3-year trends to August 2016

Parametric plots of smoothed climate variables at Manilla
“August 2016 cool and wet”

Trends to August 2016

August raw anomaly data (orange)

August 2016 was marked by low mean daily maximum temperature and high total rainfall. On the first graph the data point is in the cold wet “flooding rains” corner. However, the other five variables are close to normal.

 Fully smoothed data (red)

Fully-smoothed data is now available for the summer of 2015-16. Most variables became static in that season, but cloudiness increased, dew point fell, and subsoil temperature rose.
Most variables were close to normal: rainfall, cloudiness, daily temperature range and subsoil temperature. Daily maximum and minimum temperatures were rather high, while dew point was low. [Low dew point anomalies near the line (y = -x – 3) rather than (y = -x) may be due to an instrument error, since corrected.]


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 2015 normal weather

Vine blossom photo

Wonga-Wonga Vine

Up to the 24th of August, there had been no rainfall readings above 6 mm for 67 days, and none at all for 29 days. Then storms brought 34 mm one day and 4 mm the next. A little more fell on the 28th. Overcast skies came with the rain, and one morning had fog until after 9 am.
Two days were unusually cool: the 5th was 6° below normal and the 27th was 7° below normal. By contrast, the minimum temperature on the warm rainy morning of the 24th (13.5°) was 9.4° above normal. There were 15 frosts (normal), but the coldest morning, the 5th, reached only minus 2.1°.
The weekly average temperature was a little low in the sunny first half of the month. It was high just before and during the rain, then low again.

Weather log for August 2015

 Comparing August months

This month was close to normal, and very like August last year.
Days were a bit cool. That made the daily temperature range rather low, in line with rather cloudy skies.
The rainfall of 40.1 mm was on average, and in the 57th percentile. As happened last month, only one rainfall total was as low as the 9th percentile. That serious shortage had now moved back to the 30-month total (1255 mm). Water is flowing in Greenhatch Creek.

Climate for August 2015


Data. All data, including subsoil at 750 mm, are from 3 Monash Street, Manilla. Rainfall data up to 26/3/15 is from Manilla Post Office, Station 055031.

3-year trends to August 2015

Parametric plots of smoothed climate variables at Manilla
“August 2015: cooler, moister trend persists”

Trends to August 2015

Fully smoothed data (red)

The last fully-smoothed data point (February 2015) completes the summer of 2014-15. This summer had a steady cooling and moistening trend for all variables except subsoil temperature, which passed through a minimum. Three of these seven variables were very close to normal: daily maximum temperature, rainfall, and subsoil temperature. Skies were rather cloudy, dew point was three degrees low (as is now usual), daily temperature range was half a degree low, and daily minimum temperature was half a degree high. These four variables all relate to moisture. Only the dew point shows low moisture: the others show high moisture, while the rainfall was normal.

August raw anomaly data (orange)

The partially-smoothed data points from March to July (uncoloured) show excursions, but the unsmoothed data point for August (orange) is close to the trend established in the summer. That is, cooler and moister. However, no variables had values far from 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 August 2014

Parametric plots of smoothed climate variables at Manilla
“August 2014 back to normal”

Trends to August 2014

 August data (orange)

Most raw anomaly values for August have returned to near normal. The daily maximum temperature anomaly has finally fallen below normal and rainfall has risen above normal. The dew point anomaly remains well below normal, but its value is on the (green) trend line that has applied during the last three years.

Fully smoothed data (red)

Fully-smoothed data is now available for the summer season ending in February 2014. During the summer all variables except daily minimum temperature moved decisively away from drought. Rainfall increased rather slowly, but cloudiness increased very rapidly, and daily temperature range fell very rapidly.

The hot-arid climatic peak (drought) of spring 2013

Extreme anomaly values of climate variables came in the following order:

Highest minimum temperature (not high): July;
Highest subsoil temperature (extreme): July;
Widest temperature range (very wide): October;
Highest maximum temperature (extreme): October;
Least cloudiness (normal): October;
Lowest dew point (extreme): December;
Lowest rainfall (very low): December-January.

This is not the order that is typical in recent extreme episodes. The smoothed rainfall anomaly minimum of -22.3 mm (not nearly as low as the -27.1 mm of July 2002) came much later than the peak of daily maximum temperature. On the top left graph the trace curved anti-clockwise, which is unusual.


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.

 

August 2014 normal but with dry air

The daily weather log

Purple flowers

Early-blooming Hardenbergia

The weekly temperature was normal throughout, but the first half of the month had sunny warm days, cold nights and very dry air. The night of the 3rd (-4.0°) was the coldest August night this century, and the early morning of the 12th had the lowest August dew point (-8.7°). Two brief overcast and rainy spells began on the 16th and 26th, yielding 54.4 mm in five rain days. The reading of 26.6 mm on the 17th was one of the highest for August in recent years.
The number of frosts (12) was a little below normal (15).

Weather log August 2014

 Comparing August months

While August 2008 had been the coolest, and August 2009 the warmest in the 21st century, nearly all averages this month were near normal. As exceptions, the daily maximum temperature was slightly low and the dew point (as in the two previous August months) was very low. Few mornings had dew on the grass.
The total rainfall of 54.4 mm is in the 75th percentile, well above the August average (40 mm). This rain also raised the rainfall totals for periods of more than one month, so that only the 18-month total of 691 mm now remains as a serious shortage (9th percentile).

Climate August 2014  


Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash  Street, Manilla.