These data are 30m by 30 m grids of the mean Standardized Precipitation-Evapotranspiration Index (SPEI) between 2001-2014 in the western United States. The SPEI index was developed by Sergio M. Vicente-Serrano and coauthors (https://spei.csic.es/index.html). Source evapotranspiration and precipitation data were generated by gridMET (http://www.climatologylab.org/gridmet.html).

The dataset consists of projections of 1-12 months Standardized Precipitation Evapotranspiration Index (SPEI) between 1950-2099 for the contiguous United States from 20 climate models and 2 emission scenarios at a 4km spatial resolution. The SPEI dataset was developed using the SPEI package in R (Beguería & Vicente-Serrano, 2023). SPEI quantifies standardized departures in the balance between precipitation and potential evapotranspiration (PET) across varying timescales, making it highly suitable for assessing drought and water availability (Vicente-Serrano et al., 2010). Monthly precipitation and PET data were sourced from the MACAv2-METDATA dataset for climate projections between 1950-2099 based on 20 global climate models under RCP 4.5 and RCP 8.5 emission scenarios (Abatzoglou, 2013). Projected SPEI values were calculated relative to the 1981-2020 reference period, with SPEI computed using a log-logistic distribution fitted to the difference between precipitation and PET values. This methodology standardizes SPEI values as z-scores, allowing for comparative evaluations of drought and wetness across different regions and timescales (1 to 12 months).

The standardized precipitation evapotranspiration index (SPEI) was summarized for the Upper Green River Basin to quantify climate variability over the last century. The SPEI incorporates both precipitation and temperature data, therefore the index has the capacity to include the effects of temperature variability on drought. The SPEI considers the difference between precipitation and potential evapotranspiration to calculate a climatic water balance at a given time scale (Vicente-Serrano et al. 2010). The number of standard deviations the climatic water balance deviates from the long-term mean for a given time period represents the SPEI for the time period. Here, I calculated the SPEI for each water year (Oct–Sept) between 1896 and 2017.The SPEI score is shown on the y-axis and time on the x-axis. Years in red indicate a lower SPEI than the long-term mean, whereas years in blue indicate a higher SPEI than the long-term mean. Data (4km2 SPEI data) was obtained from the Western Regional Climate Center (http:// www.wrcc.dri.edu; accessed 14 January 2017) and calculated the water year mean (12-month data) for the Upper Green River Basin. Literature Cited Vicente-Serrano, S. M., S. Beguería, and J. I. López-Moreno. 2010. A multiscalar drought index sensitive to global warming: The standardized precipitation evapotranspiration index. Journal of Climate 23:1696–1718.

The standardized precipitation evapotranspiration index (SPEI) was summarized for the Upper Green River Basin to quantify climate variability over the last century. The SPEI incorporates both precipitation and temperature data, therefore the index has the capacity to include the effects of temperature variability on drought. The SPEI considers the difference between precipitation and potential evapotranspiration to calculate a climatic water balance at a given time scale (Vicente-Serrano et al. 2010). The number of standard deviations the climatic water balance deviates from the long-term mean for a given time period represents the SPEI for the time period. Here, I calculated the SPEI for each water year (Oct–Sept) between 1896 and 2017.The SPEI score is shown on the y-axis and time on the x-axis. Years in red indicate a lower SPEI than the long-term mean, whereas years in blue indicate a higher SPEI than the long-term mean. Data (4km2 SPEI data) was obtained from the Western Regional Climate Center (http:// www.wrcc.dri.edu; accessed 14 January 2017) and calculated the water year mean (12-month data) for the Upper Green River Basin. Literature Cited Vicente-Serrano, S. M., S. Beguería, and J. I. López-Moreno. 2010. A multiscalar drought index sensitive to global warming: The standardized precipitation evapotranspiration index. Journal of Climate 23:1696–1718.

This GIS grid atlas contains precipitation frequency estimates for Midwestern states based on precipitation data collected between 1836-2013. This atlas supersedes information in Technical Memorandum NWS Hydro 35, published in 1977, NOAA Atlas 2, published in 1973 (Colorado), Technical Paper 40, published in 1961, and Technical Paper 49,published in 1964. The grids provide information for durations from 5 minutes through 60 days, and for return periods of 1 year through 1000 years. All grids are in geographic coordinate system (NAD83 horizontal datum) and units are in 1000th of inches.

These datasets are continuous parameter grids (CPG) of total annual precipitation data for the years 2000 through 2016 in the Pacific Northwest. Source precipitation data was produced by the PRISM Climate Group at Oregon State University.

These datasets are continuous parameter grids (CPG) of total annual precipitation data for the years 2000 through 2016 in the Pacific Northwest. Source precipitation data was produced by the PRISM Climate Group at Oregon State University.

Two maps, compiled at 1:1,000,000 scale, depict mean annual runoff, precipitation, and evapotranspiration in the part of the United States east of Cleveland, Ohio and north of the southern limit of glaciation. The maps are mutually consistent in that runoff equals precipitation minus evapotranspiration everywhere. The runoff map is based on records of streamflow from 503 watersheds in the United States and southernmost Canada, adjusted to represent 1951-80 and supplemented by records of precipitation at 459 stations. Precipitation at each station was partitioned into point estimates of runoff and evapotranspiration, which were constrained such that the evapotranspiration estimates varied smoothly across the region and decreased with increasing latitude and altitude, and the runoff estimates were consistent with measured runoff from nearby watersheds. A point estimate of runoff was allowed to equal mean runoff in a nearby watershed, or to be somewhat higher (or lower) if a compensating departure from mean watershed runoff could be inferred in distant parts of the watershed on the basis of altitude or regional trends. Then, precipitation contours were drawn to parallel runoff contours but differ from them by the magnitude of nearby estimates of evapotranspiration. These maps may slightly underrepresent mean precipitation and evapotranspiration in areas of high relief because most precipitation stations in such areas are in valleys. These 3 coverages were used to produce Open-File Report 96-395. Additional information about methodology can be found in this report

Two maps, compiled at 1:1,000,000 scale, depict mean annual runoff, precipitation, and evapotranspiration in the part of the United States east of Cleveland, Ohio and north of the southern limit of glaciation. The maps are mutually consistent in that runoff equals precipitation minus evapotranspiration everywhere. The runoff map is based on records of streamflow from 503 watersheds in the United States and southernmost Canada, adjusted to represent 1951-80 and supplemented by records of precipitation at 459 stations. Precipitation at each station was partitioned into point estimates of runoff and evapotranspiration, which were constrained such that the evapotranspiration estimates varied smoothly across the region and decreased with increasing latitude and altitude, and the runoff estimates were consistent with measured runoff from nearby watersheds. A point estimate of runoff was allowed to equal mean runoff in a nearby watershed, or to be somewhat higher (or lower) if a compensating departure from mean watershed runoff could be inferred in distant parts of the watershed on the basis of altitude or regional trends. Then, precipitation contours were drawn to parallel runoff contours but differ from them by the magnitude of nearby estimates of evapotranspiration. These maps may slightly underrepresent mean precipitation and evapotranspiration in areas of high relief because most precipitation stations in such areas are in valleys. These 3 coverages were used to produce Open-File Report 96-395. Additional information about methodology can be found in this report

Two maps, compiled at 1:1,000,000 scale, depict mean annual runoff, precipitation, and evapotranspiration in the part of the United States east of Cleveland, Ohio and north of the southern limit of glaciation. The maps are mutually consistent in that runoff equals precipitation minus evapotranspiration everywhere. The runoff map is based on records of streamflow from 503 watersheds in the United States and southernmost Canada, adjusted to represent 1951-80 and supplemented by records of precipitation at 459 stations. Precipitation at each station was partitioned into point estimates of runoff and evapotranspiration, which were constrained such that the evapotranspiration estimates varied smoothly across the region and decreased with increasing latitude and altitude, and the runoff estimates were consistent with measured runoff from nearby watersheds. A point estimate of runoff was allowed to equal mean runoff in a nearby watershed, or to be somewhat higher (or lower) if a compensating departure from mean watershed runoff could be inferred in distant parts of the watershed on the basis of altitude or regional trends. Then, precipitation contours were drawn to parallel runoff contours but differ from them by the magnitude of nearby estimates of evapotranspiration. These maps may slightly underrepresent mean precipitation and evapotranspiration in areas of high relief because most precipitation stations in such areas are in valleys. These 3 coverages were used to produce Open-File Report 96-395. Additional information about methodology can be found in this report