Category Archives: Weather

Virginia Water Status Report as of the End of April 2021, Plus a Look at Flooding and Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, flooding, and drought, as of the end of April 2021.  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, groundwater, 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 April 2021 at 12 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.

LocationApril 2021 ObservedMonthly NormalMay 2020-April 2021 ObservedAnnual Normal
Blacksburg11.973.4853.8840.89  
Bluefield2  2.243.3447.6839.63
Bristol3  1.083.3346.8741.01
Charlottesville4  2.643.3648.4242.71
Danville  1.173.4653.7744.41
Lynchburg  2.733.3163.9841.57
Norfolk  2.683.4153.4046.53
Reagan National Airport52.203.0655.3239.74
Richmond  1.343.2762.9043.60
Roanoke  2.003.3759.7441.25
Wallops Island6  2.403.0749.1240.84
Washington-Dulles Airport72.283.4746.0541.54

Location notes

1 – The Blacksburg location is the Blacksburg National Weather Service Office.

2 – The Bluefield location is the Mercer County, W. Va., airport, near the Va.-W.Va. state line.

3- The Bristol location is the Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va./Tenn.

4 – The Charlottesville location is the Charlottesville-Albemarle Airport.

5 – Reagan National Airport is in Arlington County.

6 – Wallops Island is in Accomack County.

7 – Washington-Dulles Airport is in Loudoun County.


Precipitation sources:  Climate pages of the following National Weather Service Forecast Offices:

Blacksburg, Va. (https://w2.weather.gov/climate/index.php?wfo=rnk);

Morristown, Tenn. (https://w2.weather.gov/climate/index.php?wfo=mrx);

Baltimore-Washington (https://w2.weather.gov/climate/index.php?wfo=lwx); and

Wakefield, Va. (https://w2.weather.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.  New normals for the period of 1991-2020 were released on May 4, 2021; those normal will be used in the May 2021 edition of this monthly report.  For information on the normal values, see the “Climate Normals” 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 from the High Plains Center of the percent-of-normal precipitation for the southeastern United States for the previous 30 days, 60 days, and 90 days, and for Virginia for the previous 30 days, all through May 1, 2021.  Please note that the scale is different for the Virginia 30-day map.


Shown below is a color-coded percentile map of monthly average stream flow values for April 2021 at stream gages in Virginia and just beyond the state border, compared to the historical range for each gage.  The map is from the U.S. Geological Survey (USGS) WaterWatch for Virginia, accessed online at https://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map.  The chart below the map shows the color codes/percentile classes used by USGS to compare flows to historical records for the month.

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 89 Virginia sites during the 45-day period ending April 28, 2021, accessed on April 30, 2021, at https://waterwatch.usgs.gov/index.php?id=pa01d&sid=w__plot&r=va.

NATIONWIDE FLOODING OVERVIEW

Following is the National Weather Service’s Advanced Hydrologic Prediction Service’s (AHPS) map of stream and river levels relative to flood stage (color-coded) for the continental United States, as of 8:43 a.m. EDT on April 30, 2021.  The current map is available online at http://water.weather.gov/ahps/forecasts.php; at that site, one can select Virginia or any other state of interest.

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.

DROUGHT IN VIRGINIA

The weekly U.S. Drought Monitor report from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for April 27, 2021, categorized Virginia drought-free.  This has been the case since the week of April 13, 2021.

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:

3/30/21 – 7.9% abnormally dry;

3/2/21 – drought-free;

1/26/21 – 0.02% abnormally dry;

4/28/20 – drought-free.

On November 1, 2019, the Virginia Drought Monitoring Task Force (DMTF), a collaboration of state and federal agencies, issued its most recent report (as of 5-4-21).  A link to that report, along with other current drought-status information, is available online at https://www.deq.virginia.gov/water/water-quantity/drought.  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 Virginia Department of Environmental Quality uses a map rating drought-status indicators, also online at https://www.deq.virginia.gov/water/water-quantity/drought.  Shown below is the map for May 3, 2021.  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.”

DROUGHT ELSEWHERE

The April 27, 2021, U.S. Drought Monitor categorized about 60.6% of the United States (including parts of 45 states plus Puerto Rico) as being abnormally dry or worse.  (The highest percentage in the abnormally or worse categories—that is, in all categories—reported by the Drought Monitor since it began in 2000 was 72.38 % of the country for the week of July 17, 2012.)  The Drought Monitor categorized about 27.1% of the country (including parts of 19 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 38.48% 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:

3/30/21 – 58.6% abnormally dry or worse; 24.7% severe drought or worse;

3/2/21 – 55.0% abnormally dry or worse; 25.8% severe drought or worse;

1/26/21 – 54.7% abnormally dry or worse; 27.2% severe drought or worse;

4/28/20 – 24.0% abnormally dry or worse; 4.7% severe drought or worse.

The following states had 50% or more of their land area categorized by the April 27, 2021, Drought Monitor as being in severe-or-worse drought:

Arizona = 95%.

California = 88%.

Colorado = 60%.

Nevada = 92%.

New Mexico = 99%.

North Dakota = 93%.

Utah = 98%.

Following are comments from the April 13, 2021, Drought Monitor on severe drought conditions in parts of the United States.

From Nationwide Summary: “Parts of the Southwest are now experiencing record levels of dryness for the last 12 months. In New England, year-to-date precipitation ranks in the top 10 driest on record.

From West Regional Report: “In eastern Washington, D0 (abnormally dryness), D1 (moderate) and D2 (severe) drought expanded as precipitation deficits continued to increase, drying out soils and lowering streamflow.  Conditions once again deteriorated in Oregon this week with expansions in D2, D3 (extreme) and D4 (exceptional drought).  The warm, dry winter added to deficits that had been in place for more than a year, leaving soils extremely dry and limiting runoff.  …Drought conditions also expanded in northern and central California.  Another week without rainfall has continued to build upon longer deficits.  Cooperative Extension notes that the majority of the season’s creeks aren’t flowing and that stock ponds are still dry.  Decreases in water allocation and reduced or negligible forage are causing producers to respond by culling and selling herds.  Drought conditions are also prompting Cal Fire to bring in fire crews earlier in the season.”

Following are comments from the April 20, 2021, Drought Monitor on dry conditions in several regions of the United States.

From Nationwide Summary:

“Streamflow was well below normal all along the West Coast and in the interior West, in North Dakota and northwest South Dakota, parts of southern Texas, the southern and eastern Great Lakes, and parts of the Northeast.  Soils continued to dry out in the West and Southeast, according to U.S. Department of Agriculture (USDA) reports.  Satellite and station reports, as well as modeled indices, showed dry soils across the West, northern and southern Plains, the southern and eastern Great Lakes, and into the Northeast, as well as parts of the Southeast.  Groundwater observations from wells and estimated from satellite measurements revealed dry conditions across the West, northern and southern Plains, Northeast, and parts of the Southeast.”

Following are comments from the April 27, 2021, Drought Monitor on drought conditions in the western United States and the response by the Biden Administration to form an inter-agency working group.

From West Regional Report: “According to media reports, the Biden-Harris administration announced the formation of an Interagency Working Group to address worsening drought conditions in the West and support farmers, Tribes, and communities impacted by ongoing water shortages.  The Working Group will be co-chaired by the Departments of the Interior and Agriculture to build upon existing resources to help coordinate across the federal government, working in partnership with state, local, and Tribal governments to address the needs of communities suffering from drought-related impacts.  The Working Group will work to identify immediate financial and technical assistance for impacted irrigators and Tribes.”

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 April 30, 2021.

Virginia Water Status Report as of the End of March 2021, Plus a Look at Flooding and Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, flooding, and drought, as of the end of March 2021.  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, groundwater, 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 March 2021 at 12 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.

LocationMarch 2021 ObservedMonthly NormalApril 2020- March 2021 ObservedAnnual Normal
Blacksburg3.923.6458.1540.89  
Bluefield1  4.243.5152.0539.63
Bristol2  6.943.4453.3441.01
Charlottesville3  2.013.6652.0842.71
Danville  4.164.1157.3744.41
Lynchburg  3.173.5868.8141.57
Norfolk  1.983.6855.3146.53
Reagan National Airport43.803.4859.4239.74
Richmond  3.894.0466.2743.60
Roanoke  2.953.4663.5841.25
Wallops Island5  3.134.0050.3840.84
Washington-Dulles Airport62.273.3849.3341.54

Location notes

1 – The Bluefield location is the Mercer County, W. Va., airport, near the Va.-W.Va. state line.
2- The Bristol location is the Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va./Tenn.
3 – The Charlottesville location is the Charlottesville-Albemarle Airport.
4 – Reagan National Airport is in Arlington County.
5 – Wallops Island is in Accomack County.
6 – Washington-Dulles Airport is in Loudoun County.

Precipitation sources:  Climate pages of the following National Weather Service Forecast Offices:
Blacksburg, Va. (https://w2.weather.gov/climate/index.php?wfo=rnk);
Morristown, Tenn. (https://w2.weather.gov/climate/index.php?wfo=mrx);
Baltimore-Washington (https://w2.weather.gov/climate/index.php?wfo=lwx); and
Wakefield, Va. (https://w2.weather.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 (now the National Centers for Environmental Information) released these normal values in July 2011.  For information on the normal values, see the “Climate Normals” 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 from the High Plains Center of the percent-of-normal precipitation for the southeastern United States for the previous 30 days, 60 days, and 90 days, and for Virginia for the previous 30 days, all through March 31, 2021.



Shown below is a color-coded percentile map of monthly average stream flow values for March 2021 at stream gages in Virginia and just beyond the state border, compared to the historical range for each gage.  The map is from the U.S. Geological Survey (USGS) WaterWatch for Virginia, accessed online at https://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map.  The chart below the map shows the color codes/percentile classes used by USGS to compare flows to historical records for the month.

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 89 Virginia sites during the 45-day period ending March 30, 2021, accessed on April 1, 2021, at https://waterwatch.usgs.gov/index.php?id=pa01d&sid=w__plot&r=va.

NATIONWIDE FLOODING OVERVIEW

Following is the National Weather Service’s Advanced Hydrologic Prediction Service’s (AHPS) map of stream and river levels relative to flood stage (color-coded) for the continental United States, as of 1:57 p.m. EDT on April 1, 2021.  The current map is available online at http://water.weather.gov/ahps/forecasts.php; at that site, one can select Virginia or any other state of interest.


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.

DROUGHT IN VIRGINIA

The weekly U.S. Drought Monitor report from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for March 30, 2021, categorized about 7.9% of Virginia as abnormally dry.  This was the first occurrence of any level of drought for Virginia since the Drought Monitor’s report of February 23, 2021.

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:

3/2/21 – drought-free;
1/26/21 – 0.02% abnormally dry;
12/29/20 – drought-free;
3/31/20 – drought-free.

On November 1, 2019, the Virginia Drought Monitoring Task Force (DMTF), a collaboration of state and federal agencies, issued its most recent report (as of 4-1-21).  A link to that report, along with other current drought-status information, is available online at https://www.deq.virginia.gov/water/water-quantity/drought.  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 DMTF also produces a map rating drought-status indicators, also online at https://www.deq.virginia.gov/water/water-quantity/drought.  Shown below is the map for March 31, 2021.  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.”

DROUGHT ELSEWHERE

The March 30, 2021, U.S. Drought Monitor categorized about 58.6% of the United States (including parts of 42 states plus Puerto Rico) as being abnormally dry or worse.  (The highest percentage in the abnormally or worse categories—that is, in all categories—reported by the Drought Monitor since it began in 2000 was 72.38 % of the country for the week of July 17, 2012.)  The Drought Monitor categorized about 24.7% of the country (including parts of 19 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 38.48% 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:

3/2/21 – 55.0% abnormally dry or worse; 25.8% severe drought or worse;
1/26/21 – 54.7% abnormally dry or worse; 27.2% severe drought or worse;
12/29/20 – 57.0% abnormally dry or worse; 28.6% severe drought or worse;
3/31/20 – 21.1% abnormally dry or worse, 2.5% severe drought or worse.

The following states had 50% or more of their land area categorized by the March 30, 2021, Drought Monitor as being in severe-or-worse drought:

Arizona = 95%.
California = 64%.
Colorado = 62%.
Nevada = 92%.
New Mexico = 99%.
North Dakota = 85%.
Utah = 97%.

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 April 1, 2021.

On Virginia Water Radio for the Week of 3-8-21: Good-bye Winter (Soon) and Thanks for the Water

Virginia Water Radio’s episode for the week of March 8, 2021, is “Spring’s Approach and the Water that Winter Left Behind.”  The 4 min./22 sec. episode, available online at http://www.virginiawaterradio.org/2021/03/episode-567-3-8-21-springs-approach-and.html, focuses on the importance of winter precipitation. The episode features music by No Strings Attached. This is a revised repeat of an episode from March 2015.

Ice hanging from a tree twig at Heritage Park in Blacksburg, Va., February 20, 2021.

Virginia Water Radio’s is a weekly broadcast/podcast produced by the Virginia Water Resources Research Center.  The home page is http://www.virginiawaterradio.org.  Have a listen or two!

Virginia Water Status Report as of the Beginning of March 2021, Plus a Look at Flooding and Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, flooding, and drought, as of the beginning of March 2021.  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, groundwater, 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 2021 at 12 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.

LocationFebruary 2021 ObservedMonthly NormalMarch 2020- Feb. 2021 ObservedAnnual Normal
Blacksburg4.352.8159.0340.89  
Bluefield1  4.662.7653.3339.63
Bristol2  4.893.4553.3341.01
Charlottesville3  5.242.7051.6042.71
Danville  4.433.0155.1744.41
Lynchburg  4.242.9368.4341.57
Norfolk  6.443.1258.5246.53
Reagan National Airport44.662.6257.9339.74
Richmond  5.122.7665.0443.60
Roanoke  4.382.8963.8741.25
Wallops Island5  6.262.7650.8940.84
Washington-Dulles Airport64.282.7449.0541.54

Location notes

1 – The Bluefield location is the Mercer County, W. Va., airport, near the Va.-W.Va. state line.
2- The Bristol location is the Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va./Tenn.
3 – The Charlottesville location is the Charlottesville-Albemarle Airport.
4 – Reagan National Airport is in Arlington County.
5 – Wallops Island is in Accomack County.
6 – Washington-Dulles Airport is in Loudoun County.

Precipitation sources:  Climate pages of the following National Weather Service Forecast Offices:
Blacksburg, Va. (https://w2.weather.gov/climate/index.php?wfo=rnk);
Morristown, Tenn. (https://w2.weather.gov/climate/index.php?wfo=mrx);
Baltimore-Washington (https://w2.weather.gov/climate/index.php?wfo=lwx); and
Wakefield, Va. (https://w2.weather.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 (now the National Centers for Environmental Information) released these normal values in July 2011.  For information on the normal values, see the “Climate Normals” 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 from the High Plains Center of the percent-of-normal precipitation for the southeastern United States for the previous 30 days, 60 days, and 90 days, and for Virginia for the previous 30 days, all through March 2, 2021.

Shown below is a color-coded percentile map of monthly average stream flow values for February 2021 at stream gages in Virginia and just beyond the state border, compared to the historical range for each gage.  The map is from the U.S. Geological Survey (USGS) WaterWatch for Virginia, accessed online at https://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map.  The chart below the map shows the color codes/percentile classes used by USGS to compare flows to historical records for the month.


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 89 Virginia sites during the 45-day period ending March 1, 2021, accessed on March 3, 2021, at https://waterwatch.usgs.gov/index.php?id=pa01d&sid=w__plot&r=va.

NATIONWIDE FLOODING OVERVIEW

Following is the National Weather Service’s Advanced Hydrologic Prediction Service’s (AHPS) map of stream and river levels relative to flood stage (color-coded) for the continental United States, as of 3:52 p.m. EST on March 3, 2021.  The current map is available online at http://water.weather.gov/ahps/forecasts.php; at that site, one can select Virginia or any other state of interest.

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.

DROUGHT IN VIRGINIA

The weekly U.S. Drought Monitor report from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for March 2, 2021, categorized Virginia as drought-free.  This was the first drought-free categorization for Virginia since the Drought Monitor’s report of January 19, 2021.

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:
1/26/21 – 0.02% abnormally dry;
12/29/20 – drought-free;
11/24/20 – drought-free;
3/3/20 – drought-free.

On November 1, 2019, the Virginia Drought Monitoring Task Force (DMTF), a collaboration of state and federal agencies, issued its most recent report (as of 3-4-21).  A link to that report, along with other current drought-status information, is available online at https://www.deq.virginia.gov/water/water-quantity/drought.  [looks like this DEQ page is under construction as of 2-1-21].  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.

DROUGHT ELSEWHERE

The March 2, 2021, U.S. Drought Monitor categorized about 55.0% of the United States (including parts of 40 states plus Puerto Rico) as being abnormally dry or worse.  (The highest percentage in the abnormally or worse categories—that is, in all categories—reported by the Drought Monitor since it began in 2000 was 72.38 % of the country for the week of July 17, 2012.)  The Drought Monitor categorized about 25.8% of the country (including parts of 20 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 38.48% 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:

1/26/21 – 54.7% abnormally dry or worse; 27.2% severe drought or worse;
12/29/20 – 57.0% abnormally dry or worse; 28.6% severe drought or worse;
11/24/20 – 58.2% abnormally dry or worse; 26.8% severe drought or worse;
3/3/20 – 20.9% abnormally dry or worse, 2.1% severe drought or worse.

The following states had 50% or more of their land area categorized by the March 2 Drought Monitor as being in severe-or-worse drought:
Arizona = 95%;
California = 57%;
Colorado = 89%;
Nevada = 92%;
New Mexico = 100% (99.9%);
North Dakota = 69%;
Utah = 97%;
Wyoming = 60%.

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 3, 2021.

Virginia Water Status Report as of the End of January 2021, Plus a Look at Flooding and Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, flooding, and drought, as of the end of January 2021.  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, groundwater, 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 2021 at 12 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.

LocationJanuary 2021 ObservedMonthly NormalFeb. 2020- Jan. 2021 ObservedAnnual Normal
Blacksburg3.623.0860.1040.89  
Bluefield1  3.472.9053.6139.63
Bristol2  3.573.3756.6741.01
Charlottesville3  2.042.7749.0442.71
Danville  3.573.4257.0744.41
Lynchburg  3.813.1469.5641.57
Norfolk  3.813.4056.5646.53
Reagan National Airport41.932.8156.4839.74
Richmond  3.583.0463.5143.60
Roanoke  4.182.9263.5741.25
Wallops Island5  3.523.0449.4140.84
Washington-Dulles Airport61.882.6848.0141.54

Location notes
1 – The Bluefield location is the Mercer County, W. Va., airport, near the Va.-W.Va. state line.
2- The Bristol location is the Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va./Tenn.
3 – The Charlottesville location is the Charlottesville-Albemarle Airport.
4 – Reagan National Airport is in Arlington County.
5 – Wallops Island is in Accomack County.
6 – Washington-Dulles Airport is in Loudoun County.

Precipitation sources:  Climate pages of the following National Weather Service Forecast Offices:
Blacksburg, Va. (https://w2.weather.gov/climate/index.php?wfo=rnk);
Morristown, Tenn. (https://w2.weather.gov/climate/index.php?wfo=mrx);
Baltimore-Washington (https://w2.weather.gov/climate/index.php?wfo=lwx); and
Wakefield, Va. (https://w2.weather.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 (now the National Centers for Environmental Information) released these normal values in July 2011.  For information on the normal values, see the “Climate Normals” 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 from the High Plains Center of the percent-of-normal precipitation for the southeastern United States for the previous 30 days, 60 days, and 90 days, and for Virginia for the previous 30 days, all through January 31, 2021.  Please note that the scale is different for the 60-day regional map.


Shown below is a color-coded percentile map of monthly average stream flow values for January 2021 at stream gages in Virginia and just beyond the state border, compared to the historical range for each gage.  The map is from the U.S. Geological Survey (USGS) WaterWatch for Virginia, accessed online at https://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map.  The chart below the map shows the color codes/percentile classes used by USGS to compare flows to historical records for the month.

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 89 Virginia sites during the 45-day period ending January 30, 2021, accessed on February 1, 2021, at https://waterwatch.usgs.gov/index.php?id=pa01d&sid=w__plot&r=va.

NATIONWIDE FLOODING OVERVIEW

Following is the National Weather Service’s Advanced Hydrologic Prediction Service’s (AHPS) map of stream and river levels relative to flood stage (color-coded) for the continental United States, as of 3:21 p.m. EST on February 1, 2021.  The current map is available online at http://water.weather.gov/ahps/forecasts.php; at that site, one can select Virginia or any other state of interest.

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.

DROUGHT IN VIRGINIA

The weekly U.S. Drought Monitor report from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for January 26, 2021, categorized 0.02% of Virginia as abnormally dry.  This was the Drought Monitor’s first indication of any level of drought in Virginia since the report for August 11, 2020.

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:

12/29/20 – drought-free;
11/24/20 – drought-free;
10/27/20 – drought-free;
1/28/20 – 1.81% abnormally dry.

DROUGHT ELSEWHERE

The January 26, 2021, U.S. Drought Monitor categorized about 54.7% of the United States (including parts of 43 states plus Puerto Rico) as being abnormally dry or worse.  (The highest percentage in the abnormally or worse categories—that is, in all categories—reported by the Drought Monitor since it began in 2000 was 72.38 % of the country for the week of July 17, 2012.)  The Drought Monitor categorized about 27.1% 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 38.48% 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:

12/29/20 – 57.0% abnormally dry or worse; 28.6% severe drought or worse;
11/24/20 – 58.2% abnormally dry or worse; 26.8% severe drought or worse;
10/27/20 – 56.0% abnormally dry or worse; 25.0% severe drought or worse;
1/28/20 – 23.9% abnormally dry or worse, 2.0% severe drought or worse.

The following states had 50% or more of their land area categorized by the January 26, 2021, Drought Monitor as being in severe-or-worse drought:

Arizona = 97%;
California = 76%;
Colorado = 91%;
Nevada = 93%;
New Mexico = 100% (99.6%);
North Dakota = 58%;
Oregon = 60%;
Utah = 98%;
Wyoming = 68%.

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, 2021.

On Virginia Water Radio for the Week of 1-11-21: 2020 was a Good Year to Have a Rain Gauge

Virginia Water Radio’s episode for the week of January 11, 2021, is “An Abundance of Precipitation in 2020.”  The 4 min./11 sec. episode, available online at http://www.virginiawaterradio.org/2021/01/episode-559-1-11-21-abundance-of.html, focuses on the high precipitation levels in Virginia in 2020, including annual records in some locations. The episode includes music by Andrew and Noah VanNorstrand and by Torrin Hallett.

Part of Virginia’s precipitation in 2020 was this snow in Blacksburg on January 7.

Virginia Water Radio’s is a weekly broadcast/podcast produced by the Virginia Water Resources Research Center.  The home page is http://www.virginiawaterradio.org.  Have a listen or two!

Virginia Water Status Report as of the End of December 2020, Plus a Look at Flooding and Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, flooding, and drought, as of the end of December 2020.  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, groundwater, 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 December 2020 at 12 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.

LocationDecember 2020 ObservedMonthly NormalJan. 2020- Dec. 2020 ObservedAnnual Normal
Blacksburg3.442.9559.6040.89  
Bluefield1  3.052.9152.5639.63
Bristol2  3.523.3757.4641.01
Charlottesville3  5.613.1550.5742.71
Danville  4.443.2757.3244.41
Lynchburg  5.353.2469.7341.57
Norfolk  4.393.2656.3346.53
Reagan National Airport44.963.0557.3439.74
Richmond  6.703.2663.5243.60
Roanoke  3.632.9462.6541.25
Wallops Island5  5.643.4349.4740.84
Washington-Dulles Airport65.812.9649.4641.54

Location notes
1 – The Bluefield location is the Mercer County, W. Va., airport, near the Va.-W.Va. state line.
2- The Bristol location is the Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va./Tenn.
3 – The Charlottesville location is the Charlottesville-Albemarle Airport.
4 – Reagan National Airport is in Arlington County.
5 – Wallops Island is in Accomack County.
6 – Washington-Dulles Airport is in Loudoun County.

Precipitation sources:  Climate pages of the following National Weather Service Forecast Offices:

Blacksburg, Va. (https://w2.weather.gov/climate/index.php?wfo=rnk);
Morristown, Tenn. (https://w2.weather.gov/climate/index.php?wfo=mrx);
Baltimore-Washington (https://w2.weather.gov/climate/index.php?wfo=lwx); and
Wakefield, Va. (https://w2.weather.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 from the High Plains Center of the percent-of-normal precipitation for the southeastern United States for the previous 30 days, 60 days, and 90 days, and for Virginia for the previous 30 days, all through December 30, 2020.


Shown below is a color-coded percentile map of monthly average stream flow values for December 2020 at stream gages in Virginia and just beyond the state border, compared to the historical range for each gage.  The map is from the U.S. Geological Survey (USGS) WaterWatch for Virginia, accessed online at https://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map.  The chart below the map shows the color codes/percentile classes used by USGS to compare flows to historical records for the month.

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 89 Virginia sites during the 45-day period ending December 31, 2020, accessed on January 1, 2021, at https://waterwatch.usgs.gov/index.php?id=pa01d&sid=w__plot&r=va.

NATIONWIDE FLOODING OVERVIEW

Following is the National Weather Service’s Advanced Hydrologic Prediction Service’s (AHPS) map of stream and river levels relative to flood stage (color-coded) for the continental United States, as of 11:37 a.m. EST on December 31, 2020.  The current map is available online at http://water.weather.gov/ahps/forecasts.php; at that site, one can select Virginia or any other state of interest.


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.

DROUGHT IN VIRGINIA

The weekly U.S. Drought Monitor report from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for December 29, 2020, categorized Virginia as drought-free.  That drought-free categorization began the week of August 18, 2020; prior to that, Virginia had been categorized as having some level of drought since the week of June 16, 2020.

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:
11/24/20 – drought-free;
10/27/20 – drought-free;
9/29/20 – drought-free;
12/31/19 – 1.5% abnormally dry.

On November 1, 2019, the Virginia Drought Monitoring Task Force (DMTF), a collaboration of state and federal agencies, issued its most recent report (as of 9-30-20).  A link to that report, along with other current drought-status information, is available online at https://www.deq.virginia.gov/water/water-quantity/drought.  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.

DROUGHT ELSEWHERE

The December 29, 2020, U.S. Drought Monitor categorized about 57.0% of the United States (including parts of 42states plus Puerto Rico) as being abnormally dry or worse.  (The highest percentage in the abnormally or worse categories—that is, in all categories—reported by the Drought Monitor since it began in 2000 was 72.38 % of the country for the week of July 17, 2012.)  The Drought Monitor categorized about 28.6% of the country (including parts of 21 states) as being in severe drought or worse (categories D2, D3, and D4); this percentage was the highest nationwide percentage of severe-or-worse drought since the Drought Monitor report for the week of September 10, 2013.  (The highest percentage in the severe-or-worse categories reported by the Drought Monitor since it began in 2000 was 38.48% 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:

11/24/20 – 58.2% abnormally dry or worse; 26.8% severe drought or worse;
10/27/20 – 56.0% abnormally dry or worse; 25.0% severe drought or worse;
9/29/20 – 55.5% abnormally dry or worse; 22.9% severe drought or worse;
12/31/19 – 21.5% abnormally dry or worse, 2.6% severe drought or worse.

The following states had 50% or more of their land area categorized by the December 29, 2020, Drought Monitor as being in severe-or-worse drought:

Arizona = 98%;
California = 74%;
Colorado = 94%;
Nebraska = 51%;
Nevada = 92%;
New Mexico = ~100% (99.6%);
North Dakota = 69%;
Oregon = 70%;
Texas = 50%;
Utah = 97%;
Wyoming = 54%.

Following is part of the nationwide summary by the Drought Monitor earlier in December 2020 (December 8, 2020, report) on dry conditions in the western United States, particularly Arizona and California:

            “This U.S. Drought Monitor week saw intensification of drought across parts of the western U.S. including California, Nevada, and Colorado, where precipitation has been below normal since the beginning of the Water Year (Oct 1).  In California, statewide snow water content (SWE) is currently at 36% of the historical average for the date (Dec 7) and Water-Year-to-Date (WYTD) precipitation (statewide) is ranging from the bottom 10% to the bottom 33% with some areas in the Mojave Desert experiencing the driest on record for the period.  According to NOAA’s National Centers for Environmental Information (NCEI), the 6-month period from June to November 2020 was the hottest and driest on record for both Arizona and California.”

Following is part of the Southeast Region comments earlier in December 2020 (December 8, 2020, report) on wet conditions in fall 2020 across the region, including in Virginia:

            “According to NOAA NCEI climatological rankings, the September-November 2020 period was marked by above-normal precipitation across the Southeast with statewide precipitation ranks (where 1=driest on record and 126=wettest on record) for the period as follows: Virginia–123, North Carolina–118, South Carolina–107, Georgia–110, Alabama–104, and Florida–117.”

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 December 31, 2020.

On Virginia Water Radio for the Week of 12-21-20: Ice, Cells, and Survival Stategies

Virginia Water Radio’s episode for the week of December 21, 2020, is “Surviving the Freezing Season.” The 5 min./2 sec. episode, available online at http://www.virginiawaterradio.org/2020/12/episode-556-12-21-20-surviving-freezing.html, explores how organisms survive freezing temperatures. The episode features new music composed for this episode by Torrin Hallett, a graduate student at Lamont School of Music in Denver.

Ice-covered Goose Creek along Evergreen Mill Road in Loudoun County, Va., January 20, 2018.

Virginia Water Radio’s is a weekly broadcast/podcast produced by the Virginia Water Resources Research Center.  The home page is http://www.virginiawaterradio.org.  Have a listen or two!

Virginia Water Status Report as of the End of November 2020, Plus a Look at Flooding and Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, flooding, and drought, as of the end of November 2020.  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, groundwater, 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 November 2020 at 12 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.

LocationNovember 2020 ObservedMonthly NormalDec. 2019- Nov. 2020 ObservedAnnual Normal
Blacksburg5.812.8758.9640.89  
Bluefield1  2.542.6951.8839.63
Bristol2  2.083.1057.1841.01
Charlottesville3  6.443.8347.5042.71
Danville  8.803.3656.0744.41
Lynchburg  8.513.4167.2341.57
Norfolk  7.643.1553.9746.53
Reagan National Airport46.143.1755.6639.74
Richmond  4.433.2460.0943.60
Roanoke  5.843.4061.8641.25
Wallops Island5  5.232.8746.8140.84
Washington-Dulles Airport63.613.4146.6341.54

Location notes
1 – The Bluefield location is the Mercer County, W. Va., airport, near the Va.-W.Va. state line.
2- The Bristol location is the Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va./Tenn.
3 – The Charlottesville location is the Charlottesville-Albemarle Airport.
4 – Reagan National Airport is in Arlington County.
5 – Wallops Island is in Accomack County.
6 – Washington-Dulles Airport is in Loudoun County.

Precipitation sources
Climate pages of the following National Weather Service Forecast Offices:

Blacksburg, Va. (https://w2.weather.gov/climate/index.php?wfo=rnk);
Morristown, Tenn. (https://w2.weather.gov/climate/index.php?wfo=mrx);
Baltimore-Washington (https://w2.weather.gov/climate/index.php?wfo=lwx); and
Wakefield, Va. (https://w2.weather.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 from the High Plains Center of the percent-of-normal precipitation for the southeastern United States for the previous 30 days, 60 days, and 90 days, and for Virginia for the previous 30 days, all through November 30, 2020.


Shown below is a color-coded percentile map of monthly average stream flow values for November 2020 at stream gages in Virginia and just beyond the state border, compared to the historical range for each gage.  The map is from the U.S. Geological Survey (USGS) WaterWatch for Virginia, accessed online at https://waterwatch.usgs.gov/index.php?m=mv01d&r=va&w=map.  The chart below the map shows the color codes/percentile classes used by USGS to compare flows to historical records for the month.

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 89 Virginia sites during the 45-day period ending November 29, 2020, accessed on December 1 at https://waterwatch.usgs.gov/index.php?id=pa01d&sid=w__plot&r=va.

NATIONWIDE FLOODING OVERVIEW

Following is the National Weather Service’s Advanced Hydrologic Prediction Service’s (AHPS) map of stream and river levels relative to flood stage (color-coded) for the continental United States, as of 2:41 p.m. EST on November 30, 2020.  The current map is available online at http://water.weather.gov/ahps/forecasts.php; at that site, one can select Virginia or any other state of interest.

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.

DROUGHT IN VIRGINIA

The weekly U.S. Drought Monitor report from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for November 24, 2020, categorized Virginia as drought-free.  That drought-free categorization began the week of August 18, 2020; prior to that, Virginia had been categorized as having some level of drought since the week of June 16, 2020.

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:

10/27/20 – drought-free;
9/29/20 – drought-free;
8/25/20 – drought-free;
11/26/19 – 30.6% abnormally dry.

On November 1, 2019, the Virginia Drought Monitoring Task Force (DMTF), a collaboration of state and federal agencies, issued its most recent report (as of 9-30-20).  A link to that 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.

DROUGHT ELSEWHERE

The November 24, 2020, U.S. Drought Monitor categorized about 58.2% of the United States (including parts of 45 states plus Puerto Rico) as being abnormally dry or worse; this percentage was the highest  nationwide percentage of abnormally dry or worse since the Drought Monitor report for the week of February 6, 2018.  (The highest percentage in the abnormally or worse categories—that is, in all categories—reported by the Drought Monitor since it began in 2000 was 72.38% of the country for the week of July 17, 2012.)  The Drought Monitor categorized about 26.8% of the country (including parts of 28 states), as being in severe drought or worse (categories D2, D3, and D4); this percentage was the highest  nationwide percentage of severe-or-worse drought since the Drought Monitor report for the week of September 10, 2013.  (The highest percentage in the severe-or-worse categories reported by the Drought Monitor since it began in 2000 was 38.48% 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:

10/27/20 – 56.0% abnormally dry or worse; 25.0% severe drought or worse;
9/29/20 – 55.5% abnormally dry or worse; 22.9% severe drought or worse;
8/2520 – 50.0% abnormally dry or worse; 20.1% severe drought or worse;
11/26/19 – 29.1% abnormally dry or worse, 4.8% severe drought or worse.

The following states had 50% or more of their land area categorized by the November 24, 2020, Drought Monitor as being in severe-or-worse drought:

Arizona = 98%;
Colorado = 94%;
Nebraska = 50%;
Nevada = 83%;
New Mexico = 100%;
Oregon = 70%;
Utah = 93%;
Wyoming = 56%.

Following is part of the nationwide summary by the 11/24/20 Drought Monitor, on dry conditions in many parts of the country being shown by various drought indices:

“Mounting dryness was indicated in several drought indicators and indices.

*Maps of 7-day, 14-day, and 28-day USGS streamflow measurements were consistent in showing below-normal streamflow from northern California, Nevada, and southern Idaho, across the Southwest, to the central and southern High Plains; across southern Texas; across western Puerto Rico; and in parts of Hawaii, Iowa, Illinois, Indiana, and the Northeast.

*The satellite-based Vegetation Health Index shows stressed vegetation across the California valleys and southern California, the Southwest, parts of the central Plains and Ohio Valley, and especially in southeastern New Mexico to western Texas. …

*Evapotranspiration (EDDI) for the last week has been high in the southern to central Plains, southern Alabama, and the Midwest to Northeast; at the 2- to 3-week timescales, across much of the CONUS from the Southwest to Northeast; and at longer time scales (1-3 months), in the Southwest to central Plains, and from the Ohio Valley and southern Great Lakes to Northeast.

*NIFC wildfire maps show large wildfires still burning in California and Colorado, several across Oklahoma, and some in other parts of the West, Kansas, Texas, Mississippi, the Florida panhandle, and central Appalachians.

*USGS real-time groundwater level data show low groundwater at points across the West, in northern Indiana, southern Georgia, and parts of the Northeast.

*NASA GRACE satellite-based groundwater estimates show low groundwater across most of the West to central and southern High Plains, most of New York to New England, much of Texas, and parts of North Dakota, Pennsylvania, Virginia, Alabama, and Florida.

*Soil moisture is dry across the West from California to the southern and central Rockies, in the southern and central High Plains, in North Dakota, across Nebraska and Iowa, across central Illinois to northern Indiana, parts of Pennsylvania and New York, and (for some indicators) most of New England and southern Alabama (CPC, NLDAS, and UCLA/VIC models; satellite-based AAFC/SMOS, GRACE, and NASA/SPoRT analyses).

*The Standardized Precipitation Index (SPI) shows dry conditions in various places at different time scales. These include North Dakota to Minnesota, Wyoming, New England, and southern Texas to the Lower Mississippi Valley (at the 1-month time scale); California to the central and southern Rockies, much of the Great Plains, Iowa and Missouri to Indiana, parts of the Northeast, and southern AL (2 to 4 months); California to the central and southern Rockies, much of the Great Plains, Iowa, Indiana to Ohio and Michigan, most of Northeast (6 to 12 months); parts of Pacific Northwest (9 to 12 months); and the Southwest to southern and central High Plains, and parts of Pacific Northwest, Texas, Iowa, Indiana, and the Northeast (24 months).”

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 November 30, 2020.

On Virginia Water Radio for the Week of 11-30-20: Winter Preparedness

Virginia Water Radio’s episode for the week of November 30, 2020, is “Safety Suggestions and Songs for Weathering Winter.” The 5 min./5 sec. episode is available online http://www.virginiawaterradio.org/2020/12/episode-553-11-30-20-safety-suggestions.html. The episode includes music by Timothy Seaman of Williamsburg, Va., and Kat Mills of Blacksburg, Va.

Tracks in an early snowfall in Blacksburg, Va., December 1, 2020.

Virginia Water Radio’s is a weekly broadcast/podcast produced by the Virginia Water Resources Research Center.  The home page is http://www.virginiawaterradio.org.  Have a listen or two!