This was seen in ET models such as the EDDI and ESI and several soil moisture models, satellite observations of soil moisture, and agricultural field reports. But abnormal dryness or moderate drought expanded in parts of Colorado and the Dakotas, and abnormal dryness and moderate to severe drought expanded in Nebraska. Definition and comparison with other countries. And droughts are not just events that occur in the summer; rainfall deficiencies in winter are important as they result in less recharge of groundwater and less replenishment of reservoirs. Given all of this, one-category drought improvement was made across the USVI, resulting in St. Thomas having abnormally dry conditions, while St. Croix and St. John have moderate drought.For July 30-August 3, the ridge of high pressure shifts to the West with a trough setting up in the upper atmosphere over the eastern half of the CONUS. Similarly, St. Croix had only 0.36 inch of rain at the Henry E. Rohlsen airport this week, 0.38 inch of rain at the CoCoRaHS station, and 1.10 at the UVI sheep research facility (17.7160N, 64.7958W) reported. Drought or abnormal dryness expanded or intensified across parts of the West, Midwest, Southeast, and Northeast where little to no rain fell and 30- to 90-day precipitation deficits mounted. Severe drought disappeared from southwest Montana, but the rain that fell in New Mexico was not enough to improve conditions there. This normalises rainfall deficits based on the historic record, meaning the current situation is expressed relative to the past range of variability for the place in question.This means the index can be compared between localities with very different rainfall regimes (comparing, say, a wet catchment in upland Scotland with a dry catchment in low-lying East Anglia), and between times of year.This is particularly important, as droughts occur in all regions, including areas that are generally known for being wet. While the SPI value for 6 months indicated moderate drought. But little to no rain occurred in a large swath from southwest Texas to western Tennessee and northern Mississippi. In future this will be extended to include the impact of varying evaporation rates, as well as drought metrics based on river flow and groundwater conditions. But locally heavy rainfall was generated by the fronts in parts of the Plains, Midwest, and East. D1 is the least intense level and D4 the most intense.
No change was made to the depiction in Alaska.With over 3 inches of rain for the week, Palau remains in drought free conditions.This was a wet week for the Mariana Islands, with all three locations receiving over their weekly threshold of 1 inch of rain to meet most water needs. But abnormal dryness expanded in parts of eastern Oklahoma and parts of Arkansas, Mississippi, and Tennessee. Since Fananu has had close to 2 inches or more of rain the last three weeks, Fananu's drought designation was changed to drought free conditions. As a result of the uncertainty of the rainfall estimates at the 5km scale derived from a relatively sparse underpinning rain gauge network, it is not recommended that the portal be sole source of any operational analysis.There are many other sources of information for drought monitoring, notably the Hydrological Summaries produced at CEH and the Water Situation Reports produced by the Environment Agency (EA) and similar products developed by Natural Resources Wales (NRW) and the Scottish Environment Protection Agency (SEPA).