NSW - RAIN CONTINUES WITH HEAVY FALLS FOR SOME AREAS TO CONTINUE. FOLLOW UP IS POSSIBLE NEXT WEEK.

The weather continues to be wet, with many areas recording well above average rainfall through the coming days. A deep trough of low pressure is expected to remain in place, leading to widespread soaking rainfall over the eastern 2/3 of the state.


As we track through the remainder of this week, the severe weather risks will contract eastwards as the trough moves away but a cold front is forecast to take over and bring in drier air, but another focus for wet weather for southern and southeast areas and the ACT.


The time we get to around Sunday, the rainfall should be out the door for much of the state, however, we could see moisture linger over the far northeast with deep moisture remaining close by and onshore winds and showers remaining a feature. There could be some heavier rainfall about if a trough deepens, some models support that so will watch closely.


Next week the weather is forecast to remain mostly dry and mild for inland areas, some high cloud could be drifting through along the jet stream, which will be transporting moisture across the nation, but in the absence of low pressure, it should come through as just high cloud for now. It is what the moisture does as it hits the east coast and whether we see an upper-level trough offshore leading to more widespread rainfall emerging.


The medium term offers a lot of moisture and rainfall chances as we move into election weekend and to finish out the month, so while there may be a little break from the severe weather next week, the potential is still elevated with all the ingredients about for further widespread rainfall and storms to return in the coming fortnight.

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to be widespread, with moderate to locally heavy falls about tonight and tomorrow, through much of the state. The higher moisture content, which sits at about 300% of normal for some locations will lead to widespread falls and some of that rainfall would be heavy under such guidance. The deep moisture is then kicked north and east by Saturday as a front move through the southeast leading to a band of light to moderate rainfall for southern and southeast areas including the ACT before all of that leaves by Sunday. A drier airmass should come into the inland for early next week so a much drier picture is forecast for the state but coastal areas north of Taree could still see showery weather through much of next week with onshore winds and lingering moisture with a trough producing the wet weather. Later next week, the rainfall could become more widespread with another trough and moisture streaming in via the jet stream leading to increased rainfall chances. The SAM remaining positive as a response to the La Nina, the rainfall risks over the east are heightened under such guidance so we should expect the modelling to shift back to wet for the east. Zoomed in charts to return once we get this current system off the board and the next event coming in. The rainfall is contracting eastwards in the days ahead so expect the intensity of rainfall to decrease in each update.

Thunderstorm Forecast Thursday

Thunderstorms are forecast to continue for large sections of the north with some of the storms possibly severe with heavy rainfall leading to flash flooding the main concern. A drier airmass moving into the western districts should clear the focus eastwards later in the day.

Flash Flood Risk Thursday

The flash flood risk is forecast to remain in place over the north and northeast with heavy areas of rain developing with a trough pushing east. Thunderstorms along that trough will also bring the chance of heavy rainfall leading to flash flooding further south through the central and southern inland. The risk should diminish at night.

Severe Weather Watch - NSW - Remainder of Wednesday through Friday

The severe weather risk is starting to contract eastwards in the coming days. There yellow zone is broad and covers the risk of heavy rainfall leading to flash flooding with isolated to scattered thunderstorms over the inland. East of Stanthorpe through to Scone, this is where we could see heavy rainfall develop Friday with a small scale low pressure system while the risk expires over the inland. Flash flooding is the main concern. There is the risk of severe thunderstorms over the northwest of NSW and southwest QLD this evening.

MEDIUM TERM - May 18th-25th 2022

Rainfall Anomalies

It appears that the rainfall signals for the east are gathering once again above the average through this period with a very high moisture content developing over the east of QLD into NSW and a trough linking into this bringing up rainfall chances once again. This may drift into VIC. Moisture through the jet stream brings up rainfall chances for the western interior. This moisture is expected to spill through the country and feed the system in the east as well with high rainfall totals likely on current guidance for inland NSW and QLD. Ag SA may sit too far south for the weather events yet again but will watch trends.

Temperature Anomalies

Temperatures in the north and east will reflect the high moisture content and remain above average overnight and during the daytime for the most part. Cooler bias continues out west under persistent cloud cover and moisture spreading through the state with areas of rainfall. The weather over northern Australia, up to 4C above normal with high humidity values is possible about the Top End and extending southwards and east into QLD and possibly northern SA and NSW.

DATA - Refer to video for more information and the model comparison and context about all the forecast products you see from me.


00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

More details can be found in the weather video on the daily breakdown but we can see the event in the east winding down in the coming days. We have the strong cold front in the west tomorrow, this system weakening as it moves east into SA and then the southeast. But a stronger spread of moisture then moves into the northwest of the nation next week and may combine with a strong cold front to bring another burst of rainfall through the west and then into SA and the southeast states. Meanwhile another trough over QLD and NSW could see showers and storms return from mid next week through to the following week. In the medium term, yet another wave of low pressure and moisture may combine to bring a widespread band of rain and thunderstorms throughout the interior and west and that too could spread into the southeast. More moisture spreads through northern Australia while the south is dealing with moving rainfall events from west to east.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture distribution is very much following the guidance from last week and is now starting to clear east and southeast through the nation as a cold front picks up the flow pattern aloft and kicks the deep moisture over QLD and NSW off to the east and north. The next impulse of moisture that is coming over WA tonight is moving rapidly through the nation's south but weakening as it heads over SA and into the southeast. Still some rain can be expected with that feature. The next pulse of strong moisture comes in from the northwest of the nation via the jet stream next week while in the east, onshore winds will bring in moisture via easterly winds. Once again this opens the door for more rainfall events into the medium term with a deep moisture profile. As I always say, the marriage between the moisture and low pressure is key for major rainfall and where that happens remains to be seen.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z Euro - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - widespread rainfall in the coming 2 days is expected to be excessive, but the rainfall will become patchier as we go throughout the weekend and into next week and contract to the coast. More widespread rainfall is forecast to emerge mid to late next week over the southeast with moisture levels rising through SA and VIC through to inland NSW while showers continue along the coast.

More coming up from 8pm EDT with a look at the models and rainfall, I will only share information that is in reasonable agreement as too much is too confusing and I only want to share what is plausible at this time, so stay tuned for that.

60 views0 comments