[Model output discussion - proper cold spell inbound?]

24 minutes ago, Jemma Croton said:

Just want to say that this is a really super analogy Chio. I used it to explain things to my son with autism and it made sense to him straight away. It’s a gift to be able to put things into terms even those withoutbthe additional knowledge can understand 

Couldn’t agree more with this , @Catacol mentioned Dr Amy Butler and she gave an analogy on Twitter too , she wrote 

Here’s a simple (but imperfect) analogy. Think of a big bowl of water where you start stirring in one direction very fast. That’s like the winter stratosphere, 6-30 miles above the Arctic.Now you put your hand into the spinning flow. What happens? The water rapidly decelerates and the flow would become chaotic. In the atmosphere, atmospheric waves are slamming into the stratospheric flow and decelerating it. This makes the atmosphere rapidly warm.In the stratosphere when the vortex rapidly slows, those effects descend down to the surface. It generally shifts jet streams towards the equator which allows colder Arctic air to move to lower latitudes

[Model output discussion - proper cold spell inbound?]

2 minutes ago, Purga said:

A cold outlook from NOAA for February

Greenland and the Balkans anomonously warm - for a change

Greenland and Svalbard will be anonymously warm the amount of HLB that will be over them ? 

[Teleconnections learning]

Thanks @Bring Back1962-63 And also @ghoneym for your help today , trying to learn the MJO and now being distracted by Strat , head mashed  

[Model output discussion - proper cold spell inbound?]

8 minutes ago, nick sussex said:

 

 

Bang on as usual @nick sussex ! Are the Strat and Trop coupled well at the moment ? Reason I ask is after this potential ( and I say potential as I don’t want to jinx) SSW I’m wondering about the lag timeframe until the effects are felt in the troposphere ? 

[Model output discussion - proper cold spell inbound?]

I find it interesting that yesterday’s ecm 12z was showing 51/51 members heading towards +ve GPH/MSLP rises over Scandinavia by d13/14. maybe that’s where the GFS 00z OP was sniffing out ?? 

[Model output discussion - proper cold spell inbound?]

The two mild spikes the GFS had been showing for next week have been steadily getting flattened in the GEFS resulting in the mild fingers being squeezed  as we enter higher resolution time , @ T168 plenty time for this to happen again , yet it doesn’t last long anyway on this ECM run 

[Teleconnections learning]

5 minutes ago, Snowy Hibbo said:

Yes, Phases 6-7 tend to be the best for SSWs, so part of the forecast SSW involves that. I don't believe it will have much of an effect on the MJO weakening into P8 however.

Thank you , yes it’s forecast to drop amp into 8 hopefully not into the dreaded COD , what would be an overall average strength of RMM2 ? 

[Teleconnections learning]

Could the record breaking MJO ( in phase 7 ) amplification be in any way linked to this *possible* SSW ? And if so could the *possible* SSW then have an impact on the further phases of the MJO mainly 8-1 ... long way of saying can they both be linked to each and correlate ?

[Stratosphere and Polar Vortex Watch]

1 hour ago, comet said:

For the most part this is almost certainly a top down forcing. You can easily see this on the instant weather maps.

The late Jan 2009 warming and split was in a similar locale and had an almost immediate trop response, I see no reason why this should be any different.  We may only be a couple of days away from some mouth watering charts to start appearing in the model thread. I must admit my expectations are very, very high.

So nearly no lag? Think 2/3 ssw events effect the uk ? Accurate ?

[Model output discussion - proper cold spell inbound?]

5 minutes ago, Ed Stone said:

 

I'll be interested to see just how the models handle the expected SSW

 

Something that really interest me this , didn’t lurk on here when the last major one occurred , I’m presuming the models will go into a meltdown just like the Strat ? 

[Teleconnections learning]

Could someone be so kind to tell me when the MJO forecasts on NOAA update daily ? And a rough uk time ? 

[Model output discussion - proper cold spell inbound?]

Is the progression of the ECM in the latter frames just going to be blamed on model climatology bias or is there something else the model is picking up on ... out my pay grade that one ! 

[Model output discussion - proper cold spell inbound?]

Even at day 7 it’s far from the mean 

[Stratosphere and Polar Vortex Watch]

9 minutes ago, chionomaniac said:

It's a mixture of wave 1 downwell weakening the vortex and a wave 2 upwell contributing to the split

Would that have less of a lag time to effect actual weather , think I read the rule of thumb was ‘give it two weeks’ but maybe that was just based on complete downwell ? 

[Stratosphere and Polar Vortex Watch]

5 minutes ago, Snowy L said:

Yes the semi-permanent lobe over Greenland/East Canada delivers huge cold spells when the vortex elongates (e.g. slight pressure from warmings), as seen many times in the last 5 years, but a full on split stops that happening.

Is this a trop led split ? Upwell?

[Model output discussion - proper cold spell inbound?]

5 minutes ago, Mike Poole said:

Strat warming getting closer on GFS -  seems like a double warming and a split of the stratospheric PV.  

A nagging doubt though - a split like this will have significant implications for mid-latitude weather down the line, a 'reshuffling of the deck' so to speak, but if we've already got the cold in place, do we want the deck shuffled?

 

Is this an upwell split ? Trop led ? 

[Model output discussion - proper cold spell inbound?]

Even more pronounced in my area @karlos1983

 

[Model tweets]

5 hours ago, Summer Sun said:

 

You do some great scouring of the tweeter land  

[Stratosphere and Polar Vortex Watch]

1 hour ago, knocker said:

See bottom string

 

Think I read somewhere that 2/3 effect the UK ? And apparently people in the US don’t get excited as it doesn’t effect CONUS much ? 

[Model output discussion - proper cold spell inbound?]

3 minutes ago, bluearmy said:

GEFS showing a continuation of the cold in general and fairly agreed with the eps. I hadn't looked at the larger scale ec46 from yesterday - safe to say that if glosea and mogreps are broadly similar, I can see where Exeter got the theme of their extended from earlier. basically, all output continues to prog low heights into Europe and with cold in situ to begin with, any borderline situations which crop up could end up falling in the right place for coldies.

Do you get any access to ecm Strat charts , could swear I seen a spilt showing on twitter today from the ecm but I can’t find it anywhere now , I know the GFS has been signaling this and also now Glosea but the ECM? 

[Model output discussion - proper cold spell inbound?]

Just signed back up in preparation of tonight’s monumental , pivotal , crucial , edge of your seat ECMWF 12z output , tongue in cheek there,  but I’m loving the Synoptics and various debate going on today ! Shows there’s interest on the horizon and not a westerly juggernaut !