NSW - SHOWERS CLEAR THE SOUTHEAST - MILD UP NORTH. WHAT THE HELL IS THAT EVENT DOING IN QLD!?

ANALYSIS

The broader synoptic flow does not change a whole lot this week with more in the way of westerly wind dominance for the southern parts of the nation, broad ridging across the mid section and the tropics remaining relatively seasonal.


A stronger front does approach from the Southern Ocean this weekend with an upper trough in toe, this may disrupt the pattern a tad as we move into the early part of next week.


Modelling has been atrocious for the medium term and thus we are sitting in a period of high uncertainty, and rather than bore you with the 200 different solutions, the best approach is to sit and wait! There is no skill in predicting exactly what will happen and when and attempting to drill down into it for you tonight is pointless as you will wake to a new range of solutions tomorrow.


SHORT TERM

The short term offers fairly strong signals for the westerly wind belt to continue with frontal weather embedded in the flow, this leading to more unsettled weather for parts of the nation’s south and southeast with modest impact for the southwest of the country.


The stronger front of the sequence to come that may have some influence on the southeast of the nation and spread into Southern NSW will be the front that comes from Friday into the weekend and then again later Sunday into Monday.


Out of that sequence is where we may find the developing upper level trough that combines with moisture to bring rain early next week to QLD that may drift south into the state.


LONG TERM

The main area of interest in the longer term is that upper trough over the northeastern inland of the nation and whether that moves south and southeast into NSW.


How long does the rest of the nation stay dry for!? Well that is an interesting proposition that I will touch on during the coming 2 days, looking into the medium term, the Indian Ocean does go quiet and referring to this post gives great insight into that. But with the warmer waters about, it is likely it will not last as long as last year, I do think we see the rainfall return from the west and northwest into early July.


AREAS TO WATCH

Certainly the dominance of the drier air and high pressure over the northwest of the nation and southern areas through the end of the month and into early July. The pattern may be disrupted however, with a significant risk of widespread moisture being drawn back into the nation from the west with a deep jet stream returning ahead of frontal weather as the SAM turns negative again.


Moisture lurking over northern parts of the nation signifies the first part of the shift to the wetter end to Winter and Spring is on the way, with that being an element left over from the prolonged La Niña.


WEATHER VIDEO PM - TUESDAY 21ST JUNE 202

FORECAST

Rainfall Next 10 Days

Rainfall is looking lean in the 10 day window for many areas with the bulk of the wet weather found over the southern and southeast areas of the state, with the front moving through during Friday. The rest of the state, mild with northwest winds, typical negative SAM weather with a dry airmass lingering through many areas and ridging leading to sunny skies. There is still the upper trough to follow another front over the southeast during the weekend which may surge north over SA into the NT and then dive southeast into QLD and begin to drag the moisture southwards into the state with areas of moderate to heavy rainfall north of the border and some question as to where that ignites and whether that spreads southwards.

Rainfall Next 16 Days

You can see that the rainfall does continue via the westerly wind belt and the rainfall over QLD tries to come southwards with a deep tropical airmass interacting with a trough leading to those above average rainfall totals not too far away. I will leave the rainfall in place to signify risk of where the areas are most likely to be impacted, but this could increase and decrease in the coming days and totally ignoring it and not drawing in the chance of rainfall is not good forecasting.

MEDIUM TERM

June 28th - July 5th, 2022

Rainfall Anomalies

Rainfall anomalies are running high over the eastern third of the nation with a marginal risk extending back to the NT and back over the southeast of the country with an upper trough and deepening upper low wafting around, but the forecast confidence is quite low. The SWLD could see further drier weather with high pressure stuck in the region as a blocking upper-level trough sits over the east.

Temperature Anomalies

Temperatures are moving around a little bit in response to the developing troughs over the east which may pull in warmer and soupier air, but with the rainfall forecast, seasonal weather is expected in terms of temperatures. Over the north the temperatures marginally above normal and elsewhere, the weather is seasonal, but a lot is dependent on the weather situation moving forward.

DATA - Refer to the video for more context and information to explain the forecast charts above and the data below


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

Once again, the big feature to watch is the system over the north and east and the westerly wind belt impacting the south of the country.

00Z GFS - Precipitable Water Values - Next 2 Weeks

The moisture over the north of the nation without the upper-level trough is of significance and highly anomalous and opens the door to a widespread and heavy rainfall event, if the low pressure can draw it south from next week. That moisture persists throughout the period into the medium term. Elsewhere, the values are what you would expect at this time of year.

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 - it may look very exciting/concerning for many of you related to rainfall, but it remains of low confidence and so please make sure you refer to the video at the top of the page for more context for the rainfall totals into the coming 2 weeks.

More coming up from 8pm EST with a look at the models and rainfall


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