November 2017 dry again with cold nights

Cockatoos feeding in a wattle

Corellas in Acacia decora

While day temperatures were normal, many nights were below normal, around 10°. The cold night air was extremely dry. The early morning dew point on the 1st was minus 3.6°, about 14° below normal.
My rain gauge registered seven rain days, but readings were moderate, the highest being 14.0 mm on the 30th. (The automatic gauge at the Museum remained down.)

Weather log for November 2017

Comparing November months

With a mean of 20.8°, this month was cool, but not as cool as several other November months. November 1999, at 19.4°, was the coolest. On the graph, November 2014 (25.4°) stands out as very much warmer.
The rainfall of 44.2 mm is at the 31st percentile: not high, but enough to prevent any shortages. This graph still includes November 2011, the wettest on record. At 242.9 mm, it beat a record of 226 mm that had stood for fifty years.

Climate log for November


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 gauge last reported on 24 September 2017.

All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

Advertisements

3-year trends to November 2017

Dry with cold nights

3-year trends to November 2017

November raw anomaly data (orange)

November 2017 reverted to the anomalies of August and September: low moisture (top four graphs) and cold nights (bottom left), with continuing cold subsoil (bottom right). Day temperature (x-axes)had cooled to normal since September.

 Fully smoothed data (red)

Anomaly data for autumn 2017 (MAM) are now fully-smoothed, plotted in red. That season was near the centre for the last three years, but day temperatures fell from high towards normal (seen best on the top right graph). Meanwhile, moisture measures disagreed somewhat. Rainfall rose towards normal, cloudiness decreased towards normal, dew point fell through low values, and daily temperature range was static near normal.
Daily minimum temperature fell towards normal, and subsoil temperature rose to normal.


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

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.

August 2017 arid and sunny

Photo of a honey-eater feeding

Noisy Miner in Emu Bush

Very few days in August were cloudy, and only one day, the 4th, had some rain: 13.6 mm. Extremely dry air produced a 21st-century record low dew point of minus 10.0 degrees on the 20th. The dry air and clear skies dried out the soil, and also made for wide ranges of temperature. Twelve days were more than 20° warmer than their nights. The actual temperatures, however, were not extreme. Weekly average temperatures remained normal until falling to 3.3° lower in the final days.
Frosts (below +2.2° in the screen) happened on 17 mornings, just two more than normal.

Weather log

Comparing August months

Arid August months like this occurred in 2012 and 2013, but not since then. The mean early morning dew points in 2012 (-2.2°) and this time (-2.8°) were record values, far below the normal value of +2.2°. This month was also very sunny, had little rain, and had a daily temperature range of 17.9°, a record for August.
Temperatures were close to normal. The daily maximum (19.8°) was a degree above normal, and the daily minimum (1.9°) was a degree below normal.
The total rainfall of 13.8 mm (20th percentile) was far below the August average (40 mm). Added to the low total for July (13.2 mm), the two-month total is only 27.0 mm, which is at the 6th percentile. That makes it the first serious rainfall shortage of any duration since October 2015, when the 30-month total had been at the 6th percentile. For two-month rainfall totals, there has not been such a shortage since nearly four years ago (September 2013).

Climate graph for August


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. All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

3-year trends to August 2017

Arid and sunny

3-year climate trends to August 2017

August raw anomaly data (orange)

In August 2017 all moisture indicators except rainfall showed even greater aridity (high up on the graphs) than in July. Daily minimum temperature anomaly (lower left graph) fell extremely low, but both the daily maximum temperature anomaly (x-axis in all graphs) and that of subsoil (lower right graph) were just slightly above normal.

 Fully smoothed data (red)

Fully-smoothed data points now include summer 2016-17. The daily maximum temperature anomaly peaked in February 2017 at +0.9°, much the same temperature as in the previous two peaks: February 2016 and October 2014. The daily minimum temperature anomaly was just about to peak, but the subsoil temperature anomaly was rising persistently.

Moisture anomaly variables, which had moved strongly towards arid in the spring, peaked in aridity during the summer:

Lowest rainfall, in January, was just 13 mm below normal;
least cloudiness, in February, was still 11% above normal;
lowest dew point, in November, was 1.7° below normal;
widest daily temperature range, in January, was only 0.1° wider than normal.

Although aridity reached peaks, this was not an arid summer. The peak values cited were not far from normal, and the graphs show that more arid times occurred within the previous two years.


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.

July 2017 fine with cold nights

July morning photo of Manilla from the lookout

Manilla Prospect in July

Through most of the month, days were fine and sunny, but some days, mainly in the middle, were cloudy and some had a little rain. The highest reading, on the 16th, was only 7.4 mm.
No days were remarkable except the 28th which, at 23.7°, equalled the record for July set 31/07/14. It was 6.1° above normal.
Frosts (below +2.2° in the screen) happened on 23 mornings, 6 more than normal. However, the coldest morning, at -2.6°, was not nearly as cold as the record of -5.1° set in 2002.

Weather log

Comparing July months

Unlike July 2016, which had been cloudy with warm nights, this July was fine with cold nights. Days, at 18.1°, were not quite as warm as in July 2013 (18.9°), the warmest in the new century.
Moisture was scarce, as in the record-making July of 2002. Readings that reflected low moisture were:

Daily minimum temperature very low: +1.2° (2002: 0.9°);
Very many frosts: 23 (2002: 27);
Very low percentage of cloudy mornings: 29% (2002: 23%);
Very low early morning dew point: -1.4° (2002: -1.4°);
Very wide daily temperature range: 16.9° (2002: 18.5°);
Very low rainfall: 13.2 mm (2002: 1.0 mm).

Relative humidity in the early mornings, normally 90% in July, was 74%. That was the lowest July value in my 13-year record.
Despite the total rainfall of 13.2 mm (16th percentile) being far below the July average (41 mm), there are still no shortages of rainfall for groups of months. The most recent serious shortage was nearly two years ago. In October 2015, the 30-month total to that date (1216 mm) was still down at the 6th percentile. That shortage was carried over from an earlier extreme event: the 85 mm summer rainfall of 2013-14 that was 142 mm below average.

Climate graph for July


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. All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

3-year trends to July 2017

Fine with a wide daily temperature range

3-year climate trends to July 2017

July raw anomaly data (orange)

In July 2017 the largest anomaly was the very wide daily temperature range (middle right graph). This was linked to the daily minimum temperature anomaly (lower left graph) falling suddenly very low.
All moisture indicators pointed to aridity (upwards), and the anomalies of both daily maximum temperature and subsoil temperature were high.

 Fully smoothed data (red)

The latest available fully-smoothed data point, January 2017, showed continued warming in the anomalies of maximum, minimum and subsoil temperatures. These were coming to a peak: the maximum and minimum perhaps in February, but subsoil not for several months.
Moisture anomaly variables were near a peak of aridity. Dew point had peaked (low) in November, cloudiness (low) and daily temperature range (high) in January, with rainfall (low) likely in February.


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.