Effective as of 12:00 AM Sunday November 21 2021
View the latest severe weather warnings from BOM at http://www.bom.gov.au/wa/warnings/ .
Explanatory notes:
Today, some elevated showers and thunderstorms are expected to develop with instability aloft ahead of an upper level disturbance.Some uncertainty on the maximum temperature as it is dependent upon the development of the elevated showers and thunderstorms/ cloud cover and also on the timing of onset of the onshore flow. With steep vertical lapse rates and high vertical wind shear with strong winds in the mid levels ahead of the upper/middle level distrubance, the thunderstorms could be accompanied by gusty winds, heavy falls and hail.
The heat low moves southeastwards leading to some showers in the moist onshore flow during the early hours and morning of Monday. Fine conditions thereafter with the subtropical high pressure ridge building to the south. Becoming hot towards the end of the forecast period as the west coast trough deepens near the west coast with warm air advection.