Here is the Virginia Water Central News Grouper’s monthly water-status report, as of the end of March 2014. The Virginia Water Resources Research Center thanks the agencies mentioned below for providing the data and maps used in this post.
First, in precipitation: Here are National Weather Service (NWS) preliminary precipitation totals for March 2014 at 11 Virginia or near-Virginia locations, with the amount above (+) or below (-) normal for this month of the year historically in parentheses. All values are in inches, rounded to the nearest 0.1 inch from NWS values.
Blacksburg = 2.4 (-1.2)
Bluefield (Va.-W.Va. state line) = 2.0 (-1.5)
Bristol (Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va.-Tenn.)
= 2.3 (-1.1)
Charlottesville = 2.5 (-1.2)
Danville = 3.2 (-0.9)
Dulles Airport (Loudoun County) = 4.1 (+0.7)
Lynchburg = 2.9 (-0.7)
Norfolk= 3.8 (+0.1)
Richmond = 3.2 (-0.8)
Roanoke = 2.8 (-0.7)
Wallops Island (Accomack County) = 3.2 (-0.8)
Precipitation sources: Climate pages of the following National Weather Service Forecast Offices:
Blacksburg, Va. (http://www.nws.noaa.gov/climate/index.php?wfo=rnk);
Morristown, Tenn. (http://www.weather.gov/climate/index.php?wfo=mrx;
Baltimore-Washington (http://www.nws.noaa.gov/climate/index.php?wfo=lwx); and
Wakefield, Va. (http://www.nws.noaa.gov/climate/index.php?wfo=akq).
The normal values used by the National Weather Service (NWS) in these provisional reports are based on 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.
For graphs of precipitation, visit the Southeast Regional Climate Center (Chapel Hill, N.C) at http://www.sercc.com/climateinfo/precip_maps, where you can find 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 map of precipitation nationwide or by state, with capability to show county boundaries, and archives available for specific days, months, or years. Shown below are the Southeast Regional Climate Center’s provisional (still needing verification) maps of precipitation and percent-of-normal precipitation for the 30-day period of March 2 to March 31, 2014.
Next, in stream flow: According to the U.S. Geological Survey WaterWatch for Virginia, average streamflow values for March 2014 at 148 stream gages in Virginia and just beyond the state border (that is, the monthly average of streamflow readings taken at each gage) were in the normal range at about 73 percent of gages; above normal at about 4 percent; below normal at about 20 percent; and much below normal at about 3 percent. The color-coded, flow-percentile map for March 2014 is shown below. The color codes/percentile classes used by USGS to compared flows to historical records for the month are as follows:
Red and maroon dots: Below 10th percentile = much below normal to record low;
Yellow dots: 10th to 24th percentile = below normal;
Green dots: 25th to 75th percentile = normal;
Light blue dots: 76th to 90th percentile = above normal;
Dark blue and black dots: Above 90th percentile = much above normal to record high.
Finally, our drought watch:
The weekly National Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) on April 1, 2014, categorized Virginia as being drought-free. This has been the rating for Virginia since the January 14, 2014, Drought Monitor report. Prior to that, Virginia had been rated as having some percentage of the state’s area categorized as abnormally dry since the Drought Monitor report of October 29, 2013.
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 Virginia ratings from previous Drought Monitors from about one month, two months, three months, and one year ago:
3/4/14 – Drought-free;
1/28/14 – Drought-free;
12/31/13 – 0.2 percent abnormally dry;
4/2/13 – Drought-free.
Here’s a comment from the April 1, 2014, Drought Monitor report, on cold weather in Virginia in March 2014:
“…According to the National Weather Service, the month of March ended as the coldest on record at Washington Dulles Airport, breaking the previous record set in 1984.”
Looking beyond Virginia: The April 1Drought Monitor rated 44.7 percent of the United States (including all or parts of 36 states) as being abnormally dry or worse, and it rated 20.2 percent of the country (including all or parts of 15 states), as being in severe drought or worse (categories D2, D3, and D4). (On August 7, 2012, 38.5 percent of the country was in the three worst categories; that was the highest percentage in these categories reported by the Drought Monitor since it began in 2000.) The nationwide percentages for abnormally dry or worse (D0-D4) and severe or worse (D2-D4) in the previous three months and one year ago were as follows:
3/4/14 – 46.8 percent abnormally dry or worse; 18.0 percent severe drought or worse;
1/28/14 – 49.1 percent abnormally dry or worse; 17.4 percent severe drought or worse;
12/31/14 – 45.8 percent abnormally dry or worse; 14.0 percent severe drought or worse;
4/2/13 – 64.6 percent abnormally dry or worse; 29.5 percent severe drought or worse.
In six states, over 50 percent of the state was categorized by the April 1 report as being in severe-or-worse drought (this is up from five such states in the March 4 report):
Arizona – 57% (with 3% in extreme drought);
California – 95% (with 69% in extreme or exceptional drought);
Kansas – 65% (with 14% in extreme drought);
Nevada – 82% (with 34% in extreme or exceptional drought);
New Mexico – 65% (with 25% in extreme drought);
Oklahoma – 51% (with 24%in extreme or exceptional drought).
Here are some comments from the April 1 Drought Monitor on the latest developments in long-running, severe drought in California (that state has had over 45 percent of its area categorized in severe-or-worse drought since the Drought Monitor report of May 7, 2013): “During the past week, a series of disturbances pushed on-shore from the Pacific delivering much-needed rain and snow to northern California and Oregon. ….Despite short-term gains, the long-term deficits across the region remained substantial. According to the California Department of Water Resources, California’s snowpack has increased since the first snow survey on January 3rd, but the latest survey results show California’s snow-water equivalent is only 32 percent of the average April 1st measurement when the snowpack is generally at its peak level prior to spring melt.”
For previous News Grouper monthly water status reports during the past 12 months, please click these links: