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Posted at 09:37 AM ET, 07/19/2012

Historic drought covers nearly two-thirds of continental U.S.


(U.S. Drought Monitor data, graphed by Jason Samenow)
The most extensive drought since the 1950s in the continental U.S. keeps getting worse. For the 10th consecutive week, drought conditions expanded.

Almost two-thirds (64 percent) of the contiguous U.S. is experiencing at least moderate drought (as of July 17) - an increase of three percentage points from last week (on July 10), the latest U.S. Drought Monitor reports. More than 80 percent of the land surface is abnormally dry.

Link: 12 week animation of U.S. Drought Monitor

42 percent of the U.S. is in severe, extreme or exceptional drought.


Drought conditions across Lower 48 as of July 17 (U.S. Drought Montior)
The report comes out just one day after Secretary of Agriculture Tom Vilsack described the drought as “the most serious situation” in about 25 years, stating about 1,300 counties across the country had been designated “drought disaster” areas.

Vilsack cautioned food prices would increase into 2013 due to the drought.


Via NASA: The extent of the damage to crops is depicted in this vegetation anomaly map based on data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Map contrasts plant health in the central United States between June 25 and July 10, 2012, against the average conditions between 2002 and 2012

The Drought Monitor contains this sobering report on the state of crops in the Heartland:

Another week of hot and dry weather continued the deterioration of crop conditions in America’s breadbasket. U.S. Department of Agriculture (USDA) reports for the week ending July 15 indicated that 38 percent of the nation’s corn crop was in poor to very poor condition, compared to 30 percent a week ago, and 30 percent of soybeans were in poor to very poor condition (compared to 27 percent last week).


The Evaporative Stress Index (ESI) highlights areas with anomalously high or low rates of water use across the land surface. (USDA)
Fifty-four percent of the nation’s pasture and rangeland was in poor to very poor condition, which is a jump of 4 percent compared to last week and is an all-time high for the 1995-2012 growing season weekly history.

NOAA animation shows monthly composites of vegetation health index derived from satellite data. Areas colored in shades of orange are experiencing moderate through exceptional drought conditions and are consistent with areas of vegetation stress.

Blistering temperatures and lack of rain are not only desiccating soils, but also drying out rivers and streams. The Drought Monitor says:

Streamflows were in the lower tenth percentile of record, or at record low values at several time scales, across much of the Midwest and parts of the central Plains, West, Southeast, and even parts of New England.

On the plus side, wildfire activity has lessened in the West, thanks to monsoon rains. The number of wildfires burning was cut in half in the last week from about four dozen to two dozen, the Drought Monitor reported.

Looking ahead, drought conditions - for the most part - are not expected to improve and may worsen in the hardest hit areas. Over the next five days, the Drought Monitor projects no rain and excessive heat in the country’s midsection:

The southern to central Plains will likely be devoid of precipitation. Temperatures for much of the country east of the Rockies will be above normal, with departures possibly 10 to 15 degrees above normal from the central Plains to Great Lakes.

For July 24-August 1, dry weather is expected to dominate in the southern to central Plains....

Drought evolution by month from NOAA’s Environmental Visualization Laboratory

By  |  09:37 AM ET, 07/19/2012

Categories:  Latest, U.S. Weather, Droughts

 
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