Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, and drought, as of the end of February 2017. The Virginia Water Resources Research Center thanks the agencies mentioned below for providing the data and maps used in this post. Icons for precipitation, stream flow, and drought are by George Wills of Blacksburg, Va. (https://www.etsy.com/people/BlacksburgArt). For previous monthly water status reports, please see this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Water+Status.
Here are National Weather Service (NWS) preliminary (still needing verification) precipitation totals for February 2017 at 11 Virginia or near-Virginia locations, along with the “normal” (three-decade average) for this month of the year at each location. Also shown are the precipitation totals at each location for the previous 12 months and the annual precipitation normals for each location. All values are in inches.
|Location||February 2017 Observed
|Monthly Normal||March 2016-
February 2017 Observed
**Record low for the month at respective location.
1 – The Bluefield location is the Mercer County, W. Va., airport, near the Va.-W.Va. state line.
2- The Bristol location Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va./Tenn.
3 – The Charlottesville location is the (Charlottesville-Albemarle Airport.
4 – Wallops Island is in Accomack County.
5 – Washington-Dulles Airport is in Loudoun County.
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 period from 1981 to 2010. 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/data-access/land-based-station-data/land-based-datasets/climate-normals.
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 preliminary maps of the percent-of-normal precipitation for the previous 30 days, 60 days, and 90 days, through February 28, 2017. Please note that the scale is different for the 30-day map.
According to the U.S. Geological Survey WaterWatch for Virginia (online at http://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map), monthly average stream flow values for February 2017 at 156 stream gages in Virginia and just beyond the state border were in the normal range at about 8% of gages, below normal at about 39%, and much below normal at about 53%. 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 shown in the chart below the map.
An overall look at Virginia streamflow conditions is provided in the USGS WaterWatch summary plot of 7-day average streamflow conditions. Below is the summary plot for 88 Virginia sites during the 45-day period ending February 27, 2017, accessed at http://waterwatch.usgs.gov/index.php?id=pa07d&sid=w__plot&r=va on March 1, 2017.
Information on current groundwater levels in Virginia monitoring wells is available from the U.S. Geological Survey’s National Water Information System, online at http://waterdata.usgs.gov/va/nwis/current/?type=gw; and from the USGS Climate Response Network, online at http://groundwaterwatch.usgs.gov/net/ogwnetwork.asp?ncd=crn (at that page, you can find a national map showing the status of groundwater monitoring wells compared to historical values).
DROUGHT IN VIRGINIA
The weekly National Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for February 28, 2017, showed about 80.5% of Virginia as “abnormally dry”; about 17.1% in “moderate drought” (covering the northern and central Piedmont and a small area on the south-central border with North Carolina); and about 2.9% in “severe drought” (covering parts of six northern counties).
Drought Monitor categories are as follows:
D0 = abnormally dry;
D1 = moderate drought;
D2 = severe drought;
D3 = extreme drought;
D4 = exceptional drought.
The Drought Monitor notes that it “focuses on broad-scale conditions [and] local conditions may vary.”
For comparison, here are Virginia ratings from previous Drought Monitors from about one month, two months, three months, and one year ago:
1/31/17 – 30.0% abnormally dry or worse, 0.5% moderate drought;
1/3/17 – 70.9% abnormally dry or worse, 15.4% moderate drought;
12/6/16 – 68.7% abnormally dry or worse, 27.7% moderate drought or worse, 0.8% severe drought;
3/1/16 – drought-free.
The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent (as of 3/1/17) Drought Status Report on February 13, 2017. 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 Task Force is next scheduled to meet on March 16, 2017.
Following is a short excerpt from the February 13 report:
“The Virginia Drought Monitoring Task Force (DMTF) met on Thursday February 9, 2017, to discuss the status of drought monitoring and weather forecasts across the Commonwealth of Virginia. Drier-than-normal conditions extend over much of the state due to below-normal precipitation over the past month. Portions of Northern Virginia continue to experience the driest conditions. …For the current water year (October 1, 2016–February 9, 2017) precipitation totals have so far been below 85% of normal for seven of Virginia’s thirteen drought evaluation regions. Two of these regions (Northern Virginia and Northern Piedmont) have received just 57% and 56% of normal precipitation, respectively, while the Shenandoah and Roanoke regions each received 79% of normal. Since February 1, 2016, the Northern Virginia and Northern Piedmont regions received 81% and 84% of normal precipitation [respectively]. The remaining 11 drought-evaluation regions each received more than 90% of normal precipitation during the same period. …The Virginia Department of Agriculture and Consumer Services (VDACS) did not receive any reports of dry conditions that negatively impacted agriculture within Virginia over the past month.”
The Drought Monitoring Task Force also produces a map rating drought-status indicators. As of March 1, 2017, the map’s database was undergoing revisions, so no daily map was available for this post.
The February 28, 2017, U.S. Drought Monitor rated about 34.0% of the United States (including all or parts of 46 states plus Puerto Rico) as being abnormally dry or worse. The Drought Monitor rated about 3.1% of the country (including parts of 22 states), as being in severe drought or worse (categories D2, D3, and D4). (The highest percentage in the severe-or-worse categories reported by the Drought Monitor since it began in 2000 was 38.5% of the country for the week of August 7, 2012.)
The nationwide percentages for abnormally dry or worse (categories D0-D4) and severe or worse (categories D2-D4) in the previous three months and one year ago were as follows:
1/31/17 – 28.3% abnormally dry or worse, 3.2% severe drought or worse;
1/3/17 – 40.3% abnormally dry or worse, 7.2% severe drought or worse;
12/6/16 – 47.3% abnormally dry or worse, 11.7% severe drought or worse;
3/1/16 – 28.6% abnormally dry or worse, 6.5% severe drought or worse.
In one state, 50 percent or more of the state was rated by the February 28 Drought Monitor as in severe-or-worse drought:
In California, about 4% of the state was rated on 1/31/17 as being in severe-or-worse drought. This severe-or-worse rating is the lowest for the Golden State since the week of February 14, 2012. California finally seems to be nearing the end of drought that began in late 2011 to early 2012.
Following are some comments from the February 28 Drought Monitor on conditions in several parts of the country:
“According to February 27 USDA [U.S. Department of Agriculture] reports, 44% of the pasture and rangeland in Virginia was rated in poor to very poor condition.”
“D0-D2 expanded in the Carolinas, and D3 crept into the western Carolinas. Very dry conditions were evident in many drought indicators, including record low streamflow and record low precipitation. The last 12 months (02/29/16-02/28/17) have been the driest such 12-month period on record for over a dozen stations in the southern Appalachian area…. Similarly, over a dozen stations in the western Carolinas and northern Georgia had the driest 6 months on record for 8/28/16-2/28/17.”
“…February 27 USDA reports indicated that topsoil moisture was short or very short (dry to very dry) across 42% of Oklahoma and 33% of Texas, and subsoil moisture was short or very short across 43% of Oklahoma and 30% of Texas. Pasture and rangeland were in poor to very poor condition across 37% of Oklahoma and 20% of Texas, while some crops were suffering at this early stage. In Oklahoma, 21% of the canola, 27% of the oats, and 15% of the winter wheat were in poor to very poor condition.”
“February 27 USDA reports indicated that 46% of the subsoil and 51% of the topsoil in Missouri, and 27% of the subsoil and 28% of the topsoil in Illinois, were short or very short of moisture.”
Central to Northern Plains
“According to February 27 USDA reports, 56% of the subsoil and 55% of the topsoil in Kansas, and 30% of the subsoil and 25% of the topsoil in Nebraska, were short to very short of moisture, while 21% of the winter wheat in Kansas was in poor to very poor condition.”
90-DAY DROUGHT OUTLOOK
For a look ahead, the National Weather Service/Climate Prediction Center’s “U.S. Seasonal Drought Outlook” is available at http://www.cpc.ncep.noaa.gov/products/expert_assessment/sdo_summary.php. Shown below is the outlook map available on March 1, 2017.