3-year trends to July 2015

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

Trends to July 2015

July raw anomaly data (orange)

The near-normal values of June are now seen as merely interrupting a trend to cooler, moister climate. July had very low day temperature, very high cloudiness, and very low daily temperature range, but dew point was not extreme. Discordantly, rainfall, which had been very high in June, became very low in July.
Night-time and subsoil temperatures continued their trends towards higher values. (Relatively warm nights have now persisted for 17 months.)

Fully smoothed data (red)

January 2015 was relatively cooler by day than the previous month, but each of the other variables moved only slightly down the graphs.

El Niño

In this record, the last hot dry climate phase that matched an El Niño was in November-December 2009. At that time, the daily maximum temperature anomaly was very high, the rainfall anomaly was low, and the daily minimum temperature anomaly (lower left graph) was a record high.
Later, in November-December 2013, without an El Niño, Manilla had a more extreme hot dry climate phase. As seen on these graphs (marked in blue), 21st century records were set then for anomalies of high daily maximum temperature, high subsoil temperature, and low dew point.
Now, in July 2015, an El Niño is forecast, but these Manilla graphs show no movement as yet away from cool moist climate.


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.

June 2015 rather wet

Photo of the tiny blossoms of the Wilga, an Australian shrub

Wilga blossoms in June

The first week of June was cold but sunny, the second warm, and the rest not quite so warm. Rain registered (unofficially) on the 17th was 54.5 mm. That was close to the record June day of rainfall at Manilla Post Office: 55.1 mm on 18/6/1930.
The early morning minimum of the 17th was extremely warm, at 12.8°: the fifth warmest for June. There were 12 frosts (as usual) but none was severe. On two mornings, fog persisted past nine o-clock.

Weather log for June 2015

 Comparing June months

Most monthly averages were near normal. Daily minima were up one degree, and morning dew points down one degree.
While lower than in June 2013, the total rainfall of 74.4 mm is high: in the 82nd percentile. Among rainfall totals for more than one month, there are no serious shortages. The lowest percentile value (11th) is for the 24-month total of 996 mm.

Climate for June 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 June 2015

Parametric plots of smoothed climate variables at Manilla
“June 2015: back to normal”

15JunParam

June raw anomaly data (orange)

Nearly all raw anomalies for the latest month are nearer to normal than the partially-smoothed anomalies of the autumn months. They are also quite close to the smoothed values of a year ago. Rainfall stands alone as a high value.

Fully smoothed data (red)

In December 2014, most anomalies were normal, or near normal, and changing only slowly.


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.

Manilla’s Hot Days to June 2015

Log of annual hot days in 16 years This post updates a similar one by including three more years to make a total of sixteen. It is in the same format as a recent post on Manilla’s frosts. Because the summer, which has the most hot days, crosses from one calendar year to the next, I have begun each year at July. I have called days warmer than 35° “hot days”, and days warmer than 40° “very hot days”.

Note added.

I have analysed the pattern of hot days in more detail in a later post “Hot days and ENSO”. By finding the relative frequency of hot days in all of the hotter months, I show that there is a cyclic variation related to ENSO. The cycle period is near 1.5 years, not 3 years as the log of annual frequency of hot days (above) suggests.

Graphical log of hot and very hot days

The first graph is a log of the number of hot and very hot days in each year. The three years with the most hot days had almost the same number: the year ’02-’03 had 41, the year ’09-’10 had 44, and the year ’13-’14 had 43. The two years with the fewest were ’07-’08 which had 5, and ’11-’12, which had only 4. The 13-year average is 26. Counting only the very hot days, ’03-’04 had the most (6), and four years had none at all. On the average, two days exceeded 40° in a year. (These are thirteen-year averages, not updated.) The number of hot days per year seems to have a cyclic pattern, with a period that increases from two years to four years during this short record. This is just a curiosity. The pattern of hot days has a lot in common with the pattern of smoothed monthly temperature anomalies for all months. These are plotted here, on a graph that relates them to ENSO. The relation of Manilla daily maximum temperature to ENSO was quite close from 1999 to 2011, but failed almost completely since mid-2011. In the earlier post on frosts, no cyclic pattern can be seen, nor any relation to ENSO.

New Record hottest days

In the sixteen years, there have now been 37 days hotter than 40 degrees: that is, 2.4 days per year. It remains true that December has fewer very hot days than November or February. A new record was set on 12/1/2013 by a daily maximum temperature of 43.2 degrees, beating the 42.6 degrees of 20/11/2009. This record was broken again on 3/1/2014, with 43.7 degrees. In the latest year, the hottest day (41.1 degrees) ranked only 12th, and it was not in summer, but in November.

Three new annual graphs

Continue reading

Manilla’s Frosts to 2014

Graphical log of frosts

This post updates a similar one by including three more years to make a total of sixteen.

The Number of Frosts in Each Year

The first graph is a log of the number of frosts in each year. The pattern is different when counting all frosts or only severe frosts.
The log for all frosts had two periods of stable, medium numbers of frosts: from 1999 to 2003, and from 2008 to 2011. Three years had many frosts: 2004 (68), 2006 (70), and 2012 (69). The year 2007 had the fewest frosts (43) until beaten by 2013 (34).
In the logs for severe frosts below minus 2° or minus 4° in the thermometer screen, the drought year 2002 stands out as the most frosty by far. It had the coldest mornings: -5.1° on both the 2nd and 11th of July.

The Last Three Years

Monthly frosts in 2012, 2013, and 2014.

The second graph compares the mean seasonal pattern of frosts with the patterns for the three latest years: 2012, 2013, and 2014.
The frost season of 2012, which almost matched the record 70 frosts of 2006, began early and ended late. May had 13 frosts (like the 14 of 2006) and September had 10 (like the 8 of 2003).
The curve for the season of 2013 ( the new record fewest) was like that of a normal frost season, but lower.
The year 2014 was not very frosty, because the season began late, with no frosts in May and only nine in June.

Monthly frosts each year

Graphs showing the seasonal frost patterns for earlier years are copied here.

 

 

 

 

 

 


There is 2013 reserch on frost in NSW titled “Understanding frost risk in a variable and changing climate” reported here.
It is in GRDC Update Papers (Grains Research and development Corporation). The research is done by Steven Crimp and co-workers at CSIRO Climate Adaption Flagship.
Referring to the period 1960 to 2010,
“Over many parts of NSW the frost season length has broadened by as much as 40 days and the mean number of consecutive frost days has increased to 5 days.”