Jane Bunn - Snow Forecast

Sun 19:00pm 05 Jul

Updated: Sunday July 5th, 7pm

There’s one more cold front set to clip southern resorts early on Tuesday, then the next high moves through.

This front is only clipping us, so it lacks cold air. After the lovely snow earlier in the weekend, its a bit of a wet finish to this stretch of weather. But it only clips us, so northern resorts are all dry, with sunshine, light winds and cold nights.

The high moves through in the middle of the week letting that sunshine, light winds and cold nights spread to all resorts.

The next weather system is likely to have a big effect - but what that effect will be is not clear yet. One model looks amazing (GFS/US) - a big pool of cold air with lots of snow from Friday through the weekend. But other models are coming inline with what the EC has been suggesting. This scenario is a cut off low that slowly moves through. If this is the case, there is a high risk that we will get tropical moisture, while the cold pool lags too far behind to be of much help (ie rain). The models will continue to keep chopping and changing (and the snow forecast numbers will be all over the shop). I’ll keep you updated through the week - look for a new discussion around 7:30pm each night here.

Day by day details:

SUNDAY NIGHT, MONDAY and TUESDAY: Drizzly showers over southern resorts. Dry for the rest with sunny days, light winds and cold nights.

WEDNESDAY and THURSDAY: All dry with sunshine, light winds and cold nights.

FRIDAY: Cloud starting to rebuild. The chance of showers, increasing during the day.

SATURDAY and SUNDAY: Stay tuned… Very hard to pin it down with such variance in the different models.

(check individual resort pages for specific hour by hour guidance from the EC model)

HOUR BY HOUR DETAILS FOR YOUR RESORT:

Mt Buller | Hotham | Falls Creek | Mt Baw Baw 
Perisher | Thredbo | Charlotte Pass | Selwyn 
Lake Mountain | Mt Stirling | Ben Lomond | Mt Mawson 
Mt Dandenong | Mt Donna Buang | Mt Macedon 

Where is the snow?

We were in a long phase of weather known as a positive SAM (Southern Annular Mode). Over the alps in winter, it makes cold fronts weaker, puts high pressure in control, or brings cutoff/complex lows that can bring a lot of rain (as they generally don’t have the cold pool that you get from a strong front).

This positive phase turned negative late June into early July. That made cold fronts with snowy cold pools a bit more likely. Not guaranteed with every negative phase, but strong fronts can rise up and hit the alps more easily. You still get periods of high pressure in between though…

The latest: forecasts show that neutral or positive is most likely for the next month. SAM forecasts from the GFS and Australian models can be found here.

Key to terminology: Is it precipitation that lasts a long time, or starts and stops?

Showers - Precipitation that starts and stops. Bursts/cells of rain or snow that move through the area in a hit and miss fashion. ‘Widespread showers’ means they are more frequent, the dry breaks in between are shorter. ‘Isolated showers’ means there are long dry breaks, and the showers could even miss the slope (it may actually be quite sunny).

Persistent - Precipitation that is continuous for a period of several hours. Most parts of the mountain are affected for a long time. Rain or snow, it depends on the temperature.

 

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