Virginia Water Status Report as of the End of June 2012 ; Plus a Quick Look at Nationwide Drought

Here is Virginia Water Central’s monthly water-status report, as of the end of June 2012.

First, here are National Weather Service preliminary precipitation totals for June 2012 at 10 Virginia locations (with the amount above or below normal for the month historically in parentheses; rounded to nearest 1/10 inch):
Blacksburg: 3.0 inches (1.0 inches below normal)
Bristol (at Tri-Cities Airport in Tenn., about 20 miles from Bristol): 1.2 inches (2.7 inches below normal)
Charlottesville: 3.3 inches (0.5 inches below normal)
Danville: 3.5 inches (0.3 inches below normal)
Dulles Airport (in Loudoun County): 1.8 inches (2.2 inches below normal)
Lynchburg: 1.7 inches (1.9 inches below normal)
Norfolk: 5.3 inches (1.0 inches above normal)
Richmond: 4.3 inches (0.3 inches above normal)
Roanoke: 3.2 inches (0.6 inches below normal)
Wallops Island (in Accomack County): 2.7 inches (0.6 inches below normal)

The normal values used by the National Weather Service (NWS) in these provisional reports are based on normal values from the 1981-2010 period.  The National Climatic Data Center released these normal values in July 2011.  For information on the normals, see the National Climatic Data Center Web page at http://www.ncdc.noaa.gov/oa/climate/normals/usnormals.html (as of 7/5/12).

(Sources:  Climate pages of the following National Weather Service offices: Blacksburg; Morristown, Tenn. [covers the Tri-Cities area near Bristol, Va.-Tenn.]; Baltimore-Washington; and Wakefield.)

For graphs of precipitation, visit the Southeast Regional Climate Center (Chapel Hill, N.C) maps of total precipitation and percent of normal precipitation for the past 7, 30, 60, or 90 days; or the NWS’ Advanced Hydrologic Prediction Service at http://water.weather.gov/precip/ for a daily map of precipitation nationwide or by state, with capability to show county boundaries, and archives available for specific days, months, or years.

Second, in stream flow: According to the U.S. Geological Survey WaterWatch for Virginia, average streamflows over the month of June 2012 were in the normal range at about 59 percent of stream gages in Virginia and just beyond the state border; above normal at about 1 percent of gages; below normal at about 26 percent of gages; and much below normal at about 13 percent of gages.  The percentile classes used by USGS to categorize flows are as follows:

Below 10^th percentile = much below normal
10^th to 24^th percentile = below normal
25^th to 75^th percentile = normal
76^th to 90^th percentile = above normal
Above 90^th percentile = much above normal

And third, our drought watch: The weekly The National Drought Monitor map from the University of Nebraska-Lincoln on July 3, 2012, showed “abnormally dry” or worse conditions in about 91 percent of Virginia—everywhere but the southeastern corner of the state and an area around Danville and Martinsville in south-central Virginia—and “moderate drought” conditions in six percent of the Commonwealth.  (The Drought Monitor notes that it “focuses on broad-scale conditions [and] local conditions may vary.”)

The Drought Monitor categories are as follows:
D0 = abnormally dry
D1 = moderate drought
D2 = severe drought
D3 = extreme drought
D4 = exceptional drought

For comparison, here are some Virginia ratings from Drought Monitors one month, three months, and one year ago:
5/29/12: 14 percent abnormally dry;
4/3/12: 37 percent abnormally dry or worse: 0.1 percent in moderate drought;
6/28/11: 34 percent abnormally dry or worse; 19 percent in moderate drought or worse; 1 percent in severe drought.

Meanwhile, looking beyond Virginia, the July 3 Drought Monitor rated 28.7 percent of the entire United States as being in severe drought or worse.  This is the highest such percentage in almost nine years, since the Drought Monitor report of October 28, 2003.  In 12 states, over 50 percent of the state was rated in severe drought or worse; Colorado led that group with 100 percent so rated.

 

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