Effective as of 4:00 PM Tuesday December 7 2021
View the latest severe weather warnings from BOM at http://www.bom.gov.au/wa/warnings/ .
Explanatory notes:
A strong easterly gradient with the west coast trough offshore lead to strong and gusty easterlies with gusts having reached 80 km/h at Gooseberry Hills. Winds eased this afternoon with increased vertical mixing and also the land being hotter than the sea. Once the land cools down and vertical mixing decreases, winds strengthen again with gusts exceeding 80 km/h being once again possible over the hills and foothills overnight.
Also, the possibility of elevated convection overnight with instability aloft ahead of an upper level trough. Some altocumulus castellanus clouds were observed today indicative of instability aloft.
A very hot day tomorrow with the hot air mass over the region with the west coast trough depending offshore, maximum temperatures could exceed 40°C if skies are sufficiently clear.
The west coast trough likely moves inland on Thursday bringing cooler but humid conditions once the marine layer advects onshore. Maximum temperatures depend on how early the west coast trough moves inland. A later arrival of the onshore flow would lead to another very hot day.
The slight possibility of showers in the moist onshore flow on Friday and Saturday with a low pressure system to the south of the state.
Tuesday December 7:
City:
16-37 Degrees Celsius
Hot and sunny.
Chance of any rain:10%
Amount:Nil
Perth Metropolitan Area:
Hot and sunny.Winds easterly at 25-40 km/h easing to 15-25 km/h in the afternoon increasing to 20-35 km/h later at night.Gusts in excess of 80 km/h possible over the hills and foothills during the early hours, morning and later at night.
Wednesday December 8:
City:
24-40 Degrees Celsius
Very hot and mostly sunny.
Chance of any rain:20%
Amount:Nil
Perth Metropolitan Area:
Very hot and mostly sunny.A slight(20%) chance of showers and/or thunderstorms most likely in the early hours and morning.Winds east-northeasterly at 25-40 km/h becoming northeasterly in the morning, easing to 10-20 km/h in the afternoon, increasing to east-northeasterly at 20-30 km/h later at night.Gusts in excess of 80 km/h possible over the hills and foothills early.
Thursday December 9:
City:
24-36 Degrees Celsius
Mostly sunny.
Chance of any rain:5%
Amount:Nil
Perth Metropolitan Area:
Mostly sunny.Very hot inland.Winds northeasterly at 20-30 km/h shifting westerly at 15-25 km/h by afternoon, becoming light at night.
Friday December 10:
City:
19-25 Degrees Celsius
Partly cloudy.
Chance of any rain:20%
Amount:Nil
Perth Metropolitan Area:
Partly cloudy.A slight(20%) chance of a shower.Winds west-southwesterly at 10-20 km/h increasing to southwesterly at 20-30 km/h in the morning.
Saturday December 11:
City:
17-25 Degrees Celsius
Possible shower.
Chance of any rain:30%
Amount:0 to 0.4 mm
Perth Metropolitan Area:
Partly cloudy.A slight(30%) chance of a shower.Winds southwesterly at 15-25 km/h becoming south-southwesterly from evening.
Sunday December 12:
City: