First, we have a very cold airmass blasting north this evening, which has been modelled quite well. The modelling remains unchanged this evening, showers, turning to areas of light snow above 700m with a few storms and bursts of hail will continue into Tuesday morning. Some snowfalls are possible over the northern tablelands as well, but just flurries.
Frost is also a big concern as we track into mid week once we lose the high risk to stock exposed to these cold and blustery conditions.
Lets take a look at the latest.
Rainfall for the next 10 days
Not much, despite the weather being quite active tonight, the air is dry with the cold air, so light falls for the most part. Once we get to mid week, the weather turns settled under high pressure with the dry air, no further rainfall of note to find in the coming 5-6 days. Next week, as winds veer into the east, the weather may turn showery along the coast and thundery inland near a trough developing, this will become the focus of more widespread rainfall for the last week of September.
Frost Risk Wednesday
Frost risk is quite high for Wednesday morning and the speed of the low pressure system moving away and the speed of the high moving in from the west to settle the winds down will determine the frost intensity, but I am going with a higher impact event Wednesday morning out of caution. All areas should be prepared for frost with the risk of severe frost across the ranges in NSW and VIC.
Frost Risk Thursday
Similar spread of frost during Thursday morning, though the coverage could be a little more widespread over NSW as the centre of high pressure moves over the state, leading to sinking air, clear skies and light winds into Thursday. This could be quite a nasty frost over the GDR in NSW. The day will be warmer than Wednesday.
Thunderstorm Forecast Remainder of Monday
Thunderstorms are ongoing over VIC with gusty winds and small hail reported through scattered pockets. That activity is moving into NSW tonight but the coverage should weaken as the sun goes down, but hail is still a chance in the cold airmass. Thunderstorms still a chance of popping throughout this afternoon and evening over the northeast of NSW or southeast QLD, but quickly emerging offshore the coast, making for a great lightshow for avid lightning fans.
Hail Risk - Remainder of Monday
Scattered hail has been reported through southeast SA over VIC and now into southern NSW with a cold airmass moving through the region. The hail coverage will decrease over this region during the coming 12hrs and clear away by lunchtime Tuesday.
Snow Line - Monday into Tuesday
Snow line is currently at about 500m in VIC with snowfalls reported right across the ranges with squally winds. The snow flurries will spread up the NSW ranges, possibly about Canberra overnight and through the Central Tablelands overnight and during Tuesday morning and the Northern Tablelands during day. But flurries, not expecting settling snow at this time.
Farmers and Graziers - Monday through Wednesday
The high impact region is starting to shift east as the high pressure noses in and the upper level cold pool moves northeast over NSW and offshore during Tuesday afternoon. The weather should ease below impact thresholds after the frosty start Wednesday.
Euro 00z - Surface Pressure Pattern and Rainfall Distribution - Next 10 days
Drying out nicely from the south and southwest with the coldest air passing through this evening over the southeast states and moving north through eastern inland of QLD and then onwards to the west, the air modifying and warming up. Out west on the western flank of the high pressure system, a dry warm airmass is expected, that warmer air spreading through the southern states during the coming week into the weekend with dry weather for most areas. A weak front is anticipated for Friday over the southeast of the nation with a few showers. The weather then turns quite humid and unsettled over eastern areas of the nation as a trough deepens and feeds off moisture, on the other side of the nation another trough deepens over SWLD of WA with showers and storms developing next week. The difference between the Euro and GFS, is that the GFS sees the moisture and connects that with the troughs, and on tonight's run I side with GFS out of the two. The tropics also turning more humid and unsettled through next week.
Euro 00z - Precipitable Water Anomalies - Next 10 days
The shift in the pattern away from the dry airmass flooding through the nation will take about 5-6 days to overcome. The weather turning more seasonal atmospherically during the weekend and then clearly next week you can see the moisture pouring in over the eastern inland and being lifted by a trough and the Indian Ocean seeing the moisture surging from the northwest Indian Ocean.
Euro 00z - Rainfall- Next 10 days
Not much change from this morning, but is a little slower than the GFS in recognising the rainfall potential over the eastern inland of the nation but does have the system over the southwest of WA later in the run. Otherwise it is quiet for the remainder bar that lighter rainfall over the southeast with a weak front this Friday. Refer to the video to catch the GFS run down and to compare against this data set below.
I will have another wrap of the models once they all come in and a look at the GFS latest run tonight after 9pm.