NSW - WINDS INCREASING OVERNIGHT AND WEDNESDAY WITH RAIN DEVELOPING.

A windy and mild night is on the cards, likely the warmest night in many months, with a cold front increasing cloud cover over the eastern inland with rain to break out by morning from the west and southwest.


Damaging winds are the main feature of the weather system for the coming 24hrs and some locations up high in the southeast could see winds of 130km/h above 1500m.

Light rainfall, areas of thick cloud over the south with a gusty northwest to westerly flow, which will gradually become colder, will be the feature of the weather throughout the southern and southeast inland. That rainfall will roll up the GDR, with much of the measurable rainfall on and west of the divide.


Thursday it clears out, colder starts are back with a frost risk but mild sunshine to follow. That leads into a much warmer Friday with a gusty northwest flow once again drawing in a dry and very warm airmass. That could see temperatures spike well above the average.


Rain breaks out again later Friday or Saturday, at this stage for southern inland areas of the state bordering with VIC. This system last night looked to be bringing a larger burst of rainfall, now not the case but watch this space as the system approaches.


The system likely to clear through during Sunday with a cooler airmass but then another front moving in this time next week could bring more widespread rainfall with another burst of gales. But again, like the Friday system that we saw being modelled yesterday, this could change from run to run.


Lets have a look at modelling.


00Z GFS Surface Pressure Pattern for the coming 16 days

The change that is racing through the Bight is on the approach to SA this evening and then over us tomorrow before clearing east of the nation during Thursday. A squally northwesterly wind will shift westerly then gradually ease from the west during Wednesday. A weak ridge will pass through the region on Thursday with temperatures surging well above average ahead of another front with lighter rainfall and a cooler change into the region this weekend. The next front next week could bring a better chance of rainfall but from next week onwards I will slap on the low confidence forecast strap but you can see the frontal barrage continues for the southeast and then extends back to the southern coastline of the nation with the north trying to bring in moisture in the upper level northeast winds.

00z GFS Rainfall for the coming 16 days

A band of light rainfall over SA, will peak over the southern inland and along the GDR tomorrow, with maybe 5-15mm for many areas of southern NSW and perhaps around 5mm for central inland areas and 2mm for the northwest plains. Falls along the western slopes of the GDR will vary. Lighter falls still with the Friday feature but will be watching for changes in that as it was showing heavier falls this morning and some other models are a little more robust with this feature. The weekend mostly dry with a stronger system approaching early next week. That system is a piggy back upper low and trough so it will be very much one to watch as it could cut off from the westerly flow.

00z GFS Precipitable Water for the coming 16 days

Moisture values are a lot less than previous weeks hence the lower rainfall chances through the southern inland areas with the frontal weather, though it is still raining which is always a sign of a wet year if even the weakening fronts will squeeze out light rainfall over inland areas. Keeping an eye on the moisture offshore the northwest of the nation, that was covered off this afternoon in the moisture watch update, so check that out at the top of the front page.

00z Euro Surface Pressure Pattern for the coming 10 days

Fast flow pattern continues to bring the frontal weather through with the see saw temperatures, with mild days and nights then rainfall, then cooler with frosty mornings and then bouncing back to warm weather and rinse and repeat. That looks to be the case this week with the wavy flow. Some areas of rainfall with each of the systems coming through looks lighter for inland areas and coastal areas of the southeast will do better. For us the best of the rainfall this week will continue to favour the areas that have been hit hardest in recent weeks. The weather may flip still at the end of the period.

00z Euro Rainfall for the coming 10 days

Rainfall spread is coming down a little bit with the drier air winning out a little in the forecast packages which is completely normal, but it does not lead to dry weather for the state, just lighter rainfall coverage. We will see light rainfall with the system tomorrow, Friday into Saturday and maybe a little heavier rainfall during early next week with that feature. Then we have a ridge that will clear out the rainfall for NSW ahead of maybe another system later in the period.

00z Euro Precipitable Water for the coming 10 days

PW values are still hanging in there enough to provide reasonable rainfall totals for weakening systems over the southeast, but the limited moisture being lifted by stronger systems over the southwest show what is possible in these fast flow setups even in the absence of deep moisture levels. Later in the period again, keep an eye on that moisture lurking off the northwest of the nation as it surges south from the equator and starts to turn towards the mainland offshore WA.

Rainfall for the next 10 days

Rainfall numbers have come down just a little for inland areas of NSW particularly the Lower Western due to the rainfall not as heavy for the Friday system, but just keep watch on the system still or the one next week as that could still bring moderate inland rainfall, but I think going down the middle of the data is fair. 5-15mm for the week over the inland is fair. Dry weather essentially along the coast and the far north, though patchy rainfall may develop later Wednesday into Thursday as the wave clears east.

More weather details to come, including a closer look at the climate for the state in the coming 3 months tomorrow.

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