February 2016: hot, dry days

Photo of cooba blossom

Cooba in February

Weekly average temperatures began 2 or 3 degrees low, but ended with a long warm spell 3 degrees high, that extended into March. Days were especially hot, with the 26th reaching 41.5°, the equal second hottest February day. Nights were seldom very warm, and the early morning of the 26th was 25° cooler than the afternoon.
Few days were cloudy, none of them late in the month
Rain fell only on the 3rd, as three heavy showers of 7mm, 27mm and 13mm. The second shower, at 5pm, had the most intense rain of the new century: 27 mm in less than 27 minutes. Bureau of Meteorology data show that such a half-hour storm, yielding 1 mm of rain per minute, has only a 10% chance of happening here in any year. It is a “one in 10 year event”.

Weather log February 2016

Comparing February months

While the average temperature for the month (25.8°) was normal, the mean daily maximum, at 34.7°, was the hottest for February. A rather low mean daily minimum, (16.8°) made the daily temperature range a desert-like 17.9°. This is the widest February value, 3.5° wider than normal.
Other signs of dryness were the low early morning dew point (10.8°) and very few cloudy mornings (17%).
The total rainfall of 47mm was below the average of 67 mm, but right on the median 50th percentile: just half of all February months have been wetter. Again, there are no serious rainfall shortages for totals for any number of months.

Climate for February 2016


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 February 2016

Parametric plots of smoothed climate variables at Manilla
“February 2016: suddenly dry”

Trends to February 2016

February raw anomaly data (orange)

In February 2016, raw values for anomalies moved completely across the graphs, from cool and moist in January, generally to hot and dry in February. As in a desert, days became very hot, skies very sunny, and the daily temperature range extreme. Rainfall and dew point were only moderately low, while daily minimum temperature abruptly fell very low, and subsoil temperature remained very low.

 Fully smoothed data (red)

With data for August 2015, fully smoothed data is complete for winter 2015. Most anomalies for the season were quite small, but were moving away from cool and moist.

Trend lines on the graphs

Manilla’s climate often oscillates along the blue trend lines from bottom left (cool, moist) to top right (hot, dry) on the graphs. The climate can also vary along other axes.
In this time-frame the sub-soil temperature anomaly (bottom right graph) is leading the daily maximum temperature anomaly by several months. That produces a clockwise looping pattern. The daily minimum temperature anomaly (bottom left graph) sometimes moves with the daily maximum temperature anomaly, and sometimes moves against it. When against it, as from July 2013 to October 2014, the climate swings between Continental, with hot days and cool nights (as October 2013), and Maritime, with cool days and warm nights (as May 2014). Current raw data for January and February 2016 show a large swing from Maritime to Continental.


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.

January 2016: moist again

Photo of Senna-bush

Jewel-box Cassia

Unlike December, this month saw varying temperatures. The week around the 7th was quite cool. The maximum on the 3rd reached only 22.3°, but worse was to come. The 15th reached only 21.1°: equal coldest January day in the new century (with 31/1/2001). It was more than 12° below normal, and that happens less than once in a year. There was also one very hot day above 40°, which is the normal number for January.
Rain fell, mainly as showers, on ten days spaced through the month. The higher readings were 28.4 mm on the 6th, 24.2 mm on the 23rd, and 27.6 mm on the 24th.

Weather log January 2016.

Comparing January months

Like January last year, this month could be called “moist”. It was cloudy, and the rather cool days were only 14° warmer than the nights.
The total rainfall of 104.7 mm was well above the average of 87 mm, and in the 72nd percentile. Again, there are no serious rainfall shortages for totals for any number of months. In fact, totals for 2-, 3-, 4-, 5-, and 6-months are very high.

El Niño

Manilla’s climate is now out of step with the El Niño – Southern Oscillation (ENSO). This “super” El Niño has not brought dryness here, and the dryness in January 2014 (for example) came at a time without an El Niño.

Climate for January 2016


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 January 2016

Parametric plots of smoothed climate variables at Manilla
“January 2016: moist again”

Trends to January 2016

January raw anomaly data (orange)

In January 2016, raw values for nearly all anomalies moved well towards the cool and moist corner of the graphs.

 Fully smoothed data (red)

In the latest month with fully smoothed data (July 2015) anomalies were quite small, but were moving towards warm and dry. Partially smoothed data points for more recent months show that the warm and dry “El Nino” influence on values around October and November was smaller than it seemed at first. In particular, rainfall did not go below the “normal” range, but the anomaly of daily minimum temperature rose quite high.


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.