10-12 September



August has been ridiculously slow, but with the change of month we seem to be slipping straight back into a standard 7-10 day winter pattern. There’s now a pretty clear repeat event to next week’s, due late in the week following

Season in review


Our snow season is far from over, but the big melt will soon start. Now’s a good time to reflect on what we’ve seen so far, with archive charts from the Australian Bureau of Meteorology

. . . → Read More: Season in review

Understanding evaporation #4: climate change


One of a series; also see editions: #1, #2, #3

A warmer climate must mean more evaporation, a drier continent and more drought? Well, yes, that’s pretty much the prediction, but unfortunately the observed response of evaporation to climate change has long been a bit of hole in the story — a real one, unlike all that manufactured tosh.

. . . → Read More: Understanding evaporation #4: climate change

2-4 September


Updated #2…

After a very long hiatus, it looks like there may be a “real” snow event early in September. By that I don’t mean a big one, just one deriving from the typical winter meanders in the polar circulation.

Update (27 August): This is now up on BOM ACCESS-G and ECMWF

. . . → Read More: 2-4 September

August 17-18 event ... dip

How did I miss this? Like many others I expected a rain event, but as with the 15-16 June system earlier this year, this one delivered marginal wet snow to Perisher Valley and Thredbo (but little to Victoria). These upper atmosphere driven systems can be tough to pick.

. . . → Read More: August 17-18 event … dip

Understanding evaporation #3: potential rate


One of a series; also see editions: #1, #2, #4

Talk to a meteorologist about how to measure evaporation and you’ll probably be told not to bother because it can be reliably estimated from other parameters. Therein lies a simplification, an overstatement and perhaps a cop-out.

. . . → Read More: Understanding evaporation #3: potential rate

Trans-Tasman seesaw?

Mt Hutt peak snow depth vs Spencers Creek

You can’t watch snow weather in our part of the world for long without noticing that when things are good in Australia, they’re often not so good in New Zealand, and when they’re bad here, they usually look much better over there.

. . . → Read More: Trans-Tasman seesaw?

Understanding evaporation #2: evapotranspiration

Stomata on tomato leaf

One of a series; also see editions: #1, #3, #4

Evapotranspiration is one of those ugly made-up words, intended to convey the combination of transpiration from plants and evaporation from the ground under and around them. It’s the relevant meteorological and hydrological parameter at the catchment and landscape scale

. . . → Read More: Understanding evaporation #2: Evapotranspiration

10 August - placeholder


This season I’ve decided not to blog about inconsequential snow weather systems. The little front arriving around 10 August will be one of those. The next chance of a decent snow event now seems to be out to 20 August at least … hope I’m wrong.

Update (7 August): I should add, inconsequential for Australia; for New Zealand it’s bam-kapow yet again. The Tasman seesaw seems to be in effect again this season. Warrants more study…

. . . → Read More: 10 August – placeholder

Understanding evaporation #1


One of a series; also see editions: #2, #3, #4

Evaporation is that weird cousin in meteorology. The Australian Bureau of Meteorology lists over 18,000 present and past rainfall recording stations in its huge database, but only about 600 stations that have ever measured evaporation, and just 180 of those still operate. But wait, measure evaporation … what? Ok, step back a bit…

. . . → Read More: Understanding evaporation #1