Lawn and Garden Moisture Index
Alabama Office of the State Climatologist
The Lawn and Garden Moisture Index measures the capacity of current soil moisture to sustain healthy lawns and gardens in the Southeast U.S. The Index is computed in two stages, according to the Alabama Office of the State Climatologist:
"First, we estimate how much recent precipitation contributes to current soil moisture, assuming that any precipitation over the past 21 days should be included in the computation. The Index also assumes that more recent precipitation is more significant than the less recent: all precipitation during the previous 7-day period is considered equally important, but precipitation before that time is discounted according to a sliding scale. The result is the total effective precipitation during the period. The precipitation we use to compute the index is obtained from NOAA's Climate Prediction Center. It is determined from weather radar images in conjunction with precipitation reported at rain gages.
Second, we find out how much the total effective rainfall for the current day differs from a 'standard' amount of rainfall considered to be adequate for that time of year to sustain healthy lawns and gardens. The difference is the Lawn and Garden Moisture Index. Much less precipitation is needed during the cold months than in the warm ones. ... Positive values of the Index indicate adequate precipitation or better. Negative values indicate a precipitation deficit."
The Lawn and Garden Moisture Index measures the capacity of current soil moisture to sustain healthy lawns and gardens.
The index is computed in two stages. The first involves how much recent precipitation (over the past 21 days) contributes to current soil moisture. The second involves finding how much the total effective rainfall for the current day differs from a “standard” amount of rainfall considered to be adequate for that time of year to sustain healthy lawns and gardens.
Positive values of the index (green) indicate adequate precipitation or better, while negative values (yellow to red) indicate a precipitation deficit.
A drought index combines multiple drought indicators (e.g., precipitation, temperature, soil moisture) to depict drought conditions. For some products, like the U.S. Drought Monitor, authors combine their analysis of drought indicators with input from local observers. Other drought indices, like the Standardized Precipitation Index (SPI), use an objective calculation to describe the severity, location, timing, and/or duration of drought.
Learn MoreSoil moisture plays an important role in drought and flood forecasting, agricultural monitoring, forest fire prediction, water supply management, and other natural resource activities. Soil moisture observations can forewarn of impending drought or flood conditions before other more standard indicators are triggered.
Learn MoreFlash drought is the rapid onset or intensification of drought. Unlike slow-evolving drought, which is caused by a decline in precipitation, flash drought occurs when low precipitation is accompanied by abnormally high temperatures, high winds, and/or changes in radiation. These sometimes-rapid changes can quickly raise evapotranspiration rates and remove available water from the landscape.
Learn MoreDrought can result in reduced growth rates, increased stress on vegetation, and alterations or transformations to the plant community and/or the entire ecosystem. During periods of drought, plants increase their demand for water through increased evapotranspiration and longer growing seasons.
Learn MorePrecipitation Deficit
Adequate or Surplus Precipitation
The Lawn and Garden Moisture Index measures the capacity of current soil moisture to sustain healthy lawns and gardens.
The index is computed in two stages. The first involves how much recent precipitation (over the past 21 days) contributes to current soil moisture. The second involves finding how much the total effective rainfall for the current day differs from a “standard” amount of rainfall considered to be adequate for that time of year to sustain healthy lawns and gardens.
Positive values of the index (green) indicate adequate precipitation or better, while negative values (yellow to red) indicate a precipitation deficit.
The Lawn and Garden Moisture Index is updated daily with a latency of 1-2 days.
A drought index combines multiple drought indicators (e.g., precipitation, temperature, soil moisture) to depict drought conditions. For some products, like the U.S. Drought Monitor, authors combine their analysis of drought indicators with input from local observers. Other drought indices, like the Standardized Precipitation Index (SPI), use an objective calculation to describe the severity, location, timing, and/or duration of drought.
Learn MoreSoil moisture plays an important role in drought and flood forecasting, agricultural monitoring, forest fire prediction, water supply management, and other natural resource activities. Soil moisture observations can forewarn of impending drought or flood conditions before other more standard indicators are triggered.
Learn MoreFlash drought is the rapid onset or intensification of drought. Unlike slow-evolving drought, which is caused by a decline in precipitation, flash drought occurs when low precipitation is accompanied by abnormally high temperatures, high winds, and/or changes in radiation. These sometimes-rapid changes can quickly raise evapotranspiration rates and remove available water from the landscape.
Learn MoreDrought can result in reduced growth rates, increased stress on vegetation, and alterations or transformations to the plant community and/or the entire ecosystem. During periods of drought, plants increase their demand for water through increased evapotranspiration and longer growing seasons.
Learn MoreAccess
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