Friday, 1 February 2013 - Monthly Climate Summary for Western Australia - Product code IDCKGC21R0
Rainfall during January 2013 was above- to very-much-above-average through much of western and central WA, but particularly in central and western parts of the Pilbara as a result of local thunderstorm activity as well as the passage of tropical cyclone Peta through the region bringing some record daily falls. Western parts of the Gascoyne also saw above average rainfall due to local thunderstorm activity, as did northern parts of the Southwest Land Division (SWLD) as a cloudband associated with tropical cyclone Narelle brought some heavy falls. Below average rainfall was mainly confined to parts of the Kimberley and northeast Southern Interior as monsoonal activity was confined to a brief period in the middle of the month with the majority of rainfall a result of diurnal shower and thunderstorm activity.
Averaged across the state as a whole, rainfall during January 2013 was close-to-average for WA, while for the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) and the SWLD January 2013 rainfall was above average.
Although a short-lived weak system, tropical cyclone Peta moved across the Pilbara coast near Roebourne on the afternoon of the 23rd and weakened to a tropical low. It brought significant rainfall to eastern coastal and central inland parts of the Pilbara from the 20th to the 25th with numerous daily falls over 100 mm reported. The highest daily fall during the event was 261.6 mm at Hooley on the 24th, which was the highest daily rainfall in WA for the month, and the wettest day at Hooley in 29 years of record. Mount Florance recorded 220.0 mm also on the 24th, its wettest January day in 106 years of record, whilst the following day Wittenoom recorded 228.0 mm, its highest daily fall in January in 58 years of record. Between 0900 WST on 22nd and 0900 WST on 25th, Hooley, Wittenoom, and Mount Florance all reported over 300 mm, with Hooley recording the highest total of 377.0 mm. Flooding impacts were generally localised and mostly minor.
Tropical cyclone Narelle moved southward parallel with the WA west coast from the 12th to the 15th and weakened into a low as a cloudband associated with the tropical low, and consequent thunderstorm activity due to increased atmospheric moisture, brought unseasonal rainfall to western and southern parts of the State. The highest daily falls were in the 50 mm to 100 mm range in the Central West, Central Wheat Belt, and Goldfields. This event brought the majority of Kellerberrin's January rainfall total of 104.3 mm, and was the main reason for the site recording its wettest January in 119 years of recording.
Maximum temperatures during January 2013 were above- to very-much-above-average over much of western, southern, and eastern WA, as well as large parts of the Kimberley, with daytime temperatures up to 4 °C above normal in the eastern Southern Interior, as well as in the Shark Bay area of the west Gascoyne. Below average maxima were confined to the Pilbara, due to the relatively wet and cloudy month, with daytime temperatures to 2 °C below normal in central and western parts of the district.
When averaged across the state as a whole, the mean maximum temperature for WA for January 2013 was well above average and ranked eleventh-highest since comparable records commenced in 1910, continuing the run of above average monthly mean maxima for WA since April 2012. When averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), the mean maximum temperature was above average.
January 2013 began with very hot conditions in southern and southeast WA on the 1st as the trough near west coast moved eastward, and temperatures reached the low-to-mid forties. The hot conditions shifted to the southeast corner of WA on the 2nd and 3rd and intensified as the trough moved slowly eastward. Eucla recorded a daily maximum temperature of 48.2 °C on the 3rd, which exceeded the previous highest January temperature at the site in its 51 years of record of 47.9 °C on 3 January in 1979. Red Rocks Point (west of Eucla) registered 48.6 °C on the same day, which was the highest temperature at that site in its 9 years of record, and the highest temperature recorded in the Eucla district in almost 31 years, since Mundrabilla Station recorded a maximum temperature of 48.6 °C on 15 February 1983. Exceptional conditions were also experienced in the inland Gascoyne, northern Goldfields, and Northern and Southern Interior from the 7th to the 10th as a very hot airmass lay over the region with clear skies and light winds. A number of sites recorded their hottest January day on record multiple times during this period, including Paynes Find, Yeelirrie, Wiluna, and Meekatharra Airport. Leonora in the Goldfields broke its previous record of 47.8 °C twice, on the 8th (48.3 °C), and 9th (49.0 °C), with the latter being the highest temperature of the month in WA. Giles Meteorological Office in the Southern Interior saw four consecutive days with temperatures above 44 °C between the 7th and 10th, and in its 57 years of record had only recorded consecutive days over 44 °C once before, on 1 and 2 January 1973. Giles twice broke its all-time record temperature during this spell but high temperatures returned from the 13th to 17th and a daily maximum temperature of 45.7 °C on the 16th became the new record high for the site. Partly as a result of these hot spells, Giles Meteorological Office recorded its equal highest January mean maximum temperature with 40.3 °C, only 0.1 °C behind its hottest month on record; February 2007. Ongerup in the South Coastal also recorded its equal warmest January on record.
Minimum temperatures during January 2013 were above- to very-much-above-average across most of the State, with areas of highest on record in the Great Southern, South and Southeast Coastal as several sites recorded their warmest or equal warmest January on record. Overnight temperatures were up to 5 °C above average in the southeast Northern Interior, north of Giles. In contrast, parts of the southeast Pilbara and eastern Gascoyne recorded below average overnight temperatures with mean minima 2 °C to 3 °C below normal in the east Gascoyne.
When averaged across WA as a whole, the mean minimum temperature during January 2013 was well above average and ranked as the third-warmest January on record. This continues a recent very warm trend for WA January minimum temperatures with the warmest five Januarys being 2011 (1st), 2008 (2nd), 2013 (3rd), 2010 (4th), 2009 (5th) from comparable temperature records commencing in 1910. The Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay) also saw well above normal overnight minima, with the region observing its eighth-warmest January, continuing a run of above average January mean minima for the region with 2012 being the warmest on record and 2011 fifth-warmest.
Very warm nights were reported across southern WA to start the month and Cape Leeuwin in the Southwest recorded a daily minimum temperature of 23.8 °C on the 1st, breaking its previous warmest January night in 107 years of record of 23.5 °C set on 26 January 2012. Very warm nights were reported across much of WA between the 6th and 10th and several sites in the Southwest district reported record high minima on the 8th, along with Merredin in the Central Wheat Belt and Paynes Find in the southern Gascoyne. Cape Leeuwin reported a minimum of 24.2 °C, again exceeding its January record. Wiluna recorded an overnight temperature of 33.5 °C on the 9th, the highest minimum temperature of the month for WA. Very warm nights were again experienced in much of WA between the 15th and 17th and Perth Airport recorded its highest January minimum in 69 years of record on the 15th with 27.8 °C, whilst Albany Airport recorded a minimum of 20.9 °C, almost 1 °C above its previous January record. Large parts of WA welcomed cooler than normal nights in the last week of January.
Severe tropical cyclone Narelle formed well north of the Australian coast on the 8th and took a general southwesterly track, intensifying to a category four system on the 11th north-northwest of Exmouth. Narelle moved south-southwest off the WA west coast and was downgraded to a low early on the 15th, over 500 km to the west of Geraldton. Although threatening the Pilbara and Gascoyne coasts and disrupting shipping and offshore industries, Narelle remained far enough offshore not to directly impact the northwest coast. A tidal surge was recorded from Onslow to Busselton as a result of Narelle causing some inundation of low lying areas, though any impacts were minor.
A tropical low formed over in the Kimberley on the 20th and tracked southwest through the west Kimberley then close to and parallel with the Pilbara coast before turning to the southwest towards the Pilbara coast early on the 23rd. The system intensified into tropical cyclone Peta (category 1) on the morning of the 23rd and crossed the coast near Roebourne then weakened to a tropical low in the afternoon on the 23rd. Although tropical cyclone Peta was short-lived and relatively weak, its proximity to the coast resulted in disruptions to shipping and offshore industries. There was also significant rainfall along parts of the Pilbara coastline and in the Fortescue catchment, with accumulated falls over 300 mm reported, leading to minor flooding.
|Extremes in January 2013|
|Hottest day||49.0 °C at Leonora on the 9th|
|Warmest days on average||40.5 °C at Telfer Aero|
|Coolest days on average||24.5 °C at Albany|
|Coldest day||18.7 °C at Norseman Aero on the 12th|
|Coldest night||3.8 °C at Eyre on the 30th|
|Coolest nights on average||13.2 °C at Rocky Gully|
|Warmest nights on average|| 27.0 °C at Broome
27.0°C at Karratha Aero
|Warmest night||33.5 °C at Wiluna on the 9th|
|Wettest overall||430.6 mm at Wittenoom|
|Wettest day||261.6 mm at Hooley on the 24th|
|Highest wind gust|| 109 km/h at Mount Magnet
Aero on the 23rd
109 km/h at Wyndham Aero on the 27th
|Record highest January daily rainfall|
Highest daily rainfall
in January 2013 (mm)
|Mount Florance||220.0||on the 24th||176.0||on the 25th in 1961||106|
|Wittenoom||228.0||on the 25th||170.8||on the 13th in 2012||58|
|Record highest total January rainfall|
for January 2013 (mm)
|Record highest January temperature|
in January 2013 (°C)
|Meekatharra Airport||47.1||on the 8th||45.7||on the 5th in 2008||63||38.3|
|Giles Meteorological Office||45.7||on the 16th||44.8||on the 28th in 2011||57||37.3|
|Leonora||49.0||on the 9th||47.8||on the 17th in 1958||57||37.0|
|Wiluna||48.0||on the 8th||46.9||on the 1st in 1990||56||37.9|
|Eucla||48.2||on the 3rd||47.9||on the 3rd in 1979||51||25.9|
|Yeelirrie||47.9||on the 8th||45.8||on the 7th in 1983||40||37.9|
|Paynes Find||47.2||on the 8th||46.5||on the 20th in 1991||34||37.4|
|Record highest January daily minimum temperature|
Highest daily minimum
in January 2013 (°C)
|Cape Leeuwin||24.2||on the 8th||23.5||on the 26th in 2012||107||16.9|
|Broome Airport||30.5||on the 27th||30.2||on the 30th in 1988||74||26.3|
|Perth Airport||27.8||on the 15th||27.3||on the 21st in 1989||69||17.0|
|Pemberton||23.8||on the 8th||23.3||on the 16th in 1968||55||13.2|
|Albany Airport Comparison||20.9||on the 16th||20.0||on the 26th in 1974||48||13.7|
|Merredin||29.7||on the 8th||29.2||on the 5th in 1977||48||17.7|
|Paynes Find||30.8||on the 8th||= 30.8||on the 3rd in 2008||34||20.9|
|Jarrahwood||26.0||on the 8th||24.3||on the 12th in 1978||31||12.6|
|Record highest January mean daily minimum temperature|
Mean daily minimum
for January 2013 (°C)
|Albany||17.3||= 17.3||in 2011||95||15.1|
|Christmas Island Aero||23.2||23.1||in 2010||39||22.6|
|Summary statistics for January 2013|
|North Kimberley (district 01)|
|East Kimberley (district 02)|
|Halls Creek Airport||38.3||+1.6||40.6||25th||25.3||+1.0||20.9||18th||105.6||150.7||average||70%|
|West Kimberley (district 03)|
|Fitzroy Crossing Aero||38.6||+1.0||42.7||6th||25.5||+0.3||21.0||17th||119.2||165.9||low||72%|
|De Grey (district 04)|
|Pardoo Station||37.5||+1.1||44.5||7th||23.5||22nd||219.5||63.5||v high||346%|
|Port Hedland Airport||37.7||+1.3||42.8||7th||26.6||+1.0||23.3||30th||158.0||63.6||high||248%|
|Fortescue (district 05)|
|Barrow Island Airport||34.6||+1.4||39.1||30th||27.4||+1.5||24.7||15th||29.0||24.8||average||117%|
|West Gascoyne (district 06)|
|Emu Creek Station||40.0||-1.2||45.8||8th||26.0||+1.5||22.5||7th||98.8||47.4||high||208%|
|Shark Bay Airport||36.2||+2.5||44.5||31st||22.9||+1.5||19.6||5th||26.6||10.2||high||261%|
|East Gascoyne (district 07)|
|Murchison (district 07A)|
|Mount Magnet Aero||38.3||+0.5||47.4||8th||23.5||+0.1||18.7||4th||42.4||26.6||high||159%|
|North Coast (district 08)|
|Geraldton Airport Comparison||33.4||+1.7||41.9||31st||19.4||+1.1||12.0||18th|
|Wongan Hills||34.7||+0.1||44.7||8th||19.3||+1.5||13.5||18th||73.8||14.3||v high||516%|
|Central Coast (district 09)|
|Badgingarra Research Stn||34.1||-0.6||41.0||8th||18.4||+1.4||11.7||4th||26.0||9.5||high||274%|
|Garden Island HSF||27.3||0.0||33.9||31st||20.0||+1.2||15.1||18th||4.6||11.0||average||42%|
|South Coast (district 09A)|
|Albany Airport Comparison||26.3||+1.6||40.3||1st||14.7||+1.0||6.4||29th||7.2||23.7||low||30%|
|Windy Harbour||24.9||+1.7||35.4||8th||15.9||+1.6||7.8||29th||3.6||15.9||v low||23%|
|North Central (district 10)|
|South Central (district 10A)|
|Newdegate Research Station||32.2||+1.4||44.2||1st||15.4||+1.6||7.6||25th||23.8||19.0||high||125%|
|Eucla (district 11)|
|Red Rocks Point||26.6||48.6||3rd||18.7||10.4||30th||18.2||23.5||high||77%|
|South East (district 12)|
|Kalgoorlie-Boulder Airport||33.8||+0.1||46.1||9th||19.7||+1.4||13.3||18th||66.2||24.2||v high||274%|
|Salmon Gums Res.Stn.||32.0||+1.4||44.1||1st||15.3||+1.4||5.2||25th||10.8||26.7||average||40%|
|Southern Cross Airfield||35.0||+0.3||45.3||9th||18.9||+1.3||11.8||25th||30.6||29.7||average||103%|
|North East (district 13)|
|Giles Meteorological Office||40.1||+2.8||45.7||16th||25.3||+1.8||17.9||27th||2.2||30.0||v low||7%|
|Offshore Islands (district 200)|
|Christmas Island Aero||28.7||+0.8||29.7||28th||23.2||+0.6||21.6||26th||239.2||300.7||average||80%|
|Cocos Island Airport||30.3||+0.6||31.5||26th||25.3||+0.5||23.9||17th||86.0||164.0||average||52%|
A Monthly Climate Summary is prepared to list the main features of the weather in Western Australia using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.
This statement has been prepared based on information available at 10 am on Friday 1 February 2013. Some checks have been made on the data, but it is possible that results will change as new information becomes available.
Averages are long-term means based on observations from
all available years of record, which vary widely from site to site.
They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.
The Rank indicates how rainfall this time compares with the climate record for the site,
based on the
(very low rainfall is in decile 1, low in decile 2 or 3,
average in decile 4 to 7, high in decile 8 or 9
and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.
The ACORN-SAT dataset is being used for temperature area averages from December 2012 onwards. The major change from earlier datasets is that the ACORN-SAT dataset commences in 1910, rather than 1950, and hence rankings are calculated using a larger set of years.