A very warm and humid airmass will help to trigger further thunderstorm activity in Sydney this week, while overnight temperatures struggle to fall below 20 degrees.

As Sydneysiders experienced at the weekend, the warm and muggy weather is coming at a cost.

Moisture and heat are two of the main ingredients for thunderstorm development.

Another ingredient is a triggering mechanism, which is coming in the form of a broad and slow moving low pressure trough.

Thunderstorms had begun developing over western parts of Sydney early on Sunday afternoon where maximums had climbed into the low thirties.

The high humidity then played a roll in Sydney’s warm night, which failed to fall below 21 degrees and was the warmest since March.

Already on Monday, the city had soared above 28 degrees before 10am.

This pattern will be the feature of the week. Most nights will remain warmer than 20 degrees with thunderstorms a risk on almost every day until Sunday.

– Weatherzone

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