NATIONAL WEATHER PICTURE - PM EDITION - THURSDAY 15TH OF JULY 2021

Headlines


  • Showers and storms are moving through the southern parts of SA with moderate rainfall possible during the coming few days, heavier falls developing on Friday for some.

  • Rain continues for northern NSW with the rainfall increasing from the west over southern NSW and into VIC tonight with wet weather expected to develop during Friday into Saturday.

  • Becoming colder with heavy snow developing over the Alpine Areas.

  • Easing conditions over WA with new high pressure moving in.

  • Hot hot hot, the NT, northern WA and much of central and northern QLD experiencing above average temperatures.


National Satellite Picture - Valid Thursday 15th of July 2021.

A deep layer of cold air is moving through the Bight about to make landfall through the southeast of SA and into western VIC tonight with moderate to heavy rainfall and the chance of thunderstorms with hail. A mixture of clouds bringing scattered showers through NSW and VIC. Cloud decreasing over parts of northern NSW with rainfall contracting to the GDR tonight. Mainly clear over the north but that persistent moisture over the Indian Ocean continues to lurk offshore.

Temperatures -Valid Thursday 15th of July 2021.

The thermal gradient is tight over the country at the moment with a jet stream dividing the warm air from the colder air to the south, it is producing a lot of cloud in the east where the air carries more moisture. But it is sizzling over the north for a mid July afternoon. In contrast, colder than normal over the southwest of the nation with a southwest surge. Milder over in the east with a moist airmass still in place.

These temperatures are up to 5C above normal and up to 8C above normal through QLD this afternoon. Significant temperature anomalies are expected to continue during the next 2 days ahead of a cooler and drier southeasterly surge.

Radar -Valid Thursday 15th of July 2021.

Significant frontal weather and a large area of disturbed cold air is moving east producing widespread showers and storms. There is a lot of weather sitting over the Bight expected to roll through SA, VIC, NSW and TAS during Friday.

A batch of showers and storms with small hail and thunder moved through the south this afternoon with moderate falls. More of this weather expected to persist in the coming days.

Even Canberra picking up on a few showers and thunderstorms this afternoon with mainly light falls.

Rainfall for the next 10 days - Valid Thursday 15th of July 2021.

Rainfall concentrating over the southeast, drying out over the northeast and the dry and hot weather building up over the NT and much of inland WA. The rainfall very much adopting the winter pattern with a westerly wind regime likely to take over the coming 10 days, not just the coming 4 days with evidence the long wave trough over the southeast might get stuck in the Tasman releasing more cold air and showery weather into early next week ahead of follow up frontal weather mid to late week from WA which should bring decent rainfall inland.


GFS Rainfall next 10 days - Valid Thursday 15th of July 2021.

Little change in relation to the rainfall distribution for the coming 4 days with showers and storms rolling through the southeast and east this afternoon. More rainfall expected Friday and Saturday for southeast states with onshore winds and cold air combining with modest moisture to produce widespread moderate falls, some heavy in southeast VIC and southeast of Adelaide. More rainfall developing for WA next week with yet another burst of moisture and cloud drifting across from mid week. Otherwise the rain should clear out of the northern parts of NSW and southern QLD overnight into Friday. Fine an dry up north.

Euro Rainfall next 10 days -Valid Thursday 15th of July 2021.

Conditions are looking wet for the coming 3-4 days as expected over the southeast and east. Rainfall eases over WA for the weekend, but not totally clear. The models are now starting to concentrate on the long wave getting stuck in the Tasman Sea tonight, that would mean a lingering area of cold and showery weather over the southeast early in the week, will keep an eye on that trend as that could redistribute rainfall. But it does look wet through southern Australia and it is safe to say southern SA, VIC, TAS and southern NSW will likely be dealing with follow up rainfall throughout next week. The north looks dry under an upper high which will dominate the next 10-14 days

CMC Rainfall next 10 days -Valid Thursday 15th of July 2021.

Rainfall very similar to this morning, somewhat lighter for WA from this morning but this is due to the shift today in modelling to introduce another burst of cold and showery weather for the southeast later Sunday through Tuesday next week with further moderate rainfall for the southeast states. Welcome for SA and VIC who rely on winter rainfall. But with other modelling viewed tonight, there is more movement on the timing, scale and intensity of that cloud band next week, with the GFS and Euro showing a high amplitude pattern just at the end of the period with moisture attached bringing up chances for increased rainfall over the southern states and possibly eastern inland.

Models Discussion - (I have cut down the content and reading so it is a little easier for those on the fly)


GFS Upper Air Pattern next 16 days - Valid Thursday 15th of July 2021.

Certainly the westerly wind belt is taking full control of the modelling from the GFS today and continue into next week, now the system rolling through early next week could bring another round of strong winds, showers, cold air and further snowfalls, this again surging northeast on the western flank of the low wave trough over the Tasman, will have to see if this continues to strengthen. Every chance that it could be another cold outbreak for the southeast. Then another strong system emerges near WA mid next week with that likely to connect with moisture from the northwest bringing widespread inland rainfall. Otherwise the upper high over the north continues to control conditions over the north. A high keeping much of the central part of the nation dry as well into QLD.

GFS Surface Pressure Pattern and Rainfall next 16 days - Valid Thursday 15th of July 2021.

The westerly wind belt is absolutely dominating the pressure pattern for the coming 4-5 days, with now another wave of fronts to come through VIC and TAS in particular from Sunday afternoon with widespread cold weather persisting and showery periods likely. If GFS is correct this evening, then more rain would develop from the west mid next week with widespread falls expected over the course of the back half of next week. Widespread rainfall is possible with moisture surging into the frontal passage. There is yet another front that passes through into WA at the end of the period with further widespread rainfall for southern states. The north and northeast stays dry for now.

GFS Precipitable Water Anomalies next 16 days - Valid Thursday 15th of July 2021.

This paints the picture of the weather I have been speaking of during the past few weeks, moisture streaming out of the northwest and linking up with cold fronts as the race across the southern parts. More rainfall opportunities exist under this configuration, who gets what is not quite clear but certainly no real signals of dry weather away from the NT, QLD and northern WA.

Euro Surface Pressure Pattern and Rainfall next 10 days - Valid Thursday 15th of July 2021.

The latest Euro more interested in the GFS scenario this evening taking a long wave through the southeast with more rainfall early next week with then a larger scale system with moisture passing through the region mid to late week, bringing widespread falls to WA, through SA then into the southeastern inland. So the wet weather is piling up now, most areas could see their average or more in the next week through southern SA, through VIC, southern NSW and TAS.


State based forecasts will be up within the hour, there is plenty going on and I am here to break it all down.

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