Weather forecast for Perth effective as of 4:00 PM Wednesday July 18

Weather forecast for Perth effective as of 4:00 PM Wednesday July 18
Explanatory notes:
Scroll down below this section for forecast. 

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 4.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).

Thursday will likely be a dry day with a high pressure system to the east.

Another cold frontal passage is likely late on Saturday with an associated rainband.Prefrontal showers possible from Friday night.

On Sunday with very strong pressure gradient with a very strong low pressure system over the Southern Ocean strong gusty winds will occur with gusts in excess of 90 km/h possible.With deep cold air mass possibly over the region,can't rule out the possibility of thunderstorms and/or small hail.

With the subtropical high pressure ridge lying to the north continued showery weather for the rest of the forecast period.

The rest of Wednesday July 18:

City:

Possible shower or two.

Chance of any rain:40%

Perth metropolitan area:

Partly to mostly cloudy.A medium(40%) chance of showers.Winds southwesterly at 15-25 km/h becoming light at night.

Thursday July 19:

City:

5-18 Degrees Celsius

Partly cloudy.

Chance of any rain:10%

Amount:0 mm.

Perth metropolitan area:

Partly cloudy.Light winds becoming east-northeasterly at 10-20 km/h in the morning becoming light from around the middle of the day.

Friday July 19:

City:

6-21 Degrees Celsius

Late shower or two.

Chance of any rain:60%

Amount:0 to 2 mm.

Perth metropolitan area:

Mostly sunny morning.A medium(60%) chance of showers from evening.Winds north-northeasterly at 10-20 km/h becoming northwesterly at 20-30 km/h in the afternoon easing to 10-25 km/h at night.

Saturday July 20:

City:

12-20 Degrees Celsius

Rain,showers.

Chance of any rain:100%

Amount:10 to 25 mm.

Perth metropolitan area:

Partly to mostly cloudy.A very high(100%) chance of rain and showers.The chance of a thunderstorm.Winds northwesterly at 20-30 km/h shifting west-northwesterly in the afternoon.

Sunday July 21:

City:

11-18 Degrees Celsius

Windy with showers.

Chance of any rain:95%

Amount:4 to 10 mm.

Perth metropolitan area:

Partly to mostly cloudy.A very high(95%) chance of showers.The chance of thunderstorms and/or small hail.Winds westerly at 35-55 km/h.Gusty winds likely,gusts possibly exceeding 90 km/h.

Monday July 22:

City:

11-19 Degrees Celsius

Showers.

Chance of any rain:90%

Amount:1 to 6 mm.

Perth metropolitan area:

Partly to mostly cloudy.A very high(90%) chance of showers.Winds westerly at 20-35 km/h.

Tuesday July 23:

City:

10-20 Degrees Celsius

Showers.

Chance of any rain:90%

Amount:0.4 to 4 mm.

Perth metropolitan area:

Partly to mostly cloudy.A very high(90%) chance of showers.Winds west-northwesterly at 15-25 km/h.

Wednesday July 24:

City:

10-19 Degrees Celsius

Showers.

Chance of any rain:90%

Amount:4 to 10 mm.

Perth metropolitan area:

Partly to mostly cloudy.A very high(90%) chance of showers.Winds west-northwesterly at 15-25 km/h.

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.