Friday, 1 May 2015 - Monthly Climate Summary for New South Wales - Product code IDCKGC15R0

New South Wales in April 2015: Wettest April in 25 years

• Wettest April since 1990
• East Coast Low causes severe weather along central parts of the NSW coast
• Coolest April days since 1999

The statewide average rainfall for NSW during April was 47.0% above average, making it the wettest April since 1990. Rainfall was above average across most of the state, particularly along the south and central coasts, with some stations in the Hunter and Sydney regions recording their wettest April on record.

The most significant rainfall event of the month was an East Coast Low that developed in a surface trough off the Hunter coast on the evening of the 20th. This system caused very heavy rain, strong winds and high seas in the Hunter, Sydney, and Illawarra regions over subsequent days, contributing to widespread flooding as well as numerous downed trees, large scale power outages persisting for several days in some areas, and coastal erosion. Rainfall totals for the 48 hours to 9am on the 22nd were broadly above 200 mm, reaching 436 mm at Maitland, with wind gusts reaching 135 km/h at several coastal locations and waves as high as 14.9 m in waters off Sydney. The SES reported more than 20,000 jobs and more than 150 flood rescues during this event, and hourly rainfall totals of over 100 mm led to major flooding along the Williams and Patersons Rivers, with several communities temporarily isolated by floodwaters. Twelve LGAs were declared Natural Disaster Areas as a result of this event.

Earlier in the month an East Coast Low in the southeast also produced widespread totals above 50 mm on the 8th, breaking April daily rainfall records at several locations, and wind gusts of 107 km/h at Green Cape. A coastal trough with an embedded low produced rain in the northeast of the state on the 4th and 5th, while a cold front and surface trough produced rain in inland NSW over the 18th and 19th.

Daytime temperatures were 1.0 °C below average in NSW during April, the coolest April since 1999, associated with well above average rainfall. Temperatures were particularly cold associated with the two East Coast Lows during the month, with parts of central NSW more than 8 °C below average on the 7th and large areas of northern NSW more than 8 °C below average on the 20th and 21st; both of these events broke daily cool maximum temperature records for April. These were followed by a period of persistent southerly winds and cool conditions during the final week of the month. The statewide average minimum temperature was 0.4 °C above average, associated with warm sea surface temperatures and cloudy conditions.

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top

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

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Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top