Nationwide
Drought coverage and intensity continued its decline throughout the Great Plains since the spring with additional heavy rainfall during the first week of July.
Despite the extremely heavy rainfall and flash flooding this past week, long-term drought dating back multiple years remains across south-central Texas. Improving drought conditions were made to parts of New Mexico, southwestern Colorado, and Arizona, while drought expanded and intensified across the Pacific Northwest and Northern Intermountain West. Much of the Corn Belt and Midwest remains drought-free, but a continued lack of adequate precipitation led to worsening drought for northern Illinois. Following another week of summertime thunderstorms with heavy rainfall, drought ended for most of the central to southwestern Florida Peninsula. Nearly all of the East, Ohio and Tennessee Valleys, and Lower Mississippi Valley are drought-free.
Seven-day temperatures (July 1-7), averaged 2-4 degrees above normal across the Pacific Northwest, Northern Great Plains, Midwest, and New England. Cooler-than-normal temperatures were limited to the Southern Great Plains and portions of the Southwest.
The West
Based on rapidly declining soil moisture and low 28-day average streamflows, additional degradations were warranted this week for the Pacific Northwest with an expanding coverage of moderate (D1) to severe (D2) drought across Oregon and Washington.
Further to the east, extreme drought (D3) was expanded to include more of northern Idaho. Parts of Utah also had a few areas with degradations based on 28-day streamflow, soil moisture, and high evaporative demand recently. A drier end to the wet season, 60 to 90-day Standardized Precipitation Index (SPI), and low soil moisture supported an expansion of abnormal dryness (D0) across northern to central California. Following recent beneficial precipitation along with timely wetness back to the late spring, improvements were warranted for parts of north-central and eastern Montana. Drought intensity remained nearly steady for the Desert Southwest, although locally heavier Monsoon showers led to a small reduction in extreme drought (D3) for eastern and southern Arizona.
The High Plains
Another round of heavy rainfall (1-2 inches, locally more) supported a 1-category improvement to parts of the Northern and Central Great Plains. April through early July is a wet time of year, and 90-day precipitation, valid from April 9 to July 7, averaged more than 150% of normal for much of the Dakotas, Nebraska, eastern Colorado, and eastern Wyoming.
Conversely, moderate drought (D1) across northeastern North Dakota was expanded westward due to another dry week and above-normal temperatures. The D1 is supported by the 30 to 60-day SPIs along with soil moisture indicators. Eastern Kansas has missed out on the heavy rainfall recently and abnormal dryness (D0) was added to that part of the state. Although precipitation was not particularly heavy across southwestern Colorado, sufficient precipitation, combined with support from SPIs at multiple time scales and the NDMC drought blends, warranted small 1-category improvements.
The South
A broad one to two-category improvement was made this past week to much of the ongoing long-term drought areas of Texas, along with parts of New Mexico.
The heaviest precipitation (5-10 inches, or more) occurred across the Edwards Plateau and south-central portions of Texas. According to CoCoRaHS gauge measurements from July 1-7, precipitation amounts ranged from 12-18 inches in eastern Burnet and western Williamson counties of Texas. Although 1 to 2-category improvements were made, a long-term drought dating back multiple years with low groundwater and reservoir levels continues. Therefore, an area of long-term drought (D1+) was maintained. The Edwards Aquifer Authority’s long-term observation wells in Medina and Uvalde counties remain in extreme (D3) to exceptional (D4) drought levels. Elsewhere, across the Southern Great Plains and Lower Mississippi Valley, no short-term or long-term drought is designated. — UNL Drought Monitor
