Tag Archives: Gaussian smoothing

2011-12 Summer Cold and Wet

Posted in Manilla NSW, Season Weather by

Weather log summer 2011-12.In the whole of this summer, only 3 days went over 35° (usually 23) and only 5 nights went over 20° (usually 19).

The smoothed curves of temperature reached up as high as normal only twice. In early January both days and nights were normal. Later, with persistent rain around the 1st of February, nights warmed to normal, but days were extremely cold.
All the mean daily temperatures were the lowest in 13 summers: maximum 28.9°, mean 22.2°, and minimum 15.4°. Summer ’07-’08 had been just slightly warmer.
Daily temperature range this summer (13.5°) was very narrow, as in ’07-’08 and ’10-’11; all wet summers with very cloudy skies. Strangely, this cloudy wet summer had very low humidity, with morning Dew Point (12.7°) the lowest on this record.
While this was a very wet summer, at 333 mm, it was only the 19th wettest (86th percentile), and not much wetter than summers 4, 6, and 8 years ago.Climate summer 2011-12.

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 February 2012

Posted in 3-year climate trends, Manilla NSW by

Parametric plots of smoothed climate variables at Manilla

“February 2012 very cold and wet”Trends to February 2012.

Recent partly-smoothed data points generally diverge rapidly from the near-neutral values of winter. February raw anomalies include extremely high rainfall and extremely low daily maximum and minimum temperatures.
Low humidity persists, marked by negative Dew Point anomalies, despite extreme rainfall and cloud cover.

Winter 2011 a time of trend reversal

Fully smoothed data points are now available for Winter 2011. Most variables show stable near-zero anomaly values at a time of trend reversal:
Max temp anomaly (x-axes, all graphs) had been rising since cold October 2010, but peaked in June 2011 while still negative.
Rainfall anomaly, which had reached a minimum just below zero in May, rose quite rapidly during the winter.
Cloudiness varied little around a minimum in July.
Uniquely, Dew Points were very low: the anomaly reached a new record low smoothed value of -1.70 degrees in July. This beat the drought year smoothed value of -1.48 degrees of September and October 2002.
Daily temperature range was slightly low and falling; so was daily minimum temperature. Subsoil temperature was slightly high and falling.

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.

3-year trends to January 2012.

Posted in 3-year climate trends, Manilla NSW by

Parametric plots of smoothed climate variables at Manilla

“Low Dew Points and cold days persist”Trends to January 2012.

Except for humid November 2011, Dew Points at Manilla (Centre left graph) have now shown remarkable aridity for nine months. The July 2011 value for Dew Point anomaly, now fully smoothed, requires the blue line to be moved yet again. It sets a new lower limit for smoothed Dew Point anomaly: minus 1.70 degrees.
Daily maximum temperature (X-axis, all graphs), from a remarkably low value (-4.7) in December, rose only to -3.6 in January.
On the top left graph, the rainfall anomaly returned from a record positive value in November to stongly negative within two months.
Cloudiness went from very high to extreme.
Daily temperature range (centre right graph) and daily minimum temperature (bottom left graph) moved back from the extreme values of December.

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.

3-year trends to December 2011

Posted in 3-year climate trends, Manilla NSW by

Parametric plots of smoothed climate variables at Manilla

“Extreme changes”Trends to December 2011.

Raw values for some anomalies leap from one extreme to another from November to December 2011. Daily maximum temperature (X-axis, all graphs), from a very high value in November, went to such a remarkably low value (-4.7°) that the scale had to be extended by two degrees.
On the top left graph, the rainfall anomaly returned from an extreme positive value to near zero. Taking max temp and rainfall together, November values were part-way towards the climate of an interglacial epoch, while December values were part-way towards that of a glacial epoch. The centre left graph, including Dew Point anomaly, shows the same effect: hot humid (interglacial) jumping to cold arid (glacial).
While daily temperature range (centre right graph) changed little, daily minimum temperature (bottom left graph) moved with maximum temperature from an extreme of hot days and hot nights to a greater extreme of cold days and cold nights. The November and December values mentioned are far beyond the normal limits (dashed blue lines) set by smoothed data points since 1999.

The last fully-smoothed value (June 2011, in red) for Dew Point anomaly  requires the blue line to be moved. It sets a new lower limit for smoothed Dew Point anomaly: -1.58°. Next month may see the July 2011 value set a new record.
Except for humid November 2011, Dew Points at Manilla have now shown remarkable aridity for eight 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.

Spring 2011 the wettest by far

Posted in Manilla NSW, Season Weather by

 

Weather log spring 2011This spring’s rainfall of 431.7 mm far exceeded that of any other spring in the record from 1883. Winter had been very dry, with only 55 mm. While there was a lot of rain in September (91.4 mm) and October (97.4 mm), much more fell in November (242.9 mm), mainly in the second half.
The only other springs with more than 300 mm were in two small groups: 1916 (326 mm) and 1917 (327 mm); and 1949 (330 mm), 1950 (379 mm), 1954 (319 mm) and 1955 (321 mm).
Apart from the extreme rainfall, all other weather readings this spring were normal. By contrast, spring 2009 had been warm and sunny, and spring 2010, cool and cloudy.
During the season, there were two very cool spells, early in September and very early in October. They were separated by a sunny warm spell with very low humidity: it had people changing into summer gear (then back again!). By mid-November, both days and nights were very warm, but then returned to normal.Climate spring 2011

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.