Here is the Virginia Water Central News Grouper’s monthly water-status report, as of the end of March 2015. The Virginia Water Resources Research Center thanks the agencies mentioned below for providing the data and maps used in this post.
Here are National Weather Service (NWS) preliminary precipitation totals for March 2015 at 11 Virginia or near-Virginia locations, along with the normal for this month of the year. All values are in inches, rounded to the nearest 0.1 inch from NWS values:
|Normal for Month (inches)|
|Bluefield (Merc. Co. airport, near Va.-W.Va. state line)||5.1||3.5|
|Bristol (Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va.-Tenn.)||3.9||3.4|
|Charlottesville (Char.-Albemarle Airport)||3.5||3.7|
|Wallops Island (Accomack County)||3.4||4.0|
|Washington-Dulles Airport (Loudoun County)||3.9||3.4|
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 provisional (still needing verification) maps of the percent-of-normal precipitation for the previous 30 days, 60 days, and 90 days, through February 28, 2015. Please note that the scale is different for the 90-day map.
According to the U.S. Geological Survey WaterWatch for Virginia, average stream flow values for March 2015 at 150 stream gages in Virginia and just beyond the state border were in the normal range at about 61 percent of gages, below normal at about 9 percent, and above normal at about 30 percent (with much-above-normal readings for the month at several gages, particularly in far southwestern Virginia). 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:
DROUGHT IN VIRGINIA
The weekly National Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for March 31, 2015, categorized about 14 percent of Virginia as being abnormally dry. That area included a small part of upper James River basin, most of Roanoke River basin, and some of the upper New River basin.
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:
3/3/15 – 31 percent abnormally dry;
1/27/15 – 10 percent abnormally dry;
12/30/14 – 16 percent abnormally dry;
4/1/15 – drought-free.
The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on March 17, 2015. 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 April 1, 2015, map is shown below. The current map and more information on the ratings are available at the Task Force Web site listed above.
The March 31, 2015, U.S. Drought Monitor rated 54.0 percent of the United States (including all or parts of 41 states) as being abnormally dry or worse, and it rated 13.1 percent of the country (including all or parts of 12 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:
3/3/15 – 49.4 percent abnormally dry or worse; 13.1 percent severe drought or worse;
1/27/15 – 43.4 percent abnormally dry or worse; 14.1 percent severe drought or worse;
12/30/14 – 39.2 percent abnormally dry or worse; 14.1 percent severe drought or worse;
4/1/14 – 44.7 percent abnormally dry or worse; 20.2 percent severe drought or worse;
In the following states, over 50 percent of the state was categorized by the March 31 report as being in severe-or-worse drought:
California – 93% (with 67% in extreme or exceptional drought; California has had over 90 percent of its area categorized in severe-or-worse drought every week since February 11, 2014, and the Golden State had 100 percent in those categories from May 13—July 29, 2014);
Nevada – 80% (with 48% in extreme or exceptional drought);
Oklahoma – 51% (with 8% in extreme drought);
Utah – 52% (with 9 % in extreme drought).
Here are a few comments from the March 31 Drought Monitor on conditions in some parts of the country:
Midwest: “…Widespread pronounced precipitation deficits (15-50 percent of normal) are noted over most of the Midwest during the past 90 days, while 6-month precipitation stood at a meager 35 to 70 percent of normal from the Dakotas and parts of Nebraska into the central Great Lakes region….”
Southern Plains and Texas: “Soil moisture and streamflow rankings remained at or below the 5th percentile in the southern Plain’s core drought areas, while the satellite-derived Vegetation Health Index indicated rapidly declining conditions from the Texas Panhandle into northern Oklahoma….”
West: “The overall trend toward drought persistence continued, with drought intensification noted over the eastern Great Basin and central Rockies. The west continued to cope with much-above-normal temperatures, further depleting already-dire snowpacks and reducing spring runoff prospects over much of the region. …Plentiful water-year precipitation (since October 1) in the Northwest remained in sharp contrast to virtually non-existent snowpacks, with the snow-water equivalents less than 25 percent of normal (locally less than 10 percent) across Oregon as well as southern and northwestern Washington. The lack of snow maintained concerns for spring and summer water supplies despite the generally favorable 2014-15 water year. … In California, there were no changes to this week’s depiction as the state entered a fourth consecutive year of drought. … [A]s of April 1, the state’s total snowpack stood at a meager 5 percent of average. Indicative of the virtually non-existent snowpack, streamflows have dropped into the 5th percentile or lower over much of California. … Even with some precipitation in the forecast across central and northern California, any rain and mountain snow—while welcomed—would likely do little to improve the state’s dire drought prospects.”
And one more note on California: On April 1, 2015, California announced its first-ever mandatory water-use restrictions. Executive Order B-29-15 by Gov. Jerry Brown calls for the State Water Resources Control Board to implement water-use restrictions that will achieve a 25-percent reduction statewide in potable water use by February 28, 2016. The order does not impose restrictions on agricultural water use but requires irrigators or 10,000 acres or more to include details on supplies, demand, and drought-management actions in annual water-management plans. Here are three sources of information about the California action: California Imposes First Mandatory Water Restrictions to Deal With Drought, New York Times, 4/1/15; Gov. Jerry Brown: California has to change what’s comfortable to address drought, PBS NewsHour, 4/1/15; California State Water Resources Control Board Web site, http://www.swrcb.ca.gov/.
For a look ahead, the National Weather Service/Climate Prediction Center’s “U.S. Seasonal Drought Outlook” for the next 90 days is available at http://www.cpc.ncep.noaa.gov/products/expert_assessment/sdo_summary.html. Shown below is the outlook map available on April 1, 2015.
PREVIOUS MONTHLY WATER-STATUS REPORTS
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