Nationwide
Recently, precipitation has been spatially variable across the Contiguous U.S.
Over the past 30 days, heavy precipitation (4 to locally over 8 inches) fell on parts of central and southern New England, the interior Northeast (especially eastern New York state), the Ohio Valley (particularly northern Kentucky and adjacent areas), eastern South Carolina, eastern Florida, parts of the Tennessee and adjacent Mississippi Valleys, isolated sites in the central Plains, the higher elevations in the Rockies, central Arizona and other scattered locations across the Southwest, parts of the Great Basin, portions of California (where such amounts are unusual this early in the wet season), and the Pacific Northwest (where these amounts are not unusual).
In stark contrast, an inch or less of precipitation has been noted in the desert Southwest and lower elevations across the interior West, most of the central and southern Plains, the northern Great Plains, the northwestern Great Lakes, portions of northern and western Florida, and some interior sections of the Southeast and Mid-Atlantic region.
Given the regional variability, there were many changes in the Drought Monitor this week, with large parts of the West, much of the Ohio and middle Mississippi Valleys, and scattered locations across northern Mississippi, the Eastern Great Lakes, and the Northeast. At the same time, conditions have deteriorated across much of the southern and south-central Plains, the South Atlantic region from interior Georgia through eastern Virginia, the southern parts of the Lower Mississippi Valley, and scattered areas across the rest of the Southeast, the Mid-Atlantic region, the Northeast, the Upper Mississippi Valley, and the northern Plains.
In sum, the array of improvements and deterioration incorporated into this week’s Drought Monitor resulted in slight declines in overall coverage of the various drought severity levels across the Lower-48. Abnormally dry or worse conditions cover 72% of the country, down from 74% last week. About 21% of the country is experiencing Severe Drought or worse (D2-D4), down slightly from 23% last week. Across the 50 states and Puerto Rico, coverage of abnormally dry or worse conditions fell from 62% to just under 60.5%.
The West
Some unusually heavy early-season rain and snow has affected portions of the West, including areas of central and southern California, where October so far has been wetter than most such months on record.
Large portions of central and upper southern California, the Great Basin, and the western and eastern tiers of Utah saw improvement on this week’s Drought Monitor, along with patches of central and eastern Arizona, southwestern Oregon, central and eastern Washington, and parts of eastern, southern, and western Montana. Only a portion of north-central Montana saw any deterioration. The total area covered by any dryness (D0-D4) declined from 80 to a bit over 74% this week, while the coverage of the more intense drought categories (D2-D4) dropped from 38.5 percent to just over one-third of the region. D3-D4 was still entrenched over a decent proportion of the Region, but declined from almost 9% last week to about 6.5% this week. The only remaining area of the most intense category (D4) is in north-central Idaho.
The High Plains
A wide range of precipitation totals were observed last week. Generally, 1.5-3 inches hit the northern and western Dakotas, much of central and eastern Wyoming, and scattered locations in northwestern Wyoming.
An inch or a little more fell on many locations in a swath from central Nebraska into southeastern South Dakota, but other locations reported several tenths of an inch of precipitation at best, with most areas from southwestern Wyoming through western Nebraska and from eastern Nebraska through Kansas reporting little or none. This pattern resulted in less change here than in most other regions. Areas of deterioration were introduced in parts of the east-central and southeastern High Plains region, while improvement resulted from heavier precipitation farther west. The most widespread areas of improvement covered southwestern Colorado and western Wyoming.
Coverage of dryness and drought is considerably lower in this region than in others, with the total area entrenched in some degree of dryness or drought (D0-D4) dropping slightly to a bit over 36% this week. The extent of Extreme Drought (D3) was almost cut in half, from 3.3% to 1.7 %. There is no D4 in the Region, but D3 remains across much of southwestern Wyoming and part of central Colorado. The proportion of the Great Plains states in this region experiencing some degree of dryness or drought (D0-D4) is relatively low compared to much of the Lower-48; specifically, 3% of North Dakota, 32% of South Dakota, 35% of Nebraska, and 28% of Kansas.
The South
Moderate to heavy rain resulted in several areas of improvement in Tennessee, central and northern Mississippi, northeastern Louisiana, and eastern Oklahoma.
Farther south and west, subnormal precipitation continued for another week, resulting in numerous areas of deterioration from central and southern Louisiana westward across Texas and central through western Oklahoma. The proportion of the Region experiencing some degree of dryness or drought (D0+) increased slightly this week, from 79% to about 80.5% percent. There was a larger jump in areas covered by some degree of drought (37 percent, up from just over 32%). The most intense drought (D3, with isolated patches of D4) covers parts of the panhandle of western Texas and a significant part of south-central Texas. The heaviest rains this week (2-4 inches) were observed in a broken pattern from northwestern Louisiana through northern Mississippi. In contrast, southern sections of the Lower Mississippi Valley and the vast majority of Texas and Oklahoma received a few tenths of an inch at best, with most sites reporting no measurable precipitation. — UNL Drought Monitor
