NSW - SHOWERS AND COLD WEATHER SHIFTING NORTH TONIGHT - SETS UP A COLDER WEEK BUT DRYING OUT

The cold front is forecast to push through the remainder of the south tonight leading to a much colder start to the working week. There is a batch of showers and some local thunder with small hail pushing through the Riverina and the Southwest Slopes, more isolated up to the Central West with this coverage shifting eastwards this evening.


A cold an unstable westerly flow is forecast to follow the front with scattered showers with local hail and thunder during Monday but once again mainly over southern areas of the state bordering VIC. Snowfalls are expected to develop down to 600m tomorrow night but the coverage of snow may be restricted to the Alpine areas where the air combines with the precipitation in this zone. But it gives you an idea of how cold it is likely to be.


A cold and breezy week is likely further up the Great Dividing Range with not too much in the way of rainfall in this zone as the air dries out.


Into the latter part of the week, the weather is forecast to become clearer as high pressure ridges in, but the high centre being very slow to move east, the southwesterly flow will remain in place. So cold nights with areas of frost possible then dry and partly cloudy days, tending overcast towards the VIC border. Not much change is forecast to occur until we get into the weekend.


The next rain maker is still a ways off as the atmosphere and synoptic resets, with moisture building over the northwest of WA with the jet stream running further north over the northern tropics leading to cloud bands forming there, but it will drift south as the Southern Annular mode tends negative mid month. This will see more cold fronts develop over southern Australia once again.


Let’s take a look

FORECAST

Rainfall Next 10 Days

Rainfall is expected to be limited to southern and mountain areas of NSW tonight with a cold front passing through, the heaviest of the rainfall is expected on and west of the Great Dividing Range. There may be further showers on Monday and into Tuesday in the areas being impacted tonight but the weather should slowly start to dry out from Wednesday throughout. The remainder of the north, east coast and far west is likely to remain to dry with not much in the way of rainfall quite frankly for the next 10 days. This is quite normal for this time of year. The showers clearing from Wednesday means that the focus shifts to frost areas in the mornings and drier days. The next rain maker is forecast to appear over the west and northwest of the nation and whether this is allowed to travel across the country or not remains to be seen but we will be waiting into the medium term after what has been an active 2 weeks across the southeast and east.

The better rainfall as well advertised and forecast last week will be found over the southeast areas and in places exposed to the westerly wind regime that will turn drier southwesterly flow from mid-week.

Thunderstorm Forecast Monday

The chance of thunderstorms over the southern and southeast parts of the state as well as the ACT with the cold air rotating through. The better coverage of thunderstorms will be found over VIC with local hail and strong wind squalls possible. Another change will be approaching the southeast of the nation on Tuesday with further hail and thunderstorms possible.

Hail Risk Forecast Monday

A low to moderate risk of small hail about a broad region of the southeast with showers and storms moving through.

Severe Weather Watch - Damaging Winds

The strong and gusty southwesterly wind flow will continue into Monday with a strong cold front moving through the southeast during the morning and another approaching SA later in the evening, this keeping the strong gradient winds in place. Strongest winds are likely over elevation and with showers and storms about southern areas.

Farmers and Graziers - Next 5 Days

It is likely to be a cold and showery week for the southeastern inland with the colder drier air surging northwards through mid-week before conditions warm from the west and north during the latter part of the week. Conditions will ease for the southeast inland by next weekend.

MEDIUM TERM

June 12th-19th 2022

Rainfall Anomalies

Rainfall likely to be above average over the northwest and western inland with deeper moisture developing across the region, drawn in by the jet stream. Frontal weather running through southern Australia likely to keep rainfall near seasonal, but a drier bias over the southeast areas in lee of the divide from the westerly flow may turn drier than normal for this period.

Temperature Anomalies

Warmer weather redevelops over the western interior as a more humid and unstable airmass forms and winds veer into the north and northwest. Still colder than normal over in the east and southeast, but this signal should start to moderate throughout the back half of the month as the winds veer back into the west and northwest over the region ahead of the next weather maker moving out of the west of the country

DATA - Refer to the video for further information on the short- and medium-term issues.


00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks

I break down the critical information in the video at the top of the page but clearly the main weather influence is with the large scale high over the Bight, whipping up the cold showery weather over the southeast and leading to drier weather throughout the country. The weather over in the west of the nation is forecast to warm up ahead of a deepening trough leading to widespread falls coming into the western and southwestern areas of WA. Some areas could see some heavy rainfall by the end of the week. The tropics will see a drier southeast airstream move in by the end of the week and into the weekend. This will help push moisture back into the Indian Ocean to be recycled through the jet stream lifting rainfall chances into the second half of the month.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Drier air in the east and more moisture developing over the west and northwest will headline the forecast moisture spread this week. The moisture is forecast to move further east throughout the latter part of the week into the weekend and then into the medium term, further moisture will move through the nation via the jet stream lifting rainfall chances.

00Z GFS - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z CMC - Rainfall Accumulation - Next 10 Days

Refer to the video for more context and analysis

00Z GFS - Rainfall Accumulation - Next 2 Weeks

Refer to the video for more context and analysis

A closer look in - widespread rainfall continues in the southwest flow this week so expect a gradual clearance over inland areas of the nation and rainfall to adopt a more coastal bias int he southeast. This means many areas over the eastern parts of NSW and inland areas of the nation could be dry for a week! The rainfall you see in the medium term likely gone in the run to come.

More coming up from 8pm EST with a look at the models and rainfall - where is the next rain maker coming from?




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