Warm temperatures and strong winds in Sydney

Sydney experienced another very warm September day yesterday. It was the second warmest day of the month so far with a maximum of 32.9C being recorded at the Airport in the late morning. That was also the 5th day of the month above 30C, easily the highest number of instances for September in the last 5 years and there are still a couple of days left. Temperatures then dipped a few degrees between 11:30am and midday as strong west-northwesterly winds pushed through the city.

 

A windsock at Sydney Airport during the afternoon of September 26

 

Strong gale force winds with gusts up to 87km/h were recorded at the airport. In addition to weather observations I enjoy plane spotting also, so I made a visit to the airport to watch aircraft land on the east-west runway. Quite a few appeared to have rough landings, and I saw two aircraft within 90min that aborted at the last moment due to sudden wind gusts. Temperatures continued to decline throughout the afternoon and the winds only began to ease afer 7pm.

 

It has been a much cooler day in Sydney today with the temperature only topping 21.7C at the Airport. Temperatures should climb again tomorrow though with strong westerly winds forecast again also.



Did it snow in Jyväskylä yesterday?

So after a rather warm start to September, the temperature has dropped and there were even (Facebook) reports yesterday of snow in Jyväskylä. Someone even said it was hail. Further investigation reveals it was more likely a mixture of sleet and/or ice pellets, or räntä, as the Finns call it.

Being in Sydney unfortunately I wasn't able to get any photos myself, but a few decent shots can be found in this article on the website of local media source Keskisuomalainen. Sorry it's in Finnish for those who don't speak it, but I'm linking it purely for the images. Credit goes to the original photographer of course.

I got word that while there was 'snow' in the air, not a lot was settling on the ground. That would make sense seeing as the temperature only reached as low as 1.1C yesterday morning, the time when the precipitation fell. Temperatures pushed to just over 5C later in the day.

This is quite a drop in temperatures given that it was hovering around 15C less than a week ago. I'm also curious how many times, if ever, there has been the first observations of sleet after summer before the temperature has dropped below zero. Jyväskylä is still waiting for that sub-zero recording. Yesterday's low of 0.9C observed later in the evening was the lowest daily minimum since May 16.

As I write this it's only 3.15am in Finland and the temperature is currently at 1.0C in Jyväskylä. Forecasts show a brief period of clear skies and temperatures of 0C for 6am, so let's see if it finally drops below 0C. Possible wet snow followed by rain is forecast for the rest of the day with a maximum of only 5C later in the evening.

And I'm just throwing this in here, but meanwhile in Sydney, it's currently 31C at 10.20am...

How my personal Sydney records differ from official records

For someone who would ever analyse my records and compare them against the official records taken by the Bureau of Meteorology (BoM) they would find a few differences.

As mentioned in an earlier post I have been taking temperature records since 2009. The recordings I make are based on those shown on the BoM's public webpages. The webpages also show wind speeds and directions, rainfall, humidity levels, apparent temperatures etc., although I do not use those personally. I like to take note of any unusual readings such as high wind gusts or high levels of rain, but I don't actually take any daily recordings for these.

When it comes to recording daily extremes, BoM uses monthly 'blocks', which makes perfect sense, and they create a table of the extremes for each month. Daily measurements at 9am and 3pm are also recorded in this table. The table for February 2013 at Sydney Airport can be seen here.

According to this page of definitions the minimums shown are based on the minimum temperature recorded in the 24 hours to 9am, while the maximums are based on the maximum temperature recorded in the 24 hours from 9am. While this is the standard for BoM, I haven't been able to find any particular reason why it is this way. Rainfall measurements are also taken from the 24hr period prior to 9am. (If anyone has an answer for why this is, please let me know! :))

My recordings follow a more simple idea of the minimums and maximums for a calendar day. That is the 24hrs from midnight to midnight.

An example of a difference can be seen from the first 2 days of February 2013. BoM's records state the minimum and maximum for February 1 were 21.1C and 21.8C, while February 2's recordings were 14.4C and 19.9C. This is compared to my own records of 17.9C to 24.2C and 14.4C to 19.9C. So while February 2 is the same, there is quite a big difference between the February 1 recordings.

I know that BoM have given definitions for the recordings as mentioned above and that's fair enough, but I just don't understand why it is done like this. Based on that definition it is possible for a temperature recorded at 9:01am on January 31 to be the minimum temperature for February 1. Conversely, a temperature recorded at 8.59am on February 1 could be the maximum temperature for January 31. Compare that to the maximum recorded wind gusts which are actually done on a 24hr midnight to midnight basis.

I'm actually really curious to what others think about this. Or well, maybe they don't think about it, but the point of highlighting this is to show why I use the measurements from the 24hrs from midnight to midnight. At least then the temperatures recorded were actually done so on the date in question.

Showers roll through parts of Sydney during the afternoon of September 20

Yesterday afternoon saw showers roll through parts of Sydney, despite forecasts not predicting any rain. While no rainfall recording was made at the Airport there were definitely a few drops in the air.

I headed out to La Perouse in the city's south east to monitor the progress of the shower activity and took a few shots.


A block of showers heading out to sea over Kurnell



Looking west over Botany Bay



Looking north over Frenchmans Bay

There were hardly any drops of rain at La Perouse but there was a strong westerly wind blowing. I almost lost my hat at one point. Sydney Airport recorded gusts up to 74km/h while the station at Kurnell had gusts of 83km/h, which was probably more indicative of the wind speed at La Perouse.

New highest minimum for September comes fairly late in Jyväskylä

So just after I mentioned in my previous post that the minimums for Jyväskylä were at their lowest on average for the past 5 years, there were minimum recordings of 11.9C and 12.5C for September 18 and 19. This was still a little unusual if we look at how late in to September we actually are for such high minimums.

September minimums at Jyväskylä Airport for years 2009-2013

From the graph it's clear that the high minimums of the past few days are a little unusual. Of course this is only comparing the previous 5 years so the sample size is quite small, but an observation nevertheless.

The forecast predicts another couple of 'warm' nights before dropping later in the week. There have been no signs of temperatures dropping below zero just yet though. Only in the far northern provinces of Utsjoki and Inari were minimums below 5C recorded in the last couple of days. Again looking at the graph above, the latest date for the first sub-zero recording in the last 4 years was September 25. It looks like we're on track to push that date back for 2013.

Dry period comes to an end in Sydney, Jyväskylä clinging to warmth despite lower minimums

After 5 weeks of dry weather in Sydney, rain has fallen at last. The first amounts fell last Friday and continued during the weekend also with a total of 7.2mm being recorded across the 3 days. Yesterday Sydney saw much higher recordings with 54.2mm recorded at the airport, with a further 2.4mm recorded in the early hours of today.

That 54.2mm recording from yesterday was more than all the rain that had fallen since the start of July. After bushfires ravaged parts of western Sydney on the 10th during another exceptionally warm day, the rain is a welcome relief. The recorded maximum from last Tuesday of 33.6C surpassed the previous monthly high from a couple days earlier of 32.4C.

Along with the first drops of rain last Friday, the monthly's lowest maximum was also set with the temperature failing to go above 18.4C. The monthly minimum was also set on Friday at 9.4C.


On the other side of the world Jyväskylä is still clinging to warmer weather. Last Friday and Saturday were particularly warm days with 18.6C and 20.1C recorded respectively. I was told personally that the weather was awesome and sunny. The temperature dropped on Sunday though with a high of 16.6C.

While the maximums have been among the highest of the past 5 years for the start of September, the minimums are also lower on average. If we look at the first 16 days of September during the last 5 years we can see quite a large difference.

Jyväskylä	2009	2010	2011	2012	2013
Average Min.	7.1	6.2	9.2	6.2	5.5
Average Max.	17.4	14.8	16.2	14.2	18.0

Averages for the first 16 days of September for the period 2009-2013





It's not shown here but it's interesting to point out that while the 2013 average minimum is the lowest at 5.5C, the overall monthly minimum so far stands at 2.0C. Comparing to the previous 4 years, the overall monthly minimum at the same point in September was actually lower in 3 of those years with 0.5C recorded in 2009, -0.8C in 2010 and -0.4C in 2012. 2011's figure stood at 4.6C, which is represented in the higher average minimum for that year.

The highest minimum so far for September 2013 is also the lowest of the past 5 years at 9.1C compared to 13.5C, 11.6C, 12.6C and 10.8C for 2009 through to 2012. It's clear, not only from graphs of the recorded temperatures, but also by looking at these figures, that the minimum temperatures just aren't fluctuating as much this year compared to previous years.

I don't have any statistics on hours of sunshine for the past few years, but I wouldn't be surprised if this year's recordings were the highest. Warm sunny days, cool cloudless nights... Of course not every statistical observation means something in particular, but it can be interesting to point out abnormalities.

The Weather Stations - Jyväskylä

A small gap between this and my last post but let's have a look at Jyväskylä.

Jyväskylä is not a very big city with a population of just over 130,000. Most Finns tend to think of it as a student city thanks to the two large universities present. You will find Jyväskylä in Central Finland about 235km to the north of the Finnish capital Helsinki.

The main weather station for Jyväskylä is situated outside of the city centre. Jyväskylä airport in Tikkakoski, 16km north, is actually the site for weather observations.

 

 

On the Finnish Meteorology's forecast and observation page for Jyväskylä, a weather station at Joutsa a bit further to the south than shown on the map above, can also be selected. The recordings I follow are taken at the airport site.

 

Again there is a difference between recordings at the airport and those experienced in Jyväskylä's main city area. Sometimes in the winter recordings may drop to lower temperatures at the airport than the city. In the summer isolated storms and rain may cause temperatures to drop in the city while they stay high at the airport. In the end the differences are negligible as they may fluctuate either way due to various reasons.

 

The seasons are quite prominent in Jyväskylä, with a moderate and warm summer, short autumn and spring periods, and a typically Finnish winter period spanning several months. Jyväskylä represents a median between southern cities such as Helsinki and Turku and northern cities such as Rovaniemi and Sodankylä, especially in the winter.

 

Finland's record 2010 summer is responsible for Jyväskylä's all time maximum of 34.3C, which was recorded on July 29. While I'm working on finding the actual all time minimum for Jyväskylä, I have found statistics that state -38.5C is the lowest since 1966. This was recorded on two occasions; February 3 1966 and January 8 1987.

 

(Edit: So I received a reply from FMI regarding my records enquiry and while -38.5C is indeed the lowest minimum recorded, a maximum of 35.0C was actually recorded way back on July 9 1914!)

 

So quite different to Sydney if you're thinking only on meteorological terms, but that just makes it more interesting to me to compare the two!

Mixed weather in Sydney over the weekend, warm in Jyväskylä

So an up and down weekend in Sydney came to an end with cool southerly winds. The mercury reached 32.4C at Sydney Airport on Saturday afternoon. That is really quite warm, although not rare, for September. It was the warmest day for Sydney in over 5 months after the 34.9C recording on March 28.

Temperatures dropped quickly in the afternoon thanks to a cool southerly change which hit the Airport around 2.45pm. Temperatures dropped 10C in only 10 minutes.

Sunday saw a much cooler day with a maximum of only 19.5C recorded at the Airport. The minimum was a monthly high of 16.9C though. There was a hint of moisture in the air and there had been a threat of some brief showers but they held off. September 9 marks 1 month without rain in Sydney.

Meanwhile, in Jyväskylä the warm start to autumn continued. Temperatures were an above average 19.0C and 20.4C for Saturday and Sunday. That is compared to last year's 11.9C and 10.0C for the same dates. Forecasts appear to suggest the weather will cool down over the next week though. While it's still possible, I'd be surprised if the temperature went above 20C again this year.

Rain also stayed away in Jyväskylä. There has only been 1 day of rain in almost 3 weeks, a little unusual for Finland. Along with the cooler temperatures, increasing cloud is also predicted during the coming week though.

The Weather Stations - Sydney

So where does the data come from? What weather stations do I use and why?

As mentioned previously I hail from the city of Sydney, Australia. Sydney is a rather large city in terms of land area so there are several official weather stations throughout the region. These, along with all other weather stations in Australia, are run by the Australian Government's Bureau of Meteorology. Media outlets generally take information recorded by the weather station Sydney - Observatory Hill. However, for the purpose of my data I have always followed the recordings made by the weather station Sydney Airport. The main reason for this is that I do not live in the city and, living close to the airport, I've noticed that the observations taken at the airport are more indicative of those I experience myself.

The airport and observatory stations are approximately 10km apart. Observatory Hill is located quite close to the city centre at the southern end of the Sydney Harbour Bridge. Sydney Airport station is located on the western side of the Airport Tunnel, near the old airport observation tower. You can see the stations on the map below, with Observatory Hill the green marker in the north and Sydney Airport the marker in the south.

So we have different locations. Maybe you're wondering how different the observations might be? Well generally they are quite similar, as might be expected, but different weather conditions can be experienced at each location. Sydney Airport lies in a vulnerable position in the open with fewer natural and unnatural objects surrounding it compared to Observatory Hill. It could be said the station really experiences true weather.

Wind gusts tend to be stronger and temperatures tend to be higher with a northerly wind, but cooler with a southerly wind, in comparison to Observatory Hill. I've noticed that the Airport usually has higher average maximums than Observatory Hill, but lower minimums. Even if you look at the first 4 days of September averages at the Airport range from 12.1C to 23.9C whereas Observatory Hill ranges from 12.0C to 21.8C. Of course this is a small sample, but records show this is rather common.

In terms of all time records, Sydney Airport's records are also more extreme than Observatory Hill with a current all time record minimum of -0.1C and a maximum of 46.4C compared with 2.1C and 45.8C.

Hello and welcome to WeatherBout

Hello and welcome to WeatherBout!

The purpose of this blog is to highlight weather observations that have occurred in Australia and Finland. I'm an Australian currently living in Sydney, who has also lived in Finland for 5½ years, and I have been fascinated by weather and meteorology for the last 7 or 8 years. In 2009 I decided to start taking my own recordings. While I don't have any actual weather recording equipment myself (maybe in the future!), I access and monitor the publically available official records taken by Australia's Bureau of Meteorology and the Finnish Meteorological Institute to compare daily minimum and maximum temperatures between Sydney, Australia and Jyväskylä, Finland.

Obviously Australia and Finland have extremely different experiences when it comes to weather observations. While Australia is well known to be a rather warm country, it actually experiences a wide range of temperatures and there are various climatic conditions in different locations throughout the year. Finland, in comparison, shares a similar climate throughout most of the country and has those four distinct seasons we all know.

So why Sydney and Jyväskylä? How many people even know the city of Jyväskylä? We'll cover that later... but anyway, I grew up in Sydney, so that's easy enough. As for Jyväskylä, that story is slightly longer. To make it brief, I moved to Finland in 2007 and had the pleasure of studying in Jyväskylä and living there for 5yrs. And well, Sydney and Jyväskylä are totally different places, and I figured nobody else has probably ever compared the two, not only in general, but also in terms of weather observations.

So what will be on this blog? Well, I hope to able to share some interesting observations, not only for Sydney and Jyväskylä (although these two cities are the focus), but also for other locations in Australia and Finland. You can expect to see things like weather records, discussion about unusual weather events such as storms, cyclones and other weather related natural disasters, discussion about the recordings I've taken since 2009, and even smaller events like the first snow in Finland in Autumn (or even Summer as it has been known to occur) or that first day above 35C in Sydney after Winter. And because we all know pictures tell so much more than words, you'll find some weather related images as well. I'm sure as time progresses, I'll be able to go more in-depth in to the climates of both cities, and perhaps there'll be something to learn.

If anyone has absolutely any questions about my recordings, my interest in meteorology, or pretty much anything you have on your mind, just go ahead and send me a message. If you don't have any questions but you'd like to contribute some images or suggest something, I'm always open to that as well.

Thanks for taking the time to read this. I hope you stick around!