NATIONAL - THE DRY WEATHER CONTINUES THIS WEEK, THOUGH SOME RUMBLINGS FOR THAT RAIN TO RETURN.

Clearly it is the quietest week of weather for the nation as a whole in about 10 weeks with this large scale high. A weak trough passing through SWLD of WA will lift moisture coming through the Indian Ocean producing rainfall. That front passing through the southeast over the weekend.


There are signals for another rainfall event over the eastern inland which is not a surprise given the SAM edging towards positive next week, even the slight bias occasionally stirs up rainfall chances for the eastern parts of NSW and QLD.


I am sure many in the east were shocked to see rainfall appear on the apps this morning, but lets look at it in more detail.


The latest weather update below

THE MODELS - RAINFALL COMING BACK?


Moisture watch in the Medium Term

Broad areas of moisture being drawn southeast and now we are starting to see models lifting this moisture into showers and storms throughout SA, NSW, QLD and VIC, however, the modelling is divided on when, where, how heavy etc. So read it as a signal that rainfall chances are picking up for the nation next week.

ACCESS

Note the moisture now pooling up across many parts of the nation, with weak signals for showers and thunderstorms developing. I will state that this will continue to move around of the northern and eastern parts of the nation as a main trough or low pressure system is identified in the medium term. Noting troughs over inland WA could bring rainfall back through southern interior parts as well. So seeing more Spring like conditions appear on the charts now.

KMA Rainfall next 10 days

Again like ACCESS, starting to wake up with the moisture over the north, being drawn south and east from the tropics into a trough that may produce showers and storms for much of the southern and eastern inland of the nation. Again pinning down where the rainfall develops is still up in the air, but again seeing rainfall turning widespread from mid month onwards.

GFS Rainfall next 16 days

The outlier out of the bunch it seems this morning, suggesting the dry air will continue to take over the nation right through to mid month and beyond, but once again, this model is very reactive as pointed out over the years and I do expect it to fall into line with the other model guidance of increasing showers and storms for central and eastern parts of the nation. In the short term rainfall for the SWLD of WA and western TAS is looking good with moderate to heavy falls possible about coastal areas. It is picking up moisture increasing for northern parts of the nation as well but contains it through northern areas where other models bring that moisture south with favourable upper winds.

CMC Rainfall next 10 days

The sister model to GFS has more rainfall coming through the east and southeast of the nation with moisture drifting south into the central interior, so there are rumblings within the broader Amercian Models that rainfall chances are increasing for parts of the east in the medium term. Otherwise a months worth of rain is possible over the far SWLD of WA with that system sliding through Wednesday and Thursday.

THE DATA SET - (Compare with the GFS in the video)


12z Euro Surface Pressure Pattern for the coming 10 days

Remaining quiet for much of this week with the high dominating, the main rainfall through the southwest with that weakening front from tomorrow through Thursday and another front passing through the southeast with scattered showers over the weekend. It is on that front, where the models differ, where the Euro brings a parcel of colder that moves over the north and cuts off into a surface low with another months worth of rainfall for eastern NSW and the ACT, and showers up to southern QLD, the other models are not as robust so just again read this map as there is some signals for rainfall through the eastern parts of the nation next week. Otherwise the weather is expected to turn humid next week over the north with showers increasing. The west will turn drier with a new high over the weekend with warmer weather returning while the east and central areas sorts itself out with low pressure about.

12z Euro Rainfall for the coming 10 days

Rainfall clearly contained to the southwest of the nation with a front passing through during Wednesday into Thursday. A showery change over the southeast during the weekend brings the chance of showers and hail back for VIC and TAS with lighter falls back to SA. Otherwise the big elephant on the board is that low with rain and storms in the east, and I stress it will likely be gone in the next run, HOWEVER, being that it is a week from today, it is within the short term forecast envelope, so there is something lurking next week. So this will be covered off more in the medium term forecast later this morning.

12z Euro Precipitable Water Values next 10 days

The PW values are largely unchanged with the drier air taking over the nation for the coming week, however the narrow sliver of moisture over the SWLD of WA will bring a productive area of rainfall for the SWLD during Wednesday into Thursday, some areas down there could see quite a cloudy spell thanks to the elevated moisture in the upper atmosphere. The moisture passing through south of the nation and into Tasmania through Friday. The moisture over the northern parts of the nation with an increase of trade winds likely this weekend into next week.

I will have the Medium Term Forecast Update mid morning and a CLIMATE OUTLOOK for September and a first look at October from lunchtime. Keep the blog access saved on your device and come and go remaining logged in to get the latest information.


If you need more tailored forecasts, I can quote you any time - plenty of those out there getting in now ahead of harvest - karllijnders@weathermatters.org

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