July 2020: extreme drought lingers

Posted in Australian Climate, Climate events, Manilla NSW, Rainfall from 1883 by

Rain status at Manilla NSW June and July 2020

The lingering long-term drought

As shown, Manilla is still in extreme drought: the rainfall totals from 30-months to 96-months are in the lowest 1% in history. Not only that, but the 42-month total to July (1440 mm) and the 96-month total (4056 mm) are the lowest ever recorded.

Acute drought in 2018 and 2019

This worst-ever drought at Manilla had a false start in September 2017, with severe 2-month and 3-month shortages (below the 5th percentile), but began in earnest in winter (JJA) 2018, with many extreme shortages (below the 1st percentile) that were shorter than one year duration. Such seasonal extreme shortages came again in spring (SON) 2019.
These acute shortages were ended by the rain of February 2020, but extreme and record-breaking shortages with duration of two or more years have persisted up to now.

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 →

3-year trends to July 2020

Posted in 3-year climate trends, Manilla NSW by

July: warm and humid

3-year climate trends to July 2020 at Manilla

July raw anomaly data (orange)

Temperatures

Daily maximum temperature anomaly (all x-axes), remained near +1 deg.
Daily minimum temperature anomaly (lower left): rose very high (+2.5 deg).
Subsoil temperature anomaly (lower right): remained very high.

Moistures (moist is at the bottom)

Rainfall anomaly (upper left) just below normal.
Cloudiness anomaly (upper right): near normal.
Dew point anomaly (middle left): just above normal.
Daily temperature range anomaly (middle right) low (humid).

 Fully smoothed data values (red) 

Fully-smoothed data for January 2020 shows that the daily maximum temperature anomaly continued to fall from the record value of October 2019. The daily minimum and subsoil values were static.
All the moisture indicators (rainfall, cloud, dew point, and daily temperature range) continued to move downward, showing decreasing drought.

Notes:

January data points are marked by squares.

Smoothing Continue reading →

July 2020: warm and humid

Posted in Manilla NSW, Monthly weather by

Weather log for July 2020

Repeating the pattern of June, the second week of July was 3° above normal. Again, one night (11th) was remarkably high above normal (9.8°). The final week was also warm.
There were 14 frosts (normally 17), but the number of cloudless days (5) was equal lowest for July.
Seven days registered rain above 0.2 mm, the highest being 10.4 mm on the 27th.

Manilla weather log July 2020

Comparing July months

The mean monthly temperature of 11.1° was the same as last year: only 0.3° lower than the warmest July (11.4° in 2013). However, days were rather cool (18.0°), while nights (4.3°) were the 2nd warmest for July. The resulting daily temperature range of 13.7° was narrower than normal. That suggests humidity, agreeing with a high dew point (3.2°) and cloudiness (39%).
The rainfall total of 31.3 mm, being at the 44th percentile, is still well below the July average (41 mm). However, no July rainfall has been much higher at Manilla in eight years (91.4 mm in 2012).

Manilla climate July 2020

Drought

I will report separately on the on-going drought, that still breaks low-rainfall records.

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.

June 2020: warm and dry again

Posted in Manilla NSW, Monthly weather by

Weather log for June 2020

[Note.
Due to illness, the first seven days of this month were missed for some Manilla values. No actual 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. Further illness has delayed publication.]

The second week was nearly 3° above normal. One day (13th) was 5.9° above normal. and one night (14th) a remarkable 9.6° above normal. That night also recorded the highest rainfall: 15.2 mm). Later, a cold day, 5.5° below normal, occurred on the 23rd.

Weather log June 2020 Manilla

Comparing June months

All three mean monthly temperatures were one degree above normal, a little warmer than in June last year. The Subsoil temperature was 2 deg above normal.
Moisture indicators were near normal, except for rainfall.
The rainfall total of 20.8 mm was at the 28th percentile for June, which was less than half the long-term average.

Climate Manilla June 2020

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.

June 2020: return to a 42-month drought record

Posted in Australian Climate, Climate events, Manilla NSW, Rainfall from 1883 by

Rain status at June 2020 at Manilla NSW

Changing shortages

Rainfall of 20.8 mm in June 2020 was far below the average (44 mm), reaching only to the 28th percentile.
Although this low rainfall did not cause any rainfall total for 12-months or less to become a serious shortage, all totals for longer durations were serious shortages or worse. Two were serious (<10th %-ile), six were severe (<5th %-ile), and nine were extreme (<1st %-ile). Nearly all of them had become drier than in May.
The 42-month total, which had set a driest record of 1468 mm in April, now beat this with 1457 mm in June. At two other durations, rainfall totals were 2nd-driest: at 84-months, 3471 mm; and at 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 →