Drought Outlook
INTRODUCTION
Drought is an extreme climate event, characterized by below-normal precipitation over a period of months to years. Monitoring and early warning systems, based on drought forecasting, are therefore critical to effective drought mitigation planning.
The initial observed conditions come from the Combined Drought Indicator (CDI) - a combination of four different variables, Standard Precipitation Index (SPI-3 months), Evapotranspiration anomaly, Soil Moisture anomaly and the Normalized Difference Vegetation Index (NDVI) anomaly. These gridded data are in percentile rank with a spatial resolution of 0.05° x 0.05° (5 km x 5 km).
About this time scale (1-month period)
1 month forecast of drought issued on 5 May 2024 using the 1 month April 2024 CDI and the ACCESS S2 monthly forecast of rainfall for May 2024.
METHODOLOGY
The current drought conditions (CDI) are combined with a seasonal precipitation forecast from ACCESS S to produce a 1 month and 3 month Drought Outlook. The precipitation forecast is provided as probability of exceeding the median rainfall (PEMR). To determine likely future impacts on drought the current drought and PEMR is applied to a set of rules and thresholds, illustrated in the decision flow chart below.
Categories that appear in the Drought Outlook
| Category | Description |
|---|---|
| Drought Worsens | Drought is currently observed in the area, and is expected to intensify |
| Drought Persists | Drought is currently observed in the area, and is expected to remain the same. |
| Drought Develops | There is no drought currently observed in the area. Drought is expected to develop in the area. |
| Drought Improves but Persists | Drought is currently observed in the area. The drought is expected to improve, however the area may still be classified as being in drought. |
| Drought Removed | Drought is currently observed in the area, and is expected to be removed. |
| No Drought | There is no drought currently observed in the area, and drought is not expected to develop. |
REFERENCES
1. Guillory, L., Pumdenney, C., Nguyen-Huy, T., Cobon, D. & Stone, R. A drought monitor for Australia. Environmental Modelling & Software, 105812 (2023).
INTRODUCTION
Drought is an extreme climate event, characterized by below-normal precipitation over a period of months to years. Monitoring and early warning systems, based on drought forecasting, are therefore critical to effective drought mitigation planning.
The initial observed conditions come from the Combined Drought Indicator (CDI) - a combination of four different variables, Standard Precipitation Index (SPI-3 months), Evapotranspiration anomaly, Soil Moisture anomaly and the Normalized Difference Vegetation Index (NDVI) anomaly. These gridded data are in percentile rank with a spatial resolution of 0.05° x 0.05° (5 km x 5 km).
About this time scale (3-month period)
3 month forecast of drought issued on 5 May 2024 using the 1 month April 2024 CDI and the ACCESS S2 monthly forecast of rainfall for May 2024 to July 2024.
METHODOLOGY
The current drought conditions (CDI) are combined with a seasonal precipitation forecast from ACCESS S to produce a 1 month and 3 month Drought Outlook. The precipitation forecast is provided as probability of exceeding the median rainfall (PEMR). To determine likely future impacts on drought the current drought and PEMR is applied to a set of rules and thresholds, illustrated in the decision flow chart below.
Categories that appear in the Drought Outlook
| Category | Description |
|---|---|
| Drought Worsens | Drought is currently observed in the area, and is expected to intensify |
| Drought Persists | Drought is currently observed in the area, and is expected to remain the same. |
| Drought Develops | There is no drought currently observed in the area. Drought is expected to develop in the area. |
| Drought Improves but Persists | Drought is currently observed in the area. The drought is expected to improve, however the area may still be classified as being in drought. |
| Drought Removed | Drought is currently observed in the area, and is expected to be removed. |
| No Drought | There is no drought currently observed in the area, and drought is not expected to develop. |
REFERENCES
1. Guillory, L., Pumdenney, C., Nguyen-Huy, T., Cobon, D. & Stone, R. A drought monitor for Australia. Environmental Modelling & Software, 105812 (2023).