During the past week, two storm systems impacted the contiguous 48 states, with the cold front associated with the first storm system bringing generally light rains to areas from the northeast to the southern Great Plains.
The second storm system developed along the western, trailing end of that cold front, and intensified rapidly over the central Great Plains. Before departing the country to the northeast, this system spread significant amounts of rain from the Panhandle of Oklahoma to the Upper Great Lakes.
A cold front, associated with a low-pressure system over Canada, brought a round of precipitation to the Pacific Northwest. Puerto Rico was impacted over the weekend by the tropical cyclone that is now Hurricane Raphael.
The Northeast and mid-Atlantic: Minor changes were made to the depiction of abnormally dry (D0) conditions over the Great Lakes region of New York. Recent rainfall (0.5 to 1.2 inches) supported this change in conditions. No changes were made to the drought depiction across the Mid-Atlantic.
The Ohio Valley: Light rains fell across the Ohio Valley. When coupled with a recent wetter pattern during the past 60-days, the recent rains allowed for the removal of some moderate drought (D1) across Indiana, Ohio and northern Kentucky. Additionally, some minor changes were made over Kentucky to reflect a continued wetter pattern, as D2 (severe drought) was removed from western Kentucky.
The Southeast: A relatively dry week across much of the southeast prompted the expansion of abnormally dry conditions across the eastern portions of the Carolinas and southeastern Georgia. Additional intensification is indicated across central and southern Georgia, where rains continue to miss the most intensely dry areas. Across Alabama, short-term dryness back to 60-days is showing up in some of the streams, with stream flows down to the 9th percentile in Crenshaw and Pike counties.
A reduction in dry conditions was noted was across western and central North Carolina, so D0 was removed from the area west of Charlotte, NC. To reflect a continued wetter pattern, as a 1-category improvement was included over western Tennessee.
The Central and Southern Plains: Many changes to the depiction of drought were included in the map this week. Significant rains (some reports in excess of 4.5 inches) fell across eastern Oklahoma, northwestern Arkansas, southwestern Missouri, Nebraska, Kansas, and Iowa.
Broad, 1-category improvements were implemented across these regions. Across Nebraska, Missouri, Kansas and Iowa, the improvements were made across areas the received in excess of 1.5 inches of precipitation. As noted by the Nebraska state climatologist, the areas of Nebraska that are annotated as receiving the most improvement were the same areas the received rainfall (1-4 inches) during September.
The Upper Great Lakes and Northern Great Plains: Significant rains (0.5-4.1 inches) fell across lower Michigan, with slightly higher amounts reported over central Wisconsin. Based on that recent rainfall, moderate drought was removed from the lower portion of Michigan and the western most portions of the Upper Peninsula.
The area of abnormal dryness was also scaled back across most of Michigan, with areas of D0 remaining over southern Michigan, the western UP, and where the D1 (moderate drought) was indicated last week, as rains were not enough to justify to 2-category improvement.
Across central Wisconsin and southeast Minnesota, rains of 2-4 inches (3-6 times the normal amount for the week) prompted a broad 1-category improvement. Other portions of southern Wisconsin miss out on the rains, so areas receiving less than 2.0 inches of rain were largely left the same as last week.
After a dry week, minor expansions of extreme drought were pursued this week across eastern South Dakota and western Minnesota, as those areas missed out on the rains the fell south and east.
The Rockies: Minor revisions were made this week over Colorado, where a 1-category improvement was made over Chafee and eastern Gunnison counties. Recent stream flow reports are showing a slight recovery, and some recent precipitation has been beneficial. Farther north, over Jackson, Larimer, and Grand counties, recent rains have provided some moisture, but not enough to move the needle away from widespread severe drought.
A slight expansion of severe drought (D2) conditions was included over central New Mexico, while some removal of drought conditions was depicted over southeast New Mexico. The past 6 months have been dry across over central New Mexico, but areas south of Hobbs and east of Carlsbad have received precipitation that measured 125 to 200+ percent of normal during September (monthly totals from 2.9 inches to 4 inches). Improvements were limited by the return to dry conditions during October.
The Southwest: Las Vegas now has its 26th wettest year on record even if no more precipitation was to fall for the rest of the year. Precipitation amounts in excess of 2.0 inches were recorded in a large number of locations on the west and north sides of Las Vegas during the past week (County Flood Control District automated gauges) Due to hail and the intensity of the rain, some stations were likely under-reporting precipitation totals. Advanced Hydrologic Prediction System (AHPS) maps show precipitation totaling 150-400 percent of normal from Mt Charleston to Lake Mead during the past 180 days, so widespread improvements to the drought conditions were indicated across this region.
The Pacific Northwest: Abnormal dryness (D0) was removed from much of western Washington and Oregon. Rainfall amounts exceeded 5.0 inches at many reporting stations across this region. Rains did push inland, across the northern Rockies and into western Montana, so some improvement was indicated there as well.