Snowy Hibbo
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Posts posted by Snowy Hibbo
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7 minutes ago, Catacol said:
Yes - that might fit. I'll be a bit more optimistic and refuse to believe that the Autumn signal is all gone.. so maybe approaching phase 7 prior to the end of January and with luck attached to a moderate amplitude. I had hoped to see the Nina profile in the eastern Pacific moderate as winter progressed, but no sign of that yet. Phase 8 into February would be good, though vortex conditions will be key. Broad composite has a pleasing look
Nothing wrong with a bit of optimism
I still like the Early-Mid Feb period though, perhaps Late Jan too... amplitude is a big gamble at this stage unfortunately.
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3 minutes ago, Catacol said:
Sorry - I was unclear. I mean a rejuvenated convection signal along the equator towards MJO phases 7/8. As a result scrub support for mid latitude ridges, reduce extra tropical AAM and thereby open the door for a high lat block. One of the many jigsaw pieces.
Yeah, that's fine. Certainly agree with that.
POAMA40 and EC46 were looking like a return to MJO Phase 7/8 around about Early/Mid February(and that's really more of an estimate), but there is only so much the models can see. But I don't see anything like that anytime soon IMO.
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16 minutes ago, Catacol said:
some pacific momentum
You mean a Pacific jet extension(stronger jet)? Or are you referring to something different?
16 minutes ago, Catacol said:Yes - MT strongly negative. But frictional torques ought to lead MT upwards
Agree with that, that is normally the way the GWO cycle works.
16 minutes ago, Catacol said:I dont know just how much faith to put in Cohen
I do like to put faith on him, about the strat. We either see a proper disturbance to the strat PV or we don't. The GWO is probably going to progress around the cycle, should be expecting a +AAM January IMO. Of course the specifics are unknown.
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16 minutes ago, Catacol said:
I cant get my 23rd Dec frictional torque update to stick on my post - whatever I do it defaults to 22nd Dec which for the life of me I cant understand. However take it from me - frictional torque on the 23rd has climbed a fair bit - close to +1 and climbing on the gradient.
I can see the 23rd Dec update.....extremely weird, if you see the 22nd Dec one.
I am guessing MT is still strongly negative? That completely puzzles me, I will have to do some digging and talk to some people.
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24 minutes ago, Catacol said:
I contacted WDT - their customer service was pretty good and the updates seem to be online now. 23rd Dec latest. Use chrome... click on options and go to developer's tools inside of more tools. Then right click on the reload page icon (left of the web address bar at the top) and select empty cache and hard reload. This will get rid on any residual cache data in your browser that might be clogging up the update. There is something a bit odd with the WDT site....
Move to GWO phase 1 now locked in
with relative AAM plunging downwards
On the positive side frictional torques are now increasing
which ought to encourage a reversal of the negative MT trend and perhaps reignite a signal for increased AAM in general. Mid January maybe for this - until then no high lat blocking.
Didn't work unfortunately, gave WDT an email. Thank you though.
I was expecting the Frictional torque to go up higher, probably moving the GWO over to Phases 3/4 soon. Just waiting for that +MT to happen.
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On 25/12/2017 at 09:58, Catacol said:
Of course. Loss of AAM in the tropics is transferred as a higher AAM budget in the extra tropics. It is the loss of tropical AAM that has effectively hamstrung the recent forecasts for more blocked conditions at higher latitude for January as we observe westerlies taking control through our sector of the Atlantic.
The GWO is an index of net AAM in the system - and the inverse relationship between AAM at tropical and extra tropical latitudes is reflected in its value. It has nothing to do with me as to how this is related - it is a calculation that states the condition of GLAAM. Analogue data would suggest that in a Nina base state GLAAM tends to fall.. and with it chances of high lat blocking reduce as winter progresses. Hence the general idea that in a Nina year cold will tend to be front loaded. What was interesting about this year was that GLAAM levels looked to be holding up, as favourable MJO amplitude working alongside a -AO.
We have now seen this reverse... and the only question worth answering in my mind is why. Finally, after literally weeks of waiting and a few texts directly to WDT, we have updates for key AAM drivers. Frictional torques have been negative the last couple of weeks and are only just beginning to trend faintly positive
while global mountain torque has tanked through the floor almost off the scale
I really wish this data had been available over the last 10 days or so rather than not updating as expected at WDT (since 6th Dec) as it would have allowed a much earlier "warning" sign to those looking for cold that a change around was in the air. However it all falls into line with what I posted yesterday: stalled tropical signal combined with negative torques helping to scrub westerlies from the tropics and allow the trades to fire up once again. Net result = +NAO regime as westerlies take hold in the north atlantic.
What would cause both torques to fall and the MJO to stall? I cant answer that right now. There's a lot of chicken and egg about all this. I'm hungry to know more... and I'll keep hunting.
That's really weird IMO. I thought the EAMT went positive during that period, resulting to the current NP jet extension, and the Okhotsk low. And now the WDT charts aren't loading the current update for me. Very weird....
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Now I am going to proceed to elaborate a little bit on that. So yes, we are going to Phase 4 GWO.
Okay very important action occurring...
The EAMT is going to go positive in the next 24-48 hours.
Note the high and low gradient over Tibet and the Himalayas, thanks to the descending Siberian anticyclone.
This generates a +EAMT, this adds "fuel" to the East Asian Jet.
The westerly momentum generates some interesting wave activity. Which ultimately reinforces the -EPO/Alaskan High pattern, and keep the good period for snowfall in the Eastern US.
Eventually, we might also see a +MT over the Rockies, thanks to the forecast events. That would increase the AAM, and potentially send the GWO into Phase 5. Phase 4 in the meantime, will be held by an increase in frictional torque.
QuoteSo the GWO is heading over to Phase 4 (ignore GFS AAM bias please!). This phase of the GWO is associated or correlated with troughing over the Eastern US. It might be there for a while.
Slightly old GWO Phase space.
AAM now increasing....
Thanks to....
Slight Mountain Torque increase.
- East Asian Mountain Torque slightly positive.
- Rockies Mountain Torque continues to be negative.
Frictional Torque increasing now (main factor triggering move to Phase 4 of the GWO).
Interesting times for the Momentum budget....
I made these posts on a US forum. I believe they may be of broad relevance to this forum. The charts are a day old.
Anyway an elaboration.
Frictional Torque looks to be slowly increasing from negative over the next couple of days (from current charts). But it should go stay in the negative phases IMO, as a response to a strong world +MT.
A +EAMT event is currently present, and a +NAMT event is soon to start in the medium term. Both of those events should bring the GWO across from it's current GWO Phase 2/3 to Phase 4, then progressing to Phase 5. This will take Worldwide MT to a strong positive signal, and increase the AAM. What happens after, few people know.
The +EAMT is widely expected to extend the NP jetstream in the short term, and contribute to the strong -EPO block (which therefore contributes to the TPV in Eastern Canada, that may have an effect on West NAO domain). Then we are forecast to get a +AAM, GWO Phase 5.... By correlation, that GWO Phase means a ridge for the UK, so not great....
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Would somebody be able to give the link to these UKMO extended maps please?
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3 hours ago, feb1991blizzard said:
Might as well throw this in there as well then, pity we cant see a breakdown of months.
Probably should add the EC Seasonal anomalies to that.
January
February
March
You can kind of see a somewhat similar pattern, with some troughing over Canada in Feb/March, and the UK in January. And over the Atlantic throughout. Interesting times. What is also interesting is ridging anoms around the Aleutian region.
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EC Weeklies
Week 1 (12-18 Dec)
UK is under control by a Euro/Scandi low and an Atlantic ridge.
Week 2 (19-25 Dec)
UK is under ridging anomalies, with ridge extended well into Atlantic.
Week 3 (26 Dec-1 Jan)
UK is under troughing anomalies for the Inter Holiday period, with troughing across the Atlantic.
Week 4 (2-8 Jan)
Still troughing anomalies over Atlantic, extending over the UK.
Summary: AO is rather neutral/slightly negative for Week 1 & 2, but goes towards a more -AO setup in Weeks 3 & 4.
UK troughing on Weeks 1, 3 & 4.
-EPO/+PNA present through to Week 3.
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Week 1 (5-11 Dec)
Key features are the Atlantic ridge, Scandi troughing, Strong Aleutian low, +PNA. And of course the -AO.
UK looks mostly drier than normal, except north Scotland
Week 2 (12-18 Dec)
Euro trough intensifies, -AO consolidates, Aleutian low enlargens. Ireland and Western Great Britain looks dry, and Eastern Great Britain looks wetter than normal.
Week 3 (19-25 Dec)
-AO, Atlantic troughing, Aleutian still strong.... Scotland drier than normal, rest of UK average.
Week 4 26 Dec-1 Jan
-AO still present, Aleutian low finally starting to weaken. Wetter than normal for England and Ireland.
Update on the POAMA MJO probability forecasts.
5-9 Dec: 70-90% Phase 6
10-14 Dec: 50-70% Weak, 30-50% Phase 7
15-19 Dec: 10-30% Phase 6, 10-30% Phase 7, 30-50% Weak
20-24 Dec: 10-30% Phase 7, 10-30% Phase 8, 10-30% Phase 2, 30-50% Weak.
25-29 Dec: 10-30% Phase 7, 10-30% Phase 8, 10-30% Phase 1, 30-50% Weak
30 Dec-3 Jan: 30-50% Weak, 30-50% Phase 2
4-8 Jan: 30-50% Weak, 10-30% Phase 2, 10-30% Phase 3
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Week 1(28 Nov-4 Dec)
High latitude blocking, with ridging over Greenland, towards Aleutians and Euro Russia. Euro trough present, causing Higher than normal precip anomalies on UK East Coast. Rest of UK is drier than normal. UK is also colder than normal.
Week 2(5-11 Dec)
Still high latitude blocking present, with ridging over Euro Russia, Greenland and NW North America. Troughing over Europe, North Central Pacific and East Asia. British East Coast wetter than normal, and rest of UK drier than normal. Colder than normal in England.
Week 3(12-18 Dec)
High latitude blocking still present, Pacific troughing, Alaska high, East US troughing.
Drier than normal in Wales, Ireland and Scotland, average precip in England.
Week 4(19-25 Dec)
High latitude blocking still present, troughing in Pacific. Wetter than normal across much of the UK.
The EC46 shows a high lat blocking trend or -AO setup over the next 4 weeks. Interesting.
MJO
The POAMA probability modelling shows the following
Day 1-5(26-30 Nov): 70-90% Phase 4.
Day 6-10(1-5 Dec): 30-50% Weak, 30-50% Phase 6, 10-30% Phase 5
Day 11-15(6-10 Dec): 30-50% Phase 6, 10-30% Weak, 10-30% Phase 7
Day 16-20(11-15 Dec): 30-50% Phase 7, 10-30% Phase 6, 10-30% Weak, 10-30% Phase 1
Day 21-25(16-20 Dec): 30-50% Weak, 10-30% Phase 6, 10-30% Phase 7, 10-30% Phase 2
Day 26-30(21-25 Dec): 30-50% Weak, 10-30% Phase 7, 10-30% Phase 8
Day 31-35(26-30 Dec): 50-70% Weak, 10-30% Phase 7, 10-30% Phase 3
Day 36-40(31 Dec-4 Jan): 30-50% Weak, 10-30% Phase 7, 10-30% Phase 4
What to take from that guidance and the GFS and CFS as well is a good chance of a Phase 6-7 MJO in the short-medium term.
Finally the UK, Brazilian, Japanese and European MJO models.....
We are getting quite a few ens members over to that Phase 6-7 region.....
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Everyone seems excited about the UKMO's nice Atlantic ridge.
Just looking closer to the UK.
Interesting difference between the path of the low coming over the UK on Monday, between UKMO and GFS.
UKMO shows the low going straight over the UK...
And GFS shows the low heading north of the UK.
Both models agree on the stalling around Scandinavia, but they don't seem to agree on how the low crosses the U.K. This could mean quite a lot on the mesoscale side, with rain and snow accum over the UK.
CMC shows the low going over Scotland and heading SE down to Germany, rather than over to Scandinavia.
The positioning of when the low hits the UK is important, but also the positioning of the low when it slows down, and sends northerlies over the UK(and colder air) is also crucial. So I would be definitely be important to watch that low IMO to work out how that cold air is going to be directed across the UK and whether there could be widespread low level snow....
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23 minutes ago, bluearmy said:
The clusters are very specific to the n Atlantic so less of a concern to Ecmwf.
Lets not be naive here - if someone is paying a lot of money for data and they see it being reproduced for free use then eventually they are going to complain. Maue has his own agenda at the moment after his split with weatherbell.
The more you poke something, the more you risk a response.
Maue specifically said that anyone can reproduce his charts. I am sure that he consulted EC before saying that out public. Anyway it's all available for you or anyone else to use...
Anyway sorry for the OT....
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22 minutes ago, bluearmy said:
Can we avoid posting eps global data after day 10 ? I am a little concerned that Ecmwf may decide to remind their clients that this should not be reproduced and that could result in the Icelandic data becoming unavailable - the clusters are a boon for us !
It's the same data as the clusters, which is posted here all the time. And it's Maue charts, which are reproduced all over the place. I think I have said this before but given that Maue charts are free, they can be reproduced anyway. I doubt the Icelandic data will be stopped, because I'd doubt many people use it anyway.
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I realise the clusters have been posted, but just adding some points to the EPS....
10 day EPS mean
14.5 day EPS mean
What intrigues me is the weakening Greenland high and the general high lat blocking continuity. Also the Azores low completely goes in 4.5 days and the Euro trough weakens too. However you can see as the Greenland high weakens, the Euro trough takes more control of UK weather by the end of the run.
Globally the weakening of the -EPO also interests me, but its effect on the UK isn't as important. Anyway my focus is on the high latitude blocking, which should induce a -AO, similar to the EC46 outlook I posted not a long time ago. Will be interesting to see if we get the strat to weaken, as long range GFS says.
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Week 1 (28 Nov- 4 Dec)
EC46 indicates a Atlantic Ridge and a Euro trough, with the UK in between. It shows a dry Western British Isles and Wet East Coast of Great Britain, showing that trough/ridge divide. There is quite a lot of high latitude blocking about, with a Siberian low also being of note.
Week 2 (5-11 Dec)
Week 2 is mostly dry across the U.K. You still have the Atlantic/Greenland High in place and a weakening Euro trough over the UK. Colder in the southern parts of the country. Siberian low still in place, High lat blocking still somewhat present, Alaskan high building.
Week 3 (12-18 Dec)
A mostly neutral week for the UK precipitation and temperature wise, according to the UK. Weak Greenland ridging, troughing over Western Atlantic, mild Scandi/Baltic troughing. Main feature globally is the strong Alaskan High.
Week 4 (19-25 Nov)
A mostly wet outlook for the UK on the final week of my EC46 data. Neutral temperature wise. Troughing over SW Canada and into Western Atlantic. High latitude blocking present over Arctic.
Looks like the month ahead bears a fair amount of high lat blocking, which correlates with a -AO.
A quick look at the MJO....
As noted above, the MJO is forecast by some models, including the EC46, to go into a mild Phase 3/4 stage, and straddle the center circle line. POAMA (BoM) probability maps say the following:
24-28 Nov- 50-70% weak, 10-30% Phase 3, 10-30% Phase 4
Also worth of note...
9-13 Dec- 30-50% weak, 10-30% Phase 2, 10-30% Phase 4, 10-30% Phase 5.
14-17 Dec- 50-70% weak, 10-30% Phase 6
Then the ens members go all over the shop. Interesting to see some sort of prolonged progression in Phases 4-6, but probably going to be weak. But will be watching the POAMA update tomorrow. SubX also updates later today.
Interesting times....
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The NASA GMAO forecast shows that the zonal winds around the vortex at 10hPa will weaken in the next week or so.
The CFS ensembles, especially the Control, show a weakened vortex throughout the winter. However two ensemble members hold a stronger vortex until New Years.
Another way at looking at the vortex through CFS is the AO forecast, which is mostly neutral until mid January, when CFS predicts a more -AO based outlook.
Below you have the CFS 10hPa temperature forecasts for December, January and February. You can see a warmer/weaker vortex, as the winter progresses.
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EC Monthly
Week 1
Icelandic ridge, Mediterranean ridge, Scandi troughing and troughing also deeper in the Atlantic.
Warmer in England, Colder in Northern Scotland.
Wetter than normal over most of the UK.
Week 2
Euro trough and Atlantic ridge. Clear jet from the NW over the UK.
Slightly colder in the U.K. in general.
Wetter than normal in Wales and parts of Scotland. Average precipitation for the rest of the UK.
Week 3
Troughing over U.K, Atlantic ridging.
Slightly colder than normal in Scotland.
Wetter than normal for most of the UK.
Week 4
Troughing over the UK and ridging into Siberia. Zonal jetstream.
Wetter than normal for most of the UK.
Overall quite wet and cold at times on the EC46....
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57 minutes ago, karlos1983 said:
Dec-Jan-Feb ECMWF Seasonal
This site is getting bookmarked
Nothing overly inspiring, but at least no blowtorch showing in terms of temps. Is the way i would read it...
https://weather.us/monthly-charts/euro/europe/temperature-diff-f/20171201-0000z.html
While you are on the subject, here is the main official public source of EC Seasonal data, along with C3S MME data.
http://climate.copernicus.eu/s/charts/c3s_seasonal/
Quite late from the weather.us guys, I got that data ages ago. If you want the early data, just give me a buzz
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Sorry this is super late.....
Latest EC Monthly runs
Week 1 21-27 Nov
Greenland and Mediterranean ridging, Atlantic troughing extending to Northern UK and Scandi troughing as well, extending to Euro Russia.
Week 2 28 Nov- 4 Dec
Scandi troughing including over Scotland, Mediterranean ridging, causing zonal jetstream setup.
Week 3 5-11 Dec
Troughing over Norway, Atlantic Ridge present.
Week 4 12-18 Nov
Atlantic Ridge present.
sorry for lack of detail, very early morning in Aus....
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12 hours ago, Blessed Weather said:
I'd be grateful if one of the strat experts on here could check my interpretation of the JMA Zonal Mean Zonal Wind latitude-height chart please. My take:
- the zonal winds at 10 hPa 60N are westerly and slowly ticking up (yesterday 33.6 m/s, today 34.7 m/s) and that the stronger winds are slowly descending down through the strat.
- the winds at 30 hPa over the equator are easterly and thus show an e-QBO.
And finally, what is causing the burst of stronger westerlies at 300 hPa 30N? I don't understand that one! Thanks in anticipation.
This graphic of the whole atmosphere both NH and SH may help. The SH shows the two jetstreams better than the NH ATM.
The NH Polar Jet, as already mentioned, is weak with the current -AO setup. I use these charts frequently to check up on the jetstreams, along with the QBO...
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16 minutes ago, jvenge said:
From Weatherbell.
Note: Any maps, images or charts from ECMWF (License) may never be posted or re-distributed (except for WMO-Essential). All other maps, images and charts from other models may be shared in moderation under the following conditions: The images may not be used for any commercial (revenue generating) purpose including, but not limited to, ad-supported websites or private consulting. Any images must be attributed to WeatherBell Analytics.
The teleconnections doesn't fall under WMO essential :-) The WMO essential consists of some stuff related to the det run and some from the EPS, but mostly heights, anomalies, 850 temperatures, etc. Nothing that someone else doesn't receive quicker from Meteociel or somewhere else.
Never stopped me, when I had it. EC doesn't care about forums, they just care if some commercial entity is racking in money from their products, that they shouldn't be.
I do like the WMO programs, they give me free C3S and S2S data, so I ain't complaining
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45 minutes ago, jvenge said:
I'll send you what I'm looking at in private, since they aren't too happy about posting ECM stuff publicly.
You mean WxBell? You are allowed to post that stuff on a forum. Lots of people do it....
Model output discussion - heading into 2018
in Forecast Model Discussion
Posted
There is often noise with the SOI, but not for the period that the SOI has been negative for. That would be a signal. Probably associated with the MJO Phase 8 signal, and the tropical forcing that has occurred on the North Pacific. Has/is helping the +PNA event in North America, so Ninoesque for Europe I think and the ramifications the +PNA event entails on the other side of the Atlantic....