MORNING WEATHER WRAP - STORMS REDEVELOP EAST, HEATWAVE CONDITIONS FOR THE WEST AND SETTLED SOUTH.

The weather is fairly mixed across the country with a cold front passing through the southeast today with light showers and drizzle developing and cooler weather, out west, a hot spell developing with a hot northeast flow setting up camp and the tropical north is seeing their first tropical waves passing through from east to west as the monsoon north of the nation seeps further south.


Thunderstorms will be back this afternoon on and east of the divide through NSW and QLD with the chance of severe storms. The risk of storms will extend westwards through northern NSW and southern QLD with damaging winds possible for pockets of QLD. There may be severe thunderstorms for the NT as well with damaging winds a risk this afternoon.


Lets wrap it quickly this morning.


Satellite Imagery Saturday

The satellite shows a fairly settled start for the nation with ridging controlling the southern parts of the nation with a relatively dry airmass. The southeast is cloudy with onshore winds in advance of the high and a cold front is moving through this afternoon with drizzle and light showers. The front will help to promote a few thunderstorms over SE NSW this afternoon and maybe the ACT. A trough over northern NSW will fire off storms this afternoon but all quiet at the moment. And you can see the mid level disturbance over WA with very little support for rainfall and a decent tropical wave offshore WA.

Thunderstorm Forecast Saturday

Thunderstorms will return to the east of NSW and QLD this afternoon and extend inland along a trough. Storms are likely to turn severe on and north and east of the trough in NSW and QLD with all modes of severe weather possible. Up north, the routine weather is expected to develop but increase in coverage. High based dry storms over inland WA is possible but little impact today.

Flash Flood Risk Saturday

With the high atmospheric moisture levels, storms are a good chance of producing flash flooding throughout the northeast of NSW, especially where wind convergence does occur. Given the saturated catchments, heavy rainfall will lead to waterways responding quickly.

Damaging Winds Risk Saturday

Damaging winds with the strong storms quite likely through northeast NSW, especially over the Great Dividing Range and points east.

Large Hail Risk Saturday

Large hail risks remain low to moderate with a relatively moist airmass aloft. The forcing is sufficient for small hail but marginal for larger stones but will review in the morning and update if there are any changes.

Thunderstorm Forecast Saturday

Thunderstorms are expected to develop during the afternoon and evening, near and north/east of a stalled boundary that will be sitting over northern and northeast NSW. Severe storms are possible but more likely about the NSW border at this stage. Damaging winds and heavy rainfall the main issues at this time.

Flash Flood Risk Saturday

Flash flooding is a moderate to high risk given the high level of atmospheric moisture in the air aloft. This will mean that thunderstorms will be efficient rainfall producers and with catchments still very wet from months of rainfall, flash flooding will occur quite easily.

Damaging Winds Risk Saturday

Damaging winds a moderate to high risk with the storms running through a fairly gusty upper level wind profile. The heavier rainfall will help to mix the winds down to the surface.

Large Hail Risk Saturday

A low end risk for large hail to develop with thunderstorms.

Rainfall Next 10 Days

Rainfall continues to chop and change as promised on modelling but the signals are increasing for a heavy rain and storm event for NSW once again during the mid to latter part of this week coming, with some locations in SE NSW possibly seeing a month's worth of rainfall. The showers and storms persist most days for QLD with onshore winds, high humidity and troughs nearby promoting the tropical weather. The southern coastal areas back to WA are appearing to remain dry and hot with a strong easterly wind and a heat trough inland of the coast in WA may start to drag moisture southwards into the state, bringing up the chance of thundery showers mid to late week but little rainfall away from the tropical north. The tropics are very unstable with multiple waves of low pressure passing through the north and a noticeable increase in rainfall and thundery weather will mean an uptick in the amount of moisture heading southwards this week across the nation. QLD and NSW watch closely.

DATA

12Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 16 Days

The pressure pattern is very typical of early Summer with troughs over the west, north and eastern inland with moisture feeding the troughs, mainly in the north and east, promoting showers and thunderstorms. The trough in the east is expected to be invigorated by a middle level trough during mid week over NSW and QLD, possibly dipping into eastern VIC, with rainfall increasing dramatically. There is a chance of flash and riverine flooding on some of the data sets coming in this morning but will have to watch closely in the coming days. The tropics will see a sharp increase in rainfall totals in the forecast packages this week for the week leading into Christmas and this will run down south and east bringing a wetter signal for Christmas across much of Australia.

12Z GFS - Precipitable Water Anomalies - Next 16 Days

The values again no change from yesterday, the moisture building over the north, damming over the east of the nation with the drier airmass from southern Australia failing to make it north into the eastern inland thanks to the ongoing easterly flow, pushing the drier air back west. The drier airmass will heat efficiently out west leading to heatwave conditions developing.

12Z GFS - Rainfall Accumulation - Next 10 Days

Heavy rainfall for the southeast and over the tropical north with the monsoonal weather ramping up over the tropical areas. A deep slow moving trough over NSW and QLD will keep the wet weather going mid to late week for these areas. The west and south remaining in mostly sinking air for the period but the rainfall will return with the moisture and heat creeping southwards

Still image of the above for the next 10 Days.

More details coming up later today - I am travelling once again. Have a great Saturday