NSW AND QLD - SEVERE WEATHER RISK CONTINUES.

Thunderstorms are expected to fire up again along a trough meandering along the coast of NSW and into southern and central QLD. There is an upper level low sitting over the Mid North Coast which could kick off strong to severe storms through NSW and QLD again this afternoon, with all modes of severe weather possible.


As we saw yesterday, we have to expect the unexpected with severe weather season, storms dumping 16cm hail in the subtropics is not something this nation has seen before, nor hail stones of that size!


Today the atmosphere is largely unchanged for coastal areas, and while it is conceivable thunderstorms producing giant to gorilla sized hail is possible, the risk is low but will watch trends.


Satellite Imagery

Note the upper low over coastal NSW with showers and strong winds into the southern coastal areas. The weather on the southern side of this feature non severe. The weather on the northern flank of the low and along the trough in the warmer sector is the danger today. Severe thunderstorms are likely and there could be some heavier falls than what is being advertised under thunderstorms. We could see coastal falls of 100mm north of Newcastle to the Gold Coast in the coming 24hrs. The major hail risk at this time is over the Wide Bay through to about the Central Coast of QLD. Severe weather can occur outside of these areas today so refer to the forecast maps below all of this analysis to see where you stand.

Area of concern today is this region, where the atmosphere is a powder keg and the trough hopefully will lift offshore and keep the nasty weather offshore, though looking at the observations this may not be the case and further strong to severe storms may redevelop during later this morning and afternoon. Based off the convection already identified, the risk of severe weather is high today.

Current state of play.

Dangerous thunderstorms have been observed this morning offshore the Cental QLD coast across the Whitsunday Islands with large hail and destructive winds/waterspout activity. Otherwise or the remainder of QLD and essentially most of NSW, things pretty quiet with ongoing showery weather over the southern coastal areas of NSW extending north to Sydney this morning, as the upper low drifts north. The trough will be slow to move east under the blocking pattern. Anywhere to the east of that has the risk of strong to severe storms and to the west of the trough it is dry and stable.

Thunderstorm Forecast Wednesday

Thunderstorms are ongoing this morning and will increase Wednesday afternoon and evening over the southeast extending up to the Central Coast and inland to the GDR. Isolated thunderstorms possible about the Gulf Coast south of Normanton. Storms have the potential to turn severe with large hail the major concern for the Central Coast and Wide Bay with heavy rainfall and damaging winds the main concern throughout the remainder with large hail also a concern. The current observations suggest storms could be quite nasty over the Central Coast again.

Damaging Winds Risk Wednesday

A moderate risk of damaging winds with thunderstorms during the afternoon and evening over the southeast and along the coast where the wind convergence will help to promote stronger convection. These storms may organise into a line like today and move towards the coast with that stronger wind risk mid to late afternoon. There is a low risk of a tornado through Central Coast to Wide Bay regions today.

Large Hail Risk Wednesday

Large hail a moderate to high risk this morning over the Whitsundays - the risk is currently painted low for coastal areas, but this could increase to high to very high once I see the latest soundings. It is quite conceivable one or two storms over the Central Coast could spit out some large and giant hail this afternoon.

Flash Flood Risk Wednesday

Flash flooding also a risk during the afternoon and evening, and more likely over the southeast inland where the stronger storms are likely to form over higher ground inland of the Gold Coast and Brisbane. Heavy rainfall with totals over 100mm about the coastal fringe south of Brisbane is possible.

Thunderstorm Forecast Wednesday

Thunderstorms are set to return once Wednesday afternoon and evening over the NE of NSW and into SE QLD with the chance of thunderstorms turning severe with all modes of severe weather a low to moderate risk once again. The risk of heavy rainfall developing about the Mid North and Northern Rivers Coast is quite possible this evening where the upper low begins to move over the region. Some areas could see heavy rainfall rates and totals over 100mm on the coast is possible.

Flash Flood Risk Wednesday

A low to moderate risk of flash flooding with thunderstorms during the afternoon and evening, with the slopes of the GDR and hinterland under the highest risk over the Northern Rivers. I may upgrade this risk to high for pockets of the coast tonight from Taree through to Coffs Harbour.

Large Hail Risk Wednesday

A low to moderate risk of large hail through the region during Wednesday afternoon and evening, a slight risk of giant hail is forecast for inland areas where wind convergence is present closer to the QLD border.

Damaging Winds Risk Wednesday

A moderate risk of the strongest storms through the GDR and over the far northeast turning severe with wind gusts over 100km/h during the afternoon and evening with the stronger storms. A very low risk of a tornado today.

Make sure you stay weather aware today as the storms could absolutely pack a punch, which caught many by surprise yesterday with scattered supercells. Judging by the activity this morning, it could be the case again this afternoon.