3-year trends to December 2012

Parametric plots of smoothed climate variables at Manilla

“Retreat from drought”Trends to December 2012.

In December, the anomaly of daily maximum temperature retreated from the November extreme of +3 degrees to +1.5 degrees. Dew Point and daily temperature range also retreated from drought values. Cloudiness remained normal and daily minimum temperature high. Subsoil temperature returned to the very high values of the winter months.
The variables maximum temperature, minimum temperature, and temperature range are now close to the smoothed values they had three years ago, in December 2009.

Fully-smoothed data (in red) for June 2012 have reached new records for low Dew Point anomaly (-2.61 degrees) and for high subsoil temperature anomaly (+1.99 degrees).

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.

December 2012 Hot, with Rain

The daily weather logWeather log December 2012.

As in November, most days this month were warmer than normal. The 1st, at 40.6°, was the equal hottest December day on this record, with 30/12/05.
Afternoon values of Relative Humidity fell to 7 percent on the 15th and 16th.
Rain was recorded on nine days, totalling 97.4 mm, with the highest reading 29.8 mm on the 26th.

 Comparing December monthsClimate December 2012.

Days this month, at 33.3°, were not quite as hot as those of December 2005 (33.7°). Nights this month were warm (17.5°), but not nearly as warm as those of December 2009 (18.6°). In stark contrast, December 2011 was several degrees cooler.
The mean early morning Dew Point of 11.7° shows the air is almost as dry as it was a year ago. Since then, the air has been even drier, with an extremely low morning Dew Point of 1.7° in October.
The sky was less cloudy than in any of the last five Decembers.
The rainfall of 97.4 mm is high, in the 72nd percentile for December. This defers all concerns about rainfall shortages: even the five-month total of 190 mm is in the 25th percentile.

The Year 2012

In 2012, rainfall was extremely high in February, April, and July, but extremely low in August and October. The total for the year (669 mm) was a little higher than the long-term mean of 652 mm, but a lot lower than last year’s 837 mm.
By other measures, Manilla’s climate drifted during the three years 2010, 2011 and 2012, from a humid coastal type to an arid inland type. In 2010 day temperatures had been very low (24.6 degrees), and night temperatures high (11.2 degrees), as would happen on the coast. By 2012, day temperatures had risen to normal (25.5 degrees), and night temperatures had fallen very low (9.6 degrees). A typical day in 2010 had the very narrow temperature range of 13.4 degrees, while a day in 2012 had a range of 15.9 degrees.
In the same way, 2010 had been extremely cloudy and humid, while 2012 had normal cloud and extremely low humidity. Subsoil temperature (750 mm) rose from a low value of 19.6° in 2010 to a record annual high of 21.6° in 2012.


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.

 

Droughty Spring 2012

Weather log Spring 2012.Temperatures rose as normal this spring, apart from a quick rise in the last week and a cold spell in the second week of October. In the cold spell, one day failed to reach 14°! Rain fell nearly every week, but never more than 15 mm in a day.

After last spring’s record-breaking 432 mm rainfall, this spring was about as droughty as spring 2002. The rainfall total, 81 mm, was a bit higher than in spring 2002 (66 mm) and the percent of cloudy mornings higher (25% vs. 19%), but the dew point (humidity) was much lower (3.7° vs. 5.4°) and the daily temperature range was higher (17.9° vs. 17.1°).
Showers in the last days lifted the total rainfall (81 mm) to the 10th percentile for springs.Climate spring 2012.

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.

3-year trends to November 2012

Parametric plots of smoothed climate variables at Manilla

“In drought”

Trends to November 2012.

In November, the anomaly of daily maximum temperature (which had paused near zero for five months) suddenly rose to +3°. Daily minimum temperature and subsoil temperature also rose, but moisture variables (including daily temperature range) retreated from values typical of extreme drought. November was hotter, but not quite so dry.

Fully-smoothed data (in red) now include all of autumn (March-April-May) 2012. During autumn, all smoothed variables showed a steady advance towards the top right corner of the graphs (“droughts”). However, four variables were still on the “flooding rains” side of neutral: maximum temperature, rainfall, cloud, and minimum temperature. Two variables were already on the “drought” side: dew point and subsoil temperature. Temperature range was neutral.
The May 2012 value of smoothed dew point anomaly (-2.30°) is a new record low for smoothed data, beating the record of the previous month (-2.00°). Following months will be even more arid.

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.

Warm, Dry November 2012

The daily weather logWeather log November 2012

Most days this month were warmer than normal. As last seen in 2002, no November daily maxima were below 25°. The month ended with a weekly average temperature nearly seven degrees above normal.
Seven afternoons had extra-ordinarily low humidities below 10 percent, and eight mornings had very low dew points (below 5°).
Rain came mainly as showers, totalling only 48.2 mm in seven rain days.

 Comparing November monthsClimate November 2012.

Warm temperatures this month were far lower than in November 2009, when Manilla and other places suffered a heat wave.

Very dry air is shown by the low mean early morning dew point of 8.8°. This is the lowest November value in 14 years, below the 1999 value of 9.6°. However, October’s value of 1.7° was very much lower.
The rainfall of 48.2 mm is in the 35th percentile for November, well below the average of 67 mm. The four-month rainfall total (92 mm) and the nine-month rainfall total (317 mm) are serious shortages, in the 8th and 9th percentiles. The 15-month total is still over a metre, which is keeping pools of water in the bed of Greenhatch Creek.


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.

 

3-year trends to October 2012

Parametric plots of smoothed climate variables at Manilla

“Rushing into drought”Trends to October 2012.

In October, while daily maximum temperature remained not far above normal, raw values of all other monthly mean anomalies (except minimum temperature and soil temperature) moved further in the “drought” direction. Most extreme was the dew point, which was nearly seven degrees below normal! Daily temperature range was also extremely wide. Rainfall was very low,and cloudiness lower than in recent months.
Minimum temperature anomaly moves erratically. October’s extremely low value resulted from moderate maximum temperature and extreme daily temperature range.
Subsoil temperature returned to normal after seven months above normal.

Fully-smoothed data (in red) now include April 2012. All variables for that month show an advance towards the top right corner of the graphs (typical of droughts).
The April 2012 value of smoothed dew point anomaly (-2.00°) is a new record low for smoothed data, beating the record of July 2011 (-1.70°).

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.

Arid October 2012

The daily weather logWeather log October 2012.

Many days this month had weather you might expect in a desert. Cold nights and warm days made the temperature range very wide. Very dry air sent morning dew points below zero several times.
Very cold cloudy weather on the 11th and 12th brought 11.2 mm of rain, but two cool cloudy spells later brought little more.

 Comparing October monthsClimate October 2012.

Nights, at 8.6°, were the coldest for October, 2.3° colder than average.
The mean morning Dew Point of 1.7° is an amazing low-humidity value for October, 6.6° below average! Low humidity brought less October cloud than seen since 2004.
The very low rainfall of 12.6 mm is in the 11th percentile for October. While rainfall totals for 12 months or more are all above normal, there has been little recent rain. The 2-month total (33 mm) is a serious rainfall shortage (9th percentile) and the 3-month total (44 mm) is a severe rainfall shortage (3rd percentile). Similar shortages of rainfall have developed in a broad band from Sydney to Perth.


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.