Worst snow season start ever?

No, this one isn’t and probably won’t be; the coming week’s snowfalls should see to that. But it is well in the league. Judging the ‘worst ever season start’ turns out to be not quite as trivial as it seems.

 

The candidates

Here’s how recorded snow depths look for the May-July season startup interval at Spencers Creek, midway between Perisher Valley and Thredbo, NSW (data from Snowy Hydro Limited):

Snow depth at Spencers Creek, midway between Perisher valley and Thredbo, NSW; data from Snowy Hydro Limited

 
 
I reckon the line-up ranks as follows:

Fifth worst: 2017

We had a pretty decent snowfall at the end of May which has kept some snow on the highest ground throughout June, but very little really. The ‘great high pressure belt of 2017’ has kept precipitation far to the south, making for perhaps the driest June on record in Victoria (BOM map; update: now confirmed driest June on record in Victoria):

 
Because of this ‘barrier high’ pattern, more southerly places – notably Mount Buller in Victoria, even Tasmania – seem to have faired a little better.

Looking at the week’s weather ahead, there’ll be rain on Monday (3 July), which might be enough to see a July zero snow depth at Spencers Creek (if an unlikely off-day measure were taken). Then there’ll be some snow Monday night through to Wednesday, which ought to be enough to prevent a zero depth at Thursday’s usual measure. And there’ll be more snow on the weekend (though not nearly as much as a few were forecasting). That should see season 2017 lift off, but dramatically … no, probably not.

 

Fourth worst: 1957

This year is famous for having the only recorded July zero in our 63 year snow depth record — on 3 July 1957. It was a shocker of a season no doubt, right at the beginning of the big 1957-59 El Niño, but the snow depth took off sharply from zero to over 70 cm by 12 July 1957. As well, there appears to have been a substantial unrecorded fall in early May, which may have maintained some cover into June (Canberra Times, 3 May 1957):

One zero depth does not make for the worst season start on record.

 

Third worst: 1967

I’m old enough to remember 1967 pretty well, the tail end of the great 1965-67 El Niño drought. The Spencers Creek record came within a whisker of another July zero depth with a great big nought recorded on June 30. The lift off from there was far from strong, making for a poor start to July and a worse season beginning than 1957, I think.

 

Second worst: 1959

Nineteen fifty-nine was unusual in that its last zero measurement was unremarkably early at 9 June, but from there the recorded depths were: 23, 20, 15, 12, 13, 15, 17, 13, 10, 14 and 29 cm … before finally making it into the thirties in the first week of August! You could make a case for 1959 as the worst season start on record, except for the lack of zeros. Actually, some of those small depths probably offered decent skiing. I find that about 30 cm depth at Spencers Creek at the start of a season tends to indicate good skiing conditions, because a shallow early cover is necessarily fresh and tends to be extensive, without bare patches.

 

…And the winner is: 2015

Yes, that’s just two years ago. Twenty-fifteen received a couple of little falls in May, then nothing much right through to the end of the first week of July … where it, too, came within a whisker of a July zero, with just 1 cm depth recorded on 2 July. For me that awful June and terrible first week of July make 2015 the worst season start in our long snow depth record.

 
 

Is this getting worse?

In short, yes, but not as quickly as our season close is collapsing.

Spencers Creek day of first 0.5 m snow depth and last 1 m depth

 
The trend towards a later ‘first day above 0.5 m depth’ is fairly weak, but that to an earlier ‘last day above 0.5 m depth’ is not. Our season now ends about a month earlier than it once did:

Spencers Creek snow depths by decade

Spencers Creek snow depths by decade

 
The troubling thing about our poor 2017 season start is that this is not an El Niño year (yet…).
 

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