With spring 2014 well underway on April 2, here’s a look back at what happened with rainfall in the southeastern United States and stream flow in Virginia in the winter of 2013-14. The Virginia Water Resources Research Center is grateful to the agencies mentioned above for their work to providing these valuable assessment products.
The following “Percent of Normal Precipitation” graph, from the National Oceanic and Atmospheric Administration’s (NOAA) Southeast Regional Climate Center, located at the University of North Carolina in Chapel Hill (http://www.sercc.com/climateinfo/precip_maps, accessed 4/2/14), shows how the previous 90-day precipitation amounts in the southeastern United States compared to historical normal values for those periods. These data are provisional. Note that Virginia saw approximately equal areas of precipitation that were a bit below normal, about normal, and a bit above normal, with a couple of spots having well-above normal precipitation (the purple spots in the western and northwestern Virginia). These rainfall levels have removed the “abnormally dry” ratings that parts of Virginia experienced on-and-off through fall 2013, according to the weekly reports of the U.S. Drought Monitor (produced by the University of Nebraska-Lincoln, and available online at http://droughtmonitor.unl.edu/). Between January 14 and March 25, 2014, the Drought Monitor rated Virginia as drought-free.
Outside of Virginia, note that parts of the southeastern United States received below-normal precipitation during this period, but much of the region received normal or above-normal precipitation (well above normal in some areas, particularly in North Carolina and Florida). The March 25, 2014, Drought Monitor categorized about six percent of the region as abnormally dry, compared to approximately 28 percent on December 24, 2013.
For another color-coded map of precipitation in Virginia or any other state of your choosing, see the National Weather Service’s Advanced Hydrologic Prediction Service’s nationwide map of precipitation, with daily, monthly, and yearly archives; online at http://water.weather.gov/precip/.
The first graph below, from the U.S. Geological Survey’s (USGS) “WaterWatch—Current Water Resources Conditions” Web site (http://waterwatch.usgs.gov/new/index.php?id=pa01d&sid=w__plot&r=va), accessed 4/2/14), compares average daily stream flow to historical records for the period February 14-March 31, 2014. The second graph covers the period since January 2001. The data in the graphs come from 87 sites that have at least 30 years of records. Each graph uses a “stream flow index,” which measures how a site’s average stream flow over 24 hours compares to the historical average stream flow for that same site and date. The graphs shows a further average: the stream flow index averaged statewide over the 87 sites.
For links to several other sources of streamflow, precipitation, groundwater, and other water-status information, please visit the Water Center’s “Water Status Information” Web page at http://vwrrc.vt.edu/waterstatus_new.html.
Click the following for the Virginia Water Central News Grouper’s previous seasonal look-backs on precipitation and streamflow:
[Fall 2013 – Missed.]
[Fall 2012 – Missed.]
[Summer 2012 – Missed.]
And click the following for the News Grouper’s most recent monthly Virginia water status report (on precipitation, stream flow, groundwater, and drought), with links to access the previous 12 months’ reports: