Cool spring 2016

Photo of a wildflower

Nodding Chocolate Lilies

Through September, days were very cool, making for a narrow daily temperature range. Then, through October, both days and nights were very cool. In November, days and nights were nearer to normal but, in contrast to September, the daily temperature range was wide. The dew point failed to rise during the season, making the air very dry in November.
Rain fell frequently up to the middle of November, then ceased. There were 24 rain days, when there are normally 19 in spring. The highest reading was 28.8 mm on the 14th of September. The season total of 216.4 mm was rather high, in the 77th percentile.

Graphical log for spring 2016
All temperature measures were below normal by 1.5° to 2.0°. Only spring of 2001 had low values like that but in 2010 the mean daily maximum (only) was 2.5° below normal.
Measures of moisture were near normal, with cloud, rainfall, and daily temperature range on the moist side, and dew point on the dry side.

Climate for spring 2016

Data. Rainfall figures for this season began from the automatic rain gauge at Manilla, published on the internet by the Bureau of Meteorology as Station 55031. That gauge ceased reporting on the 8th of October, and later readings are from my non-standard gauge. All other data, including subsoil at 750 mm, are from 3 Monash Street, Manilla.

Very cool December 2011; wet year

The daily weather logWeather log December 2011.

Nearly all the days and nights of December were several degrees cooler than normal. None of them were very cold, but no days and few nights were above normal either. As in much of NSW, cool weather continued for the whole month. In a normal December, most days are warmer than 30°, but this time only four were. There were eleven rain days, often with cloud on the hills and sometimes valley fog (in summer!). The highest rainfall (2 day) reading was 22.0 mm.

 Comparing December monthsClimate December 2011.

This December was even cooler than the last. It set new post-1998 record lows for mean daily maximum temperature (27.0°), mean daily mean temperature (20.4°), and mean daily minimum temperature (13.9°). This December’s days and nights were cooler than those of November, by 2.8° and 2.1° respectively.
Mean early morning Dew Point (11.1°) was also a record low value.
The mean daily temperature range (13.2°) was a bit wider than last years record narrow value (11.7°). The sky was rather cloudy, and the mean subsoil temperature (24.0°) normal.
The rainfall of 79.0 mm is in the 58th percentile for December, above the long-term average of 74 mm. Totals for groups of months up to 24 months are now all extremely high: above the 80th percentile. The greatest rainfall “shortage” is in the 12-year total, which has the lowest percentile value (41st percentile): in the last 12 years 7621 mm of rain fell, which is just 82 mm short of the median 12-year total of 7703 mm.

The year 2011

After a very dry winter, record-breaking spring rain made this an extremely wet year. The rainfall for the year, 839 mm, is in the 86th percentile. It was not quite as wet as 1998 (919 mm; the 6th wettest) or 1996 (890 mm; the 10th wettest). These three years (1996, 1998, 2011) are the wettest in the third of a century since 1978, which had 979 mm.
In other ways, the year was nearer to normal than 2010. There were 91 rain days, fewer than last year’s record 112 rain days. It was much less cloudy, which allowed days to become warmer and nights cooler than last year, when the climate had been more equable: like that on the coast.

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.


November 2008 cool and very wet

The daily weather log

Weather log November 2008

This November was like last November, but wetter. Again, a sunny dry week separated times of overcast rainy days.
Sudden cold changes, which had come twice in October, came again on the 8th, 17th, and 22nd. The last was severe. The maximum on the 23rd was nearly 12° below normal. The temperature that day did not rise above 15° until 5 pm!
Steady soaking rain on the 3rd amounted to 44 mm. A long spell of six rain days from the 17th brought another 48 mm. It began as persistent drizzle but included storms (one with 15 mm size hailstones). These days had low cloud and high humidity. Extremely low humidity (Dew Point 0.1°) came with the cold change, but dew points rose to a peak of 17.4° on the 29th. Over 26 mm of rain fell that day.
Manilla missed two heavy rainstorms of 80 mm each that swept through Tamworth at 10 am and 10 pm on the 28th. There was flooding at Tamworth, at Carroll Gap, and on the plain east of Gunnedah. The Namoi River at Manilla also rose due to rain near Bendemeer.

 Comparing November months

Climate November 2008

Days were the coolest in ten Novembers. However, the mean daily minimum was high, making the daily temperature range (12.4°) even narrower than last November. This agrees with high values for cloudiness and dew point.

The rainfall total, 132 mm, is far above the long-term November average of 67 mm, but that is now common. Five of the last ten Novembers had 110 mm or more. This month and November 2000 were equal ninth wettest on record, and November 2001 (133 mm) eighth wettest.
The rainfall totals for groups of months get higher and higher. The total for 2 months (October and November) is in the 94th percentile, 3 months in the 92nd, 4 months in the 86th, 5 months in the 80th, and 6 months in the 81st percentile. Totals are now above the median for periods up to 72 months with only one exception: that for 9 months is in the 47th percentile. The six-year total rainfall is now 100 mm more than in six average years.

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Dew point values before August 2005 are from Tamworth Airport 6 am data supplied by the Bureau of Meteorology. Temperature and other data are from 3 Monash Street, Manilla.


April 2008: fog and black frosts

The daily weather log

Weather log April 2008

Usually, the air cools and dries out quickly during April. This time only the daily maximum temperature came steadily down. The average temperature hovered near 16° until the last days.
At first, the air was very dry, with a Dew Point below 5°. Under a clear sky on the 4th the early morning temperature went down to 2.1° in the screen, which would be 0.1° of frost. Because the Dew Point (-3.8°) was much lower than that, there was no ice on the grass, which made it a “black frost”. It is said that frosts seldom occur in Manilla before ANZAC Day (April 25th).
As the month went on the air got moister. By the 24th the clouds in the overcast sky were down on the hills. On the 26th the town was blanketed in fog as the humidity hit 100%. (Temperature and Dew Point were both 8°.)
Evaporation was increased by strong winds on the 27th and 28th.
Dry southerly air made the last three days cool and sunny. Black frosts came back giving screen temperatures of 0.6° and 0.1° (around 2° of frost).
Practically no rain (3.6 mm) fell in more than seven weeks from 29 February to 21 April. After that, there were four rain days, including 12.8 mm on the 24th. In total, 20.2 mm fell in April, on five rain days.

 Comparing April months

Climate April 2008

The mean temperature this month was nearly as low as the coolest  April in ten years (1999). This was the fifth cool month in a row: December (1.0° down)  January (1.9° down) February (3.1° down) March (0.9° down) and April (2.1° down). As a 5-month average the temperature was 1.8° below normal. It is as if Manilla had been moved 400 km south (near Grenfell) or 150 metres higher (like Barraba). (Note added: This was a time of global low temperature.)

The month was as cloudy as usual, but less humid.
At 20 mm, this April’s total rainfall is about 20 mm below average, as in 2001 and 2004. It is much higher than in April 2005, when Manilla was in a rainfall  drought for several months.
The rainfall total for this March and April (22 mm) is in the 4th percentile of two-monthly totals: a severe shortage. However, the three-month total (138 mm) is just below the median, and the totals for 4, 5, 6, 9 and 12 months are all at the median or above it. In particular, the 6-month total (401 mm) is quite high, at the 75th percentile.

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Dew point values before August 2005 are from Tamworth Airport 6 am data supplied by the Bureau of Meteorology. Temperature and other data are from 3 Monash Street, Manilla.


Summer 2007-08 was very cool,cloudy and wet

Weather log summer 2007-08

The daily weather log

Most summers recently have had one or two days over 40° and nights over 25°. Not this summer! The hottest day reached only 36.3°, and the warmest night 22.1°. Only 37 days went over 30°: half the usual number. Air conditioners may not have had much use!
The 7-day temperature curves show warm spells in the second week of December, and in the second and fourth weeks of January. Temperatures were then normal. The rest of the time they were well below normal.
Daily minimum temperatures were not so low. This made the daily temperature range small, especially during humid spells.
Humid weather (dew point 16°) came with rain in early December, mid-January, and early February. The air was rather dry (dew point 10°) at New Year and in the very last days of summer.
There were 33 rain days (normally 21). The longest dry spells were eight days from the 22nd of January, and nine days from the 20th of February. February the 6th was the wettest day, with 32 mm, and the summer total was high, at 311 mm.
It was a very cloudy summer. More than half the mornings were cloudy (over 4 octas) and many (18) were completely overcast. Only 13 mornings had a sky clear of cloud.

Comparing summer seasons

Mean daily maximum temperature and mean temperature this summer were the lowest in the nine year record. Mean daily minimum temperature was lower in 1999-2000, which has the next coolest mean temperature. While the cool summer of 1999-2000 had a large daily temperature range (15.6°) related to low rainfall, this summer had a very small daily temperature range (13.2°) related to high rainfall and cloud.
The mean daily maximum this summer (29.7°) is 3.3° below the nine-year average. The fall of over 4° from the very high maxima of the last two summers is dramatic.
Humidity was normal for the time of year.
For rainfall, this short record begins with the 15th driest summer (99-00, 125 mm) and includes the 19th wettest summer (05-06, 319 mm). This summer’s rainfall of 311 mm is 84 mm above the long-term summer average of 227 mm. It is on the 83rd percentile.
At 53% cloudy mornings, this summer season is by far the cloudiest of any season in the nine-year record. No others exceeded 41%.

Climate for summer 2007-08

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Dew Point values before August 2005 are from Tamworth Airport 6 am data supplied by the Bureau of Meteorology. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.