Weather forecast for Perth effective as of 12:00 AM Monday March 19

Weather forecast for Perth effective as of 12:00 AM Monday March 19:

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 2.Key features identified on True Colour RGB satellite image at around 07:00 UTC(3 PM local time today).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).

Sunday morning was the coldest since October with minimum temperatures of 10.5 Degrees Celsius at the Perth Metro station,even colder at Jandakot at 5.7 Degrees Celsius with some cold air drainage.The low temperatures were due to already cool and dry air encountering radiational cooling overnight.

Some high clouds may affect the region today streaming in a subtropical jet stream.

On Tuesday especially plenty of high clouds with moist air streaming in a subtropical jet stream and later some middle level clouds as well ahead of a middle level disturbance,virga possible but unlikely to reach the ground with a thick layer of dry air below the clouds.


A west coast trough formed near the west coast today  leading to warm air advection.Some uncertainty on how hot it will be mid week with variation between models and ensemble members but it could be very hot.

The west coast trough likely moves inland on Thursday with the marine layer advecting inland.

Plenty of uncertainty on the precise synoptic conditions late during the week as it depends on the movement of Tropical Cyclone Marcus but an easterly pressure gradient is likely.

Monday March 19:

City:

16-32 Degrees Celsius

High clouds(mostly sunny).

Chance of any rain:0%

Amount:0 mm.

Perth metropolitan area:

High clouds(mostly sunny).Winds east to southeasterly at 10-25 km/h tending south-southwesterly at 10-25 km/h in the afternoon and evening over western suburbs.

Tuesday March 20:

City:

20-34 Degrees Celsius

Clouds increasing.

Chance of any rain:5%

Amount:0 mm.

Perth metropolitan area:

Mostly sunny becoming mostly cloudy from late afternoon,high clouds.Winds easterly at 20-35 km/h easing to east-northeasterly 10-20 km/h during the afternoon increasing to easterly at 20-30 km/h later at night.

Wednesday March 21:

City:

24-36 Degrees Celsius

Partly cloudy.

Chance of any rain:10%

Amount:0 mm.

Perth metropolitan area:

Partly cloudy.Winds east-northeasterly at 15-30 km/h easing to 10-20 km/h in the afternoon from afternoon increasing to 20-30 km/h by late at night.

Thursday March 22:

City:

21-29 Degrees Celsius

Mostly sunny.

Chance of any rain:0%

Amount:0 mm.

Perth metropolitan area:

Mostly sunny.Winds northeasterly at 10-20 km/h becoming southwesterly at 15-25 km/h during the day becoming south-southwesterly at 10-20 km/h at night.

Friday March 23:

City:

17-28 Degrees Celsius

Partly cloudy.

Chance of any rain:10%

Amount:0 mm.

Perth metropolitan area:

Partly cloudy.Winds south-southwesterly at 15-25 km/h.

Saturday March 24:

City:

17-28 Degrees Celsius

Partly cloudy.

Chance of any rain:5%

Amount:0 mm.

Perth metropolitan area:

Partly cloudy,high clouds.Winds southeasterly at 15-25 km/h.

Sunday March 25:

City:

17-28 Degrees Celsius

Partly cloudy.

Chance of any rain:10%

Amount:0 mm.

Perth metropolitan area:

Partly cloudy.Winds easterly at 15-30 km/h.

Forecast for today produced at 11:00 PM Sunday March 18,forecast for the rest of the days produced at 4:20 PM Sunday March 18.Weather icons courtesy of the US National Weather Service.