NATIONAL WEATHER PICTURE - PM EDITION - THURSDAY 8TH OF JULY 2021

Headlines


  • Rainfall is in the process of increasing though central and southern QLD near a surface trough which is deepening due to an upper trough rotating through the eastern inland.

  • Rain will increase over NSW tonight with that rainfall shield looking more widespread, expected to reach the Central and Southern Tablelands.

  • Deep low pressure may cause a period of severe weather for the east coast of NSW during Friday night into Saturday.

  • Rain returns to WA with that expected to reach southeast SA and VIC during Sunday with more wet weather next week for southern Australia.

A deepening trough is clearly evident now on the satellite and rain has started to develop through the central and southern QLD. Some thunderstorms have also developed in response to the moist airmass, though these are fairly isolated and non severe through the region.


Rainfall increasing over the northern and central parts of NSW tonight, the trough is digging a little further south than east initially before carving out a path through the northeastern third of NSW. The rain then ending through QLD from northwest to southeast. The southern branch of the trough may bring a burst of light to moderate rainfall over the southern highlands/tablelands during Friday with a cold day.


A deepening low is expected to form along the trough as it moves through NSW. The quicker this happens the heavier the rainfall will be and the increasing risk of severe weather that may break out over the MNC and Hunter coasts during Friday night into Saturday, with the low expected to bomb offshore in the warmer waters. Damaging winds more than heavy rainfall the main risk IF that eventuates.


The rain will return to the other side of the nation on Friday with moderate to heavy falls. No high end severe weather risk but gusty winds and small hail with heavy rainfall along the front is possible. That front will move into the southeast during Sunday bringing the first batch of rainfall potential into the southern and southeastern states. That sets the stage for a very busy week for me!!!


National Satellite Picture - Valid 5pm Thursday 8th of July 2021.

Cloud has thickened rapidly this afternoon over the eastern inland in response to moisture surging in from the north and a trough lifting that up to produce scattered showers and thunderstorms. The rainfall increasing overnight. An upper trough is passing over SA today in dry fashion but will help the eastern system to deepen further and a low develop along the trough. Elsewhere it is clear and stable with high pressure over the central interior taking command behind the trough with a dry airmass.

Cloud over the east dominates proceedings with showers breaking out with the odd storms, that coverage expected to increase dramatically this evening and overnight with a broad area of rain and thunderstorms expected by Friday, clearing from northwest to southeast through the region.

Temperatures - Valid 4pm Thursday 8th of July 2021.

A warm to hot day over the north with above average temperatures building, that will be a theme during the coming week or two with an upper high over the region. Note the warmer air extending southeast into SA today, mild and sunny weather west of a trough. And a mostly dry and mild day for WA, enjoy it while it lasts.

A spread of temperatures now, can pick out where rainfall is ongoing under the cloud mass building through QLD and extending southeast into NSW. A milder night on the way with higher humidity and cloud cover. Cool weather further south after that freezing start but cloud coming in tonight will make it milder throughout.

Radar - Valid 5pm Thursday 8th of July 2021.

Showers increasing over the inland of QLD this afternoon and spreading into outback NSW this evening. Few storms bringing OK falls but they are elevated and are not expected to become severe at this stage.

Rainfall for the next 10 days - Valid Thursday 8th of July 2021.

Widespread rainfall developing as we speak over the east with moderate to heavy falls during the coming 24 to 36hrs. Rainfall persistent over southwest WA moving to the southeast and eastern states with moderate falls building for the coastal areas, but then spreading north through the outlook. More rainfall exists beyond this period for many regions.

00z GFS Rainfall - Next 10 days - Valid Thursday 8th of July 2021.

Rainfall looking heavy this evening and tomorrow over the northern inland of NSW, that solution looks highly probable now, with rainfall extend southeast through NSW. A low developing offshore may bring heavy falls to the coast north of Gosford to Forster. Rainfall spreading over the southern parts of the nation with multiple cold fronts. A cloud band breaking out over the battle zone between the competing hot and cold airmasses will see patchy rainfall develop next week. Keep an eye on the moisture over the northwest.

00z Euro Rainfall - Next 10 days - Valid Thursday 8th of July 2021.

Rainfall numbers still look very impressive tonight and tomorrow for the northern inland of NSW and southern QLD. Then heavy rainfall possible for the coast of NSW with that low lingering offshore Saturday. Rainfall increasing for Friday over southwest WA with that frontal weather making it over to southern Australia with improving rainfall totals expected. More rainfall sits beyond this period.

00z CMC Rainfall - Next 10 days - Valid Thursday 8th of July 2021.

Similar idea to GFS but this model trending a bit lighter with rainfall all around but this does hold the lowest skill score overall. I am siding with this model over the rainfall picking up over the southern parts of the nation and for that moisture off the northwest of the nation approaching in the day 7-10 window over WA. Heavy falls are possible about the east coast with a low on Friday night into Saturday.

Model Discussion and Analysis - Valid Thursday 8th of July 2021.


00z GFS Upper flow pattern at 500mb/18000ft

00z GFS Surface pressure pattern with rainfall


Friday 9th of July 2021

Upper trough deepening over inland NSW and QLD with a surface trough driving unsettled wet weather. A long wave approaching WA bringing another burst of strong winds and moderate to heavy winter weather. Ridging over eastern WA moving east and another ridge moving off the east coast. Heights about normal over the north.

Rain we can see is underway right now and likely to increase this evening over southern QLD before drifting into NSW and consolidating into a large mass of rain and thunder. The falls moderate about the NSW border and that rainfall intensity moving further south and east through the state. Mainly fine weather elsewhere with a few showers over southern SA and showers possible over the east coast in onshore winds.

By Friday morning, a broad area of rain and thunderstorms activity drifting south and east through NSW with moderate to heavy falls possible. The rainfall reaching the coast and extending down to as far south as Sydney to Crookwell. Other modelling brings the rainfall further south. Winds and rainfall increasing Friday morning with the passage of a trough and front through the day.

Saturday 10th of July 2021

A deep low forms off the NSW coast tomorrow night with rain and strong winds, with heavy falls for extreme coastal areas. High pressure ridging into the eastern inland dries conditions and clears the skies. A strong front races through southern WA with a new ridge pushing fine weather along the west coast. A warmer day for SA with increasing cloud across the west, and hot over the north of WA and NT with well above average maxima.

Sunday 11th of July 2021

Cold front approaching the southeast brings showers and strong winds to coastal SA with a cooler change. A low pressure system departs the NSW coast with morning showers clearing by lunch. Fine weather over WA though cloud increasing later in the day and hot over the north with dry weather, dry for much of the interior with clear skies under high pressure.

Monday 12th of July 2021

Shortwave trough and broad upper low moving through the southeast with a fast flow to the north of this feature, meaning a cold and unsettled airmass will slowly move through the southeastern inland driving unsettled weather. A new ridge over WA moving into SA clearing skies over SA, but opening the door for a strong long wave trough which will bring the next batch of strong winds and rain for WA later.

Broadly unstable over the southeast with an upper low triggering scattered showers, with some local thunder and hail possible. Showers will be relatively slow moving and wintry with a cold northerly flow. Snowfalls possible under 1000m through VIC. A strong cold front comes into WA with a band of rain with thunder. This has a severe weather look attached to it so more details on that potential during the weekend with a better look at it. Hot over the NT and WA with an upper high building.

The showers continue through Monday afternoon over VIC with moderate falls and small hail and thunder with the trough pushing east. Rain and strong winds turn to squally showers over the west with the cloud band collapsing over the western interior. Hot over the north.

Tuesday 13th of July 2021

The upper low washes out and moves east, carried by the mobile ridge through to the east. The weather clears after cold starts through the southeast. Fine over SA but a large long wave trough with a deep low passing south of WA will bring a band of rain and strong winds into SA later in the day, with severe weather continuing for the southern coast of WA with widespread showers and wintry weather. Fine weather over the NT with well above average temperatures.

Wednesday 14th of July 2021

Rain and strong winds approach the east with the first in a series of cold fronts to rotate through the east with pace. Driven by a strong low to the south. A fast moving jet stream bringing cloud through the interior, dividing the cold air from the hot air, producing patchy rainfall for interior regions. This will advance rapidly east. Showery and windy for much of the southern coastline with a mixture of shortwave troughs and fronts rotating through the region. Fine and hot over the north.

The rain becomes more extensive over VIC and NSW during Wednesday night with moderate falls possible in a gusty northwest to westerly flow. Showers to follow the rain band more widespread through SA and southern VIC with local thunder and hail. Snowfalls developing to around 1200m. The wet weather continues for southern WA.

Thursday 15th of July 2021

A broad long wave trough with multiple waves embedded with in the flow continuing to move east at pace, unsettled and cold through much of southern Australia, through northern Australia, on the northern side of the jet, hot weather with dry season conditions developing under an upper high.

Friday 16th of July 2021

The long wave moves through Thursday and Friday with gusty winds, widespread showers from southern WA through SA, into VIC, TAS and southern NSW with about four fronts in the flow pattern bringing heavier rainfall. The last front in the sequence is most aggressive with a hostile cold airmass.

That front races towards the southeast with a very cold airmass with thickness values dropping to 534 at this time, but once again, this is 7 days out and will change, but the models continue to signal more widespread cold wet and windy weather for the south and warm to hot and dry weather for the east and north in stable dry air. The other element to remember is the battle zone over the interior which could spawn more rainfall than is being advertised.

Saturday 17th of July 2021

The cold air and widespread showers and gales continues for the southeast into next weekend with moderate falls. Local hail and thunder for the coasts of SA and VIC, through to southern NSW with the passage of the cold pool. A surface low west of Tasmania may increase rainfall for southeast SA and southwest VIC. Fine over in the west with a ridge moving east northeast and hot over the NT under a broad upper high.

Sunday 18th of July 2021.

Taking it out 10 days and the long wave finally moves east with a deep low forming east of Tasmania, that would bring widespread showers/rain to southern VIC and TAS. Snowfalls would be heavier than what is advertised here. A westerly flow becoming unstable under the southern flank of the high, allowing for showers to redevelop in offshore waters, painting the picture of what is to come following this period, more wintry weather.



Need more weather information? Email me at karllijnders@weathermatters.org for tailored forecasting solutions.

0 views0 comments