3-year trends to May 2020

May, like March and April, continued cool

May raw anomaly data (orange)

Current raw anomaly values for May appeared very little changed from those of March and April. However, as noted below, many values are estimates only.

Temperatures

Daily maximum temperature anomaly (all x-axes), which had been very high until January, remained near -1.5°.
Daily minimum temperature anomaly (lower left): stayed at normal.
Subsoil temperature anomaly (lower right): stayed at normal.

Moistures (moist is at the bottom)

Rainfall anomaly (upper left) stayed near normal.
Cloudiness anomaly (upper right): remained high.
Dew point anomaly (middle left): remained normal.
Daily temperature range anomaly (middle right) stayed low, near -1.5°.

 Fully smoothed data values (red) 

Fully-smoothed data is now available for the spring season (SON) of 2019. Taking the season as a whole, smoothed daily maximum temperature anomaly peaked (at the 21st-century record value of +2.21°) in October, while daily minimum temperature rose, and subsoil temperature fell. A steady movement away from extreme drought affected rainfall, cloudiness, dew point, and daily temperature range (lower).

[Note.
Due to illness, 45 days were missed for some Manilla values, from 23/3/20 to 8/5/20. No values were noted for cloud or soil temperature; daily maximum and minimum air temperatures were estimated by regression on values from Tamworth Airport Automatic Weather Service.]


Notes:

January data points are marked by squares.

Smoothing Continue reading

April 2020: once again a new drought record

Changing shortages

Many extreme rainfall shortages persisted at Manilla in April. That is despite no serious shortages at 12-months or less. Extreme shortages, below the first percentile, occurred at 24-, 30-, 36-, 42-, 48-, 60-, 72-, 84-, 96-, and 240-month durations. Once again, the 42-month rainfall total broke the record for dryness with 1468 mm, surpassing the record of 1477 mm set in December.
The 96-month total of 4116 mm was also very close to the record low total of 4104 mm mm set in February.

How to read the graph

This graph shows all the present rainfall shortages at Manilla, short term and long term, as percentile values. The latest values are shown by a thick black line with large circles. Those from one month earlier are shown by a thinner line with small diamonds. [The method is described in “Further Explanation” below.]


Further Explanation

The following notes explain aspects of this work under these listed headings:

Data analysis

Cumulative rainfall totals
Percentile values
Severity of rainfall shortages

Limitations of this analysis

Monthly rainfalls form a single population
Observations are not retrospective
The rain gauge failed

Data analysis

Continue reading

April 2020: cool, moist

Weather log for April 2020

[Note.
Due to illness, all days of this month were missed for some Manilla values. No values were noted for cloud or soil temperature; mean values shown for the month are estimates only. Daily maximum and minimum air temperatures were estimated by regression on values from Tamworth Airport Automatic Weather Service.]

April weekly mean temperatures were one or two degrees below normal, except in the final week.
There were five rain days, with the highest reading of 18.4 mm on the 11th.

Comparing April months

The mean monthly temperature, at 17.7°, was rather low, half a degree below normal. The mean daily maximum, at 24.7°, was one-and-a-half below normal, while the mean daily minimum, at 10.7°, was normal.
Apart from rainfall, the only moisture indicator available this month is daily temperature range. At nearly 2° narrower than normal, it implies more moist conditions than the rainfall. The rainfall total of 32.8 mm was at the 50th percentile for April, which is rather below the average (44 mm).

Drought

I will report separately on the on-going drought.


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. Recording resumed on 20 July 2019. The gauge failed again during February (25/02/2020 ), but was repaired on 11/3/20.
My estimates of early morning dew point have drifted anomalously low. From August 2019, I use data from the Tamworth Airport published graphs.
All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

3-year trends to April 2020

April, like March, continued cool

April raw anomaly data (orange)

Current raw anomaly values for April appeared very little changed from those of March. However, as noted below, many values are estimates only.

Temperatures

Daily maximum temperature anomaly (all x-axes), which had been very high until January, remained near -1.5°.
Daily minimum temperature anomaly (lower left): stayed just below normal.
Subsoil temperature anomaly (lower right): stayed near normal.

Moistures (moist is at the bottom)

Rainfall anomaly (upper left) stayed near normal.
Cloudiness anomaly (upper right): fell from very high to high.
Dew point anomaly (middle left): remained normal.
Daily temperature range anomaly (middle right) stayed near -1.5°.

 Fully smoothed data values (red) 

The fully-smoothed daily maximum temperature anomaly for October 2019 again broke the 21st century record, reaching a value of 2.21° above normal. The daily minimum anomaly also rose, but the subsoil anomaly fell. Despite the high and increasing air temperatures, smoothed moisture anomalies for October 2019 did not move further towards drought.

[Note.
Due to illness, 45 days were missed for some Manilla values for the whole of April 2020. No values were noted for cloud or soil temperature; daily maximum and minimum air temperatures were estimated by regression on values from Tamworth Airport Automatic Weather Service.]


Notes:

January data points are marked by squares.

Smoothing Continue reading

March 2020: no new drought records

Changing shortages

Despite high rainfall (165 mm) in February and normal rainfall (53 mm) in March, many severe and extreme shortages persisted. Only at durations shorter than one year were rainfall totals near normal. As in February, the 12-month total remained at 432 mm: a serious shortage.

Three near-record low rainfalls

Although no records were broken this month, three rainfall totals were the third-driest ever: those for 42-months (1508 mm), 84-months (3495 mm) and 96-months (4142 mm).

How to read the graph

This graph shows all the present rainfall shortages at Manilla, short term and long term, as percentile values. The latest values are shown by a thick black line with large circles. Those from one month earlier are shown by a thinner line with small diamonds. [The method is described in “Further Explanation” below.]


Further Explanation

The following notes explain aspects of this work under these listed headings:

Data analysis

Cumulative rainfall totals
Percentile values
Severity of rainfall shortages

Limitations of this analysis

Monthly rainfalls form a single population
Observations are not retrospective
The rain gauge failed

Data analysis

Continue reading