Beaches

Following the departure of the coastal low we have visited the local beaches expecting to find many interesting things washed up.  Cutting to the chase, the flotsam was not that diverse: mainly seaweed.  However there was interest in seeing the water running out of creeks and the erosion.

Getting to Bastion Point the immediate interest was the mound of foam at the waters edge.

When we left the beach an hour later we saw the corpse of a very large fur seal right beside the steps.  I haven't included a photo as its a tad gruesome.  However I am curious as to why we didn't spot it on the way down.  Either (1) I was distracted by the foam or (2) the foam covered the body..  It will start to get stinky so has been reported to Parks.

There was more foam further down the beach.

The mouth was now quite wide and flowing very strongly.   The outgoing water was very brown: whether this was due to sand being carried out or just tannin in the run-off was unclear to me.  It meant the waves were brown all the way to the steps, and for a long way out to sea.

The next day we went to Davis beach to look at the now open Davis Creek.  The Creek opening was not greatly exciting but the amount of erosion was fairly spectacular.  This bank was 2 m high in places..

While at the Creek we were entertained by 2 sub-adult White-bellied Sea-Eagles.  They didn't dance but just soared looking attractive.  Both photos are the same bird: the second appeared too far away to get a decent picture.

Close to the Creek opening we were interested to see the various black layers visible in the exposed face of the dune.  As there has only been one recent huge source of ash we assume this reflects the way the sand has built up this year with rain events washing ash and charcoal out to sea and subsequent high constructive tides covering it with clean sand.

Going along the beach to Betka the only debris of interest was a much higher than usual number of Cuttlefish 'bones'.  When we got to Betka the water was flowing back into the estuary, reflecting the incoming tide (and presumably the run off into the River having calmed down.

Certainly the road bridge was well out of the water.

Low, and on the East Coast

This post is about the weather event of 26 to 28 July 2020.  I have done another post with some images of the impacts of the rain etc.

I have used the title of this post since the BoM seems reluctant to call the event an East Coast Low (ECL).  They have a fact sheet about such events and this event seems to tick (at least) most of the boxes for an ECL and doesn't match any of the other possibilities in that sheet.  Discussion (by meteorologists) on a forum I follow seems to conclude that this is actually an ECL - they have information that the crucial attribute (of upper level events impacting on surface level events) has happened.  

Whatever one calls it we had a lot of rain - 104.6 mm and counting - such that we are now (0640 on 29 July) 25.4mm (1 inch in old money) above the pathetic total in 2019.  Doing a pro-rata estimate for falls to date my guesstimate for 2020 is 960 mm, the highest since 2016.  

I will begin with a chart of the hourly rainfall from midnight 25 July to 0700 on 28 July.  (A small amount has fallen since then but it doesn't greatly change the picture.)  

Another way of looking at this is the cumulative amount that has fallen.

The rain was quite steady with only a couple of spikes in the rate.  Knowing that my WS has recorded some squalls well over 100 mm/hr I originally rated them as quite modest at around 70 mm/hr.  However looking at the detail shows these to be about the 16th and 17th heaviest rates (out of 16,000 observations)

Looking at the wind is interesting.  As always I am a little tentative about wind readings as the wind exposure of my WS isn't ideal.  

There didn't seem to be any outrageous gusts (37 kph was the strongest gust and the longest hourly run was only 11.2 km).   However the direction of the wind produces a somewhat strange chart.  In the lead up to the low getting down this way any of the wind observations are from the NNW (bearing 337.5 degrees).  However once the low arrived the wind settled down to ESE (112.5 degrees) with a few gusts from the SW (225 degrees) presumably reflecting the passage of embedded cells. 

A key factor of low pressure systems ins the low pressure (duuhh).  This chart shows the pressure dropping from around 768 mm until about midnight 27 July when it settled down around 758 mm for the rest of the period of recording.

The centre of the system was somewhat North of us.  By way of example, Ulladulla, 260km NNE of Mallacoota, copped a real downpour.

A chart of the accumulation shows the steady rate of rain.

The ultimate impact of the rain is to boost the inflow to the Inlet.  Here is the BoM gauge at Genoa River Gorge.  The rise was from 075m to 2.40m: as indicated it was above minor flood level from several hours.

Pictures of the Weather and Water.

Mallacoota has just had a very wet period.  I will cover the weather stats in another post but this one has some photographs of the impact of the weather (and a few other incidental items).

The wetness went well inland, unlike one recent event which was restricted to the coast.  The Genoa River rose by 1.65 m according to an official gauge at The Gorge.  We only found out about that later but did notice that the level of the Inlet was a lot higher on our morning walk.  It continued to rise during the day, going from about 0.2m on Monday to 0.86 by 1100 on Tuesday.  As a result, the jetties were going under (again).

The water is coming down from upstream,  Here is a photo of the Genoa Flats (from Facebook, taken by Lisette Read)..

At the wharf some of the Pelicans seemed to have shrunk (comments on Facebook included a reference to them eating with spoons rather than shovels and a warning about washing in hot water).

Going round to Captain Stevenson's Point some full sized Pelicans flew past going to join colleagues on the sand bank.

The mouth is well open ...

.. and the rough sea outside was fighting well to enter the Inlet against the flood flowing out.

We moved round to Bastion Point where white water was available.

Sand was in shorter supply and getting less by the minute.

There are many strange life-forms washed up in such events and I initially thought this was one of them.  However once the wash receded it became a lump of basic seaweed that had been encapsulated in foam,

Did I mention that the sea was rough?

After the Betka opened a couple of weeks ago it had closed itself off again.  That has now been remedied totally naturally and a good outflow is going.

Looking West from Betka gives another view of the rough sea.

The contractors have done an excellent job rebuilding the retaining wall along the track.  Hopefully it will be a long while before another fire comes along.

A few images of the cliffs and sea.

Some flowers are beginning to appear.  This is certainly a member of the family Fabaceae and I am pretty sure Kennedia prostrata: the leaves look very small but the Flora of Victoria indicates a size range of 6-35 mm long and 6-35mm wide (with several possible shapes)!

One of the plants that has emerged very widely since the fire is Solanum aviculare (Kangaroo Apple).  This was the first flower we spotted (and thus exciting) but along the track there were many others.

Bits and bobs

This covers a few things seen in the last couple of days that haven't quite justified a post in their own right.

The tale begins on Saturday 25th with attending Bastion Point where Frances attended a ukulele class on the beach.  As we arrived a skein of Pelicans appeared and I was able to get a few in shot before they disappeared behind vegetation.  I like the way the leader has an upturned primary: very like the winglets on large modern jets.

The sea itself was very calm.  I could almost have been persuaded to insert the kayak into it.   Note the weasel word "almost"!

It wasn't dead calm.  Moving along to the steps I was heard to request that the sand road be constructed again!

Getting through that took a little time so I didn't go all the way to the Opening.  There were quite a few birds around when peered at through my telescope.  The highlight was finding a total of 6 White-fronted Chats.  There 3 of each sex, but none of the females paused: they all bolted into clumps of reeds where I susect they might have been nesting.  Two of the males were astonishingly obliging.

Later in the day Karbeethong decided to emulate Brigadoon.

A flock of Satin Bowerbirds have been appearing withe fair regularity this year.  At one point in the arvo of the 25th there were 8 green birds probing the lawn.  The blue male doesn't turn up often.  Sorry about the quality of the photo but it was taken through a double glazed window and a pane of glass on our verandah!

Several Crimson Rosellas were also grazing on the lawn.  While these are common birds in most of SE Australia when I look at all closely at them I recall taking an English colleague for a run in Canberra.  When a Crimson landed in a bush a few feet away he stopped dead in his tracks.  Such lurid birds are not part of the UK avifauna.

On the 26th I rode down to the wharf to check the gauge.  Before doing so, a guy working nearby spotted my binoculars and thought I might know what species had laid this egg.  

I have subsequently established that it was a Pelican.  Apparently a nearby island rookery was flooded and several eggs washed ashore.  (A resident who found another egg wished she found it sooner as she has an incubator and could have tried hatching the  chick so she could  " have a Mr Percival. That would be very cool walking down the street with ya pelicans."  Way cool indeed!

The bottom of the gauge is a bit clagged but scaling from the image I estimate the level (at mid-tide) is about 0.1 metres.  So a drop of 1.5m from the high point.

A large (perhaps 0.5m)octopus had been caught out by the flush.

Moving on to the 27th and another East Coast Low has formed.  Thus far (1100 hrs) it has dropped nearly 40 mm on Mallacoota but 176 mm on Moruya!  Mallacoota is right on the edge of the range of the radar from Captains Flat as presented by BoM.

The interpretation of the radar data by weatherzone is much more like what we are experiencing.

Interestingly the radar image from the BoM phone app is much more reasonable.

The Betka River which had closed again had reopened naturally.  

A large plume of sediment was running from Mullet Creek out into the Inlet.

By 1700 hrs we were up to 65.6 mm for the day and 73.6 mm for the event.