Effective as of 4:00 PM Tuesday November 9 2021
View the latest severe weather warnings from BOM at http://www.bom.gov.au/wa/warnings/ .
Explanatory notes:
Elevated thunderstorms occurred within the Perth Metropolitan Area overnight ahead of an upper level disturbance leading to the wettest November day on record at the official Perth Metro station as 40.4 mm of rain fell in the 24 hours to 9 AM today with radar estimated rainfall totals of more than 70 mm in isolated places.
A Personal Weather Station (PWS) in Maylands saw 61.5 mm of rain, of which almost 50 mm fell within an hour. Intensity-frequency-duration (IFD) analysis done by consultant hydrologist Jim Davies and George Gaylard in 2014 found that a once in a 100 year (statistically) hourly rainfall total for a given point in Perth is around 47.5 mm.
Rainfall records at the official Perth Metro station date back to 1876.
The 40.4 mm was almost twice the average November rainfall.
Fine conditions as the upper level disturbance moves to the east with fine conditions continuing through the weekend with the subtropical high pressure ridge to the south.