STORMS BECOMING MORE ACTIVE WITH THE PASSAGE OF TROUGH IN QLD. CHANCE OF STORMS OVER SOUTHEAST SA.

Storms amongst all the rain areas today, will be limited in their ability to develop into strong storms, but the storms IF they develop, will enhance rainfall rates through the eastern third of QLD today and into Saturday.


Modelling is in good agreement of developing a heavy band of rain and thunderstorms through the Wide Bay/Burnett through the Capricornia Coasts towards the southern Central Coast and inland to the Highlands and Coalfields. The band, where it forms and how strong the storms will be with the rainfall rates, still yet to be determined and it is imperative if you live in this zone you monitor radar trends and stay up to date with official warnings.


Euro 12z run - Rainfall for the next 10 days - Valid Friday 2nd of July 2021.

Note that enhanced stirp of rainfall where falls could exceed 100mm through the areas mentioned above. Where that band sets up in real time will be interesting to compare to this data being expressed by the models. Bottom line, somewhere within this region is going to see 1-2 months worth of rainfall in a sitting.

As a result the flash flood risk is low to moderate for Saturday in particular for this region with the weather easing during Sunday morning.


Flash Flood Risk - Saturday - Valid Friday 2nd of July 2021.

5-20% chance of flash flooding within 20km of a given point during Saturday in the low zones increasing to 40% in the moderate zone. This does not guarantee flash flooding will occur but expressing the risk against the data being fed into the models this morning.

The CAPE Values and K-Index also showing relatively unstable air with the potential for scattered thunderstorms through QLD, but the limiting factor is the thick cloud cover with high precipitable water values and a lot of instability, we saw that Thursday over the east with limited thunderstorm activity and just a big ole mass of rainfall. That may occur again through the region Friday and Saturday.


Euro 18z run - CAPE Values - Next 3 days - Valid Friday 2nd of July 2021.

This measures the available energy to produce thunderstorm activity. In the warm seasons we usually see a lot of CAPE with higher temperatures and humidity combined. In the cool seasons you don't see as high values to support thunderstorms There is sufficient instability to produce scattered thunderstorms Friday and Saturday with the instability leaving with the trough on Sunday.

Euro 18z run - K-Index - Next 3 days - Valid Friday 2nd of July 2021.

Any value over about 25 is sufficient for isolated thunderstorm activity, over 30 units and we can see more scattered thunderstorms. The limiting factor within this atmosphere is the amount of cloud cover in the region that may suppress thunderstorms development.

Thunderstorm Forecast for Friday - Valid Friday 2nd of July 2021. QLD

Thunderstorms are possible through a broad area of QLD today with the most likely area of thunderstorms through the eastern inland along the Great Dividing Range during this afternoon and this evening. Thunderstorms may produce strong gusty winds but more likely heavy rainfall leading to a low end risk of flash flooding. Thunderstorms may continue overnight. There is an 80% chance of thunderstorms forming within 25km of a given point in the maroon region with the risk tapering down 10% per colour down the wheel.

Thunderstorm Forecast for Saturday - Valid Friday 2nd of July 2021. QLD

Thunderstorms may continue from Friday into Saturday with the coverage become more scattered as the trough amplifies as it moves eastwards through the central regions towards the coast. Thunderstorms may turn severe with heavy rainfall leading to flash flooding the main concern with damaging winds a lower threat. Thunderstorms should clear the southeast through the morning and be concentrated north of Brisbane during the afternoon. Thunderstorms will clear later Saturday night or Sunday morning off the coast.

There is an 90% chance of thunderstorms forming within 25km of a given point in the pink region with the risk tapering down 10% per colour down the wheel.

Thunderstorms are also a low risk today with a cold air mass moving into southeastern Australia. Small hail and gusty winds may accompany showers even without the presence of thunderstorms in the cold and unstable airmass.


Cold air moving towards the east.


Thunderstorms may extend to the southwest VIC coast tonight with small hail also a risk in this region.


Thunderstorm Forecast Friday - Valid Friday 2nd of July 2021.

Thunderstorms are possible with a cold airmass working it's way through coastal areas of southeast SA and into western VIC and TAS tonight. It is a flip of a coin at best whether these showers can graduate into thunderstorms and deliver a clap or two of thunder. The more likely area for thunderstorms will stay offshore for now. Thunderstorms may continue into Saturday and a chart will be issued if the risk remains relatively unchanged. There is an 50% chance of thunderstorms forming within 25km of a given point in the yellow region with the risk tapering down 10% per colour down the wheel.

Hail risk forecast Friday - Valid Friday 2nd of July 2021.

Small hail is a decent chance with any tall shower or thunderstorm that moves through coastal areas during the coming 24 hours. Hail size will be teeny tiny, with no large hail expected and accumulations should be light given the dry airmass and the fast forward speed of the showers and possible storms through the region. The hail risk eases during Saturday and contracts into VIC. 5-20% chance of hail within 20km of a given point during Friday in the low zones increasing to 40% in the moderate zone and 60% in the high zones.

Need more weather information? Email me at karllijnders@weathermatters.org for further information about tailored forecasting.





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