Apres le deluge, c'est moi

 Let us begin by quoting Louis XV of Frog.  And I got the sex correct, unlike a writer for Punch in the 1960s who was delighted to find "La deluge" was anagram of De Gaulle, before discovering his error.

Rather than the cheese-eaters I am referring to a couple of walks in the Mallacoota area after a rather soggy couple of days.

The first of these was the Betka River loop, including a small extension to Point Difficult.  There was little to record on the River loop as all that could be seen most of the time was 3 m high Acacia and Kennedia.  Why am I not reassured that there is nothing to burn?  I suspect that will change after a couple of 35C days in February.

The scenery became more interesting when we got to the clifftops.  Here is the view East from Point Difficult.

With a reasonable wind blowing the foam was getting plastered well up the cliffs.  We had come across a little being blown over the track.

We could see this bloke at Betka.  I spoke with him afterwards and he was just filming- mainly his Dobermann running in the froth.  He said he'd had to remember where rocks were submerged in the foam!

At beach level.

The Betka estuary. with the quite high River running out on the West side (closer to the camera) and waves bringing in more foam on the East.

This was the situation on Lakeside Drive near Mullet Creek on 10 December.  The heavy rain and high tide  were getting Bottom Lake up a bit.

We passed by around noon on 11 December and the water was now up to the level indicated by the green line.  Note that this rise is happening with the mouth of the Inlet wide open!

We were on our way to the Narrows for a walk in the rain (now just steady drizzle).  The high water level caused a bit of a scramble near the start.

The first new bridge is showing that it could have been made a bit longer and higher (the gauge at the wharf is at 0.56m, so about a metre below where it can end up with the mouth closed!)

The first fallen tree (after about 1km) was negotiated.

This one, mainly a large Exocarpos cupressiformis that had got in the way of a falling gum tree branch, after 2 km caused abandonment.

There wasn't as much blossom around as we had seen on other recent walks.  According to iNaturalist this is Ozothamnus obcordatus.

The grass seedheads were attractive.

So was this Azure Kingfisher which flew in front of us for a while.

2 White-faced Herons were being friendly, but not quite friendly enough to come as a breeding record.

Here is a nice in-focus image of a blade of grass.  It would of course have been a more interesting shot if my camera had focused on the raindrop covered snake in the background.  Or if I had realised that some adjustment was needed, but it was raining and the small camera is not waterproof so I didn't want to 💬 about.  

Severe weather event of December 2021

Cutting to the chase, this has turned into a very  intriguing story, looking at the various measures of rainfall I have available.  Looking at the period 0901 on 8 December to 0630 on 11 December the totals I have are:

The Nylex and the Davis are sited close together and I took 5 readings from the Nylex over the event.  On one earlier occasion the Davis reported 0.8mm, which matched the wetness of our drive and the road, while the Nylex had no water at the bottom of the collector, just some drops up the side.  It seems to me that the Nylex usually understates the fall by a small amount.  However I assess that we recorded at least 165 mm over the period of the event.

The positions of the 3 sites are shown in this snip from Google Earth.  The red arrow indicates the dominant wind direction recorded by my Davis and the two BoM sites .

Looking at falls for the 3 days - taking the readings to a consistent - albeit stupid - 0900 reset time shows that the vast majority of the difference between my Davis and BoM Mallacoota is due to the fall starting at 0900 on 9 December.

For the other 2 days the falls are so similar that it reassures me that the Davis is functioning correctly.

I have looked at the hour x hour results from my Davis and the BoM Mallacoota site.  Of the 44mm difference some what over half (24.6 mm) comes from 5 hours.  In addition for 2 hourly periods BoM recorded more than the Davis.

The couple of negatives increase my confidence that the devices are working correctly and the periods of large difference suggest to me that most of the difference is due to embedded cells passing over the Davis but missing Gabo and the Airport.  (In this regard I recall that on 7 December it poured at the golf club for at least 20 minutes - at least, by a guess, 2 mm - but my Davis recorded 0.2 mm and the Airport 0 mm.)

So I conclude that all devices were working correctly, that there were cells embedded in the system, and by any measure we gotta lotta rain!

Back to the future!

The potential for this event  first came to my attention on 8 December when I noticed that BoM were forecasting 70-90 mm of rain for each of 9th and 10th December 2021.  

The forecast on Meteye showed a pretty solid amount of rain right through the 9th.

At that stage Meteye only showed the probability of 'any rain' - very high - through the 10th.  By the 9th they had filled in the rest of the table.  Again a solid amount right through the day.

I have compared the 25% probability falls with the actual, from my Davis.

Meteye did a pretty good job.  The peaks that they missed are as close as I can tell, cells my Davis recorded that BoM missed at Mallacoota.  These are pretty much random events that would be impossible to forecast.  The event did subside somewhat quicker than Meteye suggested possibly due to the low pressure system staying a little further North than suggested in the 10pm Friday forecast below.

The villain in the piece - you should excuse the anthropomorphism - was a low pressure system forming off the East coast, apparently just North of Mallacoota.

I only took one image of the radar plot at 0500 on 10/12. 

The system seemed to rotate as indicated by the green arrow so that by late on the 10th the heaiest falls were occurring along the line of the red arrow, just to our North-East.  This didn't seem to dump a great deal as Green Cape only scored 108mm (similar to Gabo).  

At one point it looked as though we might be heading for Floodmageddon but the Genoa River has backed off.

The Snowy River has not been so gentle, with the gauge at Jarrahmond currently well above major flood level.  (This would not have been helped by a 9 hour release from Lake Jindabyne on 9/12).

I'll finish with chart of rain rates from my WS.  It shows the passage of cells quite well.

I had thought that there hadn't been any heavy falls but the peak fall (of 72.4 mm/hr at 11am on the 9th) was the 33rd heaviest I have recorded (from 1401 rain observations).  

Once more to Captains Creek Fire Trail

 On 7 December we walked the Heathland Loop starting on Betka Rd and including the Chip track.  We were surprised at the amount of flowering shrubs in the bush.  So feeling like another walk on the 8th we decided to try the Captains Creek Firetrail.  This is our route:

At the start we were somewhat disappointed with the diversity of flowers: a lot of Scaevola ramosissima but not much else.

Our first interesting flowers were these bright yellow peas (I have given up my campaign to get them called 'beans').  I think they are Dillwynia glaberrima.

These fuzzy balls were common in the bush but we couldn't identify them.

Then we got to this specimen with a few flowers remaining and it was easy: Ricinicarpos pinifolius (Wedding Bush).

Once we got to the top of the steep hill (where the track turns away from Genoa Rd) we saw a lot of Caleana major (Large Flying Duck Orchids).  Colonies of 10 - 20 plants were frequent.

I have no idea what this was.  Certainly not Stackhousia!  INaturalist has been consulted.

Another doubtful specimen.  Obviously some form of tea tree and iNaturalist has suggested Kunzea ambigua, which seems reasonable.  Flowers first ...

.. and then the fruit.

This is clearly Stylidium sp. but it was very large. The flower stalk was nearly 1m long, rather than the 30 cm commonly encountered with S. graminifolium.  However I can't find anything else in the genus that matches.

Here is the whole plant.  Perhaps it is on steroids?

Another mystery, which iNaturalist has suggested to be Platysace lanceolata.  That certainly matches the image in Wildflowers of the Wilderness Coast.

It definitely wasn't Pimelea linifolia.

Then Frances made the discovery of the walk.  I guessed it was a tongue orchid and it turned out to be Cryptostylis leptochila (Small Tongue Orchid).  According to Bush Beauties it is quite common in this area and we found about 20 plants in the area.

INaturalist has suggested Aotus ericoides for this pea (life is easier when one doesn't have to adopt a missionary position about names).  I have no reason to argue that call.

A large ant exploring some fresh deer poop.  I note with interest the large nematode on the turd.

A medium sized grasshopper.  I have entered it to INaturalist for ID,