Weather Report May 20206

 The overall weather for the month was very warm and a tad above average for dampness.

Rainfall

After the very dry April it was good - apart from the lawn growth - to get a fall of 76.8mm (102.8% of the median fall for May).  It was also spread well across the month.

By the end of the month my pro-rata estimate for the year was 951mm, well below last year and similar to 2024.  

It seems that some long-range  forecasts are still talking about an El Nino taking effect in the coming months but the word from the BoM seems to be taking 20c in several directions (similar to "2 bob each way" but lacking that level of certainty).  

Temperatures

The temparature anomaly ended the month at +1.84^o C.  Through the month the series was always above 1^o C after a very high value at the start of the month.  (This is discussed more under the 'maximum' subheading below.)

Looking at the historical values of the anomaly this was among the higher values recorded and leads to a slight uptick in the moving average series.

In terms of extreme temperatures the daily series shows quite consistent values above the average for the date. 

I compared the values from my WS with those from the BoM station at the Airport.  Allowing for the known differences between the sites (IMO mainly due to wind exposure)the picture is very consistent.  

Minimum Temperatures

The average minimum for the month was 11.04^o C which is 1.6^o C above the long term mean and nearly 1^o C above the next highest monthly average.   Of the top 25 May minima 6 were recorded in May 2026, while 3 would have been expected: in view of the foregoing it is not surprising that the highest minimum for the month (17.8^o C on the 3rd) was the highest minmum recorded.  At the other end of the scale the lowest minmum (6.1^o C on the 22nd) was only the 16th lowest recorded.

Not surprisingly, in my time series this year is much above all other years of WS records.

Only 1 minimum was significantly below the monthly average but 9 were significantly above average and a further 3 values were very significantly above average.

Maximum temperatures

The average maximum for the month was 20.16^o C, 1.17^o C above the average maximum for May.  To my surprise it was not the warmest May which award goes to 2007 at 20.27^o C.  (In 2007 again there were many days above 20^o C but no outstanding result such as might cause me to doubt the value recorded.  The warmest day this year was 24.6^o C on the 26th.  Looking at the history of my weather station readings the daily maxima are not dramatic - the highest reading is only the 8th highest -but a high proportion of the hotter days were recorded this year.  (Of the 25 hottest May days, 8 were recorded this year.

The time series shows this year to be above the 7 other years for which I have WS data, but not as much as for the minmum series.

3 minima were significantly below the monthly mean value, 4 values significantly above the monthly mean value and an astonishing 16 values were very significantly above the  monthly mean value.  On examing the historic series it appears that the maxima for the month do not vary as much as other months (the relative standard deviation for May is 4.7%  whereas for March it is 6.4%).  My knowledge of meteorology is too limited to explain why this is so.

Humidity 

I have discussed the issue of standard times in the report for April, being the first month with my new WS.  I have taken the standard times as 6am (representing morning values) and 2pm (1400hrs, representing afternoon values).  In general terms this is sufficiently comparable with the BoM, administratively driven stds of 9am and 3pm.

For this month the most notable feature is the high values of the afternoon readings.

The morning reading for this month is well above - 2.1% points -  the average (since 2019).

For the afternoon reading this month was on average was 4.4 percentage points higher than average and from eyeballing the daily chart above would have been even higher withough the drop in the last 2 days of the month.

Wind

With the new WS I no longer have a measure of 'run' (although I muight investigate ways of estimating that when time permits) so have used two measures of gusts as my indicator of daily windiness.

The monthly gust chart below is a little worrying as both months with the new WS appear well above average, suggeting the change is due to the new WS.  We shall see, but do not sell the farm (nor the boat) on the basis of this chart.

Solar

Only available for the last two months so all I will offer is a measure of total daily watts.

The 2 prominent peaks in this chart coincide exactly with days in which the measures of cloud cover cited on the BoM site (compiled at Gabo Island) were very low.  I shall work out a way of charting this in the near future.

Lightning

I again use data from a friend's WS reporting to the Tempest Network which gives the number of strikes estimated within 40 km of the Mallacoota Wharf.  It is graphed below using a logarithmic scale to accomodate the very large number of strikes in February 2025.  265 (= log 2.42) strikes were recorded in May 2026, a relatively high number for May.  

Weather of 7 May 2026

The Indian Summer which began the month has definitely finished.  I won't be lighting a fire today - the house is still warm inside - but it is definitely more like Winter than Summer.  Here is the BoM radar image about 1410 hrs.

It has also been a bit noisy with lightning strikes shown on this image.  White circles are very recent, red crosses are the oldest.

An image from the Ecowitt software on my Weather Station.  The lowest temperature (so far, as at 1418hrs) has been 5.7^o C with a maximum of 11.7^o C.

I don't think the water heater nor solar panels are helping much at present!

Total rain is now, 1424 hrs, 10.6mm, which will be doing some good.

I have just seen a post from BoM mentioning snow at reasonably low locations, of which the closest to Mallacoota was Bombala where the War Memorial in the centre of town is at 704m AMSL.

Insects on Camellias and other garden plants

 Frances alerted me to there being interesting insects on our full-flowering Camellia.  Of course this included a good number of European Honeybees.

But as Frances advised there were other species.  The first was what iNaturalist has suggested to be  Leptomyrmex erythrocephalus, the Red-headed Spider Ant.  It has a red head and looks like both a spider and an ant!

The third species was (again suggested by iNaturalist) Polistes humilis, Australian Paper Wasp.  I picked it as a wasp of some form, from the narrow waist.

Let us see how other experts go on confirming (or otherwise) these names.  There were other insects around - my first guess is Hoverflies - but they were not cooperative in posing.  I shall try again.

I failed again on the Hoverflies but a nearby Daisy attracted a small bee for which Genus Exoneura (Reed Bees) was suggested.

The next one wasn't on a plant but one of our sliding doors after dark.  It fell off the door and vanished before I could get a dorsal image.  iNaturalist has suggested Paracaedicia serrata (Serrated Bush Katydid) as the ID.

4 snaps from the Poo pits

Here is the full birdlist from the visit: https://ebird.org/checklist/S317102888

A new species for me (and possibly to science) the Kangaroo Egret (Egretta pachyderma(?))!

An obliging Restless Flycatcher,

Scarlet Robin is in town, courtesy of Crap Bird Photography).

Acacia terminalis marks the change of season.

Mallacoota Weather Report March 2026

 A major event was a huge storm over March 27-28.  Mallacoota and Gabo get a mention in this post (I think on Facebook) from BoM:

28 March 2026  Bureau of Meteorology 

A low pressure system sitting off the south-east coast of NSW yesterday brought damaging winds and large surf to south-east New South Wales and eastern Victoria.

Some of the strongest recorded wind gusts include  

•      118 km/h at Green Cape NSW and Mallacoota, Vic 
•         ...
•         113 km/h at Thredbo NSW and Gabo Island, Vic 

I have put some images in another blogpost but here is the view at the height of the storm on the 27th.

Technology

A general comment is that after about 15 years my Davis Weather Station appears to have reached its use by date.  The rain collector seems to have stopped working and in discussion with a person at Instrument Choice (from whom I bought it) the situation seems to be that it is a motherboard problem.  He noted that:

• The expected life of a system is 5 - 10 years (so I am well in front); and 
• Typically when one component fails the others do in short order (which I had noticed with a cheaper station before I got the Davis).

So I have acquired a rather cheaper replacement, in the expectation that we will probably be moving full time to Melbourne within a relatively brief time. The new device is an Ecowitt IC3900 costing less than half a new Davis Vantage Vue.  It will also connect to the Wunderground network so I can access data while we are in Melbourne under the current arrangement.  I intend to connect the new device sometime in the last 2 days of March.

This may mean that some of the data is on one system and other bits are on the new system but it all comes through Excel spreadsheets so shouldn't matter too much.  Rainfall stopped happening around 8 March so data for the rest of the month comes from BoM until we returned on 25 March and then from my Nylex.

In the event it came to happen that 2nd April was installation day.  It only took 3 hours including a few phone calls to Instrument Choice where Bang Hoang was very patient and knowledgeable and one to Aussie Broadband who were very helpful.  Here is the story.

Rainfall

I shall not include detail here due to the mixed nature of the records described above.

Total rainfall at Angophora Drive for March is estimated as 136.9mm somewhat more than was recorded by BoM at the Airport site (127.6mm) or on Gabo Island(105.6mm).  However my estimate for the big storm event (106mm) is comparable with totals collected by other residents in the town area.  This suggests an orographic component to the falls.  

My prorata estimate for the annual fall at 1432 mm is above the estimates at the end of March for the previous two years.

Temperatures

At the end of the month the temperature anomaly was 0.36.  The range of values of the anomaly over the month was very low.

As would be expected from the values of the anomaly the daily extremes are mainly close to the averages for the day.

In summary the temperatures for the month were pretty normal for the month.  Certainly the begetation growth around the garden has been very strong

Minimum temperatures

The lowest minimum for the month was 7.9^o C on the 14th.  Overall the average minimum was 15.68^o C a little above long term mean but about the middle of the pack for recent years.

Maximum Temperatures

The highest maximum was 32.5^o C on the 11th. Overall the average maximum was 24.05^o C, again a little above long term mean but about the middle of the pack for recent years.

Humidity

A rather muggy month.  The chart of daily relative humidity for the standard times of 0900 hrs and 1500 hrs is somewhat interesting.  Several of the afternoon reading are 96% which is very high for that time (they are higher than the morning reading  for the same day) and hardly any of the afternoon readings are less than 50%.

The average reading for both times are about 5% above average and second only to March 2022 of the years since 2019.  Plotting the values of rH against rainfall is somewhat dodgy in view of the estimated nature of the rain data, but here is a scatterplot.

The rain tended to occur on days with higher 1500 rH, but some very humid days had no rain!  I looked at the BoM data (which was on a more consistent basis) and it showed a somewhat similarly confused situation.

Wind

There were a few windy periods recorded but the main value of this chart is to show how sheltered my WS site is for wind from the South.  

The longest run recorded was on the 24th, not the 27th, and came in at 226km.  This the 15th highest (out of 248) record for a March day.

Tempest Data

These data come from a friend's WS located near the wharf, and connected to the Tempest system.

Lightning

The number of strikes in the system includes data from a range of sources, covering a 40km radius from the actual WS site.  It would have included a lot of these strikes (recorded on 25 March) which lit up this area but did not lead to any strikes close to Mallacoota (nor any fires).

The number of strikes in the 40km radius for each month are shown in this chart.

While this compares 2026 with an average. Note that I have excluded February 2025 from the average as it included 6,941 strikes which is a definite outlier.

Solar radiation

A very seasonal series.  The moving average -brown removes the seasonal influence giving an almost flatline.  [Note for the future: As my new WS includes a facility to measure radiation I will be including that in future reports.]

 

Storm Snaps 260327

These are some photos from a short drive around from Betka to Mullet Creek.  The first image was taken as 1327 on 27 March.  The sea at Betka was rather rough and running over the sandbank: however the bank held until at least the next day.

Much material on Betka road.

At Bastion Point the area beyond the breakwater was covered in foam, but this was simply the results of the wild sea not an algal bloom.

A wild sea!

All the work last year seems to have done a job of protecting the breakwater from the swells by getting the break further out..

In the recent past this would have smashed into the face of the breakwater rather than having broken some metres earlier.  Lets see if the wall survived.

Much white water towards the Mouth.

Lots of vegetation down.  (Power was out from 1136 on 27th until 1426 on 28th.)m These images are on Lakeside Drive.

Angophora Drive.

The weather was stirring up the fruit bats at Mullet Creek.  (They flew out well on 28th.)

The marsh near Fisheries Jetty had very little water visible early on the 27th.  By midday on the 28 the combination of 100mm of rain and a Southerly driving water through the Mouth had got the water level up again.