Effective as of 4:00 PM Monday April 19 2021
Explanatory notes:
As at 4 PM, smoke haze from prescribed burning activities lies over the hills and aloft the eastern suburbs.
As the gradient flow shifts to an easterly direction overnight, this is expected to move to lie above the rest of the Metropolitan Area. If the smoke gets trapped under the nocturnal inversion it may lead to some air quality and visibility reductions.
The subtropical high pressure ridge strengthens to the south leading to gradient flow becoming an easterly direction.
Some stratocumulus clouds (stratus) in the morning on Tuesday extending from east of the Darling Scarp with moist low level air.
There is also the slight chance of mist and fog especially over areas with cold air drainage given moist low level air with smoke particles also acting as condensation nuclei, if winds become sufficiently light and if radiational cooling isn't too restricted by the smoke aloft and stratus.
The west coast trough likely deepens off the coast from Thursday with warm air advection. Another upper level trough approaches from the west leading to some high and middle level clouds but conditions are expected to be dry. Warm to hot with the warm air advection and the hot air mass over the region but the decreasing solar insolation as autumn progresses is certainly having its impact.
Possible smoke haze at times depending on prescribed burning activities, air quality and visibility reductions most likely overnight and in the mornings with the nocturnal inversion.
The west coast trough likely moves inland at the end of the forecast period with the subtropical ridge lying just slightly north leading to moist onshore flow from Monday afternoon but still some uncertainty this far out.
Monday April 19:
City:
Possible smoke haze.
Chance of any rain:0%
Perth Metropolitan Area:
Partly cloudy.Smoke aloft early.Winds southeasterly at 10-20 km/h tending south-southwesterly at 15-25 km/h in the afternoon.
Tuesday April 20:
City:
13-25 Degrees Celsius
Partly cloudy.
Chance of any rain:0%
Amount:Nil.
Perth Metropolitan Area:
Partly cloudy.Possible smoke haze depending on prescribed burning activites.Winds east-southeasterly at 10-20 km/h tending south-southwesterly at 15-30 km/h in the afternoon.
Wednesday April 21:
City:
13-25 Degrees Celsius
Mostly sunny.
Chance of any rain:0%
Amount:Nil.
Perth Metropolitan Area:
Mostly sunny.Possible smoke aloft depending on prescribed burning activites.Winds east-southeasterly at 10-20 km/h.
Thursday April 22:
City:
13-27 Degrees Celsius
Partly cloudy.
Chance of any rain:0%
Amount:Nil.
Perth Metropolitan Area:
Partly cloudy.High clouds.Possible smoke aloft depending on prescribed burning activites.Winds easterly at 15-25 km/h tending southeasterly in the late afternoon and evening.
Friday April 23:
City:
14-29 Degrees Celsius
Partly cloudy.
Chance of any rain:0%
Amount:Nil.
Perth Metropolitan Area:
Partly cloudy.Winds east-northeasterly at 15-25 km/h becoming light from afternoon.
Saturday April 24:
City:
16-31 Degrees Celsius
Partly cloudy.
Chance of any rain:0%
Amount:Nil.
Perth Metropolitan Area:
Partly cloudy.Winds northeasterly at 15-25 km/h becoming light during the afternoon.
Sunday April 25:
City:
15-31 Degrees Celsius
Partly cloudy.
Chance of any rain:0%
Amount:Nil.
Perth Metropolitan Area:
Partly cloudy.Winds northeasterly at 15-25 km/h becoming light during the afternoon.
Monday April 26:
City:
17-31 Degrees Celsius
Partly cloudy.
Chance of any rain:5%
Amount:Nil.
Perth Metropolitan Area:
Partly cloudy.Winds northeasterly at 15-25 km/h shifting northwesterly later during the day.
Charts:
Figure 1.Surface synoptic chart.Image courtesy of the Australian Bureau of Meteorology(BOM).
2.
Figure 2.Key features identified on True Colour RGB satellite image.Satellite image courtesy of the Japanese Meteorological Agency(JMA).
Figure 4:Surface synoptic prognosis.Image courtesy of the Australian Bureau of Meteorology(BOM).
No liabilities held from information consumed on this site. Weather icons are from the US National Weather Service.Some information on this site is from the Australian Bureau of Meteorology (BOM).
