Tuesday, 1 October 2013 - Monthly Climate Summary for Western Australia - Product code IDCKGC11R0

Western Australia in September 2013: Wet & warm nights in the Southwest

• Rainfall: above average rainfall for WA, 6th wettest for southwest WA
• Maximum temperature: 10th warmest for WA, near average for southwest WA
• Minimum temperature: 4th warmest for WA, 2nd warmest on record for southwest WA

Extremes Maps Records Summaries Important notes the top

Rainfall

Rainfall in September 2013 was below to very much below average over the north and east Kimberley, Northern Interior and areas in the inland Pilbara, Gascoyne and Southern Interior. Much of the Southwest Land Division (SWLD), Goldfields, Eucla, as well as various parts in the Pilbara and Gascoyne received above to very much above average rainfall, with a dozen locations in the Lower Southwest registering their wettest September on record, as the result of persistent westerly winds during September in the region with the frequent passage of cold fronts, lows and troughs

For WA as a whole, rainfall in September 2013 was above average, however averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), September 2013 was the 6th wettest September on record. For the wider SWLD region, rainfall ranked as the 7th wettest September on record.

A westerly airstream produced mainly light showers in western parts of the SWLD on the 1st and 2nd before a cold front and associated cloudband moved through western parts of WA bringing widespread rainfall to the SWLD and southern Gascoyne and Goldfields on the 3rd and 4th.

A trough and associated low developed near the west coast on the 6th and moved across central and southeastern WA to bring widespread showers and thunderstorms to the southern WA on the 7th and 8th. Moderate to heavy falls were recorded in parts of the SWLD and southern Goldfields and a number of locations in the Central Wheat Belt and South Coastal witnessed their wettest September day on record during the event.

Two cold fronts moved through the SWLD on the 10th and 11th producing showers and thunderstorms in much of the SWLD, southern Gascoyne, Goldfields and Eucla. Moderate to heavy falls were mainly in the southwes of the SWLD.

A strong cold front and associated low moved slowly across the SWLD from the evening of the 13th to 14th, bringing showers and thunderstorms and strong winds to western and southern WA with moderate to heavy falls near the coast. Lort River in the Southeast Coastal recorded 32.0 mm on the 15th, which was their wettest September day in 44 years of record.

A strong cold front again moved through the SWLD on the 16th and 17th producing widespread showers across the SWLD with moderate falls in the Lower West, Southwest and South Coastal.

A westerly airstream in the wake of front continued to bring light showers between the 18th and the 20th before two strong cold fronts moved across the SWLD on the 22nd and 23rd producing damaging winds and showers to the SWLD. At least 15 homes were badly damaged in Maddington in the Perth metropolitan area. SES Service volunteers responded to more than 88 calls for help, including at least 30 in the Gosnells and Maddington area. About 20,000 properties were without electricity, in areas around Perth, Manjimup, Busselton, Pemberton and Bunbury.

A number of weak cold fronts and a westerly airstream continued to produce mainly light rainfall in parts of the SWLD from the 24th to 27th. A cold front and associated cloudband moved through the SWLD on the 29th bringing widespread rainfall to the SWLD, with moderate to heavy falls in the South Coastal and Southeast Coastal districts.

Maximum temperature

Very much above average mean maximum temperatures were observed in eastern parts of WA,the adjacent east Pilbara, and southern coastal region. The highest on record was observed in the eastern Southern Interior and adjacent Northern Interior with mean maximum temperature up to 5 °C warmer than normal. Eucla and Eyre as well as Warburton Airfield in the Southern Interior observed their warmest September on record. Mean maximum temperature was near average for the remainder of the Sate.

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

With the exception of a few mild to warm days, hot to very hot days were dominant in the Kimberley, Northern Interior and Southern Interior. The highest temperature of the month in WA was 41.6 °C at Fitzroy Crossing Aerodrome on the 26th and 27th. Halls Creek Airport recorded a daily maximum temperature of 40.2 °C on the 27th, which was the highest temperature in September on record in 66 years of record.

Mild to warm days were experienced in the southern half of WA. with daily maxima 10-12 °C warmer than normal observed in southeastern parts in the first three days of September 2013, whilst the Pilbara observed hot days for the first 5 days. Cool to cold days were recorded in the southeast Gascoyne, SWLD, Goldfields, Southern Interior and Eucla from the 4th to 9th and again on the 14th, 15th, 17th, 29th and 30th due to wet and cloudy conditions, interspersed with a hot day or two on the 10th and 11th. The lowest temperature of the month in WA was 12.5 °C on the 29th at Manjimup. Warm to hot days returned to the Eucla district from the 20th to the end of the month. Eyre recorded 3 days with daily maxima of 34 °C or higher during September, which was the equal highest number of such days on record, equaling with 2012 and 2001.

Minimum temperatures

Much of WA saw above to very much above average mean minimum temperatures in September 2013, with highest on record in parts of SWLD and Eucla, as the result of warmer than normal sea surface temperatures surrounding the WA coast. Over a dozen locations in the SWLD and Eucla recording their highest mean minimum on record. Mean minima up to 4 °C warmer than normal were recorded in the eastern Eucla and parts of the Southern Interior. Most of the Kimberley and adjacent parts of the Pilbara and Northern Interior were near average in terms of mean minimum temperature.

Averaged across the state as a whole, the mean minimum temperature for WA in September 2013 was the 4th warmest September since comparable records began in 1910. Averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), the mean minimum temperature was the 2nd warmest on record.

Nights were predominantly mild to warm in the Southwest Land Division, Goldfields, Southern Interior and Eucla, interspersed with a few cool to cold nights on the 5th, 6th, 9th, from the 16th to 18th, 26th, 27th and 30th. A number of sub-zero temperatures were registered during those cold nights and the lowest temperature of the month in WA was -1.5 °C at Salmon Gums Research Station on the 6th.

In the north, warm nights were experienced from the 2nd to 8th in the Pilbara and Gascoyne, which contrasted to cool nights in the Kimberley. Cool nights were observed on the 13th, 16th and 21st in the Pilbara and west Kimberley whilst warm nights were evident in the Gascoyne and southern Pilbara on the 22nd and 24th, and in the north and east Kimberley from the 27th to the 30th. Warmun in the Kimberley recorded the highest minimum temperature of the month in WA with 27.0 °C on the 29th.

Other Phenomena

A series of strong cold fronts, associated with a deep, complex low pressure system, affected the Southwest Land Division from early Sunday September 22 until Tuesday September 24. A wind gust of 79 knots (146km/h) was recorded at Cape Leeuwin on the 22nd. A tornado was also reported in the southeast suburbs of Perth at Maddington, where significant structural damage occurred.The second, and strongest, cold front moved over the southwest region in the early hours of Sunday the 23rd. Widespread damaging winds were experienced over the SWLD. About 20,000 properties were without electricity, in areas around Perth, Manjimup, Busselton, Pemberton and Bunbury. SES Service volunteers responded to more than 88 calls for help, including at least 30 in the Gosnells and Maddington area. Flooding has forced the closure of a northbound lane of the Kwinana Freeway before South Terrace in Como.

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

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top