Image

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 2021-11-23 57.58 42.42 13.17 0.00 0.00 0.00 56
Last Week 2021-11-16 57.58 42.42 13.17 0.00 0.00 0.00 56
Start of Water Year 2021-09-28 24.40 75.60 55.16 18.26 0.00 0.00 149
Three Months Ago 2021-08-24 17.37 82.63 57.35 33.73 10.10 0.00 184
Start of Calendar Year 2020-12-29 37.84 62.16 36.35 17.59 4.03 0.00 120
One Year Ago 2020-11-17 35.07 64.93 36.35 17.59 4.03 0.00 123

DISCUSSION

A couple Pacific weather systems moved across the contiguous U.S. (CONUS) during this U.S. Drought Monitor (USDM) week. The storm track kept to the northern states, but the systems dragged cold fronts with them that stretched the width of the CONUS, from the Great Lakes to the Gulf of Mexico coast. The systems spread rain and snow to the coastal Pacific Northwest and parts of the northern Rockies, but they weakened as they moved through a western ridge. This circulation pattern starved them of moisture, so much of the West to Great Plains received little to no precipitation, but the fronts picked up Gulf of Mexico moisture as they moved east, spreading precipitation across the Lower Mississippi to Ohio Valleys, eastern Great Lakes, and Northeast. Only a few areas received above-normal precipitation for this time of year, including spots in the Pacific Northwest, Ohio Valley, Deep South Texas, and the southern half of Florida. Weekly temperatures averaged near to cooler than normal in the Pacific Northwest, Great Lakes, Ohio Valley, and Mid-Atlantic states. Much of the West, Great Plains, and Southeast were warmer than normal. Persistent above-normal temperatures in the Plains contributed to excessive evapotranspiration in western portions of the Great Plains as well as parts of the West, as seen in EDDI and ESI indicators. Lack of precipitation, excessive evapotranspiration, and windy conditions further dried soils, again especially in western portions of the Plains, as seen in several soil moisture indicators. Drought indicators such as the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) showed dry conditions at long-term time scales in the West to northern Plains, at short-term time scales in the Southeast to Mid-Atlantic and Lower Mississippi Valley regions, and both short- and long-term time scales from the Southwest to southern and central Plains. Precipitation over the last 4 weeks lessened drought intensity slightly in parts of the West, but continued dryness expanded or intensified drought in parts of the Plains, Deep South, Southeast, and Mid-Atlantic states.

Forecast

A frontal system will sweep across the eastern CONUS during November 24-30 with another Pacific weather system moving into the Pacific Northwest near the end of the period. They will be moving through a circulation pattern consisting mainly of an upper-level ridge in the West and trough in the East. An inch to 2 inches of precipitation is forecast to fall along the Texas coast to east Texas and over northern portions of the Northeast, with half an inch or more stretching from the southern Rio Grande Valley to New England. Half an inch to an inch of precipitation is expected over the northern Rockies and coastal sections of Oregon and Washington, with up to 5 inches in the forecast for northwest portions of Washington. Up to half an inch is predicted for parts of the Four Corners states in the Southwest, parts of the Great Lakes, and coastal parts of the Mid-Atlantic to Northeast states. Little to no precipitation is expected for much of the West, Great Plains, and Upper Mississippi Valley due to the circulation pattern associated with the western ridge. With the storm track to the north and systems moving into the Great Lakes, much of the Southeast will receive little to no rainfall. Temperatures are expected to be warmer than normal in the western and central CONUS and cooler than normal along the East Coast. The outlook for December 1-6 shows drier-than-normal weather favored from the Southwest to Great Lakes, from the Ohio Valley to Southeast, and western half of Alaska, with wetter-than-normal weather favored over the Pacific Northwest to northern Rockies, parts of southern Texas, and southeast Alaska. Odds favor colder-than-normal weather over the East Coast and warmer-than-normal weather over the western and central CONUS, with the warmer-than-normal conditions shifting eastward as the period progresses. Colder-than-normal temperatures dominate Alaska in the outlook.

Midwest

Half an inch to locally 1.5 inches of precipitation occurred across the Ohio Valley, with the heaviest amounts in Kentucky. Eastern portions of the Great Lakes received half an inch of precipitation. But western portions of the region were dry, with little to no precipitation falling. Abnormal dryness expanded in western Illinois near St. Louis; otherwise, no change in drought status occurred in the Midwest.