NSW - SHOWERS INCREASING OVER THE STATE MID WEEK BEFORE A COLDER CHANGE.

The pleasant settled May weather continues today with a large ridge in control and the dry air in place leading to cool nights and sunny days. That is forecast to continue overnight and into Tuesday with a cooler shift set to move in from Wednesday. Until then another mild and sunny day is forecast for tomorrow.


An upper trough rotating through the southeast is forecast to move northwards during Wednesday and we are likely to see some showers and thunderstorms develop in advance of this feature with mainly patchy falls into Thursday before colder and drier southwest winds move in for Friday.


Frosts are also forecast to form on the weekend, with the crisp cold nights followed by once again, fairly sunny conditions for the inland.


Along the coast, we may see the emergence of showery easterly winds from the weekend into next week and some rain may redevelop from inland QLD and spread into northern NSW later in the weekend or this time next week. The confidence in the upper level system during next week remains low but there is evidence of showers and thunderstorms returning to the region from the north and spreading south.


Medium term has more active weather coming through the west of the country and this could move eastwards into the southern states, potentially impacting NSW. But some strengthening signals that once again the positive SAM phase could produce some heavy rainfall along the coast as well.


Lets take a look

FORECAST

Rainfall Next 10 Days

Rainfall is forecast to be patchy over inland parts of Victoria with a weak trough lifting the modest moisture ahead of a front during Wednesday into Thursday before the showery weather clears eastwards. A drier and colder southwest flow will develop and then clear much of the state from rainfall. The showers likely to fall as snow over Alpine areas. But as we move into the weekend, the air starts to turn more humid again along the east coast, and this is in response to the easterly winds returning. The positive SAM should start to influence the rainfall chances for the state, and we are likely to see rain developing along the coast initially and some of this could become more widespread from next week. A trough over inland QLD could also flare a rain event there and some of that could turn towards the south and move into northern inland parts at the end of this period. Fine weather and dry weather likely for much of the west and southwest at this time, but we could start to see cloud increasing next week. Some modelling wants to develop a trough along the coast with heavy rainfall threats but I am not drawing that in just yet but that is quite possible under current guidance so pay attention to the forecast.

Farmers and Graziers Alert - Mid to Late Week

A cold and gusty southwesterly flow is forecast to develop and this coupled with a few passing showers and cloudy skies about southern and mountain areas, we could see well below average temperatures, very high wind chill and the passing precipitation bring stress to stock exposed to these conditions.

Frost Risk - Late Week into the Weekend

The cold dry air over the southeast inland will remain present into the weekend, and with clear skies and light winds with the high pressure system over the region, frost is possible for many inland areas areas, heaviest over the southeast and above 600m asl.

Snowline - Mid Week

The snowline could get down as low as 900m with the current burst of colder air but with the drier airmass and the precipitation out of phase with the coldest air rotating through, the impacts may be limited to just Alpine areas.

MEDIUM TERM - May 9th-16th 2022

Rainfall Anomalies

Looking at a substantial rainfall event emerging through the northeast and east of NSW into eastern QLD as moisture via the positive SAM combines with an upper trough that will be departing the east through this time. Some of the elevated rainfall chances could extend into central and eastern NSW as well. The rainfall developing from the west could begin to spread across southern parts of the nation but the signals not overly strong for above average rainfall but will placemark the movement of that event over southern and western parts of the nation.

Temperature Anomalies

Not much change to the temperature guide as we travel into mid month, with the cooler bias continuing in the west for now with frontal weather and rainy skies. The rain event over the east of QLD could pump moisture south and west into the eastern inland leading to more seasonal weather, though cooler weather possible under persistent rainfall over SE QLD and NE NSW. Warmer than normal weather over the northern tropics with the moisture content perhaps subsiding a bit but the lingering warmer waters around the tropics leading to elevated temperatures. Perhaps warmer nights and days for the ACT and surrounding districts in NSW ahead of the rainfall developing from the west.

DATA - Refer to video for more information and the model comparison and context about all the forecast products you see from me.


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

More details on the daily breakdown over the short and medium term so refer to the video. But not much change is expected from this morning's synopsis, however there are some interesting highlights in the medium term that need watching.

00Z GFS - Precipitable Water Values - Next 2 Weeks

Moisture content across the nation is forecast to increase once we lose the colder drier airmass that is over the southeast and south for much of this period, but note that the dry colder surge struggles to get into the northeast and really, is overridden in the medium term. Also moisture profile improves in about a week in WA. And will we see another large surge of moisture via the jet stream into the medium term through WA and then across the country?

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 - the rainfall over inland QLD from the weekend into next week poses the most interest for me as we look through the region.

More coming up tomorrow including the Climate Outlook, as you can see some larger systems are ahead of us again, but do they continue into the back half of May or into June as well? That coming up from later tomorrow morning and your next update after 8am EST.



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