Updated weather report for February 2024

 We have been in Canberra since 26 February, and will be until 8 March, so I don't have weather station (WS)  data for the last 4 days of the month.  However it looks as though the BoM data will be quite adequate to plug the gap, at least in broad terms. That being said, this report will be a draft until we get back to Mallacoota and can incorporate the final WS material.  We are now back in Mallacoota and I will make updating comments (or 'no change') in red, as necessary.

In the past a climatologist has commented that for weather East Gippsland sometimes marches to its own drum.  That has been the case for the last year.  In mid 2023 our area experienced very dry conditions, typical of El Nino, but the BoM refused to call an El Nino event as that is defined by atmospheric and oceanographic indicators.  They did declare an El Nino in about October last year and we duly recorded abnormally high rainfall in November, December and January.  An emerging La Nina (wet) was suggested in February which has resulted - of course - in a return to a dry month!  Of course there are many other climatic indicators (vide http://www.bom.gov.au/climate/enso/ ) so treat 'fashionable' nicknames and acronyms, especially in lay media, with caution.

In summary a warm dry month.

Rainfall

No change needed

We totalled 22.6 mm for the month which is just below 50% of the median February fall.

We only recorded more than 5mm of rain on one day in February.  This has occurred in 6 previous Februarys, with the median number of days >5mm at 3.  So dry, but not off the scale.

Not surprisingly my pro rata estimate of the annual fall has continued the downward outcome evident in late January and is now below 1000mm.

Temperatures

The anomaly this month was +0.79C so above average no change.  There was a very warm spell early in the month followed by a cooler period and then a gradual warming.

Looking at the time series of anomaly values, the 12 month moving average (red line) continues the climb seen since December 2022.

The daily extreme temperatures through the month as usual resemble a cross section of a mountain range.  

The average maximum is a greater amount above the long term mean than is the average minimum.  It seems this is due to a few very high maxima (notably the 36.7C on the 13th) biasing the overall outcome.  This will be discussed in more detail below.  There are very small differences due to finalising the records, making no difference to the overall view.

Minimum temperatures

The average minimum temperature was 16.33C which was 0.58C above the long term mean and well above the value for 2023.  It was also 0.53C above the median minimum for February 2024 suggesting a slight bias by very high values. 

7 days had a minimum >1 SD above the long term mean minimum and only 3 days had a minimum >1 SD below the long term mean minimum.  None of these constituted long runs of extremes.

Maximum temperatures

The average maximum temperature was 26.02C which was 1.13C above the long term mean and a little above the value for 2023.  The median temperature was slightly higher as a result of the adjustments but was still 0.92C below the average minimum for February 2024 suggesting a stronger bias by very high values. 

The next chart shows monthly average maxima for financial years since 2019.  All these data are from my WS to avoid the issues of sea breezes affecting the maxima for earlier years.

Clearly 2023-24 is one of the warmer recent years.

7 days had a value>1 SD above the long term mean maximum but only 2 days had a maximum >1 SD below the long term mean maximum.  None of these constituted long runs of extremes and in 5 days the high maxima coincided with high minima.

Humidity

I suspect there is considerable differences between humidity at the BoM site and my WS, so for the sake of consistency this chart is all BoM data.  A fairly dry first half of the month and a moist second half.

Watch this space for more detail when I return to Mallacoota.

The average morning humidity was 3.1% points higher (79.9 vs 76.8) at my WS while the average afternoon reading was 4.6% points lower (66.4 vs 71.0).  There were some major differences to the daily readings most notably in the afternoon with differences of -23% on the 12th and -19% on the 22nd.  The overall pattern however was not too different.  Note that I have included the afternoon BoM data in this chart.

Wind

I know the wind readings are very different at the BoM site and my WS.  Also BoM doesn't publish - at no cost - wind run data.  So the next chart shows maximum daily gust at the BoM site.  (The BoM had no readings for 13th and 14th - probably due to lack of power - so those dates are estimated based on reports from Gabo Island.

I have now extracted the run data for my WS and show that below together with the BoM Gust data: note that they us (very) different scales.

Overall the pattern is quite similar apart from the days where either measure is an extreme.  The longest run (350km on 28 February) reflects a very windy day with the hourly runs between 12km and 19km for most of the day.  That was the 16th longest run of 1845 observations since my WS records began.