About this tool
This dynamic web application provides daily updates for precipitation, streamflow, and groundwater levels for each county in Kentucky and weekly updates of crop moisture index values for each of the four climate divisions in Kentucky.
Reading the symbology
Each county contains a four-panel square, where each panel represents a single parameter, colored by drought status:
Drought status (green = normal; yellow = drought advisory; light orange = moderate drought, orange = severe drought, red = extreme drought; gray = no data) is based on criteria outlined by the Kentucky Drought Mitigation and Response Plan (2008) (Table 1).
Table 1. Indicators displayed for each Kentucky county in the drought monitoring mapper, update frequency, and drought status evaluation criteria. [*, category thresholds not provided by the Kentucky Drought Mitigation and Response Plan]
90-day precipitation percent of normal departure
28-day streamflow percentile
|Normal||> 74.0 %||> 25.0 %|
|Advisory||> 64.0 - 74.0 %||Not assessed*|
|Moderate||> 54.0 - 64.0 %||11.0 - 25.0 %|
|Severe||> 45.0 - 54.0 %||6.0 - 10.0 %|
|Extreme||< 44.0 %||≤ 5.0 %|
|Updates||Daily, 4:30 AM Central Time||Daily, 4:30 AM Central Time|
|Scale||Summarized for each county from gridded field with a spatial resolution of approximately 4 x 4 kilometers||Summarized for each county based on representative streamgage|
|Source||National Weather Service||USGS WaterWatch, USGS National Water Information System (NWIS)|
7-day Crop Moisture Index
30-day groundwater level percentile
|Normal||> -0.5||> 25.0 %|
|Advisory||0.9 to -0.05||Not assessed*|
|Moderate||-1.9 to 1.0||11.0 - 25.0 %|
|Severe||-2.9 to -2.0||6.0 - 10.0 %|
|Extreme||≤ -3.0||≤ 5.0 %|
|Updates||Weekly, 9:00 PM Central Time Mondays||Daily, 4:30 AM Central Time|
|Scale||Summarized for each of the four Kentucky climate divisions||Summarized for four counties with adequate period of record|
|Source||Central Region Climate Prediction Center||USGS WaterWatch, USGS National Water Information System (NWIS)|
The streamflow and groundwater indicators use data from USGS WaterWatch and the National Water Information System (NWIS) to assess recent hydrological drought conditions based on the departure from historic flows or groundwater levels at each gage, called the percentile. A single, representative stream gage (red triangles on the map) has been selected to characterize the severity of current surface water conditions for each county. At present, only four counties contain groundwater wells (black circles) capable of providing groundwater level data. Consequently, groundwater indicator data are shown only for these four counties. The groundwater indicator for all other counties displays a gray square in the groundwater indicator panel (bottom-right) representing "No Data." No Data indicators may occasionally display for other panels based on data availability at the time of each application update. The streamflow indicator status is evaluated using 28-day average flow condition percentiles and the groundwater indicator status is evaluated using 30-day average groundwater level percentiles.
The precipitation indicator uses high-resolution gridded precipitation data from the National Weather Service. Observed and historic rainfall data are summarized to the county level and meteorological drought conditions are assessed based on the 90-day precipitation percent of normal value, which is calculated by dividing the 90-day observed precipitation by the 90-day normal precipitation value,
(90-day obs. precip./90-day precip. normal) x 100,
where the normal is the "expected" precipitation value represented by a regionally-specific 30-year record of precipitation measurements.
The crop moisture index (CMI) indicator uses data reported by the Central Region Climate Prediction Center. Unlike other indicators displayed in this application, the CMI indicator is only updated weekly and only a single value is provided for each of Kentucky's four climate divisions.