Mountainwatch | Reggae Elliss
The resorts called last lifts on the 2018 season yesterday and the consensus is it was one of the best winters we’ve had in recent years, with regular snowfalls from mid-June to the end of August, cold temperatures, a lot of wind and minimal rain. The result was a good, deep snowpack with Snowy Hydro’s snow depth reading at Spencer’s Creek peaking at 224.6cms on August 22. However, since then there has been minimal snowfalls and plenty of sunny days, this September being one of the driest on record and while we haven’t had any fresh turns for a long time, the spring skiing has been consistently good for the past few weeks. The snow has set up most nights thanks overnight freezes, making for some fun groomers first thing in the morning before it softened for some good spring snow off piste.
In the lead up to winter the first decent snowfall on year came through on May 10, a month before opening weekend, but it had people psyched for the season. The Grasshopper released his May seasonal outlook a few days before that storm hit and while he was excited about the forecast snow totals with that storm, he did remind us that good early snowfalls are no guarantee of a strong season. Of course, like all meteorologists, the Grasshopper isn’t one for long range forecasts and he describes his pre-season outlooks as “a discussion, not a prediction”.
Still, when you have a read of this extract from his May outlook, the Hopper was pretty well spot-on:
“Climate drivers and models are still indicating we are heading for a classic neutral ENSO pattern this season. That means we’re more likely to see snowstorms of a similar ilk to the one we’re about to get hit with, as well as more southerly winds. El Niño is threatening to show its ugly face late in the piece, but it should be too little too late to have any real effect. There is however, a real chance the IOD could swing negative for a time this season to give snowfalls a boost … I foresee that the first half of the season will be good, but then we’ll have a slight slowdown during spring. Maximum snow depths should lie within a range of 185-225 cm when comparing to a long-term average of 195 cm at Spencer’s Creek.Snow machines will be held back during the preseason due to warm temperatures anomalies. These anomalies look to settle down once the season kicks off, so the snow machines should be able to let loose from then on.”
As per the Grasshopper’s outlook, the lead up to the opening weekend saw minimal snow and limited snowmaking. The result was a just one lift open in Perisher, one in Buller and one in Baw Baw on a limited machine-made cover. However, that changed pretty quickly when a “season starter” storm hit on June 11 with a series of cold fronts crossing the mountains and over a six-day period we saw 70-100cms of snow across the Australian resorts and the cold air accompanying the fronts allowed the snowmakers to fire up at full capacity.
The result was more lifts and terrain open in all resorts, perfect timing with school holidays just around the corner. Despite June being dryer and warmer than average, the Snowy Hydro’s snow depth reading for Spencer’s Creek at the end of June was 70cms, the best in a while, which illustrates how one good multi-day storm with a lot of wind can make a big difference.
However, the week leading into school holidays was unusually warm for early July and the cover took a bit of a beating, my Thredbo snow report on July 5 reading: “A clear morning but it is very windy, and it feels like spring outside, the temp in the village +9, yes, +9 and it is 6am, and it is +3.9 up the top. A hairdryer northwest wind has been blowing all night and is currently 61ks and is expected to get up to 85ks later on in the day. We’ve lost a bit of snow with the warm wind and there are thinner, exposed wind-scoured areas on the upper slopes…”
Fortunately, the strong NW winds were a prelude to an approaching cold front which dropped 45cms over three days with the weekend of July 7-8 turning on some great powder. However, it was one for the storm skiers, with the strong WNW winds reducing visibility and the wind-chill was down to minus 18. That storm cleared on July 9 and it was cold and sunny for the next week, the daily maximum temps barely getting above zero while overnight minimum temps down to -6 maintained the quality dry snow the snowmakers also had some big nights, the guns operating for an average 12 hours each night. The school holiday crowds loved it.
While there weren’t any big three-day blizzards in the second half of July there were regular top ups with 10cms falling on July 18, 25cms on July 20/21, 15 to 20cms on July 24. Once again there were strong winds with the snowfalls which blew in a lot of snow and the cold temps ensured good snow quality.
August started with a bang, with two fronts dropping 20cms in the first few days, but the accompany winds were very strong and all resorts had chairlifts on wind-hold on some days during that first week. The fronts kept coming and another 35cms dropped on August 6/7, followed by another 20cms on August 24 and then a big one on August 18/19 with 40-50cms falling over a 48-hour period. It is typical for our storms to have pre-frontal rain before the snow hits, but the three August storms pretty well kicked off with snow and there was minimal rain as the bulk of the moisture fell when the cold air hit, the result being three consecutive weekends of cold, dry snow and some epic powder days.
As it turns out, the Australian Alps, other than Mount Buller, had below average precipitation in August, however the temps, both maximums and minimums, were also below average. There weren’t any warm rain events and good snowfall totals in those three storms were followed by cold, dry conditions, perfect for the snowmakers. Most of the resorts passed the two-metre snow depth mark in the third week of August and the Spencer’s Creek depth of 224.6cms on August 22, turned out to be the peak depth of the winter. Then, as the Grasshopper predicted, things slowed down and there hasn’t been a lot of snow since.
During the period of mid-June until late August the climate drivers the Grasshopper mentioned in his outlooks ENSO (El Nino Southern Oscillation) and the IOD (Indian Ocean Diploe) were neutral but it was a negative Southern Annular Mode (SAM) that made the difference. I’ll let the Grasshopper explain: “SAM is related to the north/south position of the belt of westerly winds roaring around the Southern Ocean. Cold fronts and storm systems lie within this belt, and a negative SAM brings them in contact with the Australian Alps to deliver lower temperatures and healthy doses of snow. A positive SAM has the opposite effect by pulling the westerly belt too far south.”
The SAM finally flipped positive around August 26thand the result has been little snow since, with 10cms on August 31 and just a few small snowfalls in 3-5cms range during September. Still, if we can’t have fresh snow, then sunshine and good spring snow is the next best thing. The fact we had one of the driest Septembers on record worked in our favour as we didn’t have the major spring rain events that we’ve experienced in other years.
There is a certain irony that we had a good season when other parts of eastern Australia were experiencing well below average rainfalls and most of NSW was in drought. Fortunately for us, the storms that did come through in winter were just far enough north to cross the Aussie alps and drop some decent snow. In an example of orographic lifting, the air cooled as it rose to higher elevations crossing the mountains, creating moisture which fell as snow. The air was dry when it moved east or north of the mountains, leaving the lower regions dry. Well, that’s my layman’s attempt to explain it!
The fact we had a couple of lifts open in Buller, Baw Baw and Perisher on June 9, albeit on limited machine-made snow, and they finally closed them on October 7, 17 weeks later, makes 2018 not only one of the better seasons, but also one of the longest in recent years. So, as we wrap it up, I think Bill Barker summed up the season well in yesterday’s Hotham snow report:
“The perfect end to an almost perfect winter. The only thing that wasn’t quite right about this year was that my days off did not really align with the best of the powder days. Apart from that, I reckon it was as good a season as I have seen over the past 30 years. It started with a bang in June, there were a heap of epic powder days during the winter months, and spring has been as good as they come with day after day of perfect weather. We had lots of super smooth groomers and plenty of deep days off piste, there was hardly any rain, and the decision makers extended so we could milk it until the end. “