gridMET

gridMET is a high-spatial resolution (~4-km, 1/24th degree) dataset of daily surface meteorological data, covering the contiguous US from 1979 to the present day, with daily updates. It also extends to southern British Columbia for its real-time products. This dataset serves as a crucial input for various ecological, agricultural, and hydrological models, and is also known as METDATA.

The dataset comprises primary climate variables such as maximum and minimum temperature, precipitation accumulation, downward surface shortwave radiation, wind-velocity, and humidity (maximum/minimum relative humidity and specific humidity). Additionally, it provides several derived variables including reference evapotranspiration (ASCE Penman-Montieth), Energy Release Component, Burning Index, 100-hour and 1000-hour dead fuel moisture, mean vapor pressure deficit, and the 10-day Palmer Drought Severity Index.

The methodologies behind gridMET involve blending the spatial attributes of gridded climate data from PRISM with the desirable temporal attributes and additional variables from regional reanalysis, specifically NLDAS-2. This process utilizes climatically aided interpolation to create a spatially and temporally complete, high-resolution gridded dataset. The product is semi-operational and is updated daily, utilizing daily PRISM and National Water Prediction Service QPE for precipitation, and CFSv2 anomalies for other variables to maintain near real-time updates and overcome data latency issues.