Below are images showing precipitation in Virginia and other areas of the southeastern United States, and stream flow in Virginia, over the seven-day period ending October 17, 2016 (information available as of October 18). Also below is the Virginia Drought Monitoring Task Force’s daily map showing the status of several drought indicators in different Virginia regions, as of October 18. The Virginia Water Resources Research Center thanks the agencies mentioned below for providing precipitation and stream-flow information and images. For the current month’s other weekly reports on stream flow and precipitation, please see the News Grouper posts available at this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Virginia+Precipitation. For monthly reviews of precipitation, stream flow, and drought, please see the posts available at this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Monthly+Water+Status. For more information on current and historical surface-water and groundwater conditions in Virginia, please see the U.S. Geological Survey (USGS) Virginia Science Center’s Web site, http://va.water.usgs.gov/.
October 2016 Gaging Station of the Month: North Fork Shenandoah River at U.S. Route 55 near Strasburg (Shenandoah County), October 13, 2012.
The following two color-coded maps show southeastern U.S. precipitation amounts (top map) and the percent of normal precipitation compared to normal for this period of the year (bottom map) over the seven-day period ending October 17, 2016. The maps were accessed from the National Oceanic and Atmospheric Administration’s (NOAA) Southeast Regional Climate Center, located at the University of North Carolina in Chapel Hill; online at http://www.sercc.com/climateinfo/precip_maps. As of that date, these data were provisional (needing to be verified for accuracy and subject to possible revision).
Another source of precipitation data is the National Weather Service’s Advanced Hydrologic Prediction Service, http://water.weather.gov/precip/, provides maps showing precipitation nationwide or by state for specific days, months, or years. The site also has the capability to show county boundaries, and other map layers available include river flood forecasts and current flood/severe weather warnings. Please note that UTC, the time shown on the maps at the site, is five hours ahead of Eastern Standard Time and four hours ahead of Eastern Daylight Time.
Seven-day-average Virginia stream flows at different gaging stations as of October 17, 2016, are indicated in the map below, from the U.S. Geological Survey WaterWatch for Virginia, accessed online at http://waterwatch.usgs.gov/index.php?m=pa07d&r=va&w=map. The map’s color-coded dots compare the previous week’s average stream flows to the normal flow levels for that week over the historical record for each gaging station. The color codes/percentile classes used by USGS are as shown in the chart following the map.
Mid-month Drought Status Update
The Virginia Drought Monitoring Task Force (DMTF), a collaboration of state and federal agencies, issued its latest Virginia drought-status report on October 17, 2016. The report is available at the DMTF Web site, http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought.aspx. The Task Force was scheduled to meet and report again in January 2017. Here’s an excerpt from the October 17 report: “Widespread precipitation due to both Hurricane Matthew and frontal systems brought abundant rainfall to most of Virginia during the past several weeks. Consequently, groundwater levels and surface water flows range from above normal to well above normal, with some observation wells reporting record high levels. Parts of northern Virginia did not receive the above-normal rainfall seen elsewhere, and parts of southwestern Virginia continued to experience dry conditions. Groundwater observation wells and surface water gauging stations in these latter areas are generally reporting normal levels and flows, however. For the current water year (October 1, 2016–October 13, 2016) precipitation totals have so far been much greater than normal for 10 of the 13 drought evaluation regions, due in part to rainfall from Hurricane Matthew. Rainfall in the Northern Piedmont region was normal, while the Northern Virginia and the Big Sandy regions received significantly less than normal precipitation.”
The Task Force also produces a daily map rating drought-status indicators. Shown below is the October 18, 2016, map. The status-indicator abbreviations on that map are as follows: GW = groundwater levels, Prcp = precipitation deficits, Res = reservoir storage, and Flow = stream flow conditions. For each region of Virginia, the indicators are color coded for “normal,” “watch,” “warning,” or “emergency conditions.” [ADD as called for: Note the emergency-conditions code (in red) for precipitation in northern Virginia and in far southwestern Virginia.] Any given day’s current map and more information on drought status in Virginia are available the Task Force Web site, http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought.aspx.