Weather report February 2019

In a past life I composed a monthly weather report for the Carwoola community.  This was based on recordings from my Davis Vantage Vue weather station.  I intend to do the same at Mallacoota, having fired up the Davis on 13 February.

For this month, as I only have 50% of the month covered by my station, much of what follows will be data I have downloaded from the BoM site.  I have included some comparative data for my site as some form of quality assurance.

The process of setting up my station and an initial comparison with BoM is included in this post.  In case folk are wondering, I have not got a 'net enabled Station: the original extra cost was a dissuasion as was the dodginess of my internet connection in Carwoola!

Summary

As far as I can tell, on limited data, it was a fairly normal February.  Rainfall was on average, maxima were a tad high  and minima were a little low.  

Rainfall

My first chart compares this year with last year and the average x month back to 1985.  BoM have some data going back to 1974, but some years have several months missing.  A 30 year series is probably long enough to give a broad picture!

 We are about on average for February after a rather dry January.

The next chart shows the annual totals from 2018 back to 1985.  Although 2018 was below average, at 757mm it is not far out of line compared with data in the period 1993 to 2010.

 Looking at falls to the end of February and expanding that pro-rata to estimate the annual total (a dodgy process at this stage of the year) we end with an estimate of  close to 800mm for this year.

Temperatures

Maximum temperatures

Again looking at this month compared with last year and the average (from 1994 onwards) the month was a little cooler than 2017, but average daily maximum was a little higher than the average.

 The next chart compares my Davis with the BoM site.  Obviously very close agreement in both values and pattern (correlation coefficient 0.96) .

Minimum Temperatures

January had high minima but for February they were well below both 2018 and 2016.

The comparison of my Davis with the BoM site is interesting in that the pattern is very similar (correlation coefficient (again) 0.96) but the actual values are fairly closely based around 1^oC higher at home than for the BoM site on the coast.  I attribute this to the Davis being sheltered from a cooling sea breeze overnight.

Wind

The BoM doesn't seem to do much about publishing data on wind and it is a cramp downloading it a month at a time.  I might explore a little more and try to get some back data for later,  In the meantime here is the comparison of my data with the BoM stuff I have got.

As might be expected from a site right on the coast with the anemometer on a 10m pole the BoM gets more wind than we do at home in a site sheltered  from the south and a 1.8m pole!

I think my site is good enough to say if a month is windy or not windy, but probably not too good  for intensive analysis.

I have now downloaded 13 months of BoM data and have a graph of average daily gust by month.

With such a limited set of data its dangerous to make big calls but there doesn't look to be any obvious seasonal pattern there and the variability (ie relative standard deviation) is quite low at ~6%

Humidity

Again it is time consuming to download the BoM data.  I'll try to build up a series before the end of March.  Been there, done that, for the 2 standard series about humidity at 9M and 3PM (1500 hrs) over the last 13 months.

June 2018 was a very wet month, seeming to have rained just about every day.  The values for other months are in a quite tight band and Relative Standard Deviation is pretty low at ~8%, even including the June value.

Here are the series for February 2018.  There is much less difference between the two readings than used to be the case in Carwoola

Comparing those series with mine, I am surprised that my site is more humid early in the day.  Possibly this is some effect of the overnight sea breeze?  The afternoon readings are very similar  in level and pattern.