Jim recommends flyfishers watch and study the weather. 

For the most of my angling life, I’ve been a student of weather. On many occasions, this has given me an unfair advantage when flyfishing for trout. Like fishing, weather is not an exact science, but it does fit a ‘bell curve’ for normalities and abnormalities. The more you weather watch, the better you become at guessing the day’s weather, albeit with a few mistakes!

When I first started out with a fly rod, it was a case of up early, hurried breakfast and lunch preparation, then out and at it all day until dusk. Sometimes, it was at breakneck speed to be the first on the water at some special river or lake. Weather was not considered. My flyfishing companions and I had coats and waders, and could put up with anything the weather gods could throw at us. We fished in howling gales, in rain, sleet and snow and also in the heat. It didn’t matter. All enthusiasm and not many brains but we were young and keen… and every minute spent fishing counted!

But as we got older and a little wiser, we discovered our speckled adversary had many habits that depended on the weather. For example, we learned that midge, mayfly, termites and terrestrials, tended to end up on the water as trout food under particular weather conditions.

Weather in south-eastern Australia usually comes from the west in a series of pressure systems called highs and lows. A high often arrives with southerly winds abating, followed by a calm period, then an increasing northerly wind with wispy ‘mare-tail’ clouds heralding the arrival of the next cold front and the next low. Then the sequence is repeated, but it’s rarely identical. Some sequences are mild, others wild!

A cold front closes in from the west – Victoria’s central highlands last week.

Sometimes, a low directs air all the way up from the Antarctic, bringing unusually cold conditions with snow, even in summer. And every now and again, a remnant low arrives from a cyclonic depression from the north-west of Western Australia, dropping rain through the deserts of the middle of the nation. On occasions, the low will track all the way down to Victoria with substantial falls.

Rarely, through what a farmer mate of mine calls a ‘Cloncurry Loop’, a tropical low will form in the Gulf of Carpentaria and eventually head south, hugging the western side of the Great Dividing Range and dropping drought-easing rains through western Queensland, NSW and even parts of Victoria. This summer we saw two of these events, filling the great inland rivers and the waters of the Channel Country; sometimes even sending flows all the way down to our inland sea, Lake Eyre, in South Australia. These rains may even help replenish the Great Artesian Basin.

Another atypical system is an east coast low that forms off NSW in the Tasman Sea, but instead of heading to New Zealand, every so often, one travels south-west. These ‘ECLs’ can give both Tasmania’s East Coast and Victoria’s Gippsland drenching easterly rains. Very occasionally, these systems can even reach the middle of Tasmania and western Victoria.

An ECL impacted Tasmania – and the fishing – on 19 Feb this year.

There’s an old adage which states ‘The trout rise least when the wind is in the east’. Well some of the best dun fishing I’ve ever experienced, has been in cloudy, drizzly easterlies on Little Pine Lagoon and Arthurs Lake in Tasmania, brought about by these easterly low-pressure systems.

As many readers will be aware, I spend most of my summers in Tasmania. However, this summer started with a two-week sojourn to Lake Strobel in southern Argentina to catch its giant and world-famous rainbow trout. We were blessed with an unusually calm period and everyone in our party caught huge trout on the dry fly, which was most unusual, because the wind down there normally blows at a gale force 30 knots or more. After returning to Oz, it was back down to my shack in Tasmania for possibly the most dismal fishing season in my memory, due to unusually cool conditions.

Whilst we were away in South America enjoying unusual calm days, Tasmania hosted the World Fly Fishing Championships for the second time in consistently atrocious weather. Although the competitors caught plenty of fish in total, it was extremely disappointing to learn that the visitors didn’t see the best of Tasmania’s wild trout ‘feature fishing’. However, they did receive outstanding hospitality. Friendships were made and those who stayed on for a few days after the competition saw vastly improved weather. Most departed promising to return to the highlands sometime again, soon.

But back to weather and fishing. Today, younger guests at my shack no doubt find me to be a little frustrating as I delay going fishing in the morning and pour copious amounts of coffee. Whilst they’re chomping at the bit to head out, I take my time to plan the day’s fishing when I’m uncertain how the weather will turn out. Quite often, a cloudy morning will turn out clear with blue skies for polaroiding trout. Other mornings, the day starts out cobalt blue but the wispy cirrus clouds out on the western horizon will ruin all polaroiding by early afternoon as they move in, heralding the next change in the weather.

For the keen, dawn can be a good time to be on the water in Tasmania, although it will be some hours before it becomes clear what rest of the day’s weather will look like.

These days, my view is, it’s better to be in the right place at the right time for four hours of good fishing, than to spend the whole day wishing I had gone elsewhere. Four hours out on the Great Lake under a flawless blue sky, sight-fishing trout in the waves; or a few prime hours on the duns at Penstock Lagoon or Little Pine under grey skies, is better than bolting out early and having the opposite transpire!

A possible thunderstorm providing an ant fall is worth waiting for, as is a calm patch with midges at dawn or even in the middle of the day. A hot northerly along the banks of a river will drive grasshoppers into the water for waiting trout. Weather creates opportunities. A calm, sultry afternoon might mean a fall of mayfly spinners so extensive, an angler might see it on only a handful of occasions in a lifetime.

Rain clearing to a promising afternoon at Bronte Lagoon, Tasmania.

Sometimes, particularly on the Great Lake, clouds will form at the northern end of the lake as warm, wet northerly air from Bass Strait reaches the Tiers and rises, ruining sight fishing in that part of the lake. However, as the air moves south and descends and dries somewhat, the southern end of the lake can remain under clear skies all afternoon. Other times, just after the peak of a high pressure system passes, a northerly wind will start at the top end of the lake but take many hours to find its way south. This gives those who have gone up north to launch their boats at Brandum Bay or Breona, a huge advantage for sight fishing in the waves compared to those who have launched at the southern end of the lake and are struggling to see fish in much calmer waters.

Anyway, hopefully these thoughts and examples may inspire those who don’t already do so, to think more about the effect of weather on trout fishing. Start by reading the weather maps, either online or printed in the newspapers. The lines on a weather map are called isobars. When they are close to each other, it indicates increased wind. When they are far apart, it usually indicates calmer weather. The more you study weather maps, then see and experience the outcome, the better an angler you will be. You will also note that sometimes the forecasting staff at the weather bureau get it wrong. As I wrote earlier, it’s a bit like angling: not a perfect science!

For further reading, I recommend David Scholes’ chapter on weather in his first book, A Fly Fisher in Tasmania. Published way back in 1961, copies are still regularly obtainable on eBay and full of handy hints on weather and fishing conditions that are just as relevant today as they were when they were written over half a century ago.