Tag Archives: September

3-year trends to September 2019

Posted in 3-year climate trends, Manilla NSW by

September extreme and arid

3-year climate trends to September 2019

September raw anomaly data (orange)

Temperatures

Daily maximum temperature anomaly (all x-axes): near the maximum for smoothed values.
Daily minimum temperature anomaly (lower left): has rapidly fallen very low.
Subsoil temperature anomaly (lower right): near normal again.

Moistures (moist is at the bottom)

Rainfall anomaly (upper left): extremely low.
Cloudiness anomaly (upper right): normal.
Dew point anomaly (middle left): now very low (arid).
Daily temperature range anomaly (middle right): extremely high.

 Latest fully smoothed data (red), for March 2019

Latest smoothed anomaly values (March 2019) all show a retreat from the extreme drought values of the summer of 2018-19.

Notes:

January data points are marked by squares.

Smoothing Continue reading →

Dry and Mild September 2018

Posted in Manilla NSW, Monthly weather by
Eucalypts dying in drought

White Box Trees Die

Temperatures were near normal, with a number of warm nights. There was just one very cool day that reached only 14.8°. The first 30° day of spring came on the 14th. The early morning dew point on the 17th, minus 10.5°, was the lowest September value, but far from the lowest recorded recently.
There were eight rain days, but the highest reading was only 3.6 mm, on the first day of the month.

Weather log September 2018

Comparing September months

Despite being within an extreme drought, moisture measures this month were not very low; not as low as in September 2017. While the mean temperature was normal, the daily temperature range was low, which is unusual in a drought.
The rainfall total of 12.5 mm (estimated) is at the 18th percentile for September.
I have reported the shortage of rainfall in another post: “Record 15-Month Drought in 2018”.

Climate in September months

Data. A Bureau of Meteorology automatic rain gauge operates in the museum yard. From 17 March 2017, 9 am daily readings are published as Manilla Museum, Station 55312.  These reports use that rainfall data when it is available.  The record was again defective in September 2018. No 9am readings were recorded. I have substituted my non-standard gauge readings for all days.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

3-year trends to September 2018

Posted in 3-year climate trends, Manilla NSW by

Equable, less sunny

3-year trends to September 2018

September raw anomaly data (orange)

Like last month, climate anomalies were in retreat from drought. All moisture measures, except rainfall, moved lower on the graphs. Both the daily temperature range and the percent of cloudy mornings recovered from extreme values.

 Fully smoothed data (red)

Fully smoothed data for March 2018 broke the previous month’s record for daily maximum temperature anomaly (x-axis), advancing from +1.58 to +1.63 degrees. The March smoothed rainfall anomaly of −27.1 mm (top left graph) equaled the 20th-century record minus value set in July 2002. Both these records may be broken by fully-smoothed figures for April 2018.
By March 2018, the trend for decreasing rainfall with increasing daily maximum temperature (top left graph) had lasted eight months. Other variables had different patterns. Most were just beginning to move towards drought after several months with little change.
Daily minimum temperature, after six months of sustained rise, then began to fall. Subsoil temperature anomaly was rising, lagging daily maximum temperature anomaly by five months.

Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.
Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

 * Normal values for rainfall are based on averages for the 125 years beginning 1883.

3-year trends to September 2017

Posted in 3-year climate trends, Manilla NSW by

More arid

3-year climate trends to September 2017

September raw anomaly data (orange)

In September 2017 all moisture indicators except cloudiness showed even greater aridity (high up on the graphs) than in August. Daily maximum temperature anomaly (x-axis in all graphs) had now risen very high, but that of the subsoil (lower right graph) had fallen. Daily minimum temperature anomaly (lower left graph) remained extremely low.

 Fully smoothed data (red)

The latest fully-smoothed data point is that for March 2017.
At that time, the climate was warm and almost static, after a minor peak in aridity. Although later anomaly values (only partially smoothed) are subject to noise, three of them have raced away towards aridity: dew point fell, daily temperature range rose, and daily minimum temperature fell.

Note:

Fully smoothed data – Gaussian smoothing with half-width 6 months – are plotted in red, partly smoothed data uncoloured, and raw data for the last data point in orange. January data points are marked by squares.
Blue diamonds and the dashed blue rectangle show the extreme values in the fully smoothed data record since September 1999.

Normal values are based on averages for the decade from March 1999.* They appear on these graphs as a turquoise (turquoise) circle at the origin (0,0). A range of anomalies called “normal” is shown by a dashed rectangle in aqua (aqua). For values in degrees, the assigned normal range is +/-0.7°; for cloudiness, +/-7%; for monthly rainfall, +/-14 mm.

 * Normal values for rainfall are based on averages for the 125 years beginning 1883.

September 2016 had near-record rain

Posted in Manilla NSW, Monthly weather by
Blooms of Acacia paradoxa

Kangaroo Thorn

There were fourteen rainy days in a month that ended no warmer than it began. The month of September normally warms up by nearly four degrees. This time it remained near 14° all month. Some plants encouraged by the plentiful moisture were discouraged by the cold.
The highest daily rainfall reading, 28.8 mm on the 14th, hardly compares with one of 71.1 mm in 2005, or even one of 40.0 mm in 2011.
No days were warm. For the first time in this 18-year record, no September day reached 25°. More days than ever (18) were below 20° but not one was as low as 15°. Temperatures at night were near normal. A frost on the 5th was the only one. It may have been the last of the year, about a fortnight earlier than usual.
Only four mornings this month had no cloud, while seven were totally overcast.

Weather log for September 2016

Comparing September months

For monthly average temperatures, the daily maximum of 19.7° stands out as a record low, 4.1° below normal. Three indicators for moisture reached their extreme September values for the new century: rainfall, percentage of cloudy mornings (63%), and (narrowest) daily temperature range (12.0°). Dew point (6.0°) was just above normal, but very much higher than in September months since 2010.
The monthly rainfall total of 122.4 mm (amended) was one of the four highest ever September readings. The others were: 1917: 124 mm; 1949: 126 mm; 1998: 166 mm.
There are not now any noteworthy shortages in rainfall totals for any number of months, up to 360 months (thirty years).

Climate for September 2016

Data. Rainfall figures for this month are from the automatic rain gauge at Manilla, published on the internet by the Bureau of Meteorology as Station 55031. All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.