Hullo, I'm Miles Peachfield (Unstable on Weatherzone), author of the website South Australian Snow http://sasnows.com
The weather system currently traversing southern South Australia does have some potential for getting snowflakes to tiny areas of land in southern South Australia. The first image below is the gfs snow level chart I saved on Saturday evening (yesterday 17th) for 930pm central standard time Sunday 18th today. It does suggest possible snow showers (or mixed salad showers including snowflakes) on the highest ground including (and perhaps confined to) the peaks and vicinity of Mt Lofty in the south and Mt Bryan in the Mid-North. I couldn't find any reference to snow in the Weather Bureau's forecasts issued yesterday evening when I checked them last night, nor could I find any snow pixel in SA on MetEye when I checked early this morning. And as usual, an unknown is whether we get suitable passing snowflake-making shower clouds. The second image below is the gfs mean sea level pressure chart for 930pm Sunday (as it was on Saturday night when I saved the image).
Thanks for commenting Adelaidometer and I'll take up your suggestion to post charts on the predictions thread next time. I haven't even explored the ski forums so far - simply plonked my first post hereIt's like we don't exist
They gave us a sheep graziers warning as a consolation
I also observed last weekend they only forecast the potential for snow on lofty at very last minute when the gurus on here knew a week in advance.
Post your charts on the 'predictions' thread, the guys on there will give it some interest. They will also be keen to hear from a weatherzone guy and a South Australian snow expert
There were some people there, and there were a few fairly brief snow showers towards the end of hail showers. The snowflakes apparently melted quickly but hail falling mostly earlier in the afternoon formed a continuous carpet on the ground.Was only 1.3 at 4pm on mount lofty with good precipitation.
Was anyone up there then?
I don't know if it's still there but from memory, in the key temperature range of three to zero degrees it red about 3 degrees higher than the actual air temperature. A Bureau-quality thermometer positioned on the summit and accurate to within a tenth of a degree is what's needed, attached to said "fairly large digital sign displaying the current temperature facing out the window of the tourist shop"There also used to be a fairly large digital sign displaying the current temperature facing out the window of the tourist shop
I haven't looked at next Saturday's computer-generated forecast yet, but here's a general comment that may answer your question The temperature on Mt Lofty can drop down to below three degrees and even below one degree on winter and spring nights when there is little wind and a clear sky. The kind of nights where there are frosts on frost-prone areas of the Adelaide Hills. One of the weather situations where this can happen is when a cold air mass from deep in the Southern Ocean comes north over southern South Australia, such as we experienced on last Sunday, and then moves east taking the showers with it and leaving clear skies and light winds on the following night(s) which are often approximately from the south or south-east. If more showers are coming it usually means a less cold air mass is coming and bringing the showers.Mount lofty forecast getting down to 3 degrees this Saturday with some precipitation. Any chance of it getting a little colder and more precipitous for you know what?
Access and EC and Gfs computer models are now predicting a cutoff low will be influencing our weather later this week. Below is the current Bureau of Meteorology's Access model prediction for 930am Friday 6th. Early days but if accurate the Royal Adelaide show may be in for a windy period with some showers maybe late Thursday-Friday?
I haven't seen any reason to think it may snow, and we may find by Wednesday or early Thursday that the models have the low tracking considerably further east than the gfs prediction above shows. Now if the low were to come right over the Adelaide Hills, that would be more encouragingBut no snow?
I notice the Bureau has issued its latest ENSO wrap-up here http://www.bom.gov.au/climate/enso/ It includes the following text:
Current state of the Pacific and Indian oceans
3 September 2019 Next issue17 September 2019
The El Niño–Southern Oscillation (ENSO) remains neutral. The positive Indian Ocean Dipole (IOD) continues to be the main influence on Australian climate. (end of text quotes).
- Positive Indian Ocean Dipole persists as ENSO remains neutral
I don't have time this morning to look up earlier wrap-ups for this year but is my memory correct in thinking that a continuation of El Nino during spring 2019 was favoured until recently? If so then it seems we may be spared from that boring and unwanted eventuality (my view of El Nino anyway)
Yes I agree that friction between the air molecules does act to slow it down but as with a cyclone, the forces that drive the continuing rotation of low pressure systems are overwhelmingly stronger and they are the key drivers of the rotation of the air mass and hence the windspeed. They are the forces that keep our lows and tropical cyclones rotating despite the friction between molecules.But to do this it must be slowing down. Conservation of energy.