Thursday, 2 January 2014 - Monthly Climate Summary for Western Australia - Product code IDCKGC11R0

Western Australia in December 2013: a warm and wet month

• Rainfall: above average for WA
• Maximum temperature: above average for WA
• Minimum temperature: above average for WA

Rainfall

December 2013 rainfall was above to very much above average rainfall over a broad area extending from the Pilbara and west Kimberley coast to eastern Southeast Coastal and western Eucla, as well as scattering areas in the north and east Kimberley, mostly due to a weak low in the Timor Sea followed by Tropical Cyclone Christine towards the end of month. Some sites in the Pilbara received their highest daily rainfall in December on record on the 31st, and Karratha Aerodrome also registered its wettest December month in 41 years of rainfall record as the result. Conversely, below to very much below average were observed in scattered areas of the Gascoyne,  Goldfields, and Southwest Land Division (SWLD).

Averaged across WA as a whole, rainfall in December 2013 was above average,though it was near average rainfall for the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) and the Southwest Land Division (SWLD).

Seasonal shower and thunderstorm activity was frequent during December in the Kimberley and Pilbara, with some moderate to heavy rainfall reported. Falls were particularly heavy from the 23rd as a low in the Timor Sea moved toward the north Kimberley. Severe Tropical cyclone Christine made landfall on the Pilbara coast between Whim Creek and Roebourne on the 30th and brought some very heavy falls, and Abydos North (southeast of Port Hedland) received a daily rainfall total of 168.6 mm on the 31st, the highest daily rainfall in WA of the month.

A trough developed near the west coast on the 5th and moved slowly eastward across southern WA over the following few days triggering isolated showers and thunderstorms in the Gascoyne, SWLD, Goldfields, Southern Interior, and Eucla, with some moderate falls from the 6th to 9th before another West Coast Trough produced thunderstorms with moderate rainfall in the Gascoyne, Central West, northern Goldfields, and Southern Interior on the 10th and 11th. Moderate falls were reported in WA south coast districts on the 19th and 20th as a cloudband moved across the region.

Maximum temperature

Above to very much above average mean maximum temperatures were observed in the western and southern WA, with up to 4 °C above warmer than normal in the western Eucla. In contrast, above to very much above average mean maximum temperatures were recorded over a band covering the west and inland east Kimberley, Northern Interior and east Pilbara, with up to 3 °C cooler than normal in the east Kimberley.

Averaged across the state as a whole, the mean maximum temperature for WA in December 2013 was above average. For the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), the mean maximum temperature in December 2013 was also above average.

Cool to cold days were observed in parts of the SWLD from the 1st to 4th, and from the 7th to 9th, with the 7th being the coldest day for the month for most sites and a daily maximum of 17.1 °C at Pemberton (Southwest) was the lowest maximum temperature of December 2013 in WA. Toward the middle of the month, a strong high moved slowly through the Bight bringing prolonged hot conditions to southern WA. A hot spell with daily maximum temperatures above 35 °C started in western parts of the SWLD on the 12th and intensified and gradually shifted south and east and ended in the Eucla district on the 18th. Temperatures above 44 °C were reported in the Central West, Central Wheat Belt, Goldfields, Southeast Coastal, and Eucla during the heat event with sites in the Central West and Southeast Coastal recording their highest December temperature on record. Red Rocks Point in the Eucla district recorded a maximum temperature of 46.0 °C on the 18th, which is the highest temperature at Red Rocks Point in December in 11 years of record. An inland trough directed very hot northely winds over the southeastern WA on the 27th. Eucla (town) recorded a daily maximum temperature of 47.4 °C, which is its hottest December day in 52 years of record, and the highest temperature of the month in WA.

Minimum temperatures

Above to very much above average mean minimum temperature were observed in a broad area from the northwest, through central, down to Southeast WA. Below to very much below average mean minimum temperatures were confined in small areas of west and south Kimberley.

Averaged across the state as a whole, the mean minimum temperature for WA in December 2013 was above average. Averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), the mean minimum temperature was near average.

In the SWLD, December 2013 started with cool to cold nights from the 1st to 5th, from the 8th to 11th, and from the 21st to 23rd. A minimum of 3.0 °C was recorded at Salmon Gums Research Station on the 10th, which was the lowest temperature of the month in WA. Warm nights were mainly observed in the SWLD on the 6th, and from the 14th to 18th. Very warm nights with daily minima over 30 °C were experienced in the inland east Pilbara and Northern and Southern Interior on the 3rd, and contracting to the inland east Pilbara and western Northern Interior on the 4th. Telfer Aerodrome in the Pilbara recorded the highest minimum temperature of the month in WA on the 4th with 32.0 °C. Parts of the central WA also saw very warm nights at the last two days of December. Wiluna in the northern Goldfields recorded a minimum of 31.0 °C on the 30th, which is the highest overnight temperature at Wiluna in 52 years of record, exceeding its previous record of 30.5 °C set on 19 December 2005.

Other Phenomena

Thunderstorms that developed over the inland eastern Pilbara on the 21st produced damage at the Jigalong Community, approximately 165km east of Newman. Overhead powerlines and some minor structural damage was reported; some roads were also made impassable in the wake of the storms. Thunderstorms produced a wind gust of 91 km/h at 1232 WST at Coondewanna, northwest of Newman.

A tropical low off the northwest coast became Tropical Cyclone Christine in the evening of the 28th and made landfall as a category 3 cyclone at the Pilbara coast between Whim Creek and Roebourne on the 30th. TC Christine brought very heavy falls, and destructive winds to the Pilbara region. Roebourne Airport recorded a wind gust of 172 km/h on the 30th. A power station be in the Roebourne and Whim Creek area was destroyed and caused a lengthy power outrage.

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top

Maps

Maps
	Observed	Anomaly	Decile rank
Total rainfall
Mean daily maximum temperatures
Mean daily minimum temperatures

Extremes Maps Records Summaries Important notes the top

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported.

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top