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Ord

                                                                                                   

Climate Overview

                             

Maps and graphs provide a summary of the rainfall, evaporation and temperature data for the reporting period.

 

Climate overview 2009–10

The Ord region experienced hot and dry conditions during 2009–10, resulting from above average evapotranspiration (ET) and maximum daily temperatures, despite receiving average annual rainfall.

 

Rainfall

The Ord region experienced average annual rainfall during 2009–10.

The total area-averaged rainfall over the Ord region during 2009–10 was 732 mm, which is above the mean annual rainfall of 671 mm. Figure C1 shows around average rainfall was experienced across most of the region during 2009–10. Above average rainfall occurred over the southeast of the region and over the lower Ord floodplains. 
 

Figure C1. Map of annual rainfall deciles for the Ord region during 2009–10

Figure C1. Map of annual rainfall deciles for the Ord region during 2009–10

During 2009–10, there was a strong north-south gradient in annual rainfall across the region (Figure C2), ranging from more than 1100 mm in the north to less than 500 mm in the south. This distribution of rainfall was similar to the long-term average rainfall pattern (Figure C3).

Figure C2. Map of total annual rainfall for the Ord region during 2009–10

Figure C2. Map of total annual rainfall for the Ord region during 2009–10

 

Figure C3. Map of average annual rainfall for the Ord region, based on data collected between 1961-1990

 

Figure C3. Map of average annual rainfall for the Ord region, based on data collected between 1961–90

Rainfall over the Ord region is strongly seasonal with almost all the annual rainfall generally occurring between October and March. On average, very little rainfall occurs between April and October (Figure C4).

 

Figure C4. Graph of total monthly rainfall for the Ord region during 2009–10 compared against the long-term percentiles for the region

Figure C4. Graph of total monthly rainfall for the Ord region during 2009–10, compared against the long-term percentiles for the region

A strong El Niño event in the Pacific Ocean caused drier conditions across the region during 2009–10, resulting in rainfall below the 50th percentile between October and December. This was offset by a moderately active Madden-Julian Oscillation event during January, ensuing high rainfall across northern Australia and rainfall well above the 50th percentile in the Ord region. Some unseasonable rainfall occurred during May 2010, with record high rainfalls recorded at several stations across the region, arising from a series of northwest cloudbands over the region.

Evapotranspiration

The Ord region experienced above average annual evapotranspiration (ET) during 2009–10.

The total area-averaged ET over the Ord region during 2009–10 was 642 mm, which is above the mean annual ET of
541 mm. ET was above average to very much above average across most of the region during 2009–10 (Figure C5). Only over Lake Argyle was ET average to below average.
 

Figure C5. Map of annual evapotranspiration deciles for the Ord region during 2009–10

Figure C5. Map of annual evapotranspiration deciles for the Ord region during 2009–10

There was a strong north-south gradient in annual ET across the region during 2009–10 (Figure C6), similar to the rainfall gradient. ET ranged from more than 900 mm in the north, to less than 400 mm in the southwest around Halls Creek. There was also a small area of low ET over Lake Argyle. The distribution of ET across the region during 2009–10 was similar to the long-term average ET pattern (Figure C7).

 

Figure C6. Map of total annual evapotranspiration for the Ord region during 2009–10

Figure C6. Map of total annual evapotranspiration for the Ord region during 2009–10

 

Figure C7. Map of average annual evapotranspiration for the Ord region, based on modelled data from 1911–2010

Figure C7. Map of average annual evapotranspiration for the Ord region, based on modelled data from 1911–2010

Temperature

The entire Ord region experienced above average maximum daily temperatures during 2009–10 (Figure C8).

 

Figure C8. Map of annual maximum daily temperature deciles for the Ord region during 2009–10

Figure C8. Map of annual maximum daily temperature deciles for the Ord region during 2009–10

Maximum daily temperatures were highest along the Ord River valley and at lower elevations in the northern parts of the region around Wyndham and lowest in the upper parts of the region around southwest and southeast boundaries
(Figure C9). The temperature pattern across the region during 2009–10 is similar to the long-term average conditions (Figure C10).

 

Figure C9. Map of annual mean maximum daily temperature for the Ord region during 2009–10

Figure C9. Map of annual mean maximum daily temperature for the Ord region during 2009–10

 

Figure C10. Map of average annual maximum daily temperature for the Ord region based on data collected between 1961-1990

Figure C10. Map of average annual maximum daily temperature for the Ord region based on data collected between 1961–90

The area-averaged monthly maximum daily temperatures were generally above the 50th percentile for most of the reporting period and were above the 90th percentile for some months (Figure C11).

 

Figure C11. Graph of average monthly maximum daily temperature for the Ord region during 2009–10 compared with the long-term percentiles for the region

Figure C11. Graph of average monthly maximum daily temperature for the Ord region during 2009–10 compared with the long-term percentiles for the region

A strong El Niño event in the Pacific Ocean caused hotter conditions across the region and maximum daily temperatures were particularly high between July and December. Maximum daily temperatures during May were below the 50th percentile due to a series of northwest cloudbands over the region.