Sydney is a place that can see very strong wind gusts, especially during summer storms and as part of gusty southerly changes, but winds during the few days were exceptional in that the strength was maintained for almost 72 hours straight. Sydney Airport saw three consecutive days with a strongest gust between 89km/h and 96km/h.
The strongest gust came on Tuesday April 21 when it peaked at 96km/h at 7:51am. The 21st was the worst day in terms of wind gusts. The Bureau of Meteorology's 30 minute recordings showed average wind speeds between 65km/h and 70km/h for almost the whole day, while gusts held in the 80-90km/h range, peaking above 90km/h several times during the day. Since I started taking wind recordings from the beginning of 2013, such consistency at such an extreme level hasn't been seen once until now.
The 96km/h gust equalled this year's record from March 1. As was mentioned then, you have to go back to October 15 last year to find the previous stronger gust at the Airport. The 96km/h gust was, however, nowhere near as strong as other gusts seen throughout the Sydney region. Both Norah Head, on the Central Coast, and Wattamolla, in the Royal National Park south of Sydney, saw a strongest gust of 135km/h on April 21, at 4:44am and 9:05am respectively. The difference between times of these strongest gusts and that of the Airport gives an indication of how the strongest part of the storm system moved south down the coast.
Heavy showers and areas rain streamed across the city in almost endless fashion during the 72 hour period. The worst hit areas were north of Sydney. Towns like Maitland and Dungog, 135km and 175km north, saw very high totals. Parts of the Blue Mountains, west of the city, also received a lot of rain. Suburbs in Sydney saw high totals too though. Some figures are shown in the table below.
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| Daily rainfall totals at locations in the Sydney region for April 20-22 2015 |
The images below show 24 hour to 9am rainfall totals across the region from April 21 to 23. Maitland is located at the top of the radar image. Maitland saw 277mm recorded across only two days.
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| 24 hours to 9am rainfall totals across Sydney for April 21-23 |
Sydney Airport saw the highest daily totals there since at least the start of last year; April 22's 111.2mm surpassing October 14's 86.0mm. October 14 last year, April 20, 21 and 22 are now the four wettest days since the start of 2014.
The Bureau's 24 hours to 9am totals for April 21, 22 and 23 totalled 241.8mm at the Airport. This was the highest three day 24 hours to 9am total in over 23 years. February 8, 9 and 10 back in 1992 saw 255.4mm recorded, with the totals at 9am for both the 9th and 10th topping 120mm.
To give the three calendar day total at the Airport of 247.8mm a bit more perspective, the whole year up until and including April 19 had seen only slightly more rain with 274.6mm. 2014 saw a fairly similar increase in the yearly rainfall total at the start of the year compared with 2015 - up until April 19 that is. The yearly total for 2015 now sits at 522.6mm. That mark wasn't surpassed last year until August 18. And if we compare it against precipitation in Jyväskylä, the same amount fell at Sydney Airport in those three days as what has been recorded in Jyväskylä since November 4 last year, a total of 113 days.
Looking at temperatures... After recording a top of only 17.2C at the Airport on Monday, Tuesday went slightly lower. It only reached 17.1C then. Wednesday saw temperatures drop to their lowest this year, down to 13.6C, but it did climb to 18.0C in the early hours of the morning.
The next week looks a lot calmer. It should be a lot sunnier in Sydney, although there's still the chance of showers around the city.
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