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MONITOR

Latest drought monitor over the midwest

OUTLOOKs



Monthly drought outlook


CHANGE OVER TIME

One Week US Drought Monitor Class Change

PRECIP. NEEDED TO END

Amount of precipitation needed to end drought

PALMER DROUGHT INDEX

Drought severity index by division

DEPARTURES

4 month precipitation departures

VEGETATION (VegDri)

Vegetation Drought Response Index (VegDRI), complete, Iowa

STANDARD PRECIP INDEX

Standard precipitation index

TOPSOIL MOISTURE

USDA Topsoil Moisture by Short-VeryShort

STATISTICS

Week Date None Abnormally Dry Moderate Severe Extreme Exceptional DSCI
Current 2023-09-26 0.01 99.99 95.65 67.41 25.00 1.17 289
Last Week 2023-09-19 0.19 99.81 96.59 72.99 25.51 4.96 300
Start of Water Year 2023-09-26 0.01 99.99 95.65 67.41 25.00 1.17 289
Three Months Ago 2023-06-27 0.60 99.40 89.15 43.93 5.34 0.00 238
Start of Calendar Year 2022-12-27 9.52 90.48 66.66 29.43 8.83 0.57 196
One Year Ago 2022-09-20 30.43 69.57 41.89 20.39 2.20 0.02 134

DISCUSSION

The upper-level circulation over the contiguous U.S. (CONUS) during this U.S. Drought Monitor (USDM) week (September 20-26) consisted of an upper-level ridge of high pressure, that extended from the southern Plains to Hudson Bay, and a low-pressure trough over the eastern Pacific. The trough sent weather systems spinning across the CONUS, with their fronts and surface low pressure systems generating areas of rain across the Pacific Northwest, northern Rockies, and Great Plains to the Mississippi Valley. Meanwhile, Tropical Storm Ophelia moved up the East Coast, spreading rain from North Carolina to southern New England. These areas were wetter than normal for the week. Some of the rain was locally heavy, with over 5 inches reported in places. Much of the rain fell over severely dry areas, which resulted in contraction or reduction in the intensity of drought in parts of the Great Plains, Upper Mississippi Valley, and Mid-Atlantic states. It was drier than normal across the rest of the West, large parts of the central to southern Plains, and most of the country between the Mississippi Valley and Appalachians. The continued dry conditions from the Ohio Valley to central Gulf of Mexico Coast resulted in expansion or intensification of drought and abnormal dryness in these areas. Temperatures averaged warmer than normal beneath the ridge across the Plains, Mississippi Valley, and Great Lakes. The week was cooler than normal in the West and across the East Coast states.

Forecast

In the two days since the Tuesday valid time of this USDM, the atmospheric river continued in the Pacific Northwest and rain has fallen across parts of the Midwest, Texas, and Florida. For September 28-October 3, a slow-moving weather system will drop 1 to locally 2 inches of rain across the Ohio Valley and parts of the Upper Mississippi Valley, while a Pacific weather system will move across the northwestern CONUS, spreading 1 to 2 inches of precipitation across the Pacific Northwest and Montana, with heavier amounts (up to 4 inches or more expected) in coastal areas of Washington and Oregon. The Florida peninsula is forecast to get 2 to 4 inches of rain, while the Gulf Coast, Rio Grande Valley, and Mid-Atlantic states can expect an inch or less. The Southwest, New England, Carolina Piedmont, and most of New York and the southern Plains to Iowa are predicted to receive little to no precipitation. Temperatures are progged to be above normal from the Plains to Northeast and near to below normal across the Southeast and West.

For much of the next 2 weeks, the atmospheric circulation will consist of an upper-level trough over the western CONUS and a ridge over the Mississippi Valley. The trough/ridge system will slowly shift east during the period. The Climate Prediction Center’s (CPC) 6-10 Day Outlook (valid October 3-7) and 8-14 Day Outlook (valid October 5-11) favor a fairly stable pattern of warmer-than-normal temperatures from the Plains to East Coast and cooler-than-normal temperatures over the West and over the southeastern half of Alaska. The outlook is for above-normal precipitation over the Plains, Upper Mississippi Valley, northern half of the West, and most of Alaska. Odds favor below-normal precipitation over the Northeast and Appalachian Mountain chain, extending into the Ohio Valley and to the central Gulf Coast, as well as in the Alaska panhandle.

Midwest

Western parts of the Midwest region were inundated with heavy rain while eastern parts received little to no rain this week. Large areas in Minnesota and Wisconsin, and parts of Iowa, Illinois, and Missouri, received 2 inches or more, with locally 5+ inches of rain observed. Abnormal dryness and moderate to exceptional drought were reduced in these states, with some 2-category changes occurring. Meanwhile, abnormal dryness and moderate drought expanded across much of Indiana, Ohio, and Kentucky, where soils were drying, streams were low, and the last 1 to 2 months were extremely dry, and in parts of Michigan, Missouri, and Illinois. Reports received by the Indiana Extension Office included rapid maturation of crops, trees losing leaves, plants dying, large cracks in soils, stunted lawns, and dropping pond levels across the state, with burn bans in place. In Missouri, there were reports of dry ponds in the Bootheel. Temperatures were warmer than normal across most of the region, with anomalies reaching 8 to 12 degrees above normal over parts of Minnesota and Wisconsin. Soils continued to dry in the Ohio Valley. According to USDA statistics, 68% of the topsoil in Indiana was short or very short of moisture; this was an increase of 12% compared to last week. The statistics were 55% in Ohio (an increase of 12% compared to last week), 52% in Kentucky (up 9%), and 30% in Michigan (up 16%). The rain in the Upper Mississippi Valley improved soil moisture, but not by much. In Iowa, 73% of the topsoil moisture was still short to very short, 70% in Minnesota, 60% in Wisconsin, and 58% in Missouri.