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Snowy Hibbo

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About Snowy Hibbo

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  • Birthday April 5

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    Melbourne, Australia

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  1. Of course. Wouldn't miss a season here. Vibes here are awesome during winter.
  2. Well get ready, because it's a long road. I don't mind the outlook at the moment. The few seasonal forecasts and charts don't look that bad. at all. Never mind the Farmers Almanac.
  3. Speaking of winter.... I wrote my first seasonal forecast on the 1st of September last year. Not sure I will be able to go that early, but my preliminary thoughts will be coming very soon. Seasonal forecasting season is almost upon us. Just need our season to wrap up. New website coming too for the NH winter.
  4. Wet and wild sounds like the name of a theme park, rather than a term to describe the weather. One of the more meaningless terms I have heard thrown around.
  5. Sorry I don’t have much to say in accordance with the Northern Hemisphere and the ENSO situation (which in my view is very “all over the shop”). But I am currently tracking some interesting developments in terms of snowfall down in SE Australia. But more importantly for this thread, some interesting teleconnections between positive Andes mountain torque and a disturbance of the SH Polar Vortex. A cycle of driver changes that is causing a -AAO shift later in August IMO. Just to elaborate on that cycle of driver changes, watch the development of the planetary wave, as momentum is ploughed into the Andes (black line) and comes out westward of the mountain range. This is what we call mountain torque Now to watch the stratospheric influences of the positive Andes Mountain Torque. Now we just rely on stratospheric-tropospheric interaction, which I touch on briefly in the blog. We should see propagation because of a more solid upper-mid strat disturbance. Which works better with the flow of the current relationship of the strat-tropo, compared to the disturbance associated with the -AAO earlier in the month. Blog post here with more on this event and other drivers for the SH. Now just to have a look at the positive Andes Mountain Torque event itself. Plumes of westerly momentum come out into the Southern Atlantic, with downstream blocking a key part of +MT events. But the key thing to look at from a tropospheric level is the troughing over the Andes, indicating the mountain torque. Another thing to note is the block pushing from behind the South American Continent. And that will bring us a rise in the AAM, via tropical to extratropical teleconnections and momentum transports. And along with other NH mountain torques. My forecast being the black line beyond the original chart heading towards August. Nothing precise or anything, just noting the trend here.
  6. @MattHugo and to all others interested, The AAM has gone down in the past few weeks, and is now negative. This explains the easterlies and the reduction in trades. The atmosphere has finally neutralised after a long winter stint into summer in the positive values. It’s hard to emphasise how long it has been without a -AAM in our world. Apart from improving snowfalls down in Australia, it also shows that we may be heading towards a more Nina-esque setup for the NH winter. For now, however we are IMO properly in a neutral ENSO. So we are basically seeing a splash of cool neutral/Nina in this -AAM period (which we obviously haven’t seen for sometime).
  7. The Effect of Climate Change on the Variability of the Northern Hemisphere Stratospheric Polar Vortex Authors: Daniel M. Mitchell, Scott M. Osprey and Lesley J. Gray Neal Butchart and Steven C. Hardiman, Andrew J. Charlton-Perez and Peter Watson Date published: January 13th 2012 Abstract With extreme variability of the Arctic polar vortex being a key link for stratosphere–troposphere influences, its evolution into the twenty-first century is important for projections of changing surface climate in response to greenhouse gases. Variability of the stratospheric vortex is examined using a state-of-the-art climate model and a suite of specifically developed vortex diagnostics. The model has a fully coupled ocean and a fully resolved stratosphere. Analysis of the standard stratospheric zonal mean wind diagnostic shows no significant increase over the twenty-first century in the number of major sudden stratospheric warmings (SSWs) from its historical value of 0.7 events per decade, although the monthly distribution of SSWs does vary, with events becoming more evenly dispersed throughout the winter. However, further analyses using geometric-based vortex diagnostics show that the vortex mean state becomes weaker, and the vortex centroid is climatologically more equatorward by up to 2.5°, especially during early winter. The results using these diagnostics not only characterize the vortex structure and evolution but also emphasize the need for vortex-centric diagnostics over zonally averaged measures. Finally, vortex variability is subdivided into wave-1 (displaced) and -2 (split) components, and it is implied that vortex displacement events increase in frequency under climate change, whereas little change is observed in splitting events. Link to paper:
  8. More Frequent Sudden Stratospheric Warming Events due to Enhanced MJO Forcing Expected in a Warmer Climate Authors: Wanying Kang and Eli Tziperman Date: January 24th 2017 Sudden stratospheric warming (SSW) events influence the Arctic Oscillation and midlatitude extreme weather. Observations show SSW events to be correlated with certain phases of the Madden–Julian oscillation (MJO), but the effect of the MJO on SSW frequency is unknown, and the teleconnection mechanism, its planetary wave propagation path, and time scale are still not completely understood. The Arctic stratosphere response to increased MJO forcing expected in a warmer climate using two models is studied: the comprehensive Whole Atmosphere Community Climate Model and an idealized dry dynamical core with and without MJO-like forcing. It is shown that the frequency of SSW events increases significantly in response to stronger MJO forcing, also affecting the averaged polar cap temperature. Two teleconnection mechanisms are identified: a direct propagation of MJO-forced transient waves to the Arctic stratosphere and a nonlinear enhancement of stationary waves by the MJO-forced transient waves. The MJO-forced waves propagate poleward in the lower stratosphere and upper troposphere and then upward. The cleaner results of the idealized model allow identifying the propagating signal and suggest a horizontal propagation time scale of 10–20 days, followed by additional time for upward propagation within the Arctic stratosphere, although there are significant uncertainties involved. Given that the MJO is predicted to be stronger in a warmer climate, these results suggest that SSW events may become more frequent, with possible implications on tropospheric high-latitude weather. However, the effect of an actual warming scenario on SSW frequency involves additional effects besides a strengthening of the MJO, requiring further investigation. Link to paper:
  9. Hope you are all having a lovely summer Just a quick look at the ENSO SSTs is to look at a rather confusing non-standard setup. +IOD brings warm ocean temps to the Western and Central Indian Ocean. And cooler temps to the Eastern Indian Ocean and Maritime Continent. This looks like a Nino pattern in a vacuum, but then you have got cooling anomalies in the ENSO regions in the Eastern Pacific. And the rest of the Pacific is warmer than normal. What this indicates to me, is that the persistent +AAM atmospheric conditions won’t be shifting too much anytime soon. Another quick thing to note is the cool/warm divide of SSTAs just off the Eastern US Coast, which would be increasing the jet stream there, and making troughing activity in the region more likely. Interesting times as we head slowly into Northern Hemisphere seasonal forecasting season for winter (but not just yet, still the whole of summer to go )
  10. EPS Teleconnection figures from 00z: A continued +AO outlook over the next 15 days. +EPO neutralising to 16th, -EPO to the 21st, neutralising afterwards. A continued +NAO outlook over the next 15 days. Relatively Strong +PNA from the 15th, throughout the rest of EPS outlook, weakening from the 21st. This shows that the Pacific is starting to cooperate in the medium term under the accords of the GSDM, with +GMT and +EAMT in particular occurring over the last few days. But the polar domains of the AO and the NAO (Greenland) are not. We can go on about how the Pacific has been poor, but another factor is that we only really saw a genuine -AO after the SSW for 10-15 days. And that never converted into a proper -NAO. The polar domain has been running against us all season. The SSW happened, but nothing really eventuated. We can't blame the strengthening SPV (in red) above the -NAM/slower zonal winds section of the atmosphere (in blue), from the last days of January, for the lack of a sustained -AO entirely. This is 1. A normal part of the stratospheric process of a SSW, and 2. It is what was actually pushing the -NAM anomalies downwards towards the surface. But however it is plausible to attribute the particular strong nature of the comeback of a strong SPV, to the weakening of the weaker zonal anomalies. But it couldn't have been the only influencer at play. I have circled in orange, a rather extraordinary period of +AO anomaly at the surface for much of February. There could have been downward heat flux from the higher levels of stronger zonal winds. But I can't see the potential for that to be the only cause to that particular anomaly. It's an interesting anomaly that I think would make an interesting topic for a research paper in the near future.
  11. I think the 9-12 March period could work out. There is definitely the spacing in time to make it work, there is certainly the cold to make it work, you really now just need a good surface setup, with adequate precipitation and coastal track. EC and GEM's latest runs have given some relatively good systems for this period. The GFS suite brings large inland rain-bearing lows, but I believe they can push further to the Coast. It has some degree of ensemble support as well. Based on them, the next period for a potential system of some quantity should be around 16-20 March. The reversing MJO signal (weird, but a good sign of things to come) and EPS' suggestion of some +AAM finally pushing through the North Pacific extratropics, makes the later stages of March more hopeful. GEFS also agrees with a D10-D15 speed up of the NP jetstream, but it comes with a +EPO, stretching into a -PNA, so not as good. We want an Aleutian Low playing a role in the mid third of March, to continue the relatively good start to March, in spite of the rest of winter.
  12. GLOBAL WIND OSCILLATION (GWO) These quarterly GWO charts were produced by Klaus Weickmann and Ed Berry from 2008 who devised the GWO phases as well as the GSDM (Global Synoptic Dynamic Model). They then produced some backdated charts from 1957-58. There is not a complete record and most of them cover the winter quarter only. The source for theses charts is on the SCW (South California Weathernotes) which has a vast amount of current and archived data on many of the teleconnections on this link: . The site is no longer fully serviced and some of the current data is no longer auto updating. It is possible that the site will close at any time. So we will prioritise capturing as much useful data as possible, links and charts We wish to ensure that access to the charts will be permanently available to us. The same applies to a number of other sites with current and archived records. 1957-58 1958-59 1963-64 1965-66 1968-69 1969-70 1972-73 1976-77 1977-78 1979-80 1982-83 1983-84 1986-87 1987-88 1991-92 1994-95 1997-98 2000-01 2002-03 2004-05 2005-06 2006-07 2009-10 2011-12 2014-15 2015-16 2018-19 2009 spring/summer 1961-62 1962-63 1964-65 1967-68 1970-71 1971-72 1973-74 1974-75 1975-76 1984-85 1988-89 1995-96 1998-99 1999-2000 2007-08 2008-09 2010-11 2017-18 2016-17 2010 Summer
  13. RELATIVE GLOBAL ATMOSPHERIC ANGULAR MOMENTUM (GLAAM) - ANNUAL CHARTS These annual charts from 1979 to 2014 have been obtained from the archive section on the Nicholas Shiraldi, Albany website which is accessible on this link: It is highly likely that the Albany (Shiraldi) charts will disappear at any time as the site is no longer being updated or serviced. It is possible that the site will close at any time. So we will prioritise capturing as much useful data as possible, links and charts We wish to ensure that access to the charts will be permanently available to us. The same applies to a number of other sites with current and archived records. and the links may stop working. 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979
  14. It's interesting to observe, because that is a +NAMT, that has a descending Alberta High. That is your ideal location for a high in theory. This chart is perfect, except for the big problem with having troughing up the Rockies and down into Mexico, is that is going to speed up the jet, which amps this low behind it, creating a rather warm mess. If there wasn't such troughing in the Rockies and a pushing low behind it, the high would pop right over all of the gradient. And we would have a far more meridional pattern across NA, without it. Instead the Low gets pushed out, and you see a high, reduce any chance of a system after the 5-6 March, for at least 5 days. That is the problem where there isn't really any pressure from the extratropical and polar domains. We want to see a +AAM and westerly momentum, we just don't want to see awkward momentum transports like this, caused by a push back into +AO territory, and possibly the consequences of the fortnight and a bit long WWB in the Pacific finally ending. You want to see solid Teleconnections pressures, not just region specific pressures. Although it creates the opportunity, it also works against us in that it rushes through way too fast. If that High pushes a few degrees further east, and push the Low further east, you would have a far colder system for NYC and surrounding regions. There's plenty of scope for the Synoptics to shift in our favour, but there is plenty of reasons against this too (the season's climatology, and the fact that not a lot of the reasons why this season was so bad have changed now). I hate to be doom and gloom, but this is probably the last good chance at getting snowfall, and it may just be blown, because of the same reasons why they have been so many clippers this season.
  15. The 6th system just moved offshore for this one run, because a more dominant lobe at the 300hPa level, and because of the moisture from the North coming in from a different angle. Westerlies pushed it offshore, and it started far too much offshore as well. It's totally plausible to come again in the next EC run, just if we get a little more Atlanticward activity from the previous low, rather than into Northern Canada. It may very well be weighing the two lows against each other, but there is certainly potential they both come through with some sort of snowfall.
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