Drier conditions returned to Iowa and the Tennessee Valley this drought monitor week, though heavy rains still remained in parts of the Northeast, the Great Lakes region, the Mississippi Valley, and the Southwest.
This past week was much drier in Iowa, with the exception of 3-inch amounts in far southwest Iowa, which is almost three times the weekly normal.
The latest USDA NASS report has only 6% of the southwest Iowa crop district as short or very short of subsoil moisture. Accordingly, the D0 was removed from this area. In southeast Iowa, the area covered by D0 received near-normal precipitation this past week, said Drought Monitor author Anthony Artusa of the National Oceanic and Atmospheric Administration.
Farther south, in southwest Arkansas and adjacent northwest Louisiana, hot temperatures and increased evaporation rates favor the expansion of abnormal dryness across this region.
Drier conditions also returned to much of Kentucky and Tennessee during the past 7 days, Artusa says. Moderate drought was introduced to parts of southeast Kentucky based on stream flows and 90-day percent of Normal Precipitation being around 60% of normal.
Declining soil moisture and pasture conditions suggest the early stages of a developing flash drought in the Southeast.
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Pasture conditions are declining, Artusa says, with now just 40% rated Good to Excellent in South Carolina, and 50-60% in North Carolina, Virginia, Delaware, and Kentucky. Based on these indicators, and low stream flows, abnormal dryness was added to the drought depiction in the westernmost counties of South Carolina, as well as a sizable portion of eastern South Carolina. D0 was also expanded in central North Carolina and north-central Georgia.
About a dozen relatively minor revisions were made to the depiction in Texas this week, some degradations and some improvements. No changes were made in Oklahoma, Kansas, or Nebraska this week, in part due to widespread areas of well above-normal precipitation in the past 30 days, according to the Drought Monitor.
The initial moisture surges of the summer monsoon commenced on schedule across Arizona and New Mexico this past week, Artusa says.
In northwest New Mexico, which missed out on the significant rainfall this past week, extreme drought was expanded eastward across all of San Juan County, and continuing across the western one-third of Rio Arriba County.
In south-central Colorado, a one-category downgrade was made, and in southeast Colorado, conditions are still "deplorable," Artusa writes, with little vegetation on the ground, and there is also the occasional dust storm kicking up.
Aside from these, minimal modifications were made throughout the Southwest and California. As an important side note, Artusa says, southern Nevada's Lake Mead is expected to fall this week to its lowest level since 1937, when the manmade lake – the largest reservoir in the United States – was first being filled.
Source: U.S. Drought Monitor