Weather Report November 2022

An interesting month of weather.  While most of the country (not counting the sandy bit in the middle and the West) has been suffering floods, Mallacoota has been quite and cool, with a little wind at times.

Rainfall

Our recent experience has been for above median falls.  However for November the total fall at my Weather Station (WS) only amounted to 43.6 mm which is 69% of the median fall.  It was also well below November 2021.

I have continued my pro-rata estimation of the annual fall which is currently standing at 1,350mm  If that is achieved (requiring 105 mm in December) it would be the 4th highest fall since records began in 1975.  (To beat the record - 1442 mm in 1985 - would require 203 mm in December: not impossible but unlikely.) This chart shows the development of the estimate through the year: in essence high falls and a high multiplier in the first quarter have declined gradully through the rest of the year

Rain fell on several days but not in great quantities, apart from the 17mm on the 1st.  The falls were also not very heavy with the peak rate of 70mm/hr not setting any records!

Temperatures

The development of the anomaly, using BoM data, through the month suggests a cool start, followed by a warm spell and ending with further cooling.  The anomaly for the month as a whole was -0.63C, quite a strong negative value, with both minimum and maximum averages negative.

The extremes from my WS show the same pattern.

I have also plotted the November extreme temperatures over the entire data set. 

A linear trend line fitted to both series gives an appearance of an upwards slope, but the value of R2 for both series is quite modest so it is not appropriate to claim an upwards trend.

Minimum temperatures

The average minimum temperature from my WS exactly matched the average of the series since 1993.  It was a little below the value for 2021.

Maximum temperatures

The average maximum was 20.93C, well below average but above the same variable for 2021.  

With Summer approaching a cliché of interest is that of a heat wave.  The BoM defines that as 3 or more days of temperatures significantly above average. I have calculated, for each month the average maximum and the Standard Deviation (SD) of that series.   For November the value of average +1SD is (20.94 + 4.35) = 25.29C.  No day in November 2022 exceeded that value.  (I have separately investigated the number of heat wave days per month in the past and will compile a post on that topic in the near future.)

Humidity

The humidity readings for the month were unremarkable, possibly with morning (0900) values a little  lower than expected.  While the afternoon (1500hrs) values were mostly well below the morning ones, there were few readings below 50%.

Wind

As suggested in the preamble it was quite a windy month, with the wind run a little above the 4 year average for my WS.

The daily runs were reasonably modest apart from the period around 10 November.  The run of 494 km on the 10th was the 4th longest I have recorded here.

It seemed likely that this was due to the passage of a front.  The next chart shows the hourly wind run gradually increasing through the 9th and 10th with a reasonably stable barometric pressure, until midday on the 10th.  Then the wind drops away quite quickly as the pressure drops.  Later on the 11th both measures look to have stabilised.