Wednesday, 1 February 2012 - Monthly Climate Summary for Western Australia - Product code IDCKGC11R0
Rainfall in WA during January 2012 was above to very much above average for much of WA, from the west Kimberley, Pilbara, Interior, to adjacent parts of the Gascoyne and Goldfields. A number of sites in the west Kimberley, Pilbara, and northern Gascoyne registered their wettest January on record as a result of an active monsoon during the month, along with the passage of Tropical Cyclone Heidi across the Pilbara coast near Port Hedland, and influence of TC Iggy though it remained off the WA coast. Above to very much above average rainfall was also observed in parts of Southwest Land Division (SWLD), mainly in the west. In contrast, below to very much below average rainfall was confined to parts of the east Kimberley as the most significant monsoonal activity remained to the west.
When averaged across the state, January 2012 rainfall was very much above average, whilst the SWLD and the Lower Southwest (southwest a line from Jurien Bay to Bremer Bay) saw above average rainfall.
Tropical Cyclone Heidi made landfall near Port Hedland on the 12th and generally moved in a southerly direction after landfall, bringing very heavy falls to the east Pilbara and west Kimberley, and unconfirmed reports of totals over 300 mm near the TC path. Wallareenya and Wittenoom in the Pilbara, and Mount Vernon in the north Gascoyne recorded January daily rainfall records on the 12th, 13th, and 14th respectively.
A surface trough near the west coast produced slow moving thunderstorms in western parts of WA on the 20th, particularly in the Perth Metropolitan area. Several sites in the Perth hills broke their daily rainfall record for January in more than 100 years of record, whilst Serpentine broke both its daily and monthly record for January with a single daily fall of 60.6 mm.
A very active monsoon over northern WA in association with Tropical Cyclone Iggy northwest of the Pilbara coast brought a very wet spell to parts of the Pilbara and Kimberley between the 26th and 29th. Cygnet Bay and Cape Leveque in the west Kimberley both recorded 4 consecutive days of rainfall over 100 mm. Such a sequence of four consecutive days over 100 mm had not been recorded before in WA. The daily falls of 206.8 mm at Cygnet Bay on the 26th and 239.6 mm at Cape Leveque on the 27th were their highest daily totals for January on record.
Below to very much below average mean maximum temperatures were observed across much of WA with up to 5 °C cooler than normal maxima in the southeast Pilbara, east Gascoyne, northern Goldfields, and western Interior. Leonora in the Goldfields experienced its coolest January in 61 years of record with a mean maximum temperature of 32.0 °C. Only in west coast parts of WA were mean maximum temperatures above to very much above average, with up to 4 °C warmer than normal maxima in the Shark Bay region. A few sites in the Lower West and Southwest districts experienced their hottest January on record. The mean maximum temperature of 29.5 °C at Cape Naturaliste was a new record in 108 years of temperature recording, and 1.0 °C warmer than its previous record set in January 1962.
When averaged over the state, January 2012 was the 3rd coolest January on record since comparable records commenced in 1950, however, the Lower Southwest recorded an above average January.
A number of hot spells were experienced in western parts of WA during January, including events in the Perth metropolitan area in the middle and latter part of month. The most notable hot spell was in the latter part of the month when many sites registered four or more consecutive days with daily maxima over 35 °C. Jurien Bay in the Central West experienced eight consecutive days with daily maxima over 35 °C, which equaled its longest hot spell on record, with January 1976 (20th-27th) and February 1995 (16th-23rd).
Mean minimum temperatures was above to very much above average in western and southern parts of WA, with up to 3 °C warmer than normal minima along the west coast from Shark Bay to Cape Leeuwin. Many sites in Lower West, Southwest, and Great Southern experienced their warmest January on record including a number with over 100 years of record.
Conversely, below to very much below average minima were observed in the west Kimberley, east Pilbara, east Gascoyne, and adjacent northern Goldfields and Interior, with up to 4 °C cooler than normal minima in the east Gascoyne.
When averaged across the state, the mean minimum temperature for WA was below average. In contrast, the Lower Southwest recorded its hottest January nights since comparable record commenced in 1950 .
Without the cooling effect of sea breezes, the warmest nights of the month for most western parts of WA coincided with the hottest days, between the 26th and 27th. Jurien Bay in the Central West broke its January minimum record on the 26th, whilst Cape Leeuwin in the Southwest recorded two consecutive days of minima over 23 °C (23.5 °C on the 26th & 23.1 °C on the 27th), which had previously never occurred in 106 years of daily records.
Tropical Cyclone Heidi formed north of the Pilbara coast on the evening on the 10th moving southward. Heidi approached Port Hedland on the 11th and crossed the Pilbara coast as a category 2 system on the morning of the 12th approximately 15 km east of Port Hedland. After landfall, Heidi moved on a south-southwest track and weakened into a tropical low over the southern Pilbara. Heidi produced sustained winds of 119 km/h and a maximum gust of 144 km/h to Bedout Island on the 11th, whilst Port Hedland Airport recorded maximum winds of 98 km/h and gusts to 131 km/h early on the 12th. Damage was mainly confined to uprooted trees and minor flooding, with large scale power outages in South Hedland and Wedgefield. The decaying TC and low brought very heavy rainfall to various locations in the Pilbara and western Kimberley, with unconfirmed reports over 300 mm, and associated flooding.
Tropical Cyclone Iggy formed 850 km northwest of Exmouth, off the west Pilbara coast, on the morning of the 26th. Iggy firstly moved southeasterly then changed to a west-southwest track on the 30 and 31 January. Iggy remained offshore and had no significant impact on the WA coast, although the associated monsoonal burst brought heavy rainfall to parts of the west Kimberley and Pilbara coast.
|Extremes in January 2012|
|Hottest day||44.9 °C at Eneabba on the 29th|
|Warmest days on average||39.1 °C at Gascoyne Junction|
|Coolest days on average||23.8 °C at Albany|
|Coldest day||17.7 °C at Shannon on the 1st|
|Coldest night||5.7 °C at Jarrahwood on the 17th|
|Coolest nights on average||14.1 °C at Rocky Gully|
|Warmest nights on average|| 26.7 °C at Troughton
26.5 °C at Wyndham
|Warmest night||30.3 °C at Wyndham on the 2nd|
|Warmest on average overall||31.8 °C at Wyndham Aero|
|Coolest on average overall||20.4 °C at Albany|
|Wettest overall||978.2 mm at Cape Leveque|
|Wettest day||239.8 mm at Cape Leveque on the 27th|
|Highest wind gust||144 km/h at Bedout Island on the 11th|
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|Record highest January daily rainfall|
Highest daily rainfall
in January 2012 (mm)
|Chidlow||86.4||on the 20th||64.3||on the 21st in 1957||105|
|Jarrahdale||60.6||on the 20th||58.2||on the 21st in 1982||105|
|Mundaring||68.8||on the 20th||36.8||on the 20th in 1923||104|
|Cape Leveque||239.8||on the 27th||209.3||on the 23rd in 1963||87|
|Serpentine||60.6||on the 20th||27.9||on the 1st in 1960||86|
|Wallareenya||132.0||on the 12th||119.1||on the 21st in 1973||78|
|Mount Vernon||117.2||on the 14th||90.7||on the 25th in 1961||72|
|Wittenoom||170.8||on the 13th||170.4||on the 8th in 1997||57|
|Cygnet Bay||206.8||on the 26th||186.0||on the 17th in 1974||49|
|Record highest total January rainfall|
for January 2012 (mm)
|Cape Leveque||978.2||787.8||in 1974||85||222.7|
|Mount Vernon||249.2||171.2||in 1990||73||36.2|
|Cygnet Bay||907.3||757.2||in 1997||49||242.2|
|Record highest January mean daily maximum temperature|
| Mean daily maximum
for January 2012 (°C)
| Previous warmest
|Cape Naturaliste||29.5||28.5||in 1962||108||25.3|
|Record lowest January mean daily maximum temperature|
Mean daily maximum
for January 2012 (°C)
|Record highest January daily minimum temperature|
Highest daily minimum
in January 2012 (°C)
|Cape Leeuwin||23.5||on the 26th||22.7||on the 23rd in 1989||106||16.9|
|Jurien Bay||27.0||on the 26th||26.5||on the 9th in 1984||42||17.1|
|Record highest January mean daily minimum temperature|
| Mean daily minimum
for January 2012 (°C)
| Previous warmest
|Cape Leeuwin||19.1||18.4||in 1956||115||16.9|
|Bridgetown Comparison||15.4||15.2||in 1961||111||12.2|
|Cape Naturaliste||18.1||17.3||in 1920||108||15.2|
|Perth Airport||19.7||19.5||in 1962||67||17.0|
|Lake Grace Comparison||16.7||16.6||in 1997||54||15.0|
|Pearce RAAF||20.0||19.8||in 1989||50||16.9|
|Albany Airport Comparison||15.2||15.1||in 1974||46||13.7|
|Badgingarra Research Stn||19.4||19.0||in 2011||43||17.0|
|Summary statistics for January 2012|
|North Kimberley (district 01)|
|East Kimberley (district 02)|
|Halls Creek Airport||36.1||-0.7||39.8||15th||24.1||-0.2||21.1||28th||90.6||151.3||low||60%|
|West Kimberley (district 03)|
|Derby Aero||34.1||-1.1||38.2||3rd||25.2||-0.5||22.3||24th||380.8||199.5||v high||191%|
|Fitzroy Crossing Aero||36.3||-1.4||41.3||20th||24.1||-1.1||21.6||27th||240.2||169.0||high||142%|
|De Grey (district 04)|
|Karratha Aero||34.5||-1.5||39.4||21st||26.0||-0.8||23.3||3rd||152.6||47.5||v high||321%|
|Marble Bar||36.4||-5.1||42.2||4th||24.8||-2.1||21.9||10th||181.2||67.3||v high||269%|
|Pardoo Station||33.9||-2.6||39.2||20th||25.4||-0.5||21.4||1st||290.9||62.0||v high||469%|
|Port Hedland Airport||34.0||-2.4||39.0||23rd||25.2||-0.3||22.6||10th||261.8||62.3||v high||420%|
|Fortescue (district 05)|
|Barrow Island Airport||32.6||-0.6||37.7||22nd||26.1||+0.3||23.3||8th||113.0||24.4||v high||463%|
|Learmonth Airport||35.9||-2.1||41.4||22nd||24.0||+1.1||19.6||4th||87.8||31.8||v high||276%|
|West Gascoyne (district 06)|
|Emu Creek Station||37.8||-3.5||40.3||8th||24.7||+0.3||20.5||2nd||174.4||46.8||v high||373%|
|Shark Bay Airport||36.2||+2.8||44.8||24th||23.1||+1.8||17.9||1st||5.2||8.8||average||59%|
|East Gascoyne (district 07)|
|Newman Aero||34.7||-4.8||41.3||3rd||23.2||-1.8||18.8||10th||238.4||62.2||v high||383%|
|Paraburdoo Aero||37.1||-4.0||42.9||4th||23.9||-2.1||19.8||9th||205.2||52.0||v high||395%|
|Murchison (district 07A)|
|Meekatharra Airport||34.4||-3.9||40.6||29th||22.3||-2.1||16.5||8th||103.4||28.2||v high||367%|
|Mount Magnet Aero||35.5||-2.5||41.9||29th||23.0||-0.4||17.9||7th||24.0||25.7||average||93%|
|North Coast (district 08)|
|Dalwallinu Comparison||34.7||-0.5||41.3||28th||19.9||+1.6||13.9||8th||58.0||15.2||v high||382%|
|Central Coast (district 09)|
|Badgingarra Research Stn||35.0||+0.3||41.1||28th||19.4||+2.4||11.8||7th||23.6||9.2||high||257%|
|Garden Island HSF||30.5||+3.5||40.2||25th||20.4||+1.7||15.0||8th||24.6||11.6||high||212%|
|Medina Research Centre||33.2||+2.7||41.8||26th||19.8||+3.0||10.6||8th||35.2||12.2||high||289%|
|Perth Airport||33.4||+1.7||41.5||26th||19.7||+2.7||11.9||8th||27.2||9.7||v high||280%|
|South Coast (district 09A)|
|Albany Airport Comparison||26.2||+1.5||37.0||21st||15.2||+1.5||8.0||17th||8.4||23.7||low||35%|
|Cape Leeuwin||25.1||+2.1||32.1||27th||19.1||+2.2||14.8||17th||2.0||16.4||v low||12%|
|Cape Naturaliste||29.5||+4.2||37.5||26th||18.1||+2.9||12.3||17th||0.6||10.7||v low||6%|
|North Central (district 10)|
|South Central (district 10A)|
|Katanning Comparison||30.0||-0.2||39.5||28th||15.2||+1.6||9.4||17th||77.0||14.7||v high||524%|
|Lake Grace Comparison||30.8||-0.7||41.0||28th||16.7||+1.7||10.9||9th||33.6||18.5||high||182%|
|Newdegate Research Station||30.8||0.0||41.3||28th||14.6||+0.8||7.6||9th||6.6||19.0||average||35%|
|Eucla (district 11)|
|Red Rocks Point||24.6||36.9||6th||18.7||14.6||29th||7.8|
|South East (district 12)|
|Salmon Gums Res.Stn.||30.1||-0.5||40.2||22nd||14.6||+0.7||6.7||31st||49.0||26.9||high||182%|
|Southern Cross Airfield||33.2||-1.6||40.8||22nd||18.5||+1.0||11.3||8th||5.4||29.6||average||18%|
|North East (district 13)|
|Giles Meteorological Office||34.6||-2.7||40.2||20th||21.4||-2.1||16.3||10th||105.4||30.5||v high||346%|
|Telfer Aero||36.8||-3.8||41.0||4th||24.4||-1.7||21.0||10th||135.0||49.1||v high||275%|
|Warburton Airfield||33.7||-4.3||40.6||22nd||21.6||-1.2||16.7||10th||128.6||29.0||v high||443%|
|Offshore Islands (district 200)|
|Christmas Island Aero||27.3||-0.6||29.2||13th||22.6||0.0||21.6||16th||631.4||302.3||v high||209%|
|Cocos Island Airport||30.2||+0.5||31.1||21st||25.3||+0.5||24.0||1st||148.4||164.7||average||90%|
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 4 pm on Wednesday 1 February 2012. 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.
Records in this summary are based on sites with at least 30 years of data.