Further to the discussion RE: standard deviation
My understanding is that in a particular year, there is a 68% probability that the maximum snow depth would be 85+/- 37 cm (48 cm - 122 cm).
Also, there is a 95% probability that the maximum snow depth would be 85+/- 2 x 37 cm (11 cm - 158 cm).
Further info on standard deviation is neatly summarised at http://www.mathsisfun.com/data/standard-deviation.html

Hope that's a little clearer

Crikey, the totals-totals index (usually abbreviated to tot-tots index) is a very commonly used index of instability in the lower to middle atmosphere. It is calculated by adding together the temperature and dewpoint at 850hPa and subtracting this number from twice the temperature at 500hPa. It is one of many dozens of instability indices, all of which are useful in one setting or situation or another. Tot-tots has tended to be commonly used by the Bureau here, and the WeatherZone charts show it for all models. The Brisbane StormChasers site I gave allows you to calculate quite a few indices and have them plotted on the chart, using the drop-down menu at top left. There's a brief description of some of the more common indices [here] but I know of, but can't at the moment find, a much better one. Will post the link to it on this thread when I find it.

Edit: Here's another good one [here] but it's still not the one I'm thinking of.

Thanks for that A1 link re standard deviation SURFERKARL
I wish my uni books were like that and l may have passed statistics with a little better score.LOL

From what l read from the lesson is that if Mt Buller's mean max was 85 cm in the 1970 /1980's then one standard deviation of that max is 38mm. and so
Adding the standard devaiation to the mean of 85cm yields 122cm
Anything above a max depth of 122mm would be considered a significant snow depth season.
Anyway ..Thats the best l can do ..

Thanks LAURIER.. Always good to add something to the knowledge base
Will check those links out

Going to have a look at this on Wednesday and ski
http://ski.com.au/snowcams/australia/vic/bawbaw/index.html

Mt Baw baw had another 18cm today. The first 11mm falling at around plus 1 deg c. But the last few hours and another 6mm the temps are below zero tonight.. Yeah
The temp at 7pm is minus 1.1 deg c and the wind is absolutely zero km/hr

http://www.bom.gov.au/products/IDV60801/IDV60801.95901.shtml
Can't believe l will see some fresh snow!!

Glad to see you have got the hang of standard deviation.

Careful with the Baw Baw weather station readings. I heard on the grapevine that they have a tendency to over exaggerate precipitation readings.

I'm hopeful for some snow later this week, as I'm heading up on Friday night

Oh Excellent Surfer Karl..Baw baw is cheaper than Buller thats why we are going there.
Already packed..
The day temps today at MT Baw baw were just a bit high today ..One deg C... wettish snow..
I wonder if that might be the case on Friday as well?
The BOM synoptic has changed and is now agreeing with WZ synoptic in that the cold front will trevail over VIC BUT it is decaying disintegrating as the front moves over VIC..
THe cold front does not appear to be marked on eastern VIC and NSW at all for this event??.
Surface temps too warm???
That must be a concern for snow watchers on the mounts
2 troughs in the vicinity on friday.
Certainly overcast and some rain / snow?

You will certainly see snow falling.on friday night.. Lucky you. Fresh snow..
Hope the surface temps boad well for you!!
Surface day Temp looks to be the critical factor?
you will have to check the wind speed. The isobars look a little close. May be high winds on the trough boundaries?
There are 2 trough fronts on friday.

The cut-off surface low the BoM places west of TAS at 10pm Friday is curious. At that time, ACCESS has a sharp trough up the NSW coast, EC has a sharp trough just west of TAS in the process of forming a cut-off to the south of the island, and GFS has a trough lying across TAS with a dying cut-off on King Island. There is still a lot of disagreement in the detail between the models.

I found the exhaustive list of instability indices that I was thinking of. Unfortunately, it is in one of Tim Vasquez's excellent weather "bibles" - the Weather Forecasting Red Book, section C14 Stability Indices. It runs to over a dozen pages. The books are available at http://www.weathergraphics.com/ and although northern hemisphere focussed are excellent value.

Meanwhile, another very good summary of instability indices, mainly thunderstorm oriented, is at http://www.teachingboxes.org/avc/content/Severe_Weather_Indices.htm

Crikey, two other more recent papers cover similar ground but use longer data runs and also look into the effects of global warming. Both are from the Australian Meteorological Magazine:

Estimation and analysis of snow cover in the Snowy Mountains between 1910 and 1991 by Alan Duus

Climate variability, climate change and the Australian snow season by Neville Nicholls

Another paper in the Aust Met Mag worth reading for anyone with an interest in Tasmanian snow is Climatology of cold outbreaks with snow over Tasmania by M C Jones.

All good bed-time reading.

Interesting to see Falls Creek with 67.0mm in the gauge since 9am. Seems someone has been watering the weather station with a garden hose.

classic

Interesting, I wonder what the cause is. I might first point out that I sometimes gets readings like this too after a snowfall when it warms enough through the day and the snow starts melting into the gauge. At Falls it also happened as the temp rose to zero, but it seems a bit extreme. Its like some icicle started gushing water into the gauge, but where would it have formed I wonder to do that.

Geez 500 temps are good on 06z GFS - huge area of sub -28c with a large area below -30c over the Southern CTs, Southern Tablelands.
Moisture lacking but don't temps like this encourage instability? I suppose the moisture has to come from somewhere.
Long way to go though - looks like Sunday afternoon is when any action will start. I would be happy to take Blizz's 1cm of settled snow above 1000m on the BMs.
Max of 4.9c yesterday - cold / drizzly & misty - I think that is the equal second coldest max I have recorded here in the last 3 winters

15cm at the Selwyn Snowfields when I last checked... good news but more is needed for snow tubing, I'm off to Corryong next Friday, hopefully blizzards will lash the NSW Snowy Mountains (and the Victorian High Country) as this cold front and low move across SE Australia between now and the end of next week

Reporting back from Mt Baw Baw mid week
Yep 4 lifts open. Skied champagne run by myself for 20 minutes .. MAGIC!!
They are making snow at night for base of most runs
They have some 25cm to 50cm of snow forecast for.. this weekend !!
No queues.. Wednesday $60 for all day ski lift. Hired ski lodge room for $90 a night..Plenty of great parking but expensine to park. some $37 a day
Road from Noojee to Mt baw baw. very, very winding and not very wide.
and took one hour to travel up..YUKK
Took the south side road down the mountain via Erica and MOE and a far better road. It is wider and less winding. although not sealed it is in good nick.. Would use this road in preference.
The general store has no perishables. Take your meat, milk, veg for ski lodge..
Had a fabulous pizza from riders bite next to hotel on the mountain
$24 but fed 2.
A nice exclusive and expensive restaurant is now located where the old chairlift building is.. $ 36 for a large meal ..looked great.

Here is a pic of the upcoming cold front. It looks nice and cold and strong on the sat pic.
However the BOM synoptic still showing the front decaying over VIC
however on livinia's weather ch 9 it is showed the cold front passing over southern NSW and not decaying.
Looking at the strength of the cold pool, l think l will guess it will power over NSW as well, but lets see
The combined model outlook from BOM WATL indicates that eastern VIC will get the 'guts of this cold front' with places like Baw Baw may get 50mm in 4 days and Hotham and Buller and falls creek getting up to 25mm
and
NSW forecast to get next to nothing.
Wondering if the models are underestimating the strength of this cold front. They have underdone the past 2 fronts/systems so...Lets see..!!
Just reckon the sat pic looks promising.!!
Heard snow down to 800metres in a forecast this arvo? VIC
Jane Bunn WIN NEWS saying

25 to 40 cm by Monday starting tomorrow night.. Take chains..compulsory

The synoptic indicating a small closed low of 995hpascls near Tasmania and eastern Vic on Friday night , so we have a nice motor to power the cold flow over VIC at least

Will be on the ground at Falls Creek from tomorrow (Friday) night to give updates on this coming weather system.
Fingers crossed for you crikey. I think this is a system where anything could happen to be honest.

Anyone seen the SAM lately? Could be a very decent July front wise if this keeps up!

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/aao_index_ensm.shtml

Heading down to Thredbo in a week. Here's hoping the big falls penetrate North of the VIC border. I'd be happy enough if Thredbo can get 20-30cm out of this front.

Wow thats some impressive progs for SAM! Havent checked in a while but its certainly looking like going way way negative in the next couple fo weeks. Bring on July! Id have to say ive been pretty pleased with June as far as the Snowies are concerned. No strong fronts up thi way yet which is a little bit disappointing but i dont really expect much until mid July anyway.

I have a question for the people who live in Mt. Dandenong or near there... has there been any snow this year down that way?

Not that i have heard of. No one has mentioned any on the other forum.
We had flurries a few weeks ago and also again last thursday 21/6, at Mount Macedon, 65km northwest of Melbs