7 day weather forecast

Effective as of 7:00 PM Thursday September 27

Explanatory notes:

Ridge of high pressure lies 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 occured this morning over the edge of the Darling Scarp.

Strong easterly winds tomorrow,gusts in excess of 65 km/h possible over the hills and foothills in the early hours,morning and at night due to easterly winds getting enhanced by "katabatic effect"

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.

The rest of Thursday September 27:

High clouds(mostly clear).

Chance of any rain:0%

Perth metropolitan area:

High clouds(mostly clear).Winds southeasterly at 15-25 km/h.

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 east to east-southeasterly at 25-40 km/h tending 15-30 km/h during the afternoon.Wind gusts in excess of 65 km/h possible over the hills and foothills in the early hours,morning and at night.

Saturday September 29:

13-25 Degrees Celsius

Showers,possible thunderstorm.

Chance of any rain:80%

Amount:2 to 6 mm.

Perth metropolitan area:

Partly to mostly cloudy.A high(80%) 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 thunderstorm.

Chance of any rain:70%

Amount:0.4 to 4 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:

11-22 Degrees Celsius

Mostly cloudy.

Chance of any rain:10%

Amount:0 mm.

Perth metropolitan area:

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

Tuesday October 2:

11-24 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.The chance of a thunderstorm over the hills in the afternoon.Light winds.

Wednesday October 3:

10-22 Degrees Celsius

Possible showers.

Chance of any rain:40%

Amount:0 to 3 mm.

Perth metropolitan area:

Partly to mostly cloudy.A medium(40%) chance of showers.The chance of a thunderstorm.Winds southeasterly at 15-25 km/h.

Thursday October 4:

12-22 Degrees Celsius

Possible showers.

Chance of any rain:40%

Amount:0 to 3 mm.

Perth metropolitan area:

Partly to mostly cloudy.A medium(40%) chance of showers.The chance of a thunderstorm.Winds east-southeasterly at 15-25 km/h.

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.