Forecast issued at 4:45 am WST on Friday 19 September 2014.
Northern Western Australia
A deep trough lies over eastern parts of the State with another trough across the inland Pilbara and Kimberley.
Southern and Central Western Australia
A deep trough lies over eastern parts of the State, gradually moving eastwards and weakening as a weak ridge of high pressure develops over southern coastal parts. A new trough will develop off the west coast on Saturday with unusually warm conditions for September over western parts of the State. A strong cold front will move across western parts of the State during Sunday, with warm and windy conditions preceding the front. A cool and unstable air mass will cover much of the southern half on Monday as a ridge of high pressure develops in the wake of the front.
Forecast for the rest of Friday
Showers south of a line from Busselton to Albany, clearing by midday. Isolated showers and thunderstorms possible about the far eastern Eucla.
Saturday 20 September
Mostly sunny. Unusually warm in the west of the State, with gusty northerly winds.
Sunday 21 September
Rain developing over western parts of the State during the day with the chance of thunderstorms. Rain reaching areas west of a line from Coral Bay to Southern Cross to Ravensthorpe by late evening. Windy and warm ahead of the rain. Moderate to heavy falls possible about western parts of the South West Land Division.
Monday 22 September
Showers and isolated thunderstorms over the South West Land Division, Goldfields and Gascoyne, easing from the west during the day. Moderate to heavy falls possible about eastern parts of the South West Land Division. Gusty winds in the Interior and Eucla.
The next routine forecast will be issued at 4:30 pm WST Friday.