Wedgies at the Narrows Car Park

Having seen 2 Buff-banded Rails at the small dam near the Narrows Car Park yesterday I decided to drive down to see if they were having an early snack on the 3rd.  (I also wondered if a Nankeen Night Heron or 5 might be there before the fisherhordes arrived.  

No fisher people nor Rail nor Night Heron.  However I did hear a whingey noise coming from the big dead tree in the paddock.  On checking there were three Wedge-tailed Eagles up there, about 200m from the fence.

They were all very chatty the whole time.

I think from the overall dark plumage this is the adult of the family.  It certainly behaved the most independently of the three.

December 2025 Weather Report

The summary is a rather cool dry month.  This is a little surprising as I had expected that a La Nina would have established itself once the Sudden Stratospheric Warming (SSW) had died down.  However I cannot find the Climate Drivers section on the new (still appalling) BoM website.

A review of the year as a whole will be compiled in the near future (mainly once I have worked out what to focus on) . 

Rainfall

A dry end to the year with my Weather Station (WS) only recording 36mm which was 53% of the median fall for December.  Obviously the prorata estimate ends up with the recorded total, but the gradual downward trend in the second half of the year is interesting.

In terms of the month itself, I found it interesting to compare the falls recorded by my WS and the BoM site near the Airport.

There are obvious differences in the daily falls, but these are occluded by the 0900hrs reset used by the BoM vs my WS reset at 0000hrs.  The cumulative fall series shows that my WS picked up squalls on the 1st and 2nd whereas the Airport scored more around the 25th.

Temperatures

The temperature anomaly finished the month at -0.56oC.  After a very cold first three days the temperature rose until the last week of the month which was quite cool/cold.

A time series of anomaly values shows a fair amount of variability, including a seasonal component.  I have used a 12 period moving average to remove the seasonality and the value of the average including this month continues the downward trend of recent months (shown by the red line).

A plot of the daily extremes shows both rising and falling around the daily averages but with 2 spikes in the maximum series.

Minimum temperatures

The average daily minimum for the month was 12.95oC.  The lowest temperature recorded was 7.6oC on the 1st day of the month: this is the second lowest December temperature recorded on my weather station, and including a further 773 values from the BoM Airport site (generally a little cooler due to greater exposure to winds from the South and East) back to 1993 only includes a further 12 records with a lower temperature.

We ended with 10 observations of minima significantly below the monthly average and 2 significantly  above the monthly average.  The high number of significantly low minima gave an overall minimum 1.5oC below the longer term average recorded by my WS.

The time series of clustered readings by year shows this month continuing the recent crawl along the bottom of the cluster.

Maximum temperatures

The average daily maximum for the month was 23.71oC, very close to the average of monthly maxima from my WS.  The highest temperature recorded was 37.7oC on the 18th day of the month: this is the 3rd highest December temperature recorded on my weather station with the other 2 reading being at the end of the month in December: and we know what happened then.  Fortunately that has not been repeated thus far.  Including a further 783 values from the BoM Airport site (generally a little cooler, even after rough adjustment for greater exposure to winds from the South and East) back to 1993 only includes a further 6 records with a higher temperature (the highest December temperature in my records was 42.0oC in 2009 with my WS having a highest ever of 40.7oC on 30 December 2019.

We ended with 14 observations of maxima significantly below the monthly average and 7 significantly (5 of them very significantly) above the monthly average.  As a result of the very significant readings the maximum ended only 0.1oC below the monthly average.

The time series of clustered readings by year shows this month in the middle of the cluster.

Important: Alternative assessments of significance

I have 2 series of readings to consider when looking at longer term averages.  The 'purest' is the (now) 7 year series  of observations from my weather station (giving 186 records for the previous 6 Decembers).  I have been using that approach for the last two years.  

The alternative is to extent that series by including observations from the BoM site at the Airport for the years 1993 to 2018 (approximately an extra 780 records allowing for days missing from the BoM record for various reasons).  The problem is that conditions at the BoM site can be somewhat different to those at Angophora Drive, due mainly to the cooling sea breezes at the Airport site: I have used regression estimation to adjust for that but it is not pure.

In the past 2 months I have felt (and my feelings, plus $5, will buy you a long black at Lucy's) that the shorter series is not including enough variation, so the standard deviation is low and a higher number of observations than should be the case are being rated as significantly above the average.  So what are the facts?

I calculated, using an ACCESS function,  from the raw data the average daily minimum and maximum temperature by month and the standard deviation of those values.  I then plotted curves for the averages and +/- 1SD for each.  Here are the results:

Without performing tests of significance, eyeballing suggests there is bugger-all difference between them (which is of course pleasing).  So what the  is going on with my gut feelings?  

I then compared the data I had first used in my anomaly analysis for December (Av Minimum 14.29oC SD 1.13oC) with the result from this later analysis (Av Minimum 14.29oC - EXCELLENT - SD 2.90oC - what the ?) .  I realised that for the anomaly analysis, instead of calculating the SD from original data I had taken the SD of the averages as calculated.  DOHHH.  So not only had I come up with some erroneous data but I had also proved Trewin (Snr)'s Law "Any interesting statistic is probably a processing error!"

The good thing to come out of this is that I am now confident I am doing the right thing - or at least a not egregiously wrong thing - in using a series restricted to my WS.

Humidity

For both the standard times the average of daily values of relative humidity (rH) are: 

• below the average for December recorded by my weather Station - the afternoon reading to a greater extent than the morning readings; and
• only greater than the value for 2019 (see comments on maximum temperature above).

The chart of daily values is largely as expected (although the first few days are a bit confused).

The comparison of 2025 with 2024 and the average since 2019 is interesting in the similarity of pattern for the two series.  In both cases 2025 is above average until September (when the SSW episode took hold) and since then November is an outlying high value.  I don't have the training or knowledge to comment further on this.

Wind

A neighbour (who I rate as being likely to have a considered view) commented on Facebook that "Seems to have been inordinately windy this month.".  My immediate response was to note that my site was not good for assessing wind due to being sheltered from the South and East.

The daily runs show a very windy period on 12-13th and a few other draughty days.

Looking at the monthly average shows this month to have a little draughtier than some other recent months but still below the average for December.

This apparent conflict caused me to look at a longer series of monthly observations.  As might be expected there is a fair level of seasonality in the raw numbers so I again calculated a 12 period moving average.  That average shows a steady decline up to March 2022 followed but a much gentler level of decline.  I wonder whether this reflects a growth in garden shrubs having blocked a greater proportion of the wind over time?  If so, tough: I like the lemons and the flowers in the gardens!

Tempest data

As previously noted a friend has given me access to his data stored on the Tempest system from his WS near the main wharf.  From this I have monitored the number of lightning strikes (in a 40km radius) and the average solar radiation.

Lightning

During the month 323 Lighting strikes were recorded on the Tempest system against the wharf site.  This is unremarkable for the month.

The Tempest system also contains data for a site at Burragate.  The snip from Google Earth below shows the two locations and the 40km lightning zones.  The Burragate site logged 1235 strikes in the month, so there was obviously a lot more electrical action up the coast and ranges.

Solar Radiation

The raw level of radiation was a little lower than expected for a dry Summer month, but the moving average continues a fairly flat trajectory.

Moonrise at Fisheries Jetty

 The moonrise on 5 December was supposed to be the final supermoon for quite a while.  So we took ourselves off to Fisheries Jetty at the appropriate time.    The rise was due at 09:03 at 57 degrees which my compass app lined up as towards Captain Stevenson's Point.  See red arrow.

By 0905 there was no sign of the moon breaking through the cloud on the horizon so we turned to leave.  As we looked in the direction of the yellow line there was a bright glow in the sky close to Howe Hill!  So I got out my camera to find a nice red battery icon.  , I said, !  Not a biggie as I had a spare battery in my bag.  Another nice red icon! So phone photos were the 'option'.

A nice line in the Inlet!

I was about over taking snaps of white poles so moved to the smaller jetty and got a nice water line.

I put that image on a Facebook post and a friend - a kayak maestro - commented that it also looks great upside down.  I think he is correct.

On getting home we went down to the back fence and the poor little phone got an atmospheric record shot of the risen moon through the Angophoras.

I have no idea why the compass app was determined to point me where it did for 57 degrees from the Jetty.  I have checked from my desk just now and it shows: 

• North to be towards Mt Imlay, which is correct according to Google Earth (GE); and
• 57 degrees is exactly where the moon was rising through the trees last night.

I also checked the bearing of the yellow line in the map image above with GE and it is the expected 57 degrees.  At the Jetty this morning a bearing of 57 degrees went exactly along the yellow line.  The direction offered last night was now 160 degrees.  I have concluded my phone is now a computer as in "To err is human.  To really stuff things up you need a computer."

My camera battery charger is also begging for mercy having been well used (enough, enough 'too late' it cried).

Tura Beach

Possibly stretching the definition of Mallacoota a tad!  We were planning a trip to Merimbula and Frances found a walk at Tura Beach which looked interesting.  So we headed off, expecting to find a sign to the walk.  That didn't happen but Google Maps were our friend so we had a tour of the area on the way to the start of the walk. 

We wondered about the nature of the residents and the occupancy of houses.  In this case, the Census is our friend, looking at the suburb of Tura Beach.  To begin with, the area looked well maintained and affluent.  It had 3,400 usual residents in 2021, approximately 3x the number of Mallacoota (which was a surprise in itself).  (I don't think the comparison is greatly affected by the Black Summer fire: Mallacoota was well on the way to recovery by August 2021.

• In terms of age of the residents of Tura Beach 47.6% were aged 60+ (Mallacoota 49.7%).  
• 44% of the residents of Tura Beach were not in the Labour Force (Mallacoota 40.4%)
• Looking at Tenure type (TEND), both areas had a high percentage of properties owned outright.  The major difference is the proportion of dwellings with a TEND of "Not Applicable" - effectively vacant dwelling at Census time.  For Tura Beach 14.7% of dwellings had this TEND, while for Mallacoota it was 28.8%.  I think this is a proxy for "holiday house".

The start of the walk was on Headland Drive, on the Northern end of the settlement.  Here is our track, as recorded on eBird.

This is the view from a lookout at '1' in the map

An insect was clinging to a railing at the lookout.  iNaturalist identified this (now confirmed) as a robber fly, Neoaratus hercules. 

Zooming in to the houses: not many tall trees in the gardens- people like their view!

A rocky outcrop below the lookout.

A view North, towards Bournda.  Any European readers may wish to look at that length of sand: that is a beach, cf the 100m of shingle at places like Brighton in the UK.

The rocky cliff at point 2.

A view of the pool at the end of the walk (point 3).

The red rock here reminds me of that at the headland at the mouth of the harbour at Merimbula (not that far to the South).

The vegetation along the track walking back.

   

Hail, hail, the Gangs all here?

 Following the dramatic hailstorm of 16 November (image by Larry Gray, from the Golf Club)

.... we had another serve, albeit of much smaller calibre on 1 December.  This is our back lawn.

After the earlier event a question was raised about how rain gauges etc handled the hail.  I was able to get a snap of some of the stones in the collector of my weather station (that which fell into my plastic Nylex backup gauge had all melted by the time I got out there).

It is possible that during the earlier event some of the stones bounced out, so my rainfall for that date could be a little understated.  For this event the WS recorded 3mm between 1500 and 1600 hrs, although some of that would have been the rain which followed.  More rain followed through the rest of the day totalling 8.6 mm for the day.

There were a few flashes and bangs around the time of the hail.  

Some more strikes were seen around 1930hrs when a very dark storm passed to the North of us (sorry, I didn't capture any radar images).  The Tempest system I follow recorded 167 strikes for the day, mainly in the mid-afternoon. (As a contrast Tempest recorded 6,941 strikes in February 2025 of which 3,444 occurred on the 7th and 1,290 on the 8th.)