STRIDERS ALMANAC – the express edition
Vol 1 Part 5 2 April 2013 page 1
Part 5 Watching Hector go up and then a monsoon burst
11 – 31 December, a period of 21 days
Tuesday 11 December 2012
I was in Darwin on this day and from there I saw a sea-breeze cloud front inland from Darwin in the afternoon. It looked as if it might be over my home at Humpty Doo. It turned out that it was, and there was 6 mm of rain in the gauge at Solar Village at 0900 hrs on the morning of Wednesday 12 December. This was the first clear case of a sea-breeze cloud front inland from Darwin that I observed this season.
Wednesday 12 December 2012
I was in Darwin staying at the Alawa Crescent house. At 0238 hrs the house instruments recorded the outside air at 30 degrees C with 73 % relative humidity. It was very warm. After this hot night there was a morning terminator thunderstorm at dawn. Only a brief storm but very nice for all that.
The day was hot and sunny and all day long there was a storm about. I can not be certain but I fancy that it was the same storm that had visited us at dawn. It is most unusual for a storm to hang about all day like that.
I went to Humpty Doo with a friend to water my baby plants and to plant some grass in a roadside drain. The idea was to plant a native semi-aquatic grass in the drain in the hope that it might help the plant community there resist invasion by the very rampant exotic weed “Tully Grass” ( Urochloa humidicola ). To that end we visited the paperbark forest at Lakewood and dug up some grass plants from the fire-break there. We thought that we were digging up Paspalum scrobiculatum but we were in fact digging up a species of Love Grass ( Eragrostris sp. ). I think that we can call it the Paperbark Love Grass for now. Evidently it looks a lot like the Paspalum at this time of year when the tussocks are small and I was confused by this similarity. We planted a line of this Love Grass across the drain on the hill-top on Dalgety Road. We also potted some of them up, and I held some individuals in a bucket of water. They are still in the bucket and look none the worse for the experience now in early April. The individuals that I potted up were eaten down to fairly short by an Agile Wallaby very soon after I put them out in my nursery area. I moved them up onto a bench. They survived and grew back.
This Paperbark Love Grass grows naturally in association with the Paspalum and we might as well plant them together. It is a very beautiful and hardy grass. It is a knee high perennial tussock grass. A few of the ones that we planted in the drain survived my neglect and the dry weather.
Thursday 13 December 2012
It was overcast at dawn and cloudy later. The standing cloud Hector went up over the Tiwi Islands early in the afternoon and the storm over the Rum Jungle Uranium Mine also went up at the same time.
There was a sea-breeze cloud front inland from Darwin later on in the day. It was a very warm night but I slept comfortably at Alawa without turning the ceiling fan on.
Friday 14 December 2012
It was an overcast day with some tiny showers of rain.
Saturday 15 December 2012
In one of my experiments with the seasons I have used this day as a New Years Eve, and the eve of a season 4 months long (16 December to 15 March) . It is quite a workable system with a lot to recommend it. I visited my home at Humpty Doo and had a lovely homecoming experience. A thunderstorm began to flash and boom as I came in sight of my little cottage in the mid-afternoon. I paused there looking at it “on the threshold of a dream”. Rain fell from that storm from 1615 hrs. There were cooling downdrafts and there was 10 mm of rain. It was nice to be at home again.
Sunday 16 December 2012
It was very hot overnight 15-16 December. The morning was overcast. In my travels I noticed the very first flowers for the season on a few of the Green Flowered Paperbark Trees ( Melaleuca viridiflora ) at several locations. That first flowering made a good ‘sign of the times’ seasonal marker.
Monday 17 December 2012
It was a hot and humid day with an early Hector storm over the Tiwi Islands. There had been an early Hector every day since the first one that I noticed on Tuesday the 13th. There was also a storm cloud over Coburg Peninsular on the 17th.
Tuesday 18 December 2012
It was an overcast and humid day. I was so tired that I had to have a rest day.
Wednesday 19 December 2012
I spent the night 18-19 December in Darwin. I noticed that the frogs were very noisy despite the fact that there was no rain. Darwin has become something of an artificial rainforest since 1974. I call it “a sprinkler jungle”. The frogs were very excited in Darwin on that night but I suspect that they were very quiet in rainless areas away from the city. Darwin probably has its own calendar in many ways these days.
There was a spectacular display of what I am calling “doldrums cumulus” on the morning of the 19th. It was a very beautiful skyscape. There was 37 mm of rain in the gauge at Solar Village at 0900 hrs, it probably fell on the afternoon of the 18th.
It was sunny with a little cloud in the afternoon. There was a termite swarming at night at Lakewood. It was a very warm and humid night. I used the ceiling fan.
Thursday 20 December 2012
The morning was overcast and calm. It was overcast all day apart from some direct and bright Sunshine around noon. This is an interesting phenomenon. “Sunshine at noon” in an otherwise overcast day is a reversal of the more common “mid-day cloudiness” on an otherwise bright and sunny day.
I discovered a fire burning in one of the bushy parts of the Taminmin High School Farm in the late afternoon. It was an area with a lot of Pandanus ( Pandanus spiralis ). I do wonder what sort of a ‘wet season burning’ experiment this was. The fire burned into and through an area of Tully Grass that did not look as if it could possibly burn. It was so dense, lush and green, but the fire burned through it and made quite a lot of smoke in the process.
I also noticed that this same Tully Grass was in flower, generally, in the roadside drains on this day. I had noticed the very first flowers in just a few places on Saturday the 8th. So it took 12 days from the first flowers opening to the flowering becoming general. It interests me that the flowering was general on the day before the Summer Solstice. Once again I was so tired that I had to have a rest day. It is hard to get enough rest and sleep at this time of the year.
It was the Eve of the Summer Solstice, and the 4 month long super-season 21 December to 20 April in my latest experiment with the seasons.
Friday 21 December 2012
This was the day of the Summer Solstice. The night 20-21 December was very hot and humid. I used the ceiling fan at Lakewood. There was rain and some cooling downdrafts from a thunderstorm at 0240 hrs. At Solar Village there was 20 mm of rain in the gauge at 0900 hrs. At 0926 I noted that6 it was “suspiciously dim”. It was so dim as to suggest the proximity of the inter-tropic convergence. The sky did clear later in the day.
The Solstice occurred at 2040 hrs CST. It seemed to me that the closest dawn to the Solstice would be on the morning of Saturday the 22nd and I made arrangements to view that dawn from a high place with a few friends.
Saturday 22 December 2012
We got up at Wrigley Creek at 0421 hrs and set out to travel to Dawn Rock in the dark. We made the last and difficult part of the climb in the twilight of the approaching dawn. Once upon a time I lived under a rock overhang below Dawn Rock. On the morning of 22 December 1974 I climbed up on top of the rock to watch the Sun rise, and I saw something that I had never seen before, and that I have not seen since. I saw a thin vertical column of condensation rise up into the air above every water hole and spring in the district. It was a most peculiar and striking phenomenon. Towards the evening of that same day I walked down the hill to the Stuart Highway and began to hitchhike to Darwin and so into the path of a great storm. Our visit in 2012 was 38 years on to the day from the morning in 1974 when I saw the columns of mist standing over the waterholes.
In 2012 the area around Dawn Rock had been burned by a fire and many bushes had been killed by it. The Spinifex tussocks had all been burned away. The only signs of new life on this day were lots and lots of young Commelina seedlings ( Commelina ensifolia ). It was very cloudy and we did not see the Sun rise.
Sunday 23 December 2012
This was another overcast day at Wrigley Creek. My friends took me through a low pass in the hills that I will call West Gate, and on to a little spring fed creek beyond it to look at the Spring Bloodwood Trees ( Corymbia ptychocarpa ) that grow there. Some of the trees were in flower.
We dug up a few of the tree seedlings so as to transplant them.
The pass at West Gate is a low saddle between the heads of two creeks. I am curious about the fire history of the place. I can see how useful a small firebreak in this saddle might be. It the area was burned out very early in the season the fuel free area would stop a fire from burning from one hill to the other , whilst the creeks were still acting as firebreaks. Later on in the season when the valley floors are ready to burn and the fires tend to follow the creek lines such a little saddle firebreak would stop a fire from crossing over from one creek to the other. So a firebreak in this saddle could prevent the spread of fire in two different directions at two different times of the year.
There is a rather similar saddle a little way away to the South East of the Solar Village. On the steep and rather rubbley hill slopes above that saddle there are some clonal patches of bushes of the Colour Tree ( Pogonolobus reticulatus ) . A friend tells me that it is the places where this tree grows that are burned first on Bathurst Island. This suggests that an early firebreak might have been burned in this saddle.
To the West of the West Gate saddle there is a relatively densely packed population of the little Sand Palm ( Livistona humilis ) in a sandy area at the head of the creek. My friend tells me that the earliest fires on Bathurst Island are made by setting fire to the dry leaves on this sort of palm. This produces an intense burst of radiant heat so that the grass under the palms will burn but the fire will not travel beyond the palm grove into the adjoining grass if you get the timing right. Right in terms of the degree of curing of the grass fuel and the time of day at which you burn. Has this practice been employed here in the past ?
Monday 24 December 2012
A real change in the weather was signalled when convergence rain began to fall at 0415 hrs. It was so nice. There was no thunder with it. This was air stream convergence rain not thunderstorm rain. It did seem as if a monsoon burst might be getting under way. In the very late afternoon the clouds were very low and they were racing overhead from the North East. I was reminded very much of the conditions in Darwin at the same time of the day on Xmas Eve in 1974.
Then, suddenly and quite unexpectedly , a very strong and steady North East wind arrived on the ground, and I freaked out. I felt myself go into a state of shock, and I was very frightened. I know that it is called ‘post traumatic stress disorder’ and that most survivors of Cyclone Tracy suffer from it to some extent. My reaction on this occasion was quite severe and I was pretty much lost in that emotional reaction over the next few days. It was not a nice experience.
Wednesday 26 December 2012
I visited Solar Village and found 7.5 mm of rain in the gauge at 0900 hrs. There were signs that there had been a strong wind there. Quite big pot plants had been thrown over by the wind. It was a very hot day. A storm or two slipped by to the North of us travelling from East to West. The wind on the ground was from the South at times. It seemed as if we were still to the South of the ITC (the inter-tropic convergence or the monsoon shear) at that time.
Thursday 27 December 2012
There was another 7.5 mm of rain in the gauge at Jimol at 0900 hrs. In the afternoon a storm arrived from the North East and it rather seems as if the ITC passed over us at that time. I took a photograph of two thunderstorms dancing back to back shortly before that combined storm swept over us.
Friday 28 December 2012
There was 31 mm of rain in the gauge at 1500 hrs on this day. That is really not a lot of rain . I expect a lot more rain than that from the transit of the ITC. The Gradient Wind Analysis Map on the internet showed the ITC lying across the base of the Top End at 0930 hrs. Evidently we were experiencing a very weak monsoon burst. There was a storm from the North East at about 1600 hrs. There was quite a bit of rain and then an overcast sky. The Full Moon occurred at 1951 hrs CST. It was quite spectacular when it rose but there was no sight of it later on in the overcast sky. There were cooling downdrafts, and a beautiful night followed. This was another big Full Moon Rain.
Monday 31 December 2012 New Years Eve
40 mm of rain had accumulated in the gauge to 0900 hrs on this day. I visited Jimol with a friend to repair the diversion blocks and other anti-erosion structures on the driveway. Whilst we were doing that we were visited by a band of Babbler Birds. I am used to them visiting just once for a period of about 3 days in every year. We did not realise it at the time but on this occasion they had arrived for a much longer visit.
In the afternoon I look some Fountain Vine seeds ( Opilia amentacea ) to Alawa and spread them around and about the neighbourhood. In the late afternoon Dan took a photograph of me. I quite like it and I think that I will use it as my ‘recent photograph’ in 2013. There was a gathering in the house in Alawa Circuit to see the New Year in, and that is where I celebrated the event.
And that my friends was how the year ended for me.
Copyright Strider Humpty Doo 2013 2013-04-06