The weather remains very unstable this morning after another batch of strong to severe storms over widespread areas of the east and north overnight. Record rainfall continues to be reported from thunderstorms, this in line with the record humidity. Simple math really.

The tropics remain very unsettled with widespread showers and thunderstorms continuing over usually dry parts of the nation, this in response to those 50C temperatures a few weeks ago. This is the response to those record values, record humidity and rainfall opportunity.

Now all the activity is expected to peak over much of VIC today, through inland NSW, across the north and northeast of SA, into western QLD and much of the NT and northwest WA. Large areas will be impacted by heavy rainfall leading to flash flooding.

Through the weekend, the trough in the east will lift north and east with thunderstorms and heavy rainfall moving into the ACT and southern NSW and back northwest to the tropics.

Within the monsoon trough, there is a chance of a tropical low or two forming within the trough bringing enhanced rainfall chances and severe weather risks once again. Flooding is expected to continue for many outback areas.

Finally for the middle and end of next week, a pattern flip. Moisture over the north of the nation will run into the western interior of WA bringing up rainfall chances finally. In the east the weather will dry out with a southerly flow moving into SA and VIC bringing about the change in atmosphere. The monsoon trough under such arrangements, will be bumped northwards with the tropical depression risk increasing as the trough sits over open water.

Lets take a look


Rainfall Next 10 Days

Not much change to the rainfall spread, with the uneven distribution of rainfall still to play out today and through the weekend with the scattered showers and storms over the southeast and eastern inland of the nation. Flood watches are in force for parts of the northern areas of the nation through the central NT and across the northwest of WA with heavy rainfall likely to form near a tropical low. The monsoon up north to drive windy, showery weather with heavy falls about. The east coast could see showers and thunderstorms continuing through much of next week as the onshore flow meets the trough moving east from inland NSW towards the east coast. There are hints of further tropical lows which is playing havoc in the rainfall spread beyond about day 7 so the low confidence strap is applied to any rainfall prognostics beyond 7 days at this time. Be aware, nationally, your rainfall forecast will change for the medium term.

Thunderstorm Forecast Friday

Thunderstorms will redevelop along a slow moving trough over VIC and NSW once again with storms turning severe with heavy rainfall leading to flash flooding possible. Dangerous flash flooding cannot be ruled out over central and eastern VIC and into southern NSW. Thunderstorms will extend back north through western NSW into northeast SA and through much of the NT and into northern WA. The storms may produce dangerous amounts of rainfall in quick time leading to flash flooding. Thunderstorms across the tropics may be gusty at times through the northern tropics into northeast tropical areas as well.

Thunderstorm Forecast Saturday

Thunderstorms will continue over large parts of the nation and now be included into the southwest and west of the nation along a developing heat trough. That marks the potential pattern flip for the west allowing for humidity to return to the region. Over the inland and the east, storms have a high risk of producing flash flooding, which could be dangerous near a tropical low deepening over the NT/WA border near Mulan. The risk of damaging winds with storms over the tropical north remains low to moderate.

Thunderstorm Forecast Sunday.

More thunderstorms are expected over a wide area of the nation with the risk of dangerous flash flooding once again possible over the central parts of the NT, spreading west into the WA region. Flash flooding also a high chance back through to the eastern inland and a high chance with squalls over the NT and Cape York. Damaging winds also possible over parts of the NT with showers and storms.

Tropical Depression Watch This Weekend

A deepening tropical low within the monsoon trough is likely to lead to heavy rainfall and squally winds to emerge through the areas identified in yellow. Heavy rainfall will spread west through much of northern WA with a flood risk. On the northern flank of the low, a strengthening westerly flow may see showers and storms increase for the northern Top End.

Severe Flash Flood Risk - Friday

The chance of severe flash flooding over parts of Central VIC on Friday is very high with slow moving thunderstorms and a robust and unstable airmass. Thunderstorms may produce high end flash flooding and disruption to major centres and surrounds.

DATA - Refer to video for more information about the short and medium term breakdown.

12Z Euro - Surface Pressure Pattern and Rainfall Distribution - Next 10 Days

More information in the daily breakdown, but no change once again from last night, still have the monsoon trough causing issues over parts of the northern inland of the nation driving a flood risk. We have the trough over the southeast and east creating a significant severe weather risk related to flash flooding. The risk is then taking into NSW over the weekend. A refreshing change is expected mid next week over the south and southeast of the nation kicking the moisture out to QLD and the NT. Some signals that a high may build in further north across the Bight and that may bring a spell of below average temperatures for the east and southeast but above average hot conditions for the west. Also the high in that position would deflect the moisture from the tropical low out of the SWLD, so the weather would remain dry over the southwest. The medium term forecast confidence has dropped to low overnight in the later data runs.

12Z Euro - Precipitable Water Values - Next 10 Days

The moisture content is remaining very high for the coming 5-7 days over the eastern and northern inland of the nation. The drier air will finally start to sweep into southern and southeast of the nation bringing about a run of cooler than average days. It will feel cold in comparison to now. The weather out west is becoming more humid but suppressed over the southwest of WA. The humidity returns to normal values nationally from this time next week which will see more seasonal weather develop but I do caution, the confidence in the forecast packages for the period ahead is quite low.

12Z Euro - Rainfall Accumulation - Next 10 Days

Refer to the video for further information

12Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for further information

12Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for further information

12Z Euro - Rainfall Accumulation - Next 15 Days

Refer to the video for further information

12Z GFS - Rainfall Accumulation - Next 16 Days

Refer to the video for further information

I will have an updated 6 week outlook this morning and a national PM update this afternoon with some severe weather information in between as well.