May 2019 had the warmest nights

Keepit Dam boom, May 2019

The month began warm, with the night of the 2nd being, at 18.0°, the warmest May night of the new century. There was a second warm spell nearly four degrees above normal about the 20th.
The first frost (by my reading) came on the 12th of May this year, and on the 15th of May last year. The middle date of first frost is May 13th.
There were three rain days (usually four) but nearly all the rain (61 mm) was recorded on the 4th.

Weather log May 2019

Comparing May months

The mean temperature this month (14.6°) was high, but not as high as in May 2007 (15.1°). However, the mean daily minimum temperature (8.1°) was the warmest for May in the new century: above normal by 2.3°.
A rather narrow daily temperature range (13.1°) and high percentage of cloudy days (45%) showed moisture above normal.
The (estimated) rainfall total of 61.8 mm was very high, in the 75th percentile. Because no rain at all had fallen in April, the total for the two months together reached only to the 26th percentile.

Climate for May 2019

Drought

The on-going unprecedented drought is reported in another post.


Data. A Bureau of Meteorology automatic rain gauge operates in the museum yard. From 17 March 2017, 9 am daily readings are published as Manilla Museum, Station 55312.  These reports use that rainfall data when it is available.  Since no 9 am readings have been recorded since August 2018, I have substituted my non-standard gauge readings for all days.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

3-year trends to May 2019

May days not warm

3-year trends to May 2019

May raw anomaly data (orange)

In May 2019, the anomaly of daily maximum temperature returned to zero after years of positive values. Both daily minimum temperature and subsoil temperature anomalies were very high. Moisture anomalies, reflecting the high rainfall value (+21 mm), were low on the graphs (away from drought), but dew point was not as far down as “normal”.

 Fully smoothed data (red)

Fully-smoothed data now include the spring season ending November 2018.
Both daily maximum and daily minimum temperature anomalies were very high and rising. The minimum was rising faster and broke the record of +1.65°. Subsoil temperature anomaly, due to a phase lag, was normal and still slowly falling.
Moisture indicators in this spring were inconsistent. Rainfall anomaly decreased slowly to a new (20th century) record of minus 29.7 mm. The dew point anomaly was also low, but rapidly increasing. Both the cloudiness and the daily temperature range were normal.


Notes:

January data points are marked by squares.

Smoothing

Smoothing uses Gaussian functions.
For fully smoothed data the function has a Standard Deviation of 2.5 months, it spans 13 monthly data points, and has a half-width of 6 months, which suppresses cycles shorter than 12 months. For partly smoothed data, the span of the function is reduced to 11 months, 9 months and so on.
Continue reading

No Rain Days in April 2019

Split Rock Reservoir 4-5-19

A warm spell in the third week was 4.2° above normal. There were 29 days over 25°, many more than usual. Anzac Day (25th) was sunny, calm and warm. It reached 28.2°, which was four degrees above average for that day, but not up to the 28.7° of Anzac Day 2002.
There were no rain days (usually four) and the dew point on the 28th reached a record low April value of minus 3.2°. There were no frosts.

Weather log for April 2019

Comparing April months

This month was warm (average 19.8°), but not as warm as April 2018, 2016 or 2005. The mean daily maximum of 27.8° was well below that of April 2005 (29.5°).
There was no rain, as in April 1912, 1925, 1942 and 1971. Dry air was shown by early morning readings of low dew point (5.8°) and very low relative humidity (67%). However, normal moisture was shown by 30% cloudy days and a daily temperature range of 15.9°.

The last seven April months

Drought

The on-going unprecedented drought is reported in another post.


Data. A Bureau of Meteorology automatic rain gauge operates in the museum yard. From 17 March 2017, 9 am daily readings are published as Manilla Museum, Station 55312.  These reports use that rainfall data when it is available.  Since no 9 am readings have been recorded since August, I have substituted my non-standard gauge readings for all days.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

3-year trends to April 2019

April no rain

3-year trends to April 2019

April raw anomaly data (orange)

In April 2019, a rainfall total of zero made the raw anomaly for rainfall minus 40 mm. Rainfall, and the other moisture indicators (cloudiness, dew point, and daily temperature range) were much further up the graphs towards drought than they had been in March.
Daily maximum, minimum and subsoil temperatures were high, near the high-side limits of (smoothed) normal temperature.

 Fully smoothed data (red)

Fully smoothed data to October 2018 show rainfall just short of the record negative anomaly set in May 2018, and both maximum and minimum temperatures near record positive anomalies. However, cloudiness, dew point, and daily temperature range continued a movement (down) away from drought.


Notes:

January data points are marked by squares.

Smoothing

Smoothing uses Gaussian functions.
For fully smoothed data the function has a Standard Deviation of 2.5 months, it spans 13 monthly data points, and has a half-width of 6 months, which suppresses cycles shorter than 12 months. For partly smoothed data, the span of the function is reduced to 11 months, 9 months and so on.
Continue reading

Very warm nights in March 2019

Photo of dead public lawn

Our Nature Strip

While there were no very high or low temperatures, weekly mean temperatures were high. Warm spells through the second and fourth week-ends were about four degrees high.
There were nine rain days (twice the usual number for March), but none had more than 5 mm until the 30th. A rain front early that morning brought 39 mm.

Weather log for March 2019

Comparing March months

This month was very warm. It was like March in 2018 and 2016, but the nights were warmer. Both the mean minimum temperature (17.9°) and the monthly mean temperature (24.9°) were record high values for March in the 21st century.
It was not a dry month: values of all the moisture indicators were near normal. The (estimated) rainfall of 54.9 mm is very close to the long-term average of 53.4 mm. However, March rainfall at Manilla is strongly skewed, having many values just below the average and just a few values up to 240 mm above it. The median March rainfall is much lower: only 39 mm. This month’s total of 54.9 mm is at the 60th percentile: it is higher than 60% of all historic March rainfall values.

The last 7 March months

Drought

The on-going drought is reported in three posts, with three different kinds of graph:

  • a line graph shows rainfall status in the last two months, with duration on the x-axis and severity on the y-axis;
  • a contour graph shows 25 months sequentially on the x-axis, duration on the y-axis and severity by tints;
  • a duration graph shows how shortages began and ended in the last 20 years, with time on the x-axis and duration on the y-axis.

 


Data. A Bureau of Meteorology automatic rain gauge operates in the museum yard. From 17 March 2017, 9 am daily readings are published as Manilla Museum, Station 55312.  These reports use that rainfall data when it is available.  Since no 9 am readings have been recorded since August, I have substituted my non-standard gauge readings for all days.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.