Dangerous storm hits Sydney's Eastern Suburbs

Today was one of those days I wish I was in Sydney. It was a nice, warm day that topped 30.7C at the Airport and it ended with a spectacular and menacing looking storm.

A low pressure trough moved north-east across New South Wales today generating showers and storm activity throughout the state. Warm northerly winds took the temperature up in Sydney during the middle of the day, but around 4:30pm a southerly change preceded an intense storm.

As a storm cell developed south west of the Airport, the Bureau issued a Severe Thunderstorm Warning for suburbs surrounding Sydney Airport warning of lightning strikes, heavy rain and potential flash flooding. The screenshot below is of the Sydney rain radar image at 4:36pm.

Terry Hills 128km rain radar image at 4:36pm AEST on March 5 2014
Source: Bureau of Meteorology (screenshot unedited from original image)

To get an idea of what the storm looked like, check out the photos in this Daily Telegraph gallery.

Sydney Airport received 13.0mm in the hour between 4:30pm and 5:30pm and experienced wind gusts up to 59km/h, the strongest since February 10. Only 1.6mm fell at Observatory Hill as the Eastern Suburbs were the worst affected. Aircraft enroute to Sydney were also kept in a holding pattern until the storm moved on.

There may be more shower and storm activity for Sydney early tomorrow morning.

February 2014 Review - Jyväskylä

Jyväskylä experienced one of the warmest Februaries on record in 2014. Temperatures throughout Finland were well above average for pretty much the whole month. This article released by the Finnish Meteorological Institute states that southern and central parts of the country were 6-8C warmer than normal, while some places in the north were even 9C above average. Rainfall was fairly average, but because of such high temperatures, snow depths were some of the lowest on record.

The graph below shows February averages at Jyväskylä Airport during the last 6 years.

February averages at Jyväskylä Airport for the period 2009-2014

February 2014 was easily the warmest of the last 6 years. In fact, Jyväskylä saw its second warmest February since at least 1961. The average temperature of -1.4C was 7.1C higher than the 1981-2010 figure of -8.5C. Only 1990 had a higher average temperature.

The warmest temperature of the month of 5.8C came on February 24. That was the earliest date for such a high temperature in the past 6 years. The warmest minimum of 3.1C, also recorded on the 24th, was the highest figure of the past 6 years as well.

Cold days were rare. February 1 was responsible for both the lowest monthly temperature and the lowest daily maximum, -10.6C and -6.8C respectively. And as I mentioned previously, that was coming off the back of the 3 week cold snap in January.

The dates above were also responsible the highest and lowest monthly temperature at a national level. The highest temperature was recorded in Pori on February 24 when it reached 8.1C. The lowest monthly temperature was -37.5C, recorded at Kiutaköngäs, north of Kuusamo, on February 1.

There were 2 key observations during the month that really stand out. One was the lack of days below -10C, and the other was the number of days above zero. The graph below highlights this.

Number of  February days below -10C and above 0C for the period 2009-2014

Precipitation was slightly below average for the month. I made a plan at the beginning of the year to start recording daily precipitation for both Sydney and Jyväskylä, but there appeared to be some problem with the equipment at Jyväskylä Airport and the measurements via the FMI website were unavailable for most of the month.

Looking at the FMI records though, 25mm was recorded. That is compared to 22mm last year and the 1981-2010 average of 32mm. Due to the warm temperatures seen throughout this winter snow depths have been unusually low. On February 15 the depth was only 12cm, well below last year's 49cm and the average of 42cm. By the end of the month, most paths were clear of snow and were even dry.

February 2014 Review - Sydney

Temperatures in Sydney for February were slightly above average for 2014. It was slightly warmer than both 2012 and 2013, but cooler than 2010 and 2011. It was a little dry though with Sydney Airport recording just under half the long term average. Despite being rather dry, the average daily sunshine of 6.5 hours was below the long term average of 7.1.

The graph below shows February averages at Sydney Airport during the last 6 years.

February averages at Sydney Airport for the period 2009-2014 plus the long term average

Both the average minimum and maximum were the third highest since 2009. Like the previous 5 years, February 2014's averages were also above the long term figures of 19.0C and 26.4C.

February's warmest day was the 26th when it got to 34.9C, one of only 3 days of the month above 30C. The highest minimum of 22.3C came on February 12. This was the lowest of the past 6 years. The lowest monthly temperature of 15.9C, the second lowest of the past 6 years, was recorded on the 7th. The last day of the month was responsible for the coolest daily maximum of only 21.9C.

Sydney Airport saw a monthly rainfall total of 56.0mm, just under half the long term average of 113.3mm. It was the third driest February out of the last 10. Observatory Hill recorded 61.0mm, just over half the long term average of 118.3mm. The graph below shows the daily rainfall totals for the month.

Daily rainfall totals during February 2014

There were 11 days on which rain was recorded at the Airport. The wettest day was February 19 when a total of 23.2mm fell. That was due to a large storm that affected Sydney and surrounding regions late in the afternoon.

Only 3 days of the month recorded wind gusts over 60km/h. The 76km/h south-southwesterly gust on February 10 was the strongest of the month. This is the strongest of the year so far, but was below February 2013's strongest of 91km/h. Both February 14 and 18 recorded the weakest daily gust of 31km/h.

Dry in Jyväskylä, wet in Sydney

Dry weather has continued in Jyväskylä during the last few days. Temperatures haven't been quite as high as early last week, but March has still seen an above average start to the month. The sun was out for most of yesterday as it reached 2.8C.

I said more than a week ago that the ice thickness has been decreasing, but as I found out yesterday, the ice on Jyväskylä's Jyväsjärvi is still thick enough to walk on.

Ice on Jyväsjärvi on March 1

Testing out the ice

Interesting patterns from old footprints

In Sydney it has been a wet weekend. Sydney Airport saw one of the lowest 3 day totals in the Sydney region. Since Friday 12.6mm has fallen there. Elsewhere in Sydney, Observatory Hill has seen 21.6mm since Friday while Bankstown Airport and Penrith saw greater 3 day totals of 39.6mm and 35.4mm respectively.

On the Central Coast north of Sydney there was flash flooding in localities around Lake Macquarie on Friday morning. The weather station at Cooranbong just west of the Pacific Motorway recorded a staggering 222.2mm throughout the day; 206.2mm of that fell in the 9 hours between midnight and 9am.

Evening storm ends hot day in Sydney

Sydney saw its second warmest day of the year today. The measurement of 34.9C at Sydney Airport at 2:29pm was 5C above the predicted top of 30C. That was the highest temperature recorded among Sydney's weather stations. Observatory Hill got to 32.4C.

The forecast was right on at least one count though. As a low pressure tough moved east across New South Wales during the afternoon, shower and storm activity increased west and south west of the city from Orange to Cooma. A thunderstorm warning was issued by the Bureau for those areas, but was later cancelled after 6pm.

In the Sydney region, Campbelltown was the first to receive rain. 14.0mm fell between 3:30pm and 4pm. A storm cell passed through Richmond in Sydney's north west just after 7pm with brief bursts of strong winds. One gust was recorded at 70km/h, the strongest there since December 5 last year.

Further showers with thunder and lightning affected locations throughout the rest of Sydney from 6pm. Sydney Airport first recorded rain just before 7pm. By midnight a total of 6.0mm had fallen there taking the monthly total to 54.0mm. Observatory Hill received 4.4mm taking its total to 55.8mm.

An early spring for Finland?

Well it certainly seems like spring is just around the corner as the remarkable warmth of this February continues in Finland.

Yesterday saw temperatures above 5C in Jyväskylä for the first time this year. Another observation that is probably even more astounding is the fact that yesterday's daily minimum was 3.1C; a minimum that high doesn't usually occur for the first time until mid-April. As the table below shows, of the past 6 years yesterday was easily the earliest date for such high temperatures.

The Finnish Meteorological Institute reported yesterday that many places throughout Finland are seeing their second warmest February on record, with only 1990's edition topping this year. The warmest location in Finland yesterday was Pori on the west coast where it reached 8.1C. It went as high as 5.8C at Jyväskylä Airport. As mentioned above this was the first time above 5C this year. It was also the warmest temperature since December 17 last year.

Today has also seen warm temperatures reaching as high as 3.6C. The sun made an appearance during the day too as the sight of snow becomes rarer.

The hint of spring will be in the air for at least the next week. The coming days will still see above average temperatures, although not quite as high as yesterday and today. Temperatures for the next few nights should also dip to minus, although anything below -5C would be surprising.

Mild weekend

Temperatures climbed back above zero in Jyväskylä early yesterday morning. That was after several centimetres of snow fell on Friday evening and into the early hours of Saturday. The top of 2.1C at Jyväskylä Airport yesterday was the warmest temperature for February so far and the warmest since January 9. Today might also see 2C or warmer; it is currently 1.8C.

Tomorrow is likely to set the highest maximum of the month again though. Earlier forecasts had predicted it to be as warm as 5C, although currently the forecast is for 4C. Tuesday should also reach around 3C. Most of the snow on the streets in the city centre of Jyväskylä has melted away and whatever is left won't be there for much longer in these conditions.

The weekend has also seen cooler, but still comfortable weather in Sydney. It didn't top 25C at Sydney Airport yesterday or today; 24.3C and 24.4C were the daily maximums. So far only 2 other days this month were cooler than yesterday. There was a brief shower earlier this morning and 0.4mm was recorded, but otherwise there hasn't been any siginificant rain. Moderate southerly winds have helped to keep temperatures down though.

Forecasts for Sydney show warmer temperatures in the next few days. There still aren't any 30C+ days on the horizon though - something that has been slightly lacking this February. There might be a few showers around throughout the week as well.