Stratosphere Temperature Watch 2012/2013

[Duane S.]

Yes look carefully!

Forecast SSW 4/1/13!

The question is - will we see propagation?

This is what we would like to see on the EP flux forecast in the coming days:

Do you think the EP flux is coming round to that?The ECM forecasts seem to be less equator bound every day but still quite a way away from a poleward surge

[bluearmy]

do the momentum flux charts give a clue here? The energy seems to be hitting a 'brick wall' at 10hpa on wave 1.

[phil nw.]

Zonal wind reversal showing up nicely at 10hPa on the ECM outputs within T240hrs now.

http://wekuw.met.fu-...l&var=u&lng=eng

confirming a SSW- surely the trophospheric vortex is on borrowed time.

[Summer Sun]

Lots of excitement in here but the models are still not showing anything colder well into January even the ensembles are mild, so at the moment theirs no signs of any cold spells even in FI

[aitchbomb]

Thats such a poor effort at trolling I feel even more positive now, cheers pal!

[UV-RAY]

Thats such a poor effort at trolling I feel even more positive now, cheers pal!

He's not trolling though, just stating what the models are currently showing.

[Jayces]

Lots of excitement in here but the models are still not showing anything colder well into January even the ensembles are mild, so at the moment theirs no signs of any cold spells even in FI

I am sure a more learned member will correct me if I am wrong but don't think the weather models will show anything until the warming cycle hits the troposphere (sp)?

Besides, the Meto 16-30 suggests colder so what are they looking at that has made them suggest that?

[chionomaniac]

Lots of excitement in here but the models are still not showing anything colder well into January even the ensembles are mild, so at the moment theirs no signs of any cold spells even in FI

That's because we don't know exactly how the forecast SSW will affect the troposphere. I do not expect to see too much on the ECM op yet - though the extended ensembles may begin to show increasing colder scenarios. The GFS ensembles may also start to hint at some colder solutions as well. Remember we are looking at around day 10 right up in the strat and that will take some time to filter down.

[Aaron]

He's not trolling though, just stating what the models are currently showing.

Pretty sure this isn't the Model Output Discussion thread - it's about the Stratosphere and what effect it could potentially have on our weather further down the line. Read through the pages, mid Jan looks like a good bet of a SSW event. Correct me if I'm wrong!

[TEITS]

Would you agree CH that the future GFS FI charts are prone to wildly different outputs due to the model figuring out how the warming will impact the troposphere. Also if you had to put a rough date on when you think this SSW could have the biggest impact on our weather when would that be?

Apologies if im asking an impossible question but its more desperation on my part.

[chionomaniac]

Would you agree CH that the future GFS FI charts are prone to wildly different outputs due to the model figuring out how the warming will impact the troposphere. Also if you had to put a rough date on when you think this SSW could have the biggest impact on our weather when would that be?

Apologies if im asking an impossible question but its more desperation on my part.

Definitely impossible questions Dave. Climatology would suggest that in the following 45 days after a SSW we will have 3 bursts of negative mean zonal winds directed towards the troposphere. At these points blocking will be increased in high latitudes. Climatology also suggests that following a displacement SSW one of the areas seeing increased heights would be around southern Greenland.

My guess is that we will see height rises towards the N/NE of the UK as there have been repeated suggestions that the displaced vortex towards the Atlantic will subsequently split in this area.

Edited December 27, 2012 by chionomaniac

[EML Network]

Would you agree CH that the future GFS FI charts are prone to wildly different outputs due to the model figuring out how the warming will impact the troposphere. Also if you had to put a rough date on when you think this SSW could have the biggest impact on our weather when would that be?

Apologies if im asking an impossible question but its more desperation on my part.

I'm no expert, but from from what I have come to learn over the past few years, the lag time between a SSW and any possible effects here in the UK sits somewhere between 2-4 weeks ?

So assuming that's right, I'd say somewhere around the end of January or the beginning of Feb ??

[TEITS]

Cheers CH for the reply mate.

Ignore my latest post on the model discussion thread then because it looks as though im being far too impatient and expecting too much too early. Personally I would love to see the impact of the SSW towards the latter part of Jan/Early Feb because although the days are slightly longer the upper temps from the N/E can be at there coldest.

Whatever happens though its been another fasinating season of following this thread.

[UV-RAY]

Pretty sure this isn't the Model Output Discussion thread - it's about the Stratosphere and what effect it could potentially have on our weather further down the line. Read through the pages, mid Jan looks like a good bet of a SSW event. Correct me if I'm wrong!

it does indeed look very likely, but that means nothing if we end up on the wrong side of things.

[Bishop Brennan]

I'm no expert, but from from what I have come to learn over the past few years, the lag time between a SSW and any possible effects here in the UK sits somewhere between 2-4 weeks ?

So assuming that's right, I'd say somewhere around the end of January or the beginning of Feb ??

I think I'm right in saying that the date of the forecasted SSW has actually moved forward somewhat, from Jan 10th to Jan 5th or thereabouts.

Bish

[Mark Bayley]

I don't think we shall be waiting long, certainly not till the start of February. But as CH iterates, we don't know how the SWW will impact upon the troposphere, i.e. blocking. Interestingly there is some support for height rises around the southern Greenland area around mid month, with a possible MJO phase 7.

Beforehand the geopotential height charts seem to show heights attempting to build north eastwards, which is shown on the NAEFS as well

[Isolated Frost]

On the latest GFS 06z suite, the stratosphere's top temperature at 10mb is above 0c from +81 to +216, peaking at an incredible 10.1c at +129.

Regardless of the overall outcome, it truly is a pleasure to witness the atmosphere change so dynamically and the processes involved.

[Luisport]

Can anyone tell me what we in europe will have? And to the south like Portugal and Spain? Cold temp to us too? Thank's!

[Isolated Frost]

Can anyone tell me what we in europe will have? And to the south like Portugal and Spain? Cold temp to us too? Thank's!

You can never tell the tropospheric response at this stage (-10d from SSW), but the overall outcome would be more conductive to northern blocking, with vortex energy moving elsewhere, potentially away from northern latitudes- the crux of the current warming will be how the vortex responds (and to a lesser extent, where the polar high and associated ridge puts itself)-

Right now, I couldn't tell you, but the chances of cold will increase for Iberia as we progress through January. Ask back in perhaps a week or so and confidence will be higher as the NWP comes to grips with the energy 'spill' from the initial warming.

[Luisport]

You can never tell the tropospheric response at this stage (-10d from SSW), but the overall outcome would be more conductive to northern blocking, with vortex energy moving elsewhere, potentially away from northern latitudes- the crux of the current warming will be how the vortex responds (and to a lesser extent, where the polar high and associated ridge puts itself)-

Right now, I couldn't tell you, but the chances of cold will increase for Iberia as we progress through January. Ask back in perhaps a week or so and confidence will be higher as the NWP comes to grips with the energy 'spill' from the initial warming.

Thank you so much for your reply... as i understand it's difficult to know what will happen, but what kind of temp we can expect in Portugal? You know we are not prepared for cold temp, so it's important i have an idea of what i should be prepared. Thank's a lot!

[Adam lufc]

Anywhere between 15c and 21c

[Duane S.]

Thats such a poor effort at trolling I feel even more positive now, cheers pal!

I don't think he is trolling but it does bring absolutely nothing to what is a fantastic thread. Hopefully the perenial knockers will keep their cynicism and reservations to themselves or better still let it all go in the model mood thread!!

So here's that age-old caveat to those that either just seem to want it to not work out or who are just generally pessimistic (or realists in their own minds)... We are heading towards a strong stratospheric warming, even a possible SSW. With that comes increased opportunities of cold weather through increased HLB that will almost certainly occur as a consequence. BUT it may not be favourable for us. Nobody knows that yet!

Think of it as getting to roll one throw of a dice once a month during winter and under 'standard' atmospheric conditions needing a '1' to get a decent cold weather period to our shores. With this warming about to get underway rolling a '2' and '3' should also do. If we then get really favourable signals on top going into January add a '4' onto the list and even in extreme circumstances a '5' may also suffice. But spoiler number '6' is always, but always, going to be on that dice.

The analogy is not saying it's JUST about luck, moreover that some degree of luck will always be required for us.

[Luisport]

Anywhere between 15c and 21c

negative???

[Isolated Frost]

negative???

I can't predict, but if pushed to, my analogues would be conductive to a negative anomaly of -1c to -3c in Portugal for January. For Coimbra, this is a high of about 10c and a low of about 1c.

[Luisport]

I can't predict, but if pushed to, my analogues would be conductive to a negative anomaly of -1c to -3c in Portugal for January. For Coimbra, this is a high of about 10c and a low of about 1c.

well that's the normal temps... today i have 0c of min temp, but below -5c, i have to take precutionary measures.