NATIONAL WEATHER PICTURE - PM EDITION - TUESDAY JUNE 8TH 2021

Headlines


  • Cold stormy wintry change moving through the southeast

  • Low level snowfalls expected over the NSW and VIC ranges during the coming days

  • Flash flood possibility over southeast NSW during Wednesday.

  • Severe weather event approaching WA.

A very active weather pattern is here, widespread showers, thunderstorms, localised hail and low level snowfall reported already through parts of the southeastern states. More of that is expected to fire off this evening and into Wednesday as a deep low begins to form in the clash between the warm air over the east and the bitterly cold air to the west moving in over the eastern inland.


Low level snowfalls remain quite possible with a deep low dragging in moisture from the east, and that moisture as it runs up the higher terrain expected to see it transition from rain through to snowfall through the deep cooling process. Areas from Cooma to Stanthorpe should pay close attention to the weather forecasts for surprise snowfalls.


Flash flooding in the milder onshore flow in easterly winds is possible about the South Coast through to West Gippsland in Victoria with wrap around rain on the southern flank of the system, heavy at times during Wednesday into Thursday morning.


Severe weather is expected to approach WA while this event goes on over the east, with damaging winds and heavy rainfall developing for parts of the SWLD and west coast of WA.


National Satellite Picture - Valid June 8th 2021.

Deep layer of cold air drifting in the southeast bringing dynamic and severe weather risks to the region with damaging winds the main risk. Severe conditions for stock over exposed terrain is likely to persist for a number of days. Large cloud band ahead of the system is in response to the large thermal gradient developing upstairs. High pressure squeezed into a narrow ridge over western SA ahead of a large cloud band over WA with a low well to the west of this. No rain is falling out of this high cloud.

Rotation starting to appear on the satellite imagery depicting the development of a surface low under this deep layer of cold air. Showers with local hail and thunder over SA and much of western NSW and VIC is moving east. Cloud thickening over NSW may start to break out into showers and storms overnight as the cold air runs into the warmer air.

Temperatures - Valid June 8th 2021 330pm EST

A large thermal gradient playing out over eastern Australia and that is denoted by where the cloud has developed this afternoon over the east. Currently 20C at Walgett. Down the road in Broken Hill it is 10C. Most of the north running hot today with 30s but these temperatures will be impacted by the southeast surge over the next 48hrs. Mild over in WA but cloud may keep the temperatures under 20C for most of the day ahead of a warmer night.

A closer look at that temperature gradient. Low teens for the west of NSW and low 20s but a matter of 200km away. Windy weather playing out in this zone and thunderstorms and showers likely to increase with reports already of hail at Coolamon and Wagga with the leading front pushing through.

Radar - Valid June 8th 2021 4pm EST.

Widespread showers hail and thunder over the southeast in the wake of the cold front that blasted through yesterday. The front is slowing down as a low forms along the front, but several bands of showers have developed on the cold air boundary and these will advance east overnight. Some of this rain may transition into areas of snow for the higher parts of NSW and the ACT overnight into Wednesday. Showers and areas of rain over SA will begin to ease overnight into Wednesday.

Rain sitting well offshore associated with a low pressure system which will propel a front onto the west coast with heavy rainfall and thunderstorms on Wednesday. Widespread gale force winds are expected to develop during the next 12 hours and persist until late Thursday.

Rainfall for the next 10 days - Valid June 8th 2021


GFS 00z run for rainfall next 10 days - Valid June 8th 2021

CMC 00z run for rainfall next 10 days - Valid June 8th 2021


Model analysis and discussion

GFS 00z run at 500mb or 18000ft off the ground

GFS MSLP and precipitation distribution


Wednesday June 9th 2021

Deep upper low advancing over to the east to be near Canberra with a surface low forming somewhere along the trough axis over that region or offshore. There is still no clear guide on that. It will determine the placement of the severe weather on Wednesday. But one this is for certain, cold and wintry weather for large parts of the east is expected. A ridge over eastern WA keeping things dry but a strong front and low pressure system will move closer to the coast later in the day.

Widespread showers, thunderstorms, areas of heavy rainfall and gale force winds over the southeast coupled with low level snowfalls and bitterly cold weather. A nasty day for the east. An organised batch of showers and thunderstorms will progress further east through the day off the QLD coast with no severe weather risks identified. Showers easing for southern VIC. Rain developing for the west coast of WA with a squally northwest flow developing. Heavy falls are possible about parts of the Gascoyne and Lower West


Thursday June 10th 2021

A very deep low sitting over Orange is setting the stage for further low level snowfalls and severe winter weather issues over the region. A deep low off WA becomes absorbed into the westerly flow and dragged south, west of a strong ridge over the Bight. A blocking pattern develops over the Tasman Sea, slowing the progress of the upper low and subsequent surface low over NSW making forecasting very tricky.

Deep surface low somewhat decoupled from the upper low producing wild weather through the southeast, with damaging winds, heavy rainfall leading to flash flooding over the far southeast and low level snowfalls. Thunderstorms also possible near the centre of the low with small hail. Snowfalls could be quite low and moderate over the northern and central Tablelands. Windy throughout the east. Rain and strong winds beginning to ease over WA as the front hits a brick wall thanks to the ridge over eastern WA. Fine over the remainder with temperatures coming down.

Friday June 11th 2021

Deep upper low starting to weaken during Friday, still slow moving to be near Sydney during the day. Severe winter weather issues continuing though the snow line should start to lift over 1000m later in the day. Rain and moderate falls continuing on its southern flank, showers easing over inland areas as the air dries out and stabalises thanks to the ridge pushing into SA. Blocking pattern still firm over NZ will force the low south. Long wave trough still producing waves of instability for WA.

Rain with moderate falls over the central and southern NSW coasts continuing in onshore easterly winds. Fresh westerly winds with showers decreasing for inland NSW during the day as the air stabalises. Showers over in WA could be thundery near the coast with a broad trough. Rain developing over East Gippsland and TAS later in the day with the approach of the low from the north.

Saturday June 12th 2021

Upper low weakening over eastern Bass Strait but still producing widespread rain for the region and cold temperatures. Another trough moving through WA bringing unsettled weather. The block over NZ still in good shape keeping the low pressure anchored over Australian waters.

Showers turning to periods of rain over East Gippsland and eastern TAS with further moderate falls. An upper trough developing over Central QLD may see showers developing just offshore and patchy rainfall over land later in the day or at night. Moisture and unstable air over WA will see numerous showers and thunderstorms develop over the SWLD more likely inland of the Southern Coast. Mainly dry elsewhere with a weak ridge. Cold nights for the inland of NSW and VIC.

Sunday June 13th 2021

Upper low finally weakening over the southern Tasman Sea with a blocking pattern still holding firm over NZ. Upper trough over QLD producing more cloudy skies for the region. Another wave of low pressure moving into western SA and another weak ridge over WA will cause a break in the wet weather. Heights recovering over far northern Australia with seasonal dry weather.

Showers clearing early from the eastern VIC coast with conditions becoming dry. Cloud increasing through SA with patchy rainfall developing over western SA with limited moisture in place. Patchy rain also developing for central QLD with an upper trough starting to form in combination with light onshore winds. Dry elsewhere once again after cold nights inland.

Monday June 14th 2021

Upper low deepening a little on approach to western QLD but limited moisture attached will see no wet weather for the region for now. Ridging over the southeast holding with the blocking pattern over NZ still in place. Another front and low approaching WA later in the day with the next batch of wet weather.

Rain breaking out over central and eastern QLD in response to the developing upper low moving in from the west. Moderate rainfall possible under this scenario but we have seen other looks at this. A few showers through western NSW with the tail of the upper low moving through. Another cold front approaching WA bringing late rain to the SWLD with some thunder. Dry elsewhere with a ridge in place. Maybe an isolated shower over VIC and TAS.

Tuesday June 15th 2021

Upper trough is progressive and moves over Central QLD with a threat of rainfall increasing and extending down the coast with a deepening trough offshore. Another wave of low pressure developing offshore WA with a strong trough over the interior producing more inclement weather. Fine in the southeast with a weak ridge.

Showers, areas of rain on the QLD coast extending south to northern NSW with moderate falls if this verifies, possibly heavy. Cloud thickening over WA in advance and with a trough producing patchy rainfall in a broad cloud band once again. A deepening low pressure system offshore WA will continue to drive showers and windy weather to much of the SWLD. Mostly fine through the southeast, with only an isolated stray shower for parts of TAS and VIC.


Thursday June 17th 2021

Deep upper trough moving through the Great Australian Bight, heights well below average over much of the nation, finally helped to move the blocking pattern over NZ along. Cold weather under this look for large areas of the southeast and east. New ridge moving into WA.

If this indeed verifies, a vigorous cold front moving into the east bringing another round of gales, widespread showers developing for SA, VIC and TAS with moderate falls. Showers streaming through the jet stream over QLD with light falls. Returning to fine over WA though still very cold with a southerly. Dry and sunny over the north and northwest with low humidity values increasing fire dangers.


Need more weather information for your part of the world, tailored forecasts are an option and I can provide you with what you need to know, email me at karllijnders@weathermatters.org

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