Nationwide
Drought coverage and intensity continued its overall decreasing trend this spring across the Great Plains.
To the east, across southern Iowa, northern Illinois, and northern Missouri, drought expanded with little to no precipitation from May 27 to June 2. The Desert Southwest experienced an unusual wet start to June, as a low-pressure system interacting with enhanced moisture from Tropical Storm Alvin in the East Pacific resulted in locally heavy rainfall and a one-category improvement in parts of Arizona. A wetter-than-normal May brought an end to drought throughout much of the Northeast.
The rainy season is well underway across Florida and heavy rainfall this past week led to improvements across the central to southern Florida Peninsula. 7-day temperatures (May 27-June 2) averaged below normal across most of the eastern and central United States, while above-normal temperatures prevailed in the West.
The West
The Desert Southwest had a rare wet start to June as a mid-level low-pressure system interacted with enhanced moisture from former Tropical Storm Alvin in the East Pacific.
Central Pima, northern Maricopa, and southern Yavapai counties of Arizona received 0.75 inches of precipitation with isolated amounts exceeding 2 inches, supporting a 1-category improvement. Although amounts were lower in southeastern Arizona, there was enough precipitation to warrant shifting the exceptional drought category (D4) to extreme drought (D3). A lack of springtime precipitation led to an expanding area of abnormal dryness (D0) and short-term drought (D1) across the Pacific Northwest. Based on worsening soil moisture and low 28-day average streamflows, a 1-category degradation was warranted for parts of central and southwestern Montana. A 1-category degradation was also made to parts of central and northeastern Utah. Elsewhere, across the West, little to no changes were made as California and Nevada enter their drier time of year.
The High Plains
From May 20 to June 2, two-week precipitation amounts ranged from 2 to 4 inches, locally more, across much of Kansas, Nebraska, and northeastern Colorado.
This precipitation, accompanied by cooler-than-normal temperatures during the latter half of May, led to improving drought conditions for the Central Great Plains. The southern half of Kansas is now drought-free. On June 2, precipitation (more than 0.5 inches) overspread southern Colorado, resulting in a 1-category improvement. Additional precipitation this past week, along with consideration of SPIs dating back 6 to 12 months and the NDMC drought blends, supported the removal of severe (D2) to extreme (D3) drought across southeastern Wyoming.
Despite only light precipitation this past week, a 1-category improvement was made to much of the Dakotas to be more consistent with SPIs at various time scales, soil moisture, and the NDMC drought blends. For the Northern Great Plains, the drought impact was changed to long-term only, given the recent wetness and the drought signal is strongest at 9 to 12 months.
The South
For the second consecutive week, heavy rainfall (more than 1 inch) prompted a 1-category improvement to central and southern Texas.
Despite this recent heavy rainfall, levels in the long-term monitoring wells of Bexar and Medina Counties remain near or at all-time lows. Additionally, many of the 28-day average USGS streamflows across south-central Texas are below the 5th percentile, which supports the D3-D4 depiction. Since the SPIs dating back 6 months are mostly neutral to positive, the drought impact is designated as long-term only for central and southern Texas. Recent precipitation and the NDMC drought blends supported 1-category improvements to northern and eastern New Mexico. Additional rainfall this past week ended the drought across Oklahoma, and the Sooner State became drought-free for the first time since July 2019. The Lower Mississippi Valley and Tennessee Valley are also drought-free, with precipitation averaging above normal over 30 to 90 days. — UNL Drought Monitor
