This U.S. Drought Monitor week saw a few notable improvements and some serious degradation. Temperatures have generally been below normal this week from the east side of the Rockies to the East Coast, with the exception of Texas, the Southeast Coast, and northern New England. This has helped ease drought impacts, particularly in those areas where beneficial precipitation fell.
One such area is in the Ohio Valley where parts of Indiana saw more than five inches of rain. This is the second straight week of beneficial precipitation for some of these areas and this precipitation has largely alleviated Exceptional Drought (D4) from the state, despite lingering impacts still being felt. Last week, drought gripped slightly less of the agricultural land in the country with 85% of the U.S. corn crop, 83% of soybeans, 63% of hay, and 71% of cattle areas experiencing drought. Nearly half of the corn (49%) and soybean (46%) areas are experiencing Extreme (D3) to Exceptional (D4) Drought. This has led to both reduced yields and earlier harvests. Additional impacts this week include closing of an 11-mile stretch of the Mississippi River near Greenville, MS to barge traffic because of low water levels and wildfires expanding from northern California to Idaho.
The Southeast: Continued beneficial precipitation in the Southeast this week helped to improve drought conditions, particularly in northern Alabama and the upstate of South Carolina. Drought continues to strongly grip Georgia, eastern Alabama and western Tennessee and to a lesser extent areas of North Carolina and northern Mississippi where conditions remain relatively unchanged.
The Northeast and Mid-Atlantic: Most of this area received enough precipitation that drought conditions held status quo with minor reductions in Abnormal Dryness (D0) in Maine and Rhode Island and a reduction in Severe Drought (D1) in Massachusetts.
The South and Southern Plains: In Oklahoma, drought intensified to Exceptional Drought (D4) status in the northeast part of the state, which continues to miss out on beneficial precipitation falling to the south, just over the Texas border. Drought conditions in parts of eastern and extreme western Texas improved with the recent rains, while a lack of rain in the central and panhandle parts of the state led to expansion of Exceptional (D4), Extreme (D3), Severe (D2), and Moderate (D1) Drought as well as Abnormal Dryness (D0). In Louisiana, Extreme (D3) and Severe (D2) Drought expanded in the north.
The Central and Northern Plains and Midwest: More widespread rains in the Midwest alleviated some D1-D4 Drought as well as Abnormal Dryness (D0) through southern Wisconsin, Illinois, Indiana, and Ohio and into western Kentucky again this week. Lingering drought impacts remain in many areas, leaving devastated agriculture in its wake. Despite a much cooler week this week, Exceptional (D4) and Extreme (D3) Drought continue to expand in the area from northern Missouri and into Kansas and Nebraska where beneficial precipitation has been hard to come by. North Dakota saw a minor change in Moderate Drought (D1) and Abnormal Dryness (D0) in the north central part of the state.
The West: The drought in southeast California, Arizona, and New Mexico has begun to respond to the recent monsoon rains. Areas of Extreme (D3) and Moderate (D2) Drought were alleviated, largely across the southern part of the states. A slight expansion of Exceptional Drought (D4) took place in eastern Colorado while in Idaho, Moderate Drought (D1) and Abnormal Dryness (D0) continue to expand and contribute to wildfires.
Hawaii, Alaska and Puerto Rico: Drought conditions remained unchanged in Alaska and Puerto Rico this week. In Hawaii, drought intensified to Extreme (D3) levels in southern Lanai.
Looking Ahead: During the August 23 - 27, 2012 time period, there is an enhanced probability of precipitation in the Northern Plains and in the extreme South throughout the entire period, as well as in the Southwest and the south Atlantic Coast early in the period, and around the Great Lakes later in the period. Below normal precipitation is expected in the Northwest, New England, and into the Ohio Valley. The northern tier of the country is expected to see above normal temperatures.
For the ensuing 5 days (August 28 – September 1, 2012), the odds favor normal to above normal temperatures everywhere in the U.S. with the exception of the Pacific Coast. Normal to below-normal precipitation is expected from the West Coast, through the Southern and Central Plains and into the Ohio Valley and South. Above-normal precipitation is expected from the Northern Plains, through the Great Lakes, and all along the East Coast. In Alaska, temperatures are expected to be normal to above-normal over the entire state and precipitation is expected to be below normal in the south and above normal in the north.
Author: Michael Brewer, National Climatic Data Center, NOAA
D0 ... Abnormally Dry ... used for areas showing dryness but not yet in drought, or for areas recovering from drought.
Drought Intensity Categories
D1 ... Moderate Drought
D2 ... Severe Drought
D3 ... Extreme Drought
D4 ... Exceptional Drought
Drought or Dryness Types
S ... Short-Term, typically <6 months (e.g. agricultural, grasslands)
L ... Long-Term, typically >6 months (e.g. hydrology, ecology)