Forecasts of the Lawn and Garden Moisture Index (LGMI)
The LGMI for a given day is calculated as a weighted sum of rainfall over the previous 21 days compared with the potential plant water use during that same period. For a more detailed description of the LGMI, please visit the website of the Alabama Office of the State Climatologist.
The LGMI has a minimum value of -2.0 and a maximum value of 2.0. Values of LGMI less than -1.5 indicate severe drought conditions. It is important to recognize that LGMI can indicate that plants experience a severe drought even when rivers and reservoirs are full. This happens because plants can extract available moisture from the shallow soils of the Southeast USA within 2 to 3 weeks.
The forecast maps below show the probability that LGMI will be less than -1.5, in other words, the likelihood of a severe drought, during 10-day periods over the next 40 to 50 days. These forecasts are based on differences in rainfall probability for the three El Niño Southern Oscillation phases.
Select specific phase and date
Compare climate phases
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February(11-20 Days) |
February 21 to month end |
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