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MONITOR

Latest drought monitor over the midwest

OUTLOOKs



Monthly drought outlook


Streamflow


Map of below normal 7-day average streamflow compared to historical streamflow for the day of the year (Iowa)


PRECIP. NEEDED TO END

Amount of precipitation needed to end drought

PALMER DROUGHT INDEX

Drought severity index by division

DEPARTURES

4 month precipitation departures

STATISTICS

Week Date None Abnormally Dry Moderate Severe Extreme Exceptional DSCI
Current 2021-07-20 30.04 69.96 55.36 26.92 0.00 0.00 152
Last Week 2021-07-13 29.08 70.92 55.77 31.49 0.00 0.00 158
Three Months Ago 2021-04-20 59.23 40.77 12.63 7.62 0.00 0.00 61
Start of Calendar Year 2020-12-29 37.84 62.16 36.35 17.59 4.03 0.00 120
Start of Water Year 2020-09-29 30.56 69.44 46.89 22.57 0.00 0.00 139
One Year Ago 2020-07-14 49.22 50.78 21.45 5.77 0.00 0.00 78

DISCUSSION

Active weather prevailed across much of the South, East, and Midwest, as well as parts of the Plains, into the middle of July, followed by a southward shift in widespread shower activity. Meanwhile, a robust monsoon circulation provided limited Southwestern drought relief, particularly in parts of Arizona, New Mexico, and southwestern Colorado. Farther north and west, however, little or no rain fell in California, the Great Basin, and the Northwest, where dozens of wildfires were in various stages of containment. Smoke and other particulate matter from those fires carried downwind at various atmospheric levels, producing hazy skies and reducing air quality—in some cases thousands of miles from the points of origin. Dry weather extended eastward across the nation’s northern tier as far east as Lake Superior, while heavy rain eased or eradicated drought in the remainder of the Great Lakes region, along with the Northeast. In the driest areas of the northern and western United States, drought’s impact on water supplies, as well as rangeland, pastures, and a variety of crops, was further amplified by ongoing heat. Weekly temperatures averaged as much as 10°F above normal from the interior Northwest to the northern High Plains. On July 19, temperatures as high as 110°F were reported in eastern Montana. Another pocket of hot weather was centered over the middle Atlantic States. In contrast, near- or slightly below-normal temperatures dominated the Plains, Midwest, and South.

Forecast

The interaction between the Southwestern monsoon circulation and a weak cold front will result in locally heavy rain in the Four Corners States but only light showers on the drought-stricken northern Plains. Five-day Southwestern rainfall totals could reach 1 to 3 inches or more, mainly in parts of Arizona, western New Mexico, and southwestern Colorado. Meanwhile, little or no rain will fall in the Pacific Coast States, northern Great Basin, northern Rockies, and central and southern Plains. Flash drought could become a concern across the central and southern Plains and upper Midwest, where building heat will accompany the dry weather. Meanwhile, significant rainfall (1 to 2 inches or more) should be limited to the Great Lakes and Northeastern States, as well as parts of the Southeast. Higher totals may occur in peninsular Florida. Elsewhere, a significant hot spell will persist into next week across an area centered over the northern Plains, with heat-related impacts reaching into the northern Rockies, Intermountain West, central Plains, and upper Midwest.

The NWS 6- to 10-day outlook for July 27 – 31 calls for the likelihood of hotter-than-normal weather nationwide, except for near-normal temperatures in the Northeast, Desert Southwest, and southern and western Alaska. Meanwhile, near- or below-normal rainfall in much of the country should contrast with wetter-than-normal weather across the Intermountain West, northern Great Basin, and western Alaska.

Midwest

An axis of heavy rain stretched from southern Missouri to northern Ohio. Secondary areas of locally heavy showers extended from Iowa and southeastern Minnesota to Michigan. The Midwestern rain intersected some existing areas of dryness (D0) and moderate to extreme drought (D1 to D3), resulting in some reductions in coverage. Some of the most dramatic improvements occurred across central Wisconsin and northern Lower Michigan. From July 13-15, more than 2 inches of rain soaked La Crosse, Wisconsin, and Traverse City, Michigan. Oshkosh, Wisconsin, received 3.34 inches. In contrast, little or no rain fell during the drought-monitoring period around Lake Superior and in central and northern Minnesota, where coverage of severe to extreme drought (D2 to D3) was greatly expanded. A broad array of indicators and indices, including streamflow, soil moisture, the Vegetation Health Index, the Evaporative Demand Drought Index, and the Standardized Precipitation Index, have shown that very serious drought conditions exist at a variety of times scales across much of northern and central Minnesota. On July 18, Minnesota led the Midwest with 63% of its pastures rated in very poor to poor condition, along with 42% of its spring wheat, 34% of its oats, 33% of its barley, 18% of its corn, and 17% of its soybeans. Minnesota also led the Midwest on that date, according to the U.S. Department of Agriculture, with topsoil moisture rated 78% very short to short.