These are the snowdays recorded for the Qld Granite Belt and Southern Downs regions, per 10-year period since 1878. It might add something to this discussion.
1878-1887 14
1888-1897 13
1898-1907 13
1908-1917 10
1918-1927 11
1928-1937 22
1938-1947 13
1948-1957 10
1958-1967 21
1968-1977 11
1978-1987 7
1988-1997 5
1998-2007 5
Total 155

Clearly the trend is down since the 60s, but where we are in the cycle is anyones guess. We do seem to have a very rough 4-year trend in SE Qld which should be at its peak for snow in 2012 or 2013.

I think few people (even climate change sceptics) would disagree that there hasn't been some warming trend over the past 100 years. I suspect the effects of this on snow falls in Australia are likely to be more pronounced at lower elevations where snowfalls were always sparse events anyway. Its hard to argue with the numbers Nicholas has posted.

Given my expectations of where were headed climate wise in the coming decade, I'm hopeful of a downward trend in temps or at worst no upward trend. If this is correct then I would hope that sometime in the coming years we might again see the big 250-300cm snow depths that occurred in the 60's through to the 80's and even the early 90's.

Whether its this year or another 5 years from now is another matter.

Something else to consider. The average recurrence rate of 250cm+ depths at Spencers Creek appears to be about 3 years. It is now 12 years since we've exceeded 250cm+.

As a comparison, the average recurrence rate for significant rainfall events (based on those that provide significant flows in the catchments) in SEQ QLD is about 3.5 years. Yet last century there were 3 occasions where we waited more than 10 years and once 14 years. I'd like to think that puts some perspective on the snow depth issue.

When you have a 3 year recurrence rate for an event, not seeing it occur in a 10 year time frame might not be so unusual.

Annual recurrence intervals (ARI) are very misleading and really the best way to describe the statistical probability of something occurring whilst avoiding confusion with those who aren't familiar with ARIs is to use the equivalent annual exceedance probability (AEP). So if a 2.5m base is a 1 in 3 year event, the AEP is 33.3% and in plain english means there is a 33.3% chance of the snow base exceeding 2.5m in any one year.

The central pressure of those surface highs is concerning too, via GFS 00z. Its not the size of the highs on the mslp charts but that pesky central pressure which is a problem. Seems to be a symptom of the Long Wave Ridge and its something that has been more common in the last decade or more.

To me its more the width and persistence of the high ridge that looks worrying. I have seen strong highs ridging south before in June, they are a common feature of a traditional June, in fact normally the highest central pressures of highs will occur in June in a normal year.

I remember at BOM's meteorological school when we were discussing these things, they asked us this very question and I knew just from my own observations that June was the month of the strongest highs. Not sure exactly what causes this, but I think its a consequence of a window of opportunity for the atmosphere to settle right down with the summer heating gone and winter cold fronts not yet very active.

However in a normal June even these strong highs normally will move away after a week and allow at least some sort of cold change through before the next one. Often there may only be one more significant front in June, that is not unusual.

During the process of the highs being weakened by increasing cold fronts near the start of winter is when the best cold outbreaks north of the Snowies will occur. This is because the highs are still tending to ridge strongly south and then the strongest of the increasing cold fronts make the push past the high and give good snow to the CT's. This should happen either end June or early July.

Then after that in a normal winter the cold fronts start increasing in regularity from mid July all the way to the first half of September with 1 to 3 fronts per week, this period gives the Snowies the best snow with the stronger of the changes giving the CT's a snowfall about once in 2 weeks.

Thanks PD. Doesn't the persistence of the surface high ridge get more pronounced via the central pressure, which is in part a symptom of a persistent long wave ridge?

The monthly anomalous mslp will be out soon, for May. Will be interesting to see how it goes:

http://www.bom.gov.au/cgi-bin/climate/cm...month&area=rsmc

Yes the higher pressure will push up the means of course. The mean monthly pressure maps certainly do indicate a persistent weather pattern when somewhere has more high or low pressure than normal. However they fail to show the variability of the pressure. Its a bit like the lack of cold fronts in our area, very hard to accurately measure because our means may be the same the variability has decreased. Lack of warm NW winds ahead of fronts and a lack of cold SW winds behind fronts, just more and more cool Easterlies fog up the issues, and then these cool nights in some places because of a lack of weather muddies up the real climate trends even more.

That's a good point re the variability, doesn't always show up well in anomaly charts. Its perhaps similar with mean min and max temps, even when they seem quite similar to decades gone bye. They don't show the lack of variability at times or indeed the missing upper level mechanisms over recent decades.

Looks like it could go either way (rain or snow) for the Snowy Mountains on the weekend - some good totals forecast but temps hovering around zero - likely to be rain lower down.
Front valley at Perisher looks good this morning - they have made the most of recent snowfalls topped up with snowmaking.

Probably will not be anything on the weekend, but perhaps a little wet snow latter Monday. Most heavy rain will stay near the coast anyway, not that much will happen down the Snowies. After that at least the long weekend is looking clear and sunny. So I think we are looking at a fairly traditional almost snowless opening long weekend, but will not be too depressing since it should be nice and sunny and frosty. Its just a big party anyway.

Beyond that possibly mid June might be a little more action looking at the way EC models are evolving, hope it turns out a bit better than the last snowfall.

SAM is forecast to dip well negative during June. Mid to late June could get very interesting.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/aao.sprd2.gif

Yeah, mid to late June is my hope. Keeping an eye on things at present. Real winter does tend to start later these days and fronts can often get a real burst going by late June.

Gday everyone. Im a new member to the forums.
I enjoy the snow and visit the CT's regularily .
Ive been enjoying your posts for a couple of years now and thought i'd join in.

I was wondering if anyone thinks a few flakes might fall on the higher parts of the CT's on tuesday morning ??

Paulh

PaulH, glad you are enjoying the forums, snow early next week is not completely impossible, but very very unlikley. There is an upper cold pool forecast but its isolated and not that cold.

PS, Some historical tv footage from 1965 snowfall will be shown on News 24, mentioned in the high country thread.

I figure the snowfields will get snow. Why? It always snows on a full moon in winter up there. Very handy for night skiing at Guthega. and in fact, looking at the Canberra forecast temperatures on Sunday, I'd say it's a dead cert, full moon not withstanding.

Thredbo temperatures heading negatives tonight and won't be back above zero for a week! Going down as far as -8C during the new week! Heavy snow ahead!

I doubt that very much, temps will not get cold until Tuesday morning by which time most precipitation has moved to the central coast. There will be a small window of opportunity for the Snowies early from late Monday to early Tuesday when its gets colder and before it dries out too much for some light snow falls. Even here could maybe just barely be one snowflake. But its all rather ordinary and unexciting, nothing much colder than normal at all and not a lot of snow.

Showed on TV weather this morning that Perisher has opened it's season a week early, it looked to have good snow cover, altho a lot is man made.

Nic where did you get that info from out of interest, because the darling downs haven't recorded any snow in the last decade ?

I will be paying attention to this from now on, interesting that it was just cold enough for snow last night, was not expecting that.