March 2021 rainfall event

 

Between 14 March and 24 March 2021 was a period of rain and showers with some thunderstorms, as a result of an succession of favourable synoptic features. During this period a total of 263.3 mm was observed and was the wettest period since 364.9 mm was observed between the 3 February and 14 February 2020.

In the past 30 years the rainfall event total was the 14th highest on record and was in top 7 % of rain event totals. For March the rain event total was the second highest on record and the highest since the current record high of 278.2 mm between the 28 March and 31 March 2017 associated with Ex-Tropical Cyclone Debbie.

During this rainfall event a large portion of the rainfall occurred during the last few days of the event where 203.3 mm was measured between the 22 and 24 March. The highest 24 hour rainfall total was 129.7 mm on 22 March 2021 and for March this was the third highest 24 hour rainfall total observed on record and which was the highest since the current record high of 153.5 mm on 6 March 2004 (squally heavy rainfall between the 5 and 6 March 2004). When compared to all previous months the highest 24 hour rainfall total was the 21st highest on record and the highest since 143.4 mm on 24 February 2018 (showers becoming heavy rainfall on the 23 and 24 February).

At the time of writing the month-to-date total is 297 mm, which is 177.4 mm above the long term median and 248.3 % of the long term median. For March so far this is the highest March total rainfall since 375.4 mm in 2017, which is the current record high. However considering that showers are expected during the rest of the month the final total may end up as the second highest on record, due to the current second highest being 301.25 mm in 1992. For all months this is the highest since 389.2 mm in February 2020.

Year to date rainfall is currently 519 mm, which is 88 mm above the long term January to March total (16.9 % above average). This is lower than the January to March rainfall total in 2020, which saw both well above average rainfall in January and February in contrast to near average rainfall in 2021 until the above average rainfall in March 2021.

The number of rain days have been 51 so far this year (of least 0.2 mm of rainfall excluding daily rainfall totals that are entirely from dew, mist or fog). This is 16 days above the long term average, is the highest on record as compared with previous January to March totals since 52 days in 2015 and the third highest on record. For March this is the highest number of rain days since 18 days in March 2019.

Note that rainfall totals are based on manually recorded daily rainfall totals measured as the 24 hours to 9am. This data is currently not displayed on this website, except as contained in the weather reviews. Therefore there will be differences to the rainfall totals shown on the website that are collected automatically from a different rain gauge and is measured as the 24 hours from midnight.

Some charts from this period are below where daily data is for the 24 hours from midnight. This is based on the existing graphs on this website, but uses a script that allows to show data between a specific date range, rather than using data in the last x days. This alternate format is not available on the website at this time which could be included in a future update.

 

December 2020 weather review

The review of the weather at Ferny Grove during December 2020 is now available.

in December 2020 overnight temperatures were over 1 ºC above average and was the highest for December in 11 years. Daytime temperatures were close to average and the lowest in 5 years. Minimum temperatures in December were predominately above average during the month and were near or below average in the middle of the month and at the end of the month. Maximum temperatures in December saw two periods of warm days at the start of the month and between the 18th and 23rd, as well as near average or below average temperatures. The first 8 days of the month saw warm days and nights that were up 7 ºC above average during a low to severe intensity heatwave .

Rainfall in December was above average with a total of 145.9 mm (112.9% of the long term average). This is the highest for December since the current record high of 450.1 mm in 2010. The annual rainfall total remained above average at 23.3% above the long term average and was the highest since 1263.6 mm in 2015. Most rainfall in the month occurred between the 7th and 18th during an active period of drizzle, showers, rain, and mild thunderstorms. The first 8 days of the month was dry and later in the month there were some drizzle and light showers on some days. The highest daily total rainfall on the 14th of 70.1 mm was the highest for December since 82 mm on 28 December 1999. This rainfall was a result of light to moderate rain from the evening of the 13th to early on the 14th that was associated with a coastal low pressure system that brought severe weather conditions to coastal areas of south-east Queensland.

Most long period rainfall totals continue to remain below or well below average, that improved for many of these periods. 6 monthly rainfall improved a little to 18.3 mm below average, while 9 monthly rainfall deteriorated from 171.9 mm above average to 52.7 mm below average. 12 month rainfall improved by 91 mm to 94.2 mm above average and 18 month rainfall improved by 100 mm at 38 mm below average. 24 month to 48 month rainfall was between 156.7 mm below average for 48 month rainfall and 366.1 mm below average for 24 month rainfall. Compared with the same period in the previous year these periods improved, and the greatest improvement was 12 monthly rainfall that improved by 564 mm.

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

November 2020 weather review

The review of the weather at Ferny Grove during November 2020 is now available.

in November 2020 overnight and daytime temperatures were close to average. Minimum temperatures were near average or below average in the first half of the month and then warm nights during the rest of the month with some cool nights. Daytime temperatures were mostly below average in the first half of the month before most days were warm during the rest of the month. An 8 day cool period occurred for the daily maximum temperatures between the 6th and 13th that peaked at 7 ºC below average.

Rainfall in November was well below average with a total of 4.7 mm (4.9% of the long term average). This is a new record low for this location for the past thirty years beating the previous record low of 14.2 mm in 2019. The year to date rainfall remained above average at 3.8% above the long term average. Most rainfall in the month occurred on the 17th from the edge of two mild thunderstorms when 4 mm was measured. On the 5th there was a mid-afternoon brief light shower from a thunderstorm passing to the south with 0.5 mm of rainfall. On the 13th there was some light rain but with no measurable rainfall.

Most long period rainfall totals continue to remain well below average, that improved for some of these periods. 6 monthly rainfall improved slightly to 58 mm below average, while 9 monthly rainfall reduced significantly from 97.2 mm in the previous month to 205.9 mm below average. 12 month rainfall remained nearly the same as the previous month at 3.4 mm above average. 18 month to 48-month rainfall was between 140.7 mm below average for 48 month rainfall and 384 mm below average for 24 month rainfall. Compared with the same period in the previous year most of these periods improved, except for 36 monthly rainfall which have worsened and was the lowest since 2008 when it was 334.2 mm below average.

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

October 2020 weather review

The review of the weather at Ferny Grove during October 2020 is now available.

During October 2020 overnight temperatures were close to average and daytime temperatures were above average. Overnight temperatures were near or below average in the first half of the month before warm nights during most of the second half of the month. The 22nd to 29th saw warm nights of up to 6 ºC above average. Daytime temperatures were above average throughout the month with some days that were cool.

Rainfall in October was above average with a total of 119.5 mm (185.4% of the long term average). The year to date rainfall remained above average at 11.5 % above the long term average. From the 19th was an active period of showers, rain and thunderstorms with some moderate to heavy falls. 14 mm of rainfall fell in 8 minutes on the 25th during a severe thunderstorm with marble size hail. On the 31st was 2 hours of thunder from 4 nearby thunderstorms with very little rainfall.

Long period rainfall totals remained well below average during most periods though improved for some periods. 6 monthly rainfall improved by 130 mm to 64.5 mm below average. 9 monthly rainfall remained above average at 97.2 mm above average while 12 month rainfall was 12.2 mm above average, improving from 58.6 mm below average in the previous month. Periods between 18 to 48-month remained below average and was as much as 624.9 mm below average for 36 month rainfall.

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

September 2020 weather review

The review of the weather at Ferny Grove during September 2020 is now available.

During September 2020 overnight temperatures were above average and were the highest in 10 years. Similarly to August 2020, the month saw very few cool nights and many warm nights throughout the month. The 18th to 25th saw overnight temperatures peak at 9 ºC above average. Daytime temperatures were close to average and saw a mixture of above and below average temperatures.

Rainfall in September was below average but was close to the long term median, with a total of 14.2 mm (42.7% of the long term average). The long term rainfall for September is generally quite low, hence the close to median rainfall. While the rainfall total was quite low and continuation of the trend of low monthly rainfall totals, the year to date rainfall however remains above average at 9.8 % above the long term average and the highest since 2015. Low daily rainfall totals with light showers during some days during the month. A thunderstorm passed to the south on the 25th, as well as another thunderstorm to the north and brought a brief light shower.

Long period rainfall totals remained well below average during most periods while deteriorating further. 6 monthly rainfall fell significantly to 161.7 mm below average being more than 6 months since significant rainfall at the start of the year. 9 monthly rainfall was 79.4 mm above average while 12 to 48-month rainfall was between 72.4 mm below average for 12 month rainfall and 245.3 mm below average for 24 month rainfall.

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

August 2020 weather review

The review of the weather at Ferny Grove during August 2020 is now available.

In August 2020 overnight temperatures were above average and were the highest in 6 years. During the month there were very few cool nights and many warm nights that were as much as 5 ºC above average. Daytime temperatures were also above average but was the lowest in 4 years. Throughout the month daytime temperatures were above average with several warm periods occurring with temperatures of up to 5 ºC above average. Persistent overnight breezes and cloud cover during much of the month slowed the fall in the overnight temperatures.

Rainfall in August was below average but was close to the long term median, with a total of 14.8 mm (40.9% of the long term average). With the continuing trend of low monthly rainfall totals the year to date rainfall however remains above average at 12 % above the long term average and the highest since 2015. Some light rain with brief heavy falls in the afternoon on the 7th (12.2 mm of rainfall). The 15th saw some light rain at times early in the day with the passage of a front. Light showers on the 15th accompanied with gusty winds brought 1.4 mm.

Long period rainfall totals have remained well below average while deteriorating further. The shorter time spans remained above average. 6 monthly rainfall slipped significantly to 161.7 mm below average being more than 6 months since significant rainfall earlier in the year. 9 monthly rainfall was 79.4 mm above average while 12 to 48-month rainfall was between 72.4 mm below average for 12 month rainfall and 245.3 mm below average for 24 month rainfall.

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

July 2020 weather review

The review of the weather at Ferny Grove during July 2020 is now available.

In July 2020 overnight temperatures were above average and were the highest in 4 years. During the month there were very few cool nights and many warm nights. The 21st to 28th was above average as much as 7 ºC above average. Daytime temperatures were close to average and in contrast to the overnight temperatures was the lowest in 4 years. Most of first 18 days of the month saw above average daytime temperatures. There were several cool days between the 21st and 25th associated with cloud coverage and rainfall. Persistent overnight breezes during much of the month slowed the fall in the temperature and prevented cold mornings from occurring.

July rainfall was below average, with a total of 50.4 mm (150.3% of the long term average). Even though most preceding months during autumn and winter observed below average rainfall totals the year to date rainfall however remains above average at 15.6 % above the long term average and the highest since 2015. On the 9th, 10th and 12th were light showers and drizzle with some light rain. Rainfall returned later in the month with further light rain at times and showers between the 24th and 26th as a result of a frontal system and the coastal trough that shifted southwards along the coastline. On the 26th the passage of gust front brought showers but with no measurable rainfall.

Long period rainfall totals remained well below average but improved a little for most periods. The shorter time spans have remained above average, given the significant or near average rainfall was experienced in February and March. 6 monthly rainfall remained above average but was below average for 9 monthly to 48 monthly, with the greatest being 18 monthly rainfall at 236.9 mm below average.

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

June 2020 weather review

The review of the weather at Ferny Grove during June 2020 is now available.

June 2020 saw above average overnight and daytime temperatures. A record warm morning was observed on the 14th that exceeded the previous record set 5 years ago. Most of first 18 days of the month saw above average daytime temperatures. Following the passage of a front there were cool nights between the 22nd and 26th, but was partially affected by persistent overnight breezes that slowed the falling in the temperature during much of these nights.

In June rainfall was slightly below average, with a total of 45.5 mm (73.5% of the long term average). This follows below average rainfall that occurred in the previous 2 months in autumn. Year to date rainfall however remains above average at 14 % above the long term average and the highest since 2015. During the middle of the month were showers with mostly light falls. A shower on the 14th brought brief heavy falls of 5.8 mm in 3 minutes. With the passage of the trough that preceded the cool nights later in the month were further light showers before some light showers returned at the end of the month.

Long period rainfall totals over the shorter time-spans improved slightly due to the near median rainfall in June but the longer time-spans have remained the same or deteriorated further given past months has seen below average rainfall totals. 6 monthly rainfall remained above average given the significant or near average rainfall was experienced in February and March. However 9 monthly to 48 monthly rainfall remain well below average with the greatest being 18 monthly rainfall at 285.5 mm below average.

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

Autumn 2020 weather review

The review of the weather at Ferny Grove during autumn 2020 is now available.

Autumn 2020 brought close to average overnight temperatures, whilst daytime temperature were 1 ºC above average. The mean daytime temperature was very similar to autumn in 2019 while the overnight temperatures were nearly 1 ºC lower. The lowest overnight temperature during the season of 9 ºC was the highest on record for autumn. Between the 22 May and 24 May were cool to cold days that brought a record low daily maximum temperature of 16 ºC on the 23 May.

After close to average rainfall during March, the following months in April and May saw low rainfall totals. The rainfall total for May (12.1 mm) was the lowest since 2004, and 70 % of the rainfall in May occurred on the 21st due to the passage of the trough followed by a cold and dry air mass brought by a complex low pressure over southern Australia. The highest hourly rainfall total in March was a new record high when a severe thunderstorm on 6 March brought 40 mm in 30 minutes with very heavy rainfall. The total for the season was the lowest since 2016 with a total of 168 mm (52.3 % of the long term average).

By the end of the season long period rainfall totals fell with the low rainfall totals during much of the season. Anomalies from the long term average were in the negative for all periods between 9 and 48 months, with the lowest being 18 month rainfall being 368 mm below average. However, because significant rain was experienced at the start of the year 6 monthly rainfall is still above average (60.5 mm above average and in the highest 20% of records).

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.

May 2020 weather review

The review of the weather at Ferny Grove during May 2020 is now available.

May 2020 experienced near average overnight and daytime temperatures. Daytime temperatures were 1 ºC above average during the month until a number of cool to cold days between the 22nd and 24th reduced the mean maximum temperature to near average.

In May very little rainfall was observed during the month, with a total of 12.1 mm (12% of the long term average) and the lowest for May since 2004. 70 % of the rainfall occurred on the 21st due to the passage of the trough followed by a cold and dry air mass brought by a complex low pressure over southern Australia. Rainfall otherwise during the month was comprised of light showers with low daily rainfall totals, mostly in the middle of the month.

Long period rainfall totals also continued to reduce further in May followed continued below average rainfall during autumn. Anomalies from the long term average reduced further as a result with 9 monthly to 48 monthly below average, with the lowest being 18 month rainfall being 368 mm. But given that significant rainfall was experienced at the start of the year, 6 monthly rainfall is still above average (60.5 mm above average and in the highest 20% of records).

The summary containing the key information can be found here.

The full report of more detailed analysis is available here.