FrenchScotPilot1
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Posts posted by FrenchScotPilot1
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Does it not depend on where the fragmenting vortex goes and how it intereacts with the blocking high?
Is it fair to assume that it will always strengthen the block?
EDIT: Disregard. Chiono answered as I was typing.
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I haven't had much time yet but I now take this opportunity to repeat what has already been said: thanks very much Ed and other contributors to make this thread, abeit quite technical, VERY VERY interesting and informative!!
It really furthers our knowledge of atmospheric physics every time.
Best regards,
Stephane
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On behalf of one of my estimated twitter user, find below something about Global wind Oscillation (GWO).
GWO is arguably the best all round measure of atmosphere because it encompasses GLAAM (see above), Rossby waves, responses to torques (which include global patterns like nao, pna, etc...) and MJO if coherent.
What is missing now is a composite comparison height anomaly set of charts.
Another bit on Atmospheric Angular Momentum (AAM) and espacially its calculated tendency relative
It includes (Gravity Wave Drag + Coriolis + Mountain + Frictional) Torques + Relative AAM Flux Convergence
It is shown at the bottom of the page: http://www.esrl.noaa.gov/psd/map/clim/aam.90day.total.shtml
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Great link here to teleconnections technical papers http://forum.netweather.tv/topic/73911-technical-teleconnective-papers/ but it would take years to read them all and summarise findings.
What I had in mind was (and I hope it is not too naive/utopistic) AMO, PDO, MJO, ENSO, AAM, etc have the following effects on European weather:
AMO: effects
PDO: effects
MJO: effects
ENSO: effects
AAM: effects
etc...
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On behalf of one of my estimated twitter user, find below a random bit on Globally Averaged Angular Momentum (GLAAM). It's assessed as a global (averaged in latitude and longitude) anomaly of AAM.
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[*]+AM in late summer normally equates to neutral NAO with ridge in mid latitudes
[*]+AM can help develop ridges at high latitudes in winter months
[*]-AM can help develop ridges in high latitudes in summer months
For info, last March ('13), which was ended up the coldest in 50 years, had a very defined positive GLAAM.
Climate indices, monthly atmospheric and Ocean Time Series: http://www.esrl.noaa.gov/psd/data/climateindices/list/Note: This post will be edited as and when.
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[*]+AM in late summer normally equates to neutral NAO with ridge in mid latitudes
[*]+AM can help develop ridges at high latitudes in winter months
[*]-AM can help develop ridges in high latitudes in summer months
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Hello. This thread seems to have a similar theme to one from last year here http://forum.netweather.tv/topic/74566-the-hunt-for-white-december/?hl=+white%20+december
I was hoping to get more contributors to it then, but it seemed to die. Perhaps they could be merged?
Sounds good thanks. I'll have a look.
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Thanks Supercell89.
Ok, what do Iknow so far when it comes to global influences.
It's a bit like paper rock scissors:
Sun influences SST.
Atmosphere and Ocean influence each other (ENSO).
ENSO influences MJO.
MJO influences upper/lower tropical winds.
Upper winds influence pressure patterns (e.g. jet stream drives NAO)
Oceans drive PDO and AMO.
AAM is the result of frictional torque (surface friction) and mountain torque (pressure difference on W and E side of mountains).
AAM is conserved therefore changes are done through torques above.
Stronger W'lies = Atm AM increase = Earth AM decrease
Atm AM increase with E'lies in the Tropics, decrease with W'lies in mid latitudes. There is therefore a poleward trasfer of AM.
ENSO changes E'ly trades into W'ly trades. Atm AM increases, Earth AM decreases.
This is what I have so far. My next read is on GWO vs MJO.
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I'm creating this topic as some sort of research thread to try to establish how we could improve long range forecasting (1-3 months in advance) using teleconnections and variability indices:
QBO, ENSO, PDO, GWO, AMO, AAM, Mountain/Frictional torque, etc...
Some analysis/forecasting sites to start with:
AAM, Mountain/frictional torque: http://www.esrl.noaa.gov/psd/map/clim/aam.90day.total.shtml
GWO, MJO composites: http://www.esrl.noaa.gov/psd/map/clim/gsdm.composites.shtml
GWO: http://www.atmos.albany.edu/student/nschiral/gwo.html
MJO: http://www.daculaweather.com/4_mjo_phase_forecast.php
TIGGE MJO: http://tparc.mri-jma.go.jp/TIGGE/tigge_MJO.html
MJO composites: http://www.americanwx.com/raleighwx/MJO/MJO.html
Various: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/climwx.shtml
Various: http://www.ncdc.noaa.gov/teleconnections/index.php
And there are many many more. We could also include SSW.
I've laid out the foundations, please start building the walls :-)
Let's make it a great place to learn...
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With High to the E and S'ly winds, models give warmth for start of next week (above 15 degrees away from coasts).
Let's see what really happens.
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I have no idea if this will help, but it popped up when I searched on Google:
http://www.examiner.com/article/atmospheric-angular-momentum-aam-oversimplified
Thanks Catch, I'll have a look, it looks good.
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Looking for a good clear explanation about atmospheric angular momentum and how it affects jet stream, northern blocking and ultimately the UK weather in various season.
Any pointers guys?
Thanks!
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a look at this winters SSW through the NASA GEOS-5
Very nice vortex disintegration from the SSW. Thanks BUS
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Where are the locusts?
The 7 plagues of Scotland? Grasshoppers are definitely replaced by midgies!
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Aye, it looks quite unsettled, but perhaps the odd nice day in between? Friday looks not too bad at least down here. Tomorrow looks a little breezy for a large chunk of the population across the central belt, and very wet for some too.
I've started looking ahead at the long range charts for the 12th May as I'm getting married...so far each time I've looked the forecast is for rain! I haven't told the soon to be proper Mrs Catch yet, hopefully the charts are wrong but only time will tell
Congratulations! You haven't told her about the weather or about getting married
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Glorious bright and cold morning, waiting for wind and rain I suppose...
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Well, charts for Saturday/Sunday bring very warm tropical air via a rather deep low W of Ireland.
Temperatures at lower level look to be in the mid teens on Sunday afternoon, so I'd expect the snow to go away pretty fast.
I like snow too and we've been blessed a lot this year but we had to expect warmer temperatures at some point.
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Moderate snow coming off a SE'ly direction for the last 15 minutes in Aberdeen.
And sunny again...
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Moderate snow coming off a SE'ly direction for the last 15 minutes in Aberdeen.
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i've been barred from posting in the model thread
Oh sorry I didn't know. You can pm if you want to elaborate.
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i so wish i could post in the model thread would be good to go in there and wind them all up just now that while we are still seeing some winter through this week they are going to get a soaking
You mean the Englanshire lads, what stops you
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GFS show some heavy precipitation Wed/Thu from the low SW of Ireland tracking east too.
Unsure about snow yet and Scotland specifically, I'll need to dig deeper into it.
Never ending story, feels like...
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About 1" and 0C also near Aberdeen.
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April sun provides quite mild conditions during the day (circa 8C) but the very cold 850hPa air (-7/-8C) makes them drop again below freezing at night.
The consequence could be one new (last?) snow/sleet attack tonight from the cold front moving from the N.
During the day, the last few hundred feet temperature profile is positive but, at night, the whole profile is in the negative range.
Mid month onwards, 850 hPa temps look to get positive and stay around 0. Tentative spring is likely to appear at this point.
AO and NAO becoming neutral should ensure that no further incursions of cold air disturb the spring plan.
Ideally, they both need to be positive to see proper spring temperatures.
As explained above, moderate sleet/snow has started over Aberdeen 30 min ago. Nice to see flakes again. Ok after this, spring warmth, promise
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April sun provides quite mild conditions during the day (circa 8C) but the very cold 850hPa air (-7/-8C) makes them drop again below freezing at night.
The consequence could be one new (last?) snow/sleet attack tonight from the cold front moving from the N.
During the day, the last few hundred feet temperature profile is positive but, at night, the whole profile is in the negative range.
Mid month onwards, 850 hPa temps look to get positive and stay around 0. Tentative spring is likely to appear at this point.
AO and NAO becoming neutral should ensure that no further incursions of cold air disturb the spring plan.
Ideally, they both need to be positive to see proper spring temperatures.
Stratosphere Temperature Watch 2013/2014
in Spring Weather Discussion
Posted
I'm after an explanation about the link between Mountain Torque (there's one in Asia just now, so it is topical) and SSWs.
What is the physics behind it, what happens during the event?
Many thanks!