night jet changed from a very strong state to a moderate state during 12–19 January, and the moderate westerlies directly reversed to easterlies during 5–15 February. The intensified East Asian trough, Alaskan blocking, and East U.S. trough amplified the extratropical climatological wave 2, which propagated upward into the stratosphere, leading to a vortex-splitting SSW event. Predictions of the February 2018 SSW event are explored in hindcasts initialized 0–4 weeks in advance by the Beijing Climate Center Climate System Model. Less than 20% of the 28 ensemble members predict the reversal of [U]60°N, 10hPa hindcasts initialized 3 or 4 weeks in advance if a 5-day error is allowed, while this ratio increases to 43% in hindcasts initialized 1 week in advance. Based on the climatological occurrence of SSW events in the forecast system, the maximum deterministic predictable limit of this event is 1–2 weeks in this forecast system. The eddy heat flux and its domination by wave 2 can only be predicted within the predictable time limit. A comparison between hindcast members initialized 2 weeks in advance suggests that the extratropical troughs and blockings are responsible for the upward propagation of waves from the troposphere to the stratosphere. The predictable limit of the stratospheric circulation pattern for the February 2018 SSW, 1–2 weeks, also generalizes to other vortex split SSW events such as the January 2009 and February 1999 cases.

good night my British friends

hopefully. But the graph shows 0 for me

But phase 0?

Normal swings for me in an unknown condition (ssw on the horizon, displacement of pv and stuff)

What if gfs sniffed something like a true (but tiny little) SSW-mw the days before and had it as a starting parameter leading to scandi-blocking? Now, after the first peak it disappeared from the starting parameters and this leads us to no scandi high?

Then I am watching different charts… sorry my fault

Are you serious?