Rainy days in March 2017

March 2017 had 17 rain days. In 134 years, this was beaten only by June 1950, which had 18. [More about Manilla rain days here.]

Fronds of Acacia pendula

Weeping Myall

After the record high temperatures of February, day and night temperatures in March were normal, without extremes. On a weekly basis, the first half of the month was cooler than the second half. The subsoil temperature followed the weekly air temperature down, to be a degree below normal by the 20th.
The second week had mainly clear skies and low dew points, Then the skies became persistently cloudy and dew points were high. A number of afternoons had oppressive humidity, with minimum values over 70%.
Of the 17 rain days, only three were early in the month, and they had little rain. The highest daily reading of 15.0 mm came on the 22nd.

Weather log for March 2017

Comparing March months

March had been sunny and very warm in both 2016 and 2015. This March was like that of 2014 and 2013, but with even more moisture. The mean average temperature was normal but, due to the cloudiness (58% cloudy mornings), the mean daily maximum, 29.1° was low and the mean daily minimum, 16.4°, was high, yielding the record narrow daily temperature range for March of 12.7°. The mean early morning dew point, 13.7°, was the highest March value in a decade, and the mean afternoon humidity minimum, at 53%, was far above the usual value of 30%.
The total rainfall of 113.2 mm was at the 90th percentile, far above the March average of 54 mm. The previous month, February, had only 4.1 mm, at the 4th percentile for that month. Taken together the two-month total of 117.3 mm was well above normal, at the 63rd percentile.

Climate for March 2017


Data. In 2016, a Bureau of Meteorology automatic rain gauge (formerly used for flood prediction) was set up in the museum yard as the official Manilla rain gauge. From 23 May 2016, its daily readings were published as if from Manilla Post Office, Station 55031. The gauge ceased transmitting five months later, on 7 October 2016. This month, after repair, it came into operation again. From 17 March 2017, daily readings are now published as Manilla Museum, Station 55312.

In these reports,the rainfall data is from Station 55031 or Station 55312 when available. Otherwise, rainfall data is from 3 Monash Street, Manilla.  All other data, including subsoil at 750 mm, are also from there. 

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3-year trends to March 2017

Parametric plots of smoothed climate variables at Manilla
“Very rainy and cloudy”

3-year trends to March 2017

March raw anomaly data (orange)

March 2017 was dramatically cooler and more moist than the extremely hot and dry February. March days were cooler than normal and both rainfall and cloud were very high. Dew point and daily temperature range moved to the moist side of normal.

 Fully smoothed data (red)

The most recent fully-smoothed data is for September 2016. Following a winter that was cool and moist, September days remained cool but the climate became drier.
The smoothed anomaly of daily minimum temperature, which had hit a record high value in May 2016, approached normal. Subsoil temperature fell rapidly to below normal.


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.

March 2016 had a warm dry spell

Photo of Pittosporum berries

“Native Apricots”

In the first half of March the average weekly temperature was more than three degrees above normal. Nine days had maxima above 35°, when the month usually has only one. However, no day reached 40°, as happened in March last year (20/03/15).
No rain fell in this time: the period of 43 days between February 4 and March 19 may have been the seventh longest rain-free period in 133 years. (No official record is now kept.)
Normal weather returned in the second half of the month. I recorded 20.8 mm of rain on the 19th, and further rain on the 30th and 31st.

Weather log for March 2016

Comparing March months

Despite the cool change, this was the warmest March of the new century. Daily maxima, minima, and means were all 2° above average. The subsoil temperature was also 1° high, as in March 2012 and 2013, but not as high as in 2007 (2° high).
This was not a dry month. The moisture indicators cloudiness, humidity, and (low) daily temperature range were just slightly on the dry side.
The total rainfall of 35mm was below the average of 53 mm, but in the 46th percentile, not far below the median. Again, there are no serious rainfall shortages for totals for any number of months. In fact, the five-month total of 362 mm is high, in the 81st percentile. Ponds persist in Greenhatch Creek.

Climate graph for March 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.

March 2015 was hot

Photo of bird in a gum tree

Blue-faced honeyeater in a White Box tree

March had 5 hot days over 35°: more than January (2) or February (3), but less than December (7) or November (10!). On the 20th the temperature reached 40.0°, making it the hottest March day of the century, 10.2° above normal. It came in a warm spell, with a weekly mean temperature 3.6° above normal. Some days had extremely low humidity, with afternoon values below 10%. The morning dew point on the 28th, minus 4.2°, was the lowest March value.
There were five rain days, with the highest reading 22.0 mm on the 12th.

Weather log for March 2015

Comparing March months

The average daily maximum temperature, at 31.8°, was the hottest of any March in this short record. It was almost the same as in each of the months of this summer, but not as high as that of last November (33.9°). The daily mean temperature (23.6°) was also the highest for March, just beating the 23.4° of March 2000. Night temperatures were normal, making the daily temperature range wider than normal. The mean early morning dew point of 8.3° was a record low value.
The total rainfall of 35.8 mm, while well below the average of 53 mm, is quite normal. It is in the 46th percentile: nearly half of all March totals were lower. Among rainfall totals for more than one month, there is little change. Again, the only serious shortage is in the 24-month total, which is now in the 5th percentile.

Climate for March 2015


Data. Rainfall data up to 26/3/15 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 March 2015

Parametric plots of smoothed climate variables at Manilla
“March 2015: hot”

Trends to March 2015

 March raw anomaly data (orange)

In March, the daily maximum temperature anomaly became very high (+1.6 degrees), but not nearly as high as the raw value had been in November (+5.1 degrees). Most other anomalies moved up the graphs towards “droughts” but not beyond normal values. Dew point remained as low as in February, and rainfall returned from very low to normal.

Fully smoothed data (red)

The latest fully-smoothed data anomalies (September 2014) moved a little towards “droughts” from the near-normal values of the winter.


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.

March Climate Anomalies Log

Heat Indicators log for March months

This post is the first in a set for the 12 calendar months. Graphs are sixteen-year logs of the monthly mean anomaly values of nine climate variables for Manilla, NSW, with fitted trend lines. I have explained the method in notes at the foot of the page.

Raw anomaly values for March

Extreme values for March anomalies in this period were:
Daily Minimum Temperature anomaly -2.9°: March 2008;
Morning Dew Point Anomaly +3.5°: March 2000;
Morning Dew Point Anomaly -3.2°: March 2008;
Rainfall anomaly +61 mm: March 2007;
Percent cloudy mornings anomaly +37%: March 2011.

Trend lines for March

Heat Indicators

Daily maximum temperature showed minima about -1 deg in 2001 and 2014, and a maximum about zero in 2007.
Daily minimum showed a minimum two years later, about 2003, then rose in parallel with daily maximum, but ended very high.
Subsoil temperature did not agree, and varied less. It had maxima in 2002 and 2012. It may show a lag of five years behind daily maximum.

Moisture Indicators log for March months

Continue reading

3-year trends to March 2014

Parametric plots of smoothed climate variables at Manilla

“Plunge toward ‘flooding rains’ *Trends to March 2014.

Raw values of climate anomalies for March 2014 are nearly all in the bottom left corner “flooding rains” after months in the opposite corner “droughts”. Daily minimum temperature remains high: nights are warm.
Fully-smoothed values for September 2013 show that the drought was becoming as severe as in 2002. The dew point anomaly reached a new record low value of -3.94°.


* By arrangement with the Licensor, The Dorothea Mackellar Estate, c/- Curtis Brown (Aust) Pty Ltd.


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.