Hot, windy weather lifts fire danger, again

Hot air from central Australia will be transported across south-eastern Australia on Friday as north-westerly winds strengthen ahead of an approaching cold front.

This hot air mass will cause temperatures to exceed 45 degrees in the state's far west on Friday, while some near-coastal areas should reach the high thirties.

Fortunately, this week's pulse of heat won't be as intense as that of recent weeks and the air will be more humid for many areas, leading to lower fire danger ratings.

However, Very High to Severe ratings are still likely over most of the state on Friday. It's also worth noting that more than 100 fires were still burning across NSW earlier this week.

Following the spike in temperatures, a blustery cool change will sweep into south-western NSW on Friday afternoon before spreading northwards across the state during Friday night and Saturday morning.

This overnight wind change could cause dangerous conditions as it passes through active fire grounds.

In addition to the cool change, moisture associated with the remnants of Tropical Cyclone Blake should help generate some showers and thunderstorms over parts of NSW on Friday night and Saturday.

While this rain will be welcome in many areas, it won't be enough to extinguish all of the fires in NSW. There's also a risk that lightning strikes could ignite new fires.

Further isolated showers and thunderstorms are likely over parts of eastern and north-east NSW on Sunday.

The fires burning in NSW this month come off the back of the state's warmest and driest year on record.

Statewide rainfall during 2019 was more than 300mm below the long-term annual average, which is more than 50mm lower than the previous record set in 1944.

The state's mean annual temperature was 1.95 degrees warmer than average, beating the old record of 1.68 degrees from 2018.

This prolonged warm and dry weather has left an abundance of parched bush and grassland across the state, which is fuelling this season's fires.