Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, and drought, as of the end of January 2018. 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 January 2018 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. The values are in inches.
|Location||January 2018 Observed||Monthly Normal||February 2017-January 2018 Observed||Annual Normal|
*NWS reported nine days of data missing at Danville in January 2018.
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 High Plains Regional Climate Center at https://hprcc.unl.edu/maps.php?map=ACISClimateMaps), where you can find maps of total precipitation and percent of normal precipitation for the past 7, 30, 60, or 90 days for all U.S. regions; 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 preliminary maps of the percent-of-normal precipitation for the southeastern United States for the previous 30 days, 60 days, and 90 days, through January 31, 2018. Please note that the scale is different for the 30-day map.
According to the U.S. Geological Survey WaterWatch for Virginia (online at https://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map), monthly average stream flow values for January 2018 at ??? stream gages in Virginia and just beyond the state border were as follows, compared to the historical range for each given gage:
within the normal historical range – about 12% of gages;
below normal – about 46%;
much below normal – about 41%;
above normal – about 1%.
Shown below is the color-coded, flow-percentile map for this period, accessed on February 6, 2018, at the site given in the paragraph aboe. 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 daily average streamflow conditions, compared to historical records for any given date. Below is the summary plot for 88 Virginia sites during the 45-day period ending January 31, 2018, accessed on February 1, 2018, at https://waterwatch.usgs.gov/index.php?id=pa01d&sid=w__plot&r=va.
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 U.S. Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for January 30, 2018, categorized 97.9% of Virginia as “abnormally dry” or worse (covering all of the Commonwealth except for parts of three far southwestern counties); 48.6% in “moderate drought” or worse (covering essentially all of the Piedmont region); and 2.9% in “severe drought” (covering all or part of several northern Virginia counties). The occurrence of severe drought in Virginia began in the Drought Monitor for January 23, 2018, for the first time since the report for March 28, 2017.
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:
12/26/17 – 97.4% abnormally dry or worse; 42.9% moderate drought;
11/28/17 – 44.1% abnormally dry or worse; 3.9% moderate drought;
10/31/17 – 41.5% abnormally dry or worse; 3.8% moderate drought;
1/31/17 – 30.0% abnormally dry or worse; 0.5% moderate drought.
Here are some comments from the January 30 Drought Monitor on conditions in or near Virginia:
“…As summarized by the National Drought Mitigation Center, fall crops (such as wheat and barley) were stunted in southern Virginia, and wells were going dry, groundwater levels dropping, and streams and ponds running dry in northern Virginia….”
“…The Bristol Tri-Cities Airport station in Tennessee has received only 3.73 inches of precipitation since November 11, 2017, which is the driest November 11-January 30 period on record.”
In early February 2018, the Virginia Drought Monitoring Task Force (DMTF), a collaboration of state and federal agencies, issued its most recent report (as of 2/6/18). 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 DMTF’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 8, 2018.
The following four paragraphs are excerpted from the DMTF’s February 2018 report:
“Recorded precipitation during January was variable across the Commonwealth, with generally above normal amounts in eastern Virginia and continued below normal amounts across most of the central and western regions. The majority of stream flow gaging stations continue to report below-normal seven-day average flows. Wells in the Virginia Climate Response network of groundwater level observation wells located in central Virginia also continued to report below normal to much-below-normal levels….
“The National Weather Service Monthly Drought Outlook released on January 31, 2018, indicated a likelihood of continuing drought across central Virginia through February. The current U. S. Seasonal Drought Outlook for the period through April 30, 2018 [see below in this post] also indicated drought persistence across the same region.
“The DMTF discussed the continuing drought conditions throughout the central half of the state, as well as the abnormally dry conditions in the southwest. The Task Force decided to recommend that a Drought Watch Advisory should be issued for the Upper James drought evaluation region based upon below normal groundwater levels, stream flows and subsequent below-normal reservoir levels. [See below for a map of the drought evaluation regions used by the DMTF.] The group also agreed that the existing Drought Watch Advisories in six regions (Chowan, Middle James, Northern Piedmont, Northern Virginia, Roanoke River and Shenandoah) should continue. If the pattern of below-normal precipitation during the winter ‘leaf-off’ period continues through February, most of the state will have experienced a second consecutive winter season with low recharge to the groundwater system. These conditions may have serious impacts upon water availability during the next growing season due to low water table levels and subsequent low base flow in streams.
“VDACS [Virginia Department of Agriculture and Consumer Services] has received reports that cover crops have been affected and that in some areas, particularly in the upper Shenandoah region, livestock watering ponds have been affected. VDGIF [the Virginia Department of Game and Inland Fisheries] noted that due to low water levels, trout stocking has been delayed, and VDOF [Virginia Department of Forestry] reported that there is some concern regarding central Virginia for the spring wildfire season. The U.S. Army Corps of Engineers (USACE) Wilmington N.C., District described conditions affecting Philpott and J.H. Kerr reservoirs in the Roanoke drought evaluation region. The Kerr project’s Drought Management Plan has been in effect for several weeks, and inflows have been well below normal.”
The DMTF also produces a map rating drought-status indicators, also online at http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought/DroughtMonitoring.aspx. Shown below is the map for January 31, 2018, followed by a map identifying the Drought Evaluation Regions used by the DMTF. 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.” Note the widespread watch, warning, and emergency conditions as of the end of January.
Following are recent drought-related news headlines (hyperlinked to the online articles):
Despite rain, region approaching long-term drought, WTOP FM-Washington, D.C., 2/2/18.
Augusta County sets up water filling station in Verona, Waynesboro News Virginian, 2/3/18.
The January 30, 2018, U.S. Drought Monitor categorized 61.9% of the United States (including all or parts of 47 states) as being abnormally dry or worse. The Drought Monitor categorized 14.4% 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:
12/26/17 – 45.8% abnormally dry or worse; 4.1% severe drought or worse;
11/28/17 – 35.7% abnormally dry or worse; 4.1% severe drought or worse;
10/31/17 – 28.1% abnormally dry or worse; 2.3% severe drought or worse;
1/31/17 – 28.3% abnormally dry or worse; 3.2% severe drought or worse.
The following states had 50% or more categorized by the January 30 Drought Monitor in severe-or-worse drought:
Arizona – 64%;
New Mexico – 68%;
Oklahoma – 81%.
Following are some comments from the January 30 Drought Monitor on conditions in three regions:
“…This week was a continuation of very dry conditions in western Texas, western Oklahoma, and eastern New Mexico which have lasted for over three months…. In Texas, the Amarillo International Airport has had 109 consecutive days with no measurable precipitation as of January 30, edging out January 3, 1957, whose dry run lasted 75 consecutive days. Canyon went 102 days without measurable rain through January 16, which was the second longest dry streak behind the 104 days ending on January 15, 1956. Guymon, Oklahoma, has had only 0.04 inch of precipitation since October 11, 2017….”
“…[D]ry weather [dominated] the West this week and [has for] much of the last six or more months…. As reported to the National Weather Service, in southern Arizona ranchers were already starting (or preparing) to haul water for livestock as ponds were drying up. This is more typical of spring than mid-winter. …Mountain snowpack was abysmally low, reaching record low levels for this time of year in parts of New Mexico and Colorado. …D2 was added to southern California to reflect long-term precipitation deficits in Santa Barbara, Ventura, and Los Angeles Counties.”
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 February 1, 2018.