Tag Archives: 2012

3-year trends to October 2012

Posted in 3-year climate trends, Manilla NSW by

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

Posted in Manilla NSW, Monthly weather by

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.

 

3-year trends to September 2012

Posted in 3-year climate trends, Manilla NSW by

Parametric plots of smoothed climate variables at Manilla

“Still Very Dry Air”Trends to September 2012.

In September, daily maximum temperatures finally rose above normal. As in August, Dew Points (humidity) remained extremely low, daily minimum temperature very low, rainfall low, and daily temperature range very high. Cloudiness finally fell below normal, and subsoil temperature fell towards normal.

Fully-smoothed data (in red) now include March 2012. All variables for that month show a retreat from the “flooding rains” climate peak. Because the daily minimum temperature anomaly did not reach a minimum in March as I expected, the sequence of peaks for individual variables must be amended as follows:
Nov-11: Rainfall (max); Subsoil temp (min);
Dec-11: Temp range (min); Dew Pt (max);
Jan-12: Temp max (min);
Feb-12: Temp min (min).
The February 2012 value of smoothed minimum daily temperature anomaly (-1.11 degrees) was not quite as low as the record set in March 2008 (-1.17 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.

Frosty Dry September 2012

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log September 2012.

The severe frost of -2.7° on the 2nd was the coldest September night on this 14-year record. Having ten frosts in the month had not happened before, either. Most were “black frosts” because there was no dew to freeze. The extremely low Dew Point of minus 7.4° on the 2nd has been exceeded only once: minus 9.3 on 17/5/11.
With such dry air, two of the sunniest days had maximum temperatures more than 25° above the night-time minima.
Rain showers occurred on 5 days (normal), but the total was only 20.4 mm.

 Comparing September monthsClimate September 2012.

Days (24.0°) were 0.2° warmer than average, and nights (5.8°) were 1.2° colder than average.
The mean Dew Point of 0.8° is a new record low-humidity value for September, beating last year’s value of 1.7°. Low humidity brought less September cloud than in the last four years.
The low rainfall of 20.4 mm is in the 29th percentile for September. While the 12-month rainfall total to date is still extremely high (over 900 mm), the 2-month total (31 mm) is now a serious rainfall shortage, in the 9th percentile of 2-month totals.

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 August 2012

Posted in 3-year climate trends, Manilla NSW by

Parametric plots of smoothed climate variables at Manilla

“Dry Air: Warm Soil”Trends to August 2012.

Daily maximum temperatures remained just below normal in August, as in May, June, and July. Cloudiness was also stable, at about 8% above normal.
From July to August:
* Rainfall went from very high to very low;
* Dew Point went from low to extremely low;
* Temperature Range went from low to high;
* Daily min temps went from very high to very low;
* The subsoil remained extraordinarily warm.
The subsoil temperature anomaly has moved with the anomaly of maximum air temperature for eight months, but is tracking 2.5 degrees higher. This relation is shown by a green line on the bottom left graph.

Fully-smoothed data (in red) now include the whole summer season ending February 2012. At Manilla, this covered a “flooding rains” climate peak that was very much wetter, and somewhat cooler than that a year earlier. The variables reached peaks in sequence as follows:
Nov-11: Rainfall (max); Subsoil temp (min);
Dec-11: Temp range (min); Dew Pt (max);
Jan-12: Temp max (min);
Mar-12: Temp min (min).
Peaks for some variables are not in the usual sequence.

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.