Tuesday, 3 March 2015

February Weather Report

That is not really a click-bait title but at least it does indicate what the post is about.  Having had a month's experience I shall try to mix in the comparative material with the current month commentary.  I have also added in more information from old records so any multi-year averages are likely to be rather different to the examples I published last month.

Rain

A pretty dry month, especially for February which is usually one of the wetter months.
The total of 38.6 mm  represents 4 days with >5mm of which only 1 got over 10mm.  This reflects few thunderstorms getting through to this area (although one of them was kind enough to nuke our friends modem {and set fire to a tree across the road from them}).

Temperature

The main presenter on ABC TV News burbled about not having had a Summer as it had been mild.  We didn't have any days >35oC but exceeded 30oC on 4 occasions so I reckon that is OK as a Summer goes.
My average includes 2 years for some months, 1 for others and 3 for the two months of 2015, so isn't really representative but I think gives a starting point for thought.  The graph does show that February was a touch cooler than January, and this year somewhat below the 3 year average (so Ms Hausegger's burbles are not completely off the planet).
For minimum temperatures February was little different to January.  As average minima for both months were higher than the 3 year average this supports my feeling that the month was in fact reasonably warm: my view of warmth in Summer is largely driven by how little it cools overnight!

Humidity

It has been suggested that in Summer 40% is a reasonable value for Relative Humidity at 1500hrs (or 3pm for readers in old-fashioned countries).  That being the case, the word "Muggy" might summarise February 2015.
Both January and February were more humid than the average of the 3 previous years (although only marginally so for February)
This February was much more humid than 2014.  There are only 7 days (25%) in which 2014 was more humid than 2015.

Wind

I had no recollection of strong winds for most of February.  Indeed after dark it seemed very still, adding to the mugginess.  That seems to be supported by the data for the month.
The average situation is, always seems to be the case with matters relating to wind, a little complicated.   It appears that the readings from my older (non-Davis) weather station are not comparable with the Davis readings.  Since the Davis readings are themselves only indicative (as a result of where I have placed the station, not the equipment) I have not included the readings for early 2013.  This graph shows the current state of play, which does seem to show February 2015 as a relatively still month.
In that case I have taken the simplest approach of the average gust in each 30 minute period through the day.  An alternate approach would be to extract the maximum gust each day and then average them.
Again as always seems to be the case with aeolian matters, while the absolute numbers are a bit different there is really no difference in pattern between the two approaches.  It is sensible therefore to take the simple monthly average since it involves less work (which apart from anything else reduces the chance of a subsequent cock-up).

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