Tag Archives: rainy

Cool, cloudy, wet October 2010

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log October 2010 Manilla

 

October days were very cool: no days went above 30°, when usually seven days do, and the 16th, at 14.2°, was 13° below normal. The following night (the only frost) was 10° below normal. A day earlier, overcast skies brought an extremely narrow daily temperature range (2.3°) on the 15th.
Rain fell on 8 days. The highest reading was 20.4 mm on the 4th.

Comparing October monthsClimate October 2010 Manilla

 

The mean daily maximum temperature (24.2°) was the lowest for October on this 12-year record. The mean daily mean temperature (17.7°) was low, but the mean daily minimum temperature (11.2°) was normal. The mean daily temperature range (13.1°) was a record low value.
Mean subsoil temperature was remarkably low: 17.4° against a 12-year October mean of 19.4°. The month ended with subsoil temperature (then 18.8°) trailing 22 days later than its usual date.
There were more cloudy mornings (58%) than in any October on this record. The mean early morning Dew Point (9.6°) was also high.
The rainfall of 85.4 mm is in the 80th percentile for October, far above the long-term average of 58 mm. Totals for groups of months up to six months are now all above the median, as is the thirty-year total.

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.

Rainy, very cloudy September 2010

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log September 2010 Manilla

 

Like August, September had no extremes. Many days had normal temperatures, especially late in the month, and many others were cool. Nights varied, with two frosts, but most were warm.
Rain fell on 11 days, a September record number for the decade. The highest reading was 22.2 mm on the 10th. A reading of 12.6 mm was due to a brief afternoon shower on the 27th.

Comparing September monthsClimate September 2010 Manilla

 

The mean daily temperature (14.9°) was normal, but days (21.5°) were only 13.3° warmer than nights (8.2°). Usually, September has the highest daily temperature range of the year: 16.9°.
Along with cool days and warm nights, there were more cloudy mornings (57%) than in any September on this record. Very high humidity made the mean early morning Dew Point (7.3°) nearly two degrees higher than normal.
The rainfall of 59.3 mm is in the 76th percentile for September, well above the long-term average of 41 mm. Totals for two, three, and four months are now all above the median. The thirty-year total has now reached the median value, after three years below it.

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.

Winter 2010 wet, with few frosts

Posted in Manilla NSW, Season Weather by

 An episode of maritime climate

I have posted this seasonal report for winter 2010 on the front page, as a sticky post, to show how the climate of that season was not normal. It was not the average temperature or the rainfall that were unusual. The sky was very cloudy, the humidity very high, and the daily temperature range very low. The climate was equable, as one would expect at a place near the sea: a maritime climate. More in the footnote*

Weather log winter 2010

Temperatures this winter changed little from month to month. June, July and August each had temperatures near the season averages: maximum 17.0°, mean 10.7° and minimum 4.5°. Warm days were rare: only 11 exceeded 20° (usually 25). This winter was even less frosty than the last, with only 32 frosts (usually 44). The lowest minimum was -3.1°.
There were 33 rain days, about twice the usual number.

In terms of daily mean temperature, this winter was normal, However, cool days and warm nights made the daily temperature range (12.5°) narrower than in any winter in the 12-year record. It was also the cloudiest, at 49% cloudy mornings. Manilla’s climate became much more cloudy three years ago, when the average number of cloudy mornings in a month jumped suddenly from nine to twelve (See also these other graphs.). Humidity, as shown by early morning Dew Point was also very high this winter. All these changes reflect a more maritime climate, as on the coast.
Each month would have had rainfall close to average, were it not for one reading of 34.2 mm at the end of July. The total of 160 mm is in the 70th percentile, like that of the wet winters of 2005 and 2007.

Climate winter 2010

*Footnote. The nature of this episode is clear on the 3-year graphs of climate trends, such as that for August 2011. The top left graph shows that, in June, July, and August 2010, rainfall was a little high and daily maximum temperature rather low. The bottom left graph shows the main anomaly: daily minimum temperature remained extremely high while daily maximum rapidly fell, reaching a record low value by October 2010. From July to November that year the difference between daily maximum and daily minimum temperature was some three degrees less than normal.
The middle graph on the right shows directly that the daily temperature range in those months was at record low (narrow) values.

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.

July 2010 Rain Twice Average

Posted in Manilla NSW, Monthly weather by

The daily weather logWeather log July 2010 Manilla

July began cold. The 2nd, with a maximum temperature of 9.1°, was the coldest July day in the record from 1999. The only two colder days were: 8/06/07 (8.8°), and 20/06/07 (8.3°).

Two warm spells followed, marked mainly by nights that were very warm for mid-winter. The minimum on the 12th (11.8°) was 10° above normal, and that on the 31st (13.5°) was 11.3° above normal. Colder nights included twelve mild frosts, the fewest on record.
There were 13 rain days spread through the month. The reading of 17.2 mm on the 29th was topped by 34.2 mm on the 31st.

“Normal Temperature”

Each Manilla monthly weather graph has dashed curves to show the temperatures that are normal for each day of the year. They are harmonic curves matching 10-year averages from March 1999. On this July graph, the lowest values are marked with a double “X”. Winter cold is due to lack of heat from the sun, which yields least heat on the 21st of June (the winter solstice). On that day the sun is lowest and shines the shortest time. However, it takes many days for the air to cool down. On average, the coldest day in Manilla comes 17 days later (July 8th) and the coldest night 22 days later (July 13th). Manilla’s coldest day and night follow the solstice with an unusually short lag time. (See Wikipedia: “Seasonal lag”.)

See the monthly weather report for January 2010 for the highest normal temperatures of the year. These relationships are shown on a graph here.

Comparing July monthsClimate July 2010 Manilla

Due to cloudy nights, the mean daily minimum temperature (4.6°) was by far the highest in the 12-year record for July, and 2.4° above the average. Because the mean maximum temperature was normal (16.9°), the mean average temperature was also high (10.8°). The mean daily temperature range (12.3°) was the narrowest in the July record.

Very high humidity was shown by a mean early morning Dew Point of 4.6°, higher than any since July 1999 (5.7°). The percentage of cloudy mornings (61%) was the highest, not only for July months, but for any month in this record. Nineteen mornings were completely overcast.
The rainfall of 79.8 mm is in the 90th percentile for July: only 12 July months have been wetter. It is close to double the long-term average of 41 mm. As a result, total rainfalls for the last two months and three months are now above the median. No serious rainfall shortages remain. The worst shortages are far from serious: the 15-month and the 9-year totals are both in the 14th percentile.

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.

February 2009: swelter and shiver

Posted in Manilla NSW, Monthly weather by

The daily weather log

Weather log February 2009

February days began hot (37.8°), and got hotter. The 9th reached 40.9°: that was 7.5° above normal, and the hottest day of the summer. At 20°, nights were unpleasantly warm, but it is normal for the first week of February to have the hottest nights of the year (18.4°).
The daily maximum on the 14th was an amazingly cool 17.8°, that is, 23.1° lower than five days before! The reading was 15.2° below normal. On that day, half of NSW, excluding only the borders on the east, south and west, had daily maximum temperatures more than 12° below normal.
A wet spell from the 11th to the 17th brought most of the month’s rain.At Manilla the highest reading was 51.2 mm on the 15th.
The month ended dry, with temperatures normal, except that nights became cool.

 Comparing February months

Climate February 2009

This month’s climate was normal, if rather wet. Other Februaries on the graph vary in every way:

February 2005 was sunny, dry, and not humid;
February 2006 was hot and humid;
February 2007 was very rainy;
February 2008 was very cloudy and very cold.
The rainfall total (94.5 mm) was in the 75th percentile for the month; well above the February average of 67 mm. This neatly makes up the January shortfall. Rainfall totals for groups of months remain very high. The 6 month total (525 mm) is in the 92nd percentile, and more than 200 mm above the median value. Totals are still above the median for all periods up to 72 months, with the exception of the 36-month total, and that has now risen to the 46th 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.