Friday, 1 March 2013

A summary of February 2013 Weather

After the unpleasant heat of January 2013, February was somewhat more temperate (but could still be considered Summer).  By my records the average temperature for February was 18.62C  a decrease of about 3 degrees from the 21.78C recorded in January.

This chart shows the daily maxima and minima.
In terms of maximum temperature we exceeded 30C on 7 days and couldn't struggle past 20C on 4.  In terms of overnight comfort 4 days failed to drop below 15C while 6 required a blanket when it dipped below 10C.

Rainfall was also more moderate for the month with 56.7mm recorded for the month, falling on 11 days (although 3 of those days had minimal records of 0.3mm - possibly a very heavy dew!).  As shown in the following chart most of this fell towards the end of the month.

Using my old gauge  I recorded 198mm over 16 days in 2012.
(To emphasise the sogginess of this part of 2012 we recorded a further 84mm on 1 March.)

The wind continues to come mainly from the East - South West segment of the compass.
As I have noted before this preference for Easterly winds is against received wisdom, which says that the prevailing wind direction is from the NW.  For this month I checked my findings against information available from the BoM site for Canberra.  This gives the wind direction at 9am and 3pm (while my records give every hour).

An initial scatter plot of the 16 major directions does not show a high level of correlation between the two series.  However inspecting the data reveals that the distribution of observations between the three adjacent categories ENE, E and ESE was rather different while the three categories as a group provided a very similar proportion of observations.  A similar situation applied to the group SSW, SW and WSW.  Combing these two clusters to a single group gives the scatterplot below.
I consider that this shows the two series are telling pretty much the same story, allowing for diferences in::
  • recording frequency
  • the position of the sites; and
  • equipment being used.
Saying something sensible about humidity proved a little more "interesting" since I started off in the wrong way, by looking at maximum daily humidity.  As most days in Februarygot well above 90% at some point this was not informative.  However, plotting maximum and minimum RH seemed to provoke a few thoughts.
February is clearly a moister month than January, reflecting the weather patterns being driven more by what was passing down the coast, rather than a high pressure system squatting in the middle of the country.  I need to think a bit more about this.

2 comments:

Ian Fraser said...

18.6 degrees?! Call THAT a summer?! Barely pleasant... signed Grumpy of Duffy.

Flabmeister said...

Dear Grumpy of Duffy

You are obviously hankering for the delights of Adelaide with overnight minima in the high 20s or worse! At those temperatures it is hard to enjoy red wine!

I shall explore the BoM site to find out ab bit of history about average Summer temperatures.

Best wishes to Snow White (and watch the apples - there are worse things than codling moth)!

Sneezy of Carwoola