Here is the Virginia Water Central News Grouper’s monthly water-status report, as of the end of October 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 October 2014 at 11 Virginia or near-Virginia locations, with the amount above (+) or below (-) normal for this month of the year historically. All values are in inches, rounded to the nearest 0.1 inch from NWS values.
|Location||Observed Precipitation(inches)||Above (+) or Below (-) Normal (inches)|
|Bluefield (Va.-W.Va. state line)||5.4||+2.9|
|Bristol (Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va.-Tenn.)||6.2*||+2.1|
|Dulles Airport (Loudoun County)||3.0||-0.2|
|Wallops Island (Accomack County)||1.3||-1.9|
*Record high for month at this location.
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 normal values, 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 the percent-of-normal precipitation for the previous 30 days, 60 days, and 90 days, through October 31, 2014.
Next, in stream flow: According to the U.S. Geological Survey WaterWatch for Virginia, average stream flow values for the October 2014 at 149 stream gages in Virginia and just beyond the state border were in the normal range at about 71 percent of gages; below normal at about 3 percent; above normal at about 15 percent; and much above normal at about 11 percent. The color-coded, flow-percentile map for this period is shown below. The color codes/percentile classes used by USGS to compared flows to historical records for the month are as follows:
Finally, our drought watch:
The weekly National Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) on October 28, 2014, categorized about 23 percent of Virginia as being abnormally dry. The area covered an arc from the central Shenandoah Valley across the Blue Ridge to the tidal Potomac basin and most of the non-tidal Rappahannock and York basins; plus two areas in Southside: Charlotte County and part of Halifax County, and an area in four counties around Danville and Martinsville.
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:
9/30/14 – 48 percent abnormally dry;
9/2/14 – 11 percent abnormally dry;
7/29/14 – 27 percent abnormally dry;
10/29/13 – 5 percent abnormally dry.
The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on October 10, 2014. A link to the report, along with other current drought-status information, is available online at http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought.aspx. The Task Force’s reports typically include information from some or all of the following agencies: University of Virginia Climatology Office, U.S. Geological Survey (USGS), and the Virginia departments of Agriculture and Consumer Services, Health, and Environmental Quality. The Drought Monitoring Task Force also produces a daily map rating groundwater levels (GW), precipitation deficits (Prcp), reservoir storage (Res), and stream flow (Flow) conditions across the Commonwealth. In each area, a color code indicates “normal,” “watch,” “warning,” or “emergency conditions.” The November 3, 2014, map is shown below. The current map and more information on the ratings are available the Task Force Web site listed above.
Looking at drought beyond Virginia: The October 28 U.S. Drought Monitor rated 36.4 percent of the United States (including all or parts of 43 states) as being abnormally dry or worse, and it rated 15.1 percent of the country (including all or parts of 13 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:
9/30/14 – 40.1 percent abnormally dry or worse; 15.6 percent severe drought or worse;
9/2/14 – 39.2 percent abnormally dry or worse; 17.5 percent severe drought or worse;
7/29/14 – 39.8 percent abnormally dry or worse; 19.0 percent severe drought or worse;
10/29/13 – 52.0 percent abnormally dry or worse; 15.1 percent severe drought or worse.
In the following four states, over 50 percent of the state was categorized by the October 28 report as being in severe-or-worse drought:
California – 95% (with 82% in extreme or exceptional drought; California was rated as having 100 percent severe-or-worse drought from May 13—July 29, 2014);
Nevada – 70% (with 48% in extreme or exceptional drought);
Oklahoma – 56% (with 23% in extreme or exceptional drought);
Oregon – 55% (with 35% in extreme drought).
For previous News Grouper monthly water status reports during the past 12 months, please click these links: