7 day weather forecast

 Effective as of 4:00 AM Tuesday March 2 2021

Explanatory notes:

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​Showers and thunderstorms until Thursday as an upper level disturbance stalls to the west as it is being blocked by an upper level ridge then over Central Australia.

With the cold pool aloft with 500 hPa temperatures down to -13°C, hail is possible with thunderstorms over Perth but the intensity of thunderstorms would depend on the extent to which earlier precipitation and cloud holds surface temperatures down thus limiting instability, the most intense thunderstorms are most likely to occur in the afternoon and evening today should there be sufficient solar heating and thus instability buildup.

There is still plenty of variation in ensemble members and between different models on how unstable the atmosphere would be in the afternoon due to sensitivity to small differences in low level dew points and on the possibility of earlier elevated convection and middle level cloud limiting solar heating and instability buildup.  

Users are expected to monitor the latest severe weather warnings at http://www.bom.gov.au/wa/warnings/.

Latest model guidance suggests that solar heating on Wednesday would be constrained by earlier elevated convection and middle level clouds.

Steering winds would be from the north-northeast until Wednesday allowing for thunderstorms which form inland to be steered towards Perth, steering winds shift northwesterly from Thursday thus making the most intense thunderstorms more likely over the eastern suburbs and the hills.

Gusty winds and heavy rainfall is also possible with the thunderstorms with higher than usual low level moisture.

The upper level disturbance lies to the east by Friday but it remains unusually humid with the slight chance of showers due to the precipitation earlier in the week having moistened soils.

 

Tuesday March 2:

City:

19-31  Degrees Celsius

Showers and thunderstorms.

Chance of any rain:70%

Amount:2 to 10 mm

Perth Metropolitan Area:

Partly to mostly cloudy.A high(70%) chance of showers and thunderstorms especially from afternoon.Gusty winds, heavy rainfall and hail possible with thunderstorms in the afternoon and evening. Winds easterly at 20-30 km/h.

Wednesday March 3:

City:

20-28  Degrees Celsius

Showers and thunderstorms.

Chance of any rain:90%

Amount:5 to 20 mm

Perth Metropolitan Area:

Partly to mostly cloudy.A very high(90%) chance of showers and thunderstorms. Winds east-northeasterly at 20-30 km/h becoming northeasterly and easing to 10-20 km/h in the afternoon.

Thursday March 4:

City:

20-27  Degrees Celsius

Showers and thunderstorm.

Chance of any rain:60%

Amount:0 to 6 mm

Perth Metropolitan Area:

Partly to mostly cloudy.A medium(60%) chance of showers and thunderstorms most likely in the afternoon and over the eastern suburbs and the hills. Winds northeasterly at 10-20 km/h shifting westerly from early afternoon.

Friday March 5:

City:

18-27  Degrees Celsius

Possible shower.

Chance of any rain:30%

Amount:0 to 1 mm

Perth Metropolitan Area:

Partly cloudy.A slight(30%) chance of showers..Light winds tending west-southwesterly at 10-20 km/h during the afternoon.

Saturday March 6:

City:

18-28  Degrees Celsius

Partly cloudy.

Chance of any rain:10%

Amount:Nil

Perth Metropolitan Area:

Partly cloudy.Light winds tending southwesterly at 10-20 km/h during the afternoon.

Sunday March 7:

City:

18-30  Degrees Celsius

Partly cloudy.

Chance of any rain:5%

Amount:Nil

Perth Metropolitan Area:

Partly cloudy.Winds southeasterly at 10-20 km/h tending south-southwesterly at 15-25 km/h during the afternoon.

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Cha

                                   

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

 2. 

Figure 2.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).