MODELS AND ALL THINGS RAINFALL - NOW WE CAN SEE BEYOND THE SEVERE WEATHER TO WHAT IS AHEAD FOR MARCH

The last of the severe weather moving out of the east and southeast makes it now much easier to measure what sort of rainfall we are likely to see emerge through the short, medium and the longer term.


It is likely to be one of the drier periods as a whole across the nation on average than what we have experienced since last September. So this is a long time coming for many communities.


However there are areas that have missed out and these areas need rainfall, an Autumn Break and just something to get domestic water supplies up before heading into the cooler season which is traditionally a lot drier.


I have updated the 6 WEEK FORECAST today but this is to cover off the rainfall across all models and where things are heading.


Lets take a look


FORECAST


SHORT TERM

The short term, much drier as a nation. We have severe storms and heavy showers over parts of the north and eastern coastal areas of the nation. There are troughs over the NT and SE QLD which offer the better chances of rainfall. We have onshore winds in the southeast of VIC producing drizzle and light showers and coastal showers for NSW are light in the coming days. A new trough will develop over the west of the nation bringing the chance of showers and thunderstorms with mainly light falls. This trough will move eastwards next week and could also bring patchy rainfall to the east and southeast but no organised rain and severe weather events are expected.


UKMET - Rainfall Next 7 Days - LOW CHANCE.

The UKmet going for a bit more rainfall than the ICON over the eastern inland in the short term which I don't think will occur. The south and southeast looking relatively dry through the coming 7 days. For the north of the nation we could see an increase in the tropical rainfall coverage and this may feed down into parts of WA with rainfall on the rise. Heavier rainfall for parts of the FNQ coast with onshore trade winds bringing periods of moderate to heavy rainfall.

ICON - Rainfall Next 8 Days - HIGH CHANCE

Probably more reflective of the state of the atmosphere moving through the coming week with high pressure, drier air and more ridging through out the upper atmosphere holding out the more productive rainfall bearing systems.

MEDIUM TERM

Some signals that the showery weather along the east coast may begin to increase next week and into the medium term as high pressure slowly moves into the Tasman Sea. The rainfall moderate and scattered at this time, with no evidence of upper level troughs or lows in the region which means no severe weather evident at this time. The tropics may see an uptick in the unsettled weather as the MJO moves into the Indian Ocean and then the Eastern Indian Ocean. Overall no severe weather is expected at this time on a broad scale.


CMC - Rainfall Next 10 Days - HIGH CHANCE

The CMC is leaning to a drier period ahead and I think that is the right solution. The tropics returning to being the wettest part of the nation. Otherwise a few showers and storms with a trough over the western interior from Friday into the weekend will bring light falls. This trough will move into SA early next week and may kick off a few showers and thunderstorms. This will then move into the east with isolated falls as you can see. So much quieter weather on the way.

EURO - Rainfall Next 10 Days - MODERATE CHANCE

Clearing rainfall over the east of the nation but showers continue for the coast in NSW and QLD in the wake of severe weather. A trough over the inland of NSW and QLD later in the weekend and next week may produce a few showers and storms. Noting no rainfall for much of WA, SA and the NT with drier air and stable weather, this is an outlier against other data. Note the MJO increasing over the Indian ocean as well. Much drier nationally.

ACCESS - Rainfall Next 10 Days - LOW CHANCE

Rain heavy tonight in the east clearing and the weather over much of the north and through the northeast looking wetter with deeper moisture and troughs sticking around. A trough in the west moving slowly east through the weekend and into next week with a decent chance of scattered showers and storms moving through the southwest and south of the nation, with the drier spot being over the southeast inland.

KMA - Rainfall Next 12 Days - LOW CHANCE.

Similar to ACCESS in showing the moisture a little deeper through the nation with rainfall returning through the interior of WA and through to SA in the medium term as moisture coming in from the northwest and feeding a trough inland. The weather over the tropics seasonal though heavier rainfall expected for tropical QLD. Some of that moisture may increase over the central inland of QLD while showers continue for the east coast in onshore winds following the severe weather.


GFS - Rainfall Next 16 Days - MODERATE CHANCE

Lighter falls from tomorrow for the eastern inland with clearing conditions along parts of the coast in NSW and QLD but it doesn't last long according to the GFS with rainfall increasing via onshore winds strengthening with more wet weather next week. A trough in A will move into SA early next week with a few showers and thunderstorms over inland WA moving into southeast and eastern SA and then merging with a trough over the eastern inland with showers and storms increasing. The tropics also firing up in the medium term which is reflecting the possibility of the MJO moving through the north of the country. The forecast is looking more low confidence in the medium term. The wettest part of the nation is likely to be over the tropical north and northeast.



ENSEMBLE DATA

The broader longer term data sets support more rainfall to return over the nation as the weather turns more humid over northern Australia and via easterly winds over QLD and NSW. The weather across the south looks drier but keep an eye on WA as there may be moisture that develops via tropical mischief that forms north of the NT and runs west bound. That could introduce some rainfall chances for the western interior.


GFS - Rainfall Next 16 Days (median of 35 members) - LOW CHANCE

Clearly the wettest out of the three models and is banking off the MJO moving through the Indian Ocean and over the north of Australia. Something to watch in the medium term. Also has heavier rainfall over the east and southeast inland with troughs hanging up over NSW and QLD. Lighter falls back for SA and the Ag areas of WA. This carries a lower confidence due to be an outlier amongst the data sets.

CMC - Rainfall Next 15 Days (median of 30 members) - MODERATE CHANCE

Also picking up on the MJO rolling through the north of the nation in the medium term which could lead to widespread rainfall developing in the north towards the end of the month. The showers and storms in the east continue with onshore southeast winds but no widespread severe weather expected. Light rainfall chances elsewhere with this model suggesting the rainfall with the tropical influence to stay over the northeast and north of the nation.

EURO - Rainfall Next 15 Days (median of 51 members) - MODERATE CHANCE.

Aligned more with CMC showing lighter rainfall nationally, but the wet spots are over the north, northeast and over the southeast but the intensity is way less.

LONG TERM

The longer term which I covered off this morning still supports above average rainfall for the east and north, but likely not at the same levels as we have experienced as the last few months. This follows the trend from last year where the east saw record rainfall in the March and then it eased slowly through April and May before drying out in Winter. Rainfall looks to return through southern and western parts of the nation as we track into April.


GFS - Rainfall Next 5 Weeks

You can catch up on more on this longer term data sets in the 6 week outlook from earlier today. Moisture looks to be moving around into different areas of the nation through this period which will be interesting to watch in the coming weeks.

CFS - Rainfall Next 6 Weeks

As above, we are seeing the shift in the pattern through this period which will redistribute rainfall across the nation.

More coming up from 8am EDT and a look at the Winter Outlook for 2022 is due as well. With the quieter period coming up, this will give me a chance to work on the other products that have had to take a backseat during this very volatile period so I will be around as normal, but the coverage of posts will be reduced so I can get that other stuff sorted for you and take care of the tailored forecasts that are coming through thick and fast.


You can get a tailored forecast at karllijnders@weathermatters.org It is charged by the hour and can add huge value to your specific region with hyperlocal weather information to give you guidance as to what you may expect and working with a range rather than flying blind.