Posted 25th Feb 2018 forecast for Monday 26th. Severe thunderstorms are very likely to develop across North East NSW and South East QLD on Monday afternoon. They are likely to contain damaging to possibly destructive winds over 125km hr and heavy rain. Above image: 500 vorticity via WRF / Weatherzone.
A very strong Northward moving coastal trough is forecast to sweep through North East NSW on Monday reaching South East QLD late in the afternoon and evening. High amounts of instability and moisture is expected to lead to scattered thunderstorms across both regions on Monday but its the late Southerly change that needs to be watched closely.
A Southerly change moving North along the coast has the tendancy to greatly enhance weather activity along the wind boundary. In Monday’s case all the right ingredients are there to produce damaging microbursts. What we are likely to see is storms developing earlier on that get injected with force from the South. This can often lead to storms rapidly becoming severe as they head North to North East across the region. Recently we have seen 2 similar system do significant damage to Landsborough, Maleny, Montville and Mapleton.
They produce areas of extremely heavy rainfall leading to damaging wind microbursts. Basically it’s caused by the intensity and force of huge water volumes falling from significant heights of around 50,000ft which drags a severe gusts of wind down to the surface.