Monday, 2 May 2011 - Monthly Climate Summary for Tasmania - Product code IDCKGC17R0

Tasmania in April 2011: Wet continues in the east

It was another wet month in the east of Tasmania after very heavy falls between the 10th and 13th. In the west it was drier than usual, despite cold fronts that brought some rain. Temperatures were were mostly slightly warmer than usual, but neither extremely hot nor extremely cold.

• 153 mm in a day and 57 mm in an hour at Eddystone Point
• Wettest April day on record in parts of the southeast
• Hobart's wettest day in over 50 years

Extremes Maps Records Summaries Important notes the top

Extreme rainfall in the east

Heavy rain fell in eastern Tasmania between the 10th and 13th as an active and complex low pressure system moved nearby, bringing the fourth heavy rain event to the state for the year. The heaviest rain fell in the far northeast overnight on the 10-11th, with Eddystone Point receiving 57 mm in the hour around midnight and 153 mm in the 24 hours to 9 am on the 11th. Rainfall of this intensity is expected to occur less than once every 100 years in this region.

The heaviest rain moved slowly southwards, affecting the area around St Helens on the 11th and 12th (with the airport receiving 176 mm in 2 days) and the southeast of Tasmania from the afternoon of the 12th until the morning of the 13th. Hastings Chalet (125 mm), Mount Nelson (124 mm), Leslie Vale (112 mm) and Kingston (107 mm) were some of the sites in the southeast that had over 100 mm in a day, and several sites had their wettest April day on record.

Although not as damaging as the events in January or March, the rain did cause local flash flooding and minor to moderate flooding of some rivers.

Very wet in the east but drier than usual in the west

Heavy rain between the 10th and 13th ensured it was a very wet April in eastern Tasmania with many sites having at least double their April average. Eddystone Point (268 mm) and Gladstone (247 mm) reported the most rain for the month, both having their second-wettest April on record. They also had their wettest April in over 20 years along with Bicheno, Huonville and Scamander.

The west was drier than usual despite cold fronts bringing light to moderate falls between the 1st and 4th and again from the 19th to 24th. Zeehan (99 mm) had only half of its normal April rainfall. Still, most areas reported over 50 mm except for the Derwent Valley between New Norfolk and Ouse, and the Midlands around Campbell Town and Cressy. Ouse was the driest site with a total of 27.6 mm for the month.

The heavy rain in the east added to record falls during January and March (and local heavy falls in February) to give some sites, particularly in the northeast, their wettest start to a year on record. North-eastern Tasmania has already had a much wetter than usual autumn, and Gladstone (511 mm) and Pyengana (589 mm) have already had their wettest autumn on record although there is still a month to go.

Temperatures mostly near normal

There were no great extremes of temperatures during April: most days and nights were not too far from normal. Averaged over the month, minimum temperatures were just slightly warmer than usual, while maximum temperatures were warmer than usual in the west but cooler than usual in the east.

The warmest days occurred between the 5th and 9th as northerly winds blew over the state, pushing Bushy Park's temperature up to 26.5 °C on the 8th. The coolest days for the month followed between the 11th and 15th as rain fell in a southeast to southerly airstream, but the coldest day overall was at Mount Wellington on the 22nd when it only reached 3.6 °C in snowy weather. 

Cool and warm nights were interspersed through the month. Cloud, rain and wind meant the morning of  the 9th was one of the warmest with several sites not falling below 15 °C. The minimum temperature at King Island on this morning was 16.6 °C. A week later, the morning of the 16th was one of the coldest with light winds and clear skies allowing Liawenee's temperature to dip to -4.7 °C.

Hobart's wettest day in 50 years and wettest April since 1996

Hobart had its wettest day in over 50 years when 78.8 mm fell in the 24 hours to 9 am on the 13th. The last time there was so much rain in a day was 23 April 1960. Another 44 mm was reported between the 10th and 15th, and combined with few millimetres on other days to give a monthly total of 125 mm. This was well above the average of 52 mm, and made it Hobart's wettest April since 1996. 

Temperatures in Hobart were warm between the 7th and 9th, with 3 days in a row over 23 °C suggesting a return to summer conditions. But a cold week followed, with no day warmer than 14.4 °C between the 11th and 15th, and a minimum of just 5.0 °C on the 16th. The last week of the month was warmer again with daytime temperatures around 20 °C. The average minimum and maximum temperatures for the month were 10.0 °C and 18.1 °C respectively, around a degree warmer than normal.

Extremes Maps Records Summaries Important notes the top

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

Click on a map to show it full size in a pop-up window

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top