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    Departure from Average Precipitation represents the accumulated precipitation value for a location, subtracted by the long term average value. The long term average value is defined as the average amount over the 1981 – 2010 period. A negative value indicates that the location has received less than the normal amount of precipitation (mm) for that timeframe. A positive value indicates that the location has received more than the normal amount of precipitation (mm). Products are produced for the following timeframes: Agricultural Year, Growing Season, Winter Season as well as rolling products for 30, 60, 90, 180, 270, 365, 730, 1095, 1460 and 1825 days.

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    Accumulated Precipitation represents the amount of total precipitation in mm (solid and/or liquid) which has been recorded over a given period of time. Products are produced for the following timeframes: Agricultural Year, Growing Season, Winter Season, as well as rolling products for 7, 14, 30, 60, 90, 180, 270, 365, 730, 1095, 1460 and 1825 days.

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    The Moisture Anomaly Index (Palmer-Z) is an estimate of the moisture difference from normal (a 30-year mean). It attempts to express conditions for the current month regardless of what may have occurred before the month in question.

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    Precipitation Percentiles represents the accumulated precipitation (mm) for the time period compared to historical information for the same time period. This comparison ranks the current precipitation amount and assigns it a percentile value based on a historic record. Products are produced for the following timeframes: Agricultural Year, Growing Season and Winter Season as well as rolling products for 30, 60, 90 and 180 days

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    Percent of Average Precipitation represents the accumulation of precipitation for a location, divided by the long term average value. The long term average value is defined as the average amount over the 1981 – 2010 period. Products are produced for the following timeframes: Agricultural Year, Growing Season, Winter Season, as well as rolling products for 30, 60, 90, 180, 270, 365, 730, 1095, 1460 and 1825 days.

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    The term "Palmer Drought Index" has been used collectively to represent multiple indices. This index is simply a water balance model which analyzes precipitation and temperature, and used as a tool to measure meteorological and hydrological drought across space and time. All versions of the index uses the Versatile Soil Moisture Budget to model the movement of water within the system, and a daily Priestly-Taylor model to estimate evapotranspiration. The Palmer Drought Index (PDI) uses monthly temperature and precipitation data to calculate a simple soil water balance. The index is a relative measure that typically ranges from -4 (extremely dry) to +4 (extremely wet) and represents how soil moisture availability differs from that expected for a given place and time of year. The PDI includes a "memory" component that considers past conditions and persistence of soil moisture surplus or deficit. The Palmer Hydrological Drought Index (PHDI) is a specific version of the PDI that accounts for longer-term drought that reduces surface and groundwater supply.

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    Total soil moisture is the modelled amount of plant available water (mm) in the root zone of the soil. The value given is the amount calculated to be present on the modeled day of the product. Values are computed using the Versatile Soil Moisture Budget (VSMB)

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    Dry spell periods are defined as the number of days (April 1 – October 31) where daily precipitation is less than 0.5 mm. This is not an accumulation of precipitation, simply a count of days. Dry spell products are only generated during the Growing Season, April 1 through October 31.

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    The Blended Index (BI) is a model which employs multiple potential indicators of drought and excess moisture, such as the Palmer drought index, rolling precipitation amounts and soil moisture, and combines them into a weighted, normalized value between 0 and 100. The inputs and weights used in this model are subject to change periodically as it is optimized to best represent extent, duration and severity of impactful weather conditions. The blended index is deployed as two variations; short term (st) focusing on 1 to 3 months, and long term (lt) focusing on 6 months to 5 years.

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    Mean Temperature Difference From Normal values are computed by subtracting the normal monthly average temperature from the average monthly temperature of the month. The average monthly temperature is computed by obtaining the mean value of average daily temperatures for a month. If the month was colder than normal the value computed will be negative and if it was warmer the value will be positive.