October 2018 weather report

Here is the updated (the maximum on 31/10 continued to rise) Gazette format report.
In summary the month was pretty close to average for temperatures - with somewhat high minima - humidity and wind gust.  Of course it continued appallingly dry.

Rainfall

At the risk of stating the obvious, it has continued very dry.  Despite a few damp forecasts we only got significant rain on one day.  Well below average and last year.
The drought has now been running for 22 months.  Looking at the total period for which there are Carwoola records shows clearly how this event (green box) is now considerably worse than the millenial drought (red ellipse).
 Focusing on the period since 2011 shows that there has been a quite significant linear trend (dashed line) in the data, while putting in a 4th order polynomial trend (heavy red line) shows how the descent has accelerated in the last 2 years.
The one day of rain on the 20th featured a very heavy storm in the morning.  This included a spell with my weather station recording a rate of 180mm per hour, which is the third highest rate I have recorded.  This got the Creek flowing ...
... but only for a couple of days.

Temperatures

I'll get to the detail below, but this chart, comparing daily maxima and minima for this year and earlier years  ...
.... suggest that temperatures were quite reasonable during the month.

Maximum temperatures

The average maximum temperature for the month was very close to average and somewhat below last year.

The highest maximum recorded was 30.8 on the 31st of the month.  Looking at past years it is normal to have 1 or 2 days over 30oC in October.

Minimum temperatures

With a burst of very high minima mid-month and no real cold snaps it is not surprising that the average minimum was quite high compared to the ling term (ie since 2010) average, and a tad higher than last year..
We had no hard frosts (minimum below 0oC) while the average is 2.5 hard frosts and only 2 total frosts (minimum below 2oC) compared to the average of  ~7 frosts.

Average temperatures

The average temperature for October was the same (to 2 decimal places) as the average since 2013 and just a little above zero when compared to the average since 2010.  This is illustrated in this depiction of the temperature anomaly.

Humidity

I now plot two time specific humidities for 9 am and 3pm.  For October this shows how later in the month the afternoon is much drier than mid-morning.  The notable exception is - not surprisingly - the 20th with storms.
 The 0900 values average out to a little lower than the average of the past 5 years
 The 1500 hours values are surprisingly a little higher than average, probably reflectin higher values early in the month.

Wind

Subject to the vagaries of my site the average gust through the month was very close to average.


Comments

Popular posts from this blog

Insects from pine trees

A tour of the West (part 1)

Maslins beach rules