WA’s north has been battered by rain at a time when it is usually preparing for the annual dry season, while a blast of polar air has put a pre-winter chill through the State’s south.
The weather event, including a cold front and low pressure system which hit several parts of WA from Saturday, is set to continue its record-breaking run through the Pilbara region into Monday.
The Bureau of Meteorology warned that the major cold outbreak would break most winter records, let alone records for the last days of autumn.
Varanus Island recorded a record daily total rainfall for May of 158mm, up from the previous high of just 102.6mm on May 17 this year.
Newman is also expecting a record May low temperature of 13 degrees on Tuesday, with the previous coldest day for the month set at 14.7 degrees in 2015.
The heavy rainfall prompted warnings from the Department of Fire and Emergency Services for Pilbara residents to prepare to relocate to higher grounds because of the threat of “unseasonal” flash flooding from Exmouth to Port Hedland.
DFES warned that campers and caravans near rivers were at risk as the severe weather was expected to create some dangerous conditions.
Earlier Sunday morning DFES also notified West Aussies of bad weather conditions in WA’s north via Twitter.
There were also forced road closures for the Nanutarra Munjina Road and Paraburdoo Tom Price Road over, as well as the North West Coastal Highway between Onslow and Karratha. Yarraloola Station, 47km west of Pannawonica, recorded two-day rainfall of 145.2mm to Sunday morning.
“It’s pretty unusual what’s happening up there at the moment this late in the season,” BOM duty forecaster Catherine Schelfhout said.
“There was a strong upper trough and tropical moisture which came down from a long way to the North West.
“There will be significant and heavy rainfall today (Sunday) and tomorrow (Monday) for all parts of the Pilbara and then for the western Kimberley on Tuesday, still potentially heavy rain which will ease on Wednesday.”
Ms Schelfhout said that while WA’s south did not receive significant rainfall, with a high of 17mm recorded just west of Esperance at Neds Corner, it was indeed cold.
Esperance recorded 85kmh winds with Hopetoun experiencing gusts of 83kmh – both only marginally under what is usually deemed “severe”. Chilly temperatures of around 10 degrees remained in Esperance through Sunday morning.
“They are getting a real surge of cold air pushing up,” Ms Schelfhout said.
“It’s a strong amplitude trough where the wind is coming through from behind the cold front and directly up from the Southern Ocean.
“It’s common to get cold fronts at this time of year, but this is a more significant southerly flow.”
Ms Schelfhout said the southern storms had started to move east into South Australia by Sunday morning.
She expects SA, Victoria and NSW to be impacted in the coming days, and for both winds to drop and temperatures to grow a little warmer in WA’s south.
Some dangerous surf conditions were still, however, prevailing, with higher-than-usual tides and swells.