Weather forecast for Perth effective as of 12:00 AM Friday July 20

Weather forecast for Perth effective as of 12:00 AM Friday July 20
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).

A cold frontal passage is likely on Saturday with an associated rainband.Pre frontal 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.

Friday July 19:

City:

6-21 Degrees Celsius

Late shower or two.

Chance of any rain:50%

Amount:0 to 1 mm.

Perth metropolitan area:

Sunny morning.A medium(50%) chance of showers from late afternoon.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 near the coast.

Monday July 22:

City:

11-19 Degrees Celsius

Showers.

Chance of any rain:90%

Amount:0.4 to 3 mm.

Perth metropolitan area:

Partly to mostly cloudy.A very high(90%) chance of showers.Winds westerly at 20-35 km/h easing to 10-20 km/h at night.

Tuesday July 23:

City:

10-20 Degrees Celsius

Showers.

Chance of any rain:70%

Amount:0 to 2 mm.

Perth metropolitan area:

Partly to mostly cloudy.A high(70%) chance of showers.Light winds tending northwesterly at 10-20 km/h during the day.

Wednesday July 24:

City:

10-20 Degrees Celsius

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.Winds northwesterly at 20-30 km/h shifting southwesterly at 15-25 km/h later.

Thursday July 25:

City:

8-19 Degrees Celsius

Shower or two.

Chance of any rain:50%

Amount:0 to 2 mm.

Perth metropolitan area:

Partly cloudy.A medium(50%) chance of showers.Light winds tending west-northwesterly at 10-20 km/h during the day.

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.