Short term dryness indicator

(For the 21 days to 28 February 2025)

Soil water values are variable across NSW.

• High Relative Soil Water values are present in eastern NSW due to rainfall over February which has increased moisture in the soil profile.
• In the west, the Relative Soil Water values range between 0-30% of the profile’s water holding capacity.

The 21-day Relative Soil Water indicator is a short-range physical drought indicator for detecting rapid drying events. It is calculated by using the 21-day rolling mean of daily modelled rootzone soil moisture (mm) and normalises that, relative to the water holding capacity (drained upper limit) of the soil at that location.

While it is an indicator that cis a closer reflection of field conditions at the time of observation, it is also more volatile (changes rapidly). This contrasts to the SWI which is less sensitive to short range variability and designed to detect long term seasonal conditions.