7 day weather forecast

Effective as of 12:00 AM Thursday September 27

Explanatory notes:

Ridge of high pressure builds to the south,a west trough coast deepens down the west coast during the weekend as an upper/middle level trough/disturbance arrives bringing showers and possible thunderstorms and the formation of a low.

High clouds today and tomorrow.Some low clouds encountering "katabatic waterfall effect" also likely this morning over the edge of the Darling Scarp.

Another west coast trough possibly deepens near the west coast by mid next working week with another upper/middle level trough/disturbance arriving possibly bringing showers and thunderstorms.

Thursday September 27:

9-23 Degrees Celsius

High clouds(partly cloudy).

Chance of any rain:0%

Amount:0 mm.

Perth metropolitan area:

High clouds(partly cloudy).Winds southeasterly at 10-25 km/h tending southerly at 20-30 km/h over coastal suburbs in the afternoon.

Friday September 28:

9-24 Degrees Celsius

High clouds(partly cloudy)

Chance of any rain:0%

Amount:0 mm.

Perth metropolitan area:

High clouds(partly cloudy).Winds easterly at 20-30 km/h tending 15-25 km/h during the afternoon.

Saturday September 29:

13-25 Degrees Celsius

Showers.

Chance of any rain:70%

Amount:0.4 to 3 mm.

Perth metropolitan area:

Partly to mostly cloudy.A high(70%) chance of showers.The chance of a thunderstorm.Winds east-northeasterly at 20-35 km/h shifting easterly from late morning shifting east-southeasterly from late afternoon.

Sunday September 30:

13-22 Degrees Celsius

Showers,possible thunderstorms.

Chance of any rain:70%

Amount:0.4 to 5 mm.

Perth metropolitan area:

Partly to mostly cloudy.A high(70%) chance of showers.The chance of thunderstorms.Light winds shifting southwesterly at 10-25 km/h during the afternoon.

Monday October 1:

11-23 Degrees Celsius

Partly cloudy.

Chance of any rain:10%

Amount:0 mm.

Perth metropolitan area:

Partly cloudy.Winds southeasterly at 10-20 km/h tending southwesterly during the afternoon.

Tuesday October 2:

11-23 Degrees Celsius

Partly cloudy.

Chance of any rain:20%

Amount:0 mm.

Perth metropolitan area:

Partly cloudy.A slight(20%) chance of a shower most likely in the afternoon and over the hills and eastern suburbs.Light winds.

Wednesday October 3:

12-23 Degrees Celsius

Possible shower or thunderstorm.

Chance of any rain:30%

Amount:0 to 1 mm.

Perth metropolitan area:

Partly cloudy.A slight(30%) chance of showers.The chance of a thunderstorm.Light winds tending southwesterly at 15-25 km/h during the afternoon.

Charts:

Figure 1.Surface synoptic chart at 12 UTC(8 PM local time yesterday).Image courtesy of the Australian Bureau of Meteorology(BOM)

Figure 3.Key features identified on True Colour RGB satellite image at around 06:00 UTC(2 PM local time yesterday).Satellite image courtesy of the Japanese Meteorological Agency(JMA).

Figure 3.Mean Sea Level Pressure(MSLP) analysis with infrared greyscale satellite image at 12 UTC(8 PM 
local time yesterday).Image courtesy of the Australian Bureau of Meteorology(BOM).

Figure 4:Surface synoptic prognosis.Image courtesy of the Australian Bureau of Meteorology(BOM).

Forecast for today produced at 12:00 AM,forecast for the rest of the days produced at 4:20 PM Wednesday July 11.Weather icons courtesy of the US National Weather Service.