Weather Report December 2019

In summary hot and dry.  What follows is nearly all based on BoM data as I haven't had access to my WS since 30 December, when we left for Canberra.

Rainfall

By the time we left my WS had recorded 3.4 mm for the month, which was the total.  While this is a little less than the BoM total (11.2 mm the second lowest for the month since 1975) the reading for Gabo Island was 6.6 mm and I overheard someone in town saying they had only recorded 1.8 mm for the month.  Using BoM data for every month here is the sorry picture for the year.

Looking at annual totals the BoM result for 2019 (595.2 mm) is the lowest on record since 1975.  The previous low (in 1980) was 675 mm.  Taking BoM data for January (before we arrived) my estimate for Ango[hora Dr was 536 mm. 

Temperatures

A first overall comment is that the BoM have not given a maximum temperature for 30 December.  I initially thought that was because their station recorded - in the hourly records  -  a maximum of 49.1^oC at 0800 hrs as the fire front came through. However the fire came through on the 31st - but as it was before 0900 it got "counted" for the 30th: complete rubbish. For the 30th I have used an estimated maximum for that day of  26.9^oC which is the value at 0835 on the 31st.  This is possibly an understatement but I can no longer access the hourly records for the 30th. For most of the 31st the site offered 16 - 19^oC, probably due to the heavy smoke cover and the SW wind.

.The overall view of the temperature is given by the anomaly, which is the difference between the current and long term mean temperatures.  For December 2019 that ended up at +2.41^oC.  The month began cool but then steadily heated up.

A second overall approach is to look at the daily extremes.

Maximum temperatures

Overall the average daily maximum was well above both long term average and 2018.

The maximum temperature was above average on 25 of 31 days!

Minimum temperatures

Surprisingly the mean minimum was below average, I think reflecting the cool mornings from the 1st to the 3rd.

The minimum was above average - sometimes less than 1^oC - on 20 days.

Humidity

Referring only to the BoM data the most surprising fact is how closely the 2 series mirror each other.

 The average for 0900 was 61.4% well down on last year and the average

Wind

The BoM data for Mallacoota includes a maximum gust of 100 kph on 31 December.  I suspect that is fire-related anomaly.  I can't really work out which of the BoM are reliable or what they mean in the absence of my WS data so will say no more.