Category Archives: Weather

On Virginia Water Radio for 6-29-15: A 20-year Look-back at the June 27, 1995, Madison County Flood

Virginia Water Radio’s latest episode, Episode 272, 6-29-15, is “Remembering the 1995 Day that Madison County, Virginia, was the Center of Too Much Atmospheric Attention”  The 4 min./44 sec. episode looks back on the historic rainfall along Virginia’s Blue Ridge on June 27, 2015, and the resulting flash floods, mudslides, and debris flows.

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!

Virginia Precipitation and Stream Flow for the 7-day Period Ending June 16, 2015, Plus a Mid-Month Drought Assessment

Below are images showing precipitation in Virginia and other areas of the southeastern United States, and stream flow in Virginia, over the seven-day period ending June 16, 2015. Also below is a map showing the status of several drought indicators in different Virginia regions, as of June 15. The Virginia Water Resources Research Center thanks the agencies mentioned below for providing precipitation and stream-flow information and images. For monthly reviews of precipitation, stream flow, and drought, please see the News Grouper posts available at this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Monthly+Water+Status. For more information on current and historical surface-water and groundwater conditions in Virginia, please see the U.S. Geological Survey (USGS) Virginia Science Center’s Web site, http://va.water.usgs.gov/.

Precipitation

The following maps show southeastern U.S. precipitation amounts (top map) and the percent of normal precipitation for the given location at this time of year (bottom map) over the seven-day period ending June 16, 2015. The maps were accessed 6/17/15 from the National Oceanic and Atmospheric Administration’s (NOAA) Southeast Regional Climate Center, located at the University of North Carolina in Chapel Hill; online at http://www.sercc.com/climateinfo/precip_maps. As of that date, these data were provisional (needing to be verified for accuracy and subject to possible revision).

Precip Jun16Precip perc Jun16

For another precipitation-information source:
The National Weather Service’s Advanced Hydrologic Prediction Service, http://water.weather.gov/precip/, provides maps showing precipitation nationwide or by state for specific days, months, or years. The site also has the capability to show county boundaries. Shown below are maps of observed precipitation and percent of normal precipitation for the seven-day precipitation ending at 8 a.m. Eastern Daylight Time on June 17, 2015. (Please note that UTC, the time shown on the map below, is five hours ahead of Eastern Standard Time and four hours ahead of Eastern Daylight Time.)
Precip US Jun17Precip perc US Jun17

Stream Flow

Average Virginia stream flow over the seven-day period ending June 16, 2015, is indicated in the map below, from the U.S. Geological Survey WaterWatch for Virginia (online at http://waterwatch.usgs.gov/classic.php?m=pa07d&r=va&w=mv01d%2Cmap, accessed 6/17/15). For 138 stream-gaging stations in Virginia and just beyond the state border, the map’s color-coded dots compare the previous week’s average stream flows to the normal flow levels for that week over the historical record for each gaging station. The “bluer” the color of the dots, the higher the percentile and flow relative to normal for the site and time of year; the “wetter” the dots, the lower the percentile and flow relative to normal. The color codes/percentile classes used by USGS are as shown in the chart following the map.

Streams Jun16KEEP on deskto - Stream flow code graph

Mid-month Drought Status Update

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, produces a daily map rating drought-status indicators. Shown below is the June 15, 2015, map.  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.”  Any given day’s current map and more information on drought status in Virginia are available the Task Force Web site, http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought.aspx.

Drought VA Jun15

Tropical Storm Bill Over the Gulf Coast of Texas on June 16, 2015; Predicted to Bring Heavy Rain as far East as Indiana

As of the afternoon of June 16, 2015, Tropical Storm Bill was centered over Matagorda Island on the Gulf of Mexico coast of Texas.  The storm was predicted to bring very heavy rainfall to eastern Texas and Oklahoma, further complicating recent wet-weather problems in two states that, prior to May 2015, had experienced serious drought over large areas since 2010.  (For more on flooding in Louisiana, Oklahoma, and Texas in May-June 2015, please see this Grouper link.)  Between June 16 and June 19, Bill was expected to turn towards the northeast and bring substantial rainfall to parts of Nebraska, Arkansas, Missouri, Illinois, and Indiana.

You can find predictions, advisories, photos, and other information on Tropical Storm Bill–and all other U.S. tropical storms–at the National Hurricane Center’s Web site, http://www.nhc.noaa.gov/.

Bill photo

Tropical Storm Bill over Matagorda Island, Tex., 6/16/15, 1:45 p.m. EDT. Photo taken from the National Hurricane Center’s “Latest Satellite Imagery” Web site at http://www.nhc.noaa.gov/satellite.php, on 6/16/15, 2:45 p.m. EDT.

Bill graph

72-hour rainfall potential graph for Bill, valid for 8 a.m. EDT on 6/16/15 to 8 a.m. EDT on 6/19/15. Graph taken from the National Hurricane Center’s main Web site, http://www.nhc.noaa.gov/, on 6/16/15, 3 p.m. EDT.

Virginia Precipitation and Stream Flow for the 7-day Period Ending June 9, 2015

Below are images showing precipitation in Virginia and other areas of the southeastern United States, and stream flow in Virginia, over the seven-day period ending June 9, 2015.  The Virginia Water Resources Research Center thanks the agencies mentioned below for providing precipitation and stream-flow information and images.  For monthly reviews of precipitation, stream flow, and drought, please see the News Grouper posts available at this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Monthly+Water+Status.  For more information on current and historical surface-water and groundwater conditions in Virginia, please see the U.S. Geological Survey (USGS) Virginia Science Center’s Web site, http://va.water.usgs.gov/.

Precipitation

The following maps show southeastern U.S. precipitation amounts (top map) and the percent of normal precipitation for the given location at this time of year (bottom map) over the seven-day period ending June 9, 2015.  The maps were accessed 6/10/15 from the National Oceanic and Atmospheric Administration’s (NOAA) Southeast Regional Climate Center, located at the University of North Carolina in Chapel Hill; online at http://www.sercc.com/climateinfo/precip_maps.  As of that date, these data were provisional (needing to be verified for accuracy and subject to possible revision).

Precip Jun9Precip perc Jun9

For another precipitation-information source: The National Weather Service’s Advanced Hydrologic Prediction Service, http://water.weather.gov/precip/, provides maps showing precipitation nationwide or by state for specific days, months, or years. T he site also has the capability to show county boundaries.  Shown below are maps of precipitation and percent of normal precipitation for the seven-day precipitation ending at 8 a.m. Eastern Daylight Time on June 10, 2015.  (Please note that UTC, the time shown on the map below, is five hours ahead of Eastern Standard Time and four hours ahead of Eastern Daylight Time.)

Precip US Jun 10Precip perc US Jun 9

Stream Flow

Average Virginia stream flow over the seven-day period ending June 9, 2015, is indicated in the map below, from the U.S. Geological Survey WaterWatch for Virginia (online at http://waterwatch.usgs.gov/classic.php?m=pa07d&r=va&w=mv01d%2Cmap, accessed 6/10/15).   For 140 stream-gaging stations in Virginia and just beyond the state border, the map’s color-coded dots compare the previous week’s average stream flows to the normal flow levels for that week over the historical record for each gaging station.  The “bluer” the color of the dots, the higher the percentile and flow relative to normal for the site and time of year; the “redder” the dots, the lower the percentile and flow relative to normal.  The color codes/percentile classes used by USGS are as shown in the chart following the map.

Streams Jun9

KEEP on deskto - Stream flow code graph

Multi-year Drought Impacts on Hydropower in Western U.S. Described in Winter 2015 Issue of Arizona Water Resource

Drought Diminshes Hydropower Capacity in Western U.S., by Mary Ann Capehart, Arizona Water Resource, Winter 2015, from the Arizona Water Resources Research Center in Tucson.

This two-page article gives an introduction to the role of hydroelectric power in the western United States–particularly along the Colorado River—and describes some of the impacts of the current multi-year drought on hydropower production in several western states.

The article is online at https://wrrc.arizona.edu/drought-diminishes-hydropower, or contact the Arizona center at (520) 621-9591, or e-mail: wrrc@cals.arizona.edu.

Hoover Dam from BLM Web site

Hoover Dam and Lake Mead along the Colorado River between Arizona and Nevada. Lake Mead is highest-volume reservoir in the United States. Photo courtesy of the U.S. Bureau of Reclamation, accessed online at http://www.usbr.gov/lc/hooverdam/gallery/picindex.html, 6/10/15.

Virginia Water Status Report as of the End of May 2015, Plus a Look at Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report on precipitation, stream flow, and drought, as of the end of May 2015. 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).

Precipitation Icon by George Wills

Here are National Weather Service (NWS) preliminary (still needing verification) precipitation totals for May 2015 at 11 Virginia or near-Virginia locations, along with the normal for this month of the year at each location; note the record monthly lows at Bristol and Danville. Also shown are the precipitation totals at each location for the previous 12 months and the normal annual precipitation for each location. All values are in inches.

Location May 2015

Precipitation

 

Normal for Month June 2014-May 2015 Precipitation

 

Normal Annual Precipitation
Blacksburg 2.24 4.33 40.00 40.89
Bluefield (Merc. Co. airport, near Va.-W.Va. state line) 1.82 4.31 41.38 39.63
Bristol (Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va.-Tenn.) 0.70 – record low for May at this location 3.80 41.04 41.01
Charlottesville (Char.-Albemarle Airport) 1.82 3.98 33.06 42.71
Danville 1.12 – record low for May at this location 3.88 34.47 44.41
Lynchburg 1.66 3.73 37.06 41.57
Norfolk 1.51 3.41 45.67 46.53
Richmond 1.61 3.78 37.68 43.60
Roanoke 1.75 4.06 38.81 41.25
Wallops Island (Accomack County) 2.73 2.95 39.54 40.84
Washington-Dulles Airport (Loudoun County) 2.46 4.55 35.58 41.54

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 May 31, 2015.
Precip perc 30 day May 31Precip perc 60 day May 31Precip perc 90 day May 31

 Stream flow icon by George Wills

According to the U.S. Geological Survey WaterWatch for Virginia (online at http://waterwatch.usgs.gov/classic.php?m=mv01d&r=va&w=real%2Cmap), average stream flow values for May 2015 at 151 stream gages in Virginia and just beyond the state border were in the normal range at about 63 percent of gages, below normal at about 28 percent, and much below normal at about 9 percent. 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.

Streams May KEEP on deskto - Stream flow code graph

Drought Watch icon by George Wills DROUGHT IN VIRGINIA

The weekly National Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) for May 26, 2015, showed about 32 percent of Virginia as abnormally dry, covering an area from far southwestern Virginia across the Commonwealth’s southern tier as far east as Sussex County. Before this week, Virginia had been categorized as drought-free since the Drought Monitor report for April 21, 2015. Before that, some area of Virginia had been categorized as at least “abnormally dry” since the Drought Monitor report for April 22, 2014.

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:
4/28/15 – drought-free;
3/31/15 – 14 percent abnormally dry;
3/3/15 – 31 percent abnormally dry;
5/27/14 – 8 percent abnormally dry.

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on May 19, 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 next report is scheduled for June 2015. 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 drought-status indicators. Shown below is the May 29, 2015, map. 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.” Any given day’s current map and more information on drought status in Virginia are available the Task Force Web site listed above.

Drought Status VA May 29

MORE ON GROUNDWATER LEVELS

More 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 ELSEWHERE

The May 26, 2015, U.S. Drought Monitor rated 46.4 percent of the United States (including all or parts of 48 states) as being abnormally dry or worse, and it rated 11.9 percent of the country (including all or parts of 9 states), as being in severe drought or worse (categories D2, D3, and D4). (This was the lowest nationwide percentage of severe-or-worse since the March 15, 2011, Drought Monitor, when 10.9% of the country was rated in severe-or-worse drought. 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:
4/28/15 – 48.5 percent abnormally dry or worse; 16.7 percent severe drought or worse;
3/31/15 – 54.0 percent abnormally dry or worse; 15.5 percent severe drought or worse;
3/3/15 – 49.4 percent abnormally dry or worse; 13.1 percent severe drought or worse;
5/27/14 – 40.5 percent abnormally dry or worse; 23.2 percent severe drought or worse.

In the following states, over 50 percent of the state was categorized by the May 26 report as being in severe-or-worse drought.

California – 94% (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 – 87% (with 49% in extreme or exceptional drought).

Oregon – 68% (with 34% in extreme drought).

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 June 1, 2015.

Drought outlook US 90 days as of May 21

PREVIOUS MONTHLY WATER-STATUS REPORTS

Please see this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Water+Status.

Louisiana/Oklahoma/Texas Severe Weather and Flooding, May-June 2015

Beginning the first week of May 2015, severe storms and heavy rain in Oklahoma and Texas caused tornadoes and flooding that resulted in significant loss of life and property damage.  As of May 26, the respective governors had issued disaster declarations for all of Oklahoma’s 77 counties and over 40 of Texas’ 254 counties.

On May 29, the governor of Louisiana issued a State of Emergency proclamation regarding flooding on the Red River and other Louisiana water bodies.  By June 10, the River was well above flood stage at several locations, including Shreveport.

You can get a quick overview of May 2015 rainfall and river rises in Oklahoma and Texas from the following comment from U.S. Drought Monitor for May 26, 2015 (the weekly Drought Monitor, produced by the University of Lincoln-Nebraska, is available online at http://droughtmonitor.unl.edu/).

“…By May 26, month-to-date rainfall totals climbed to 18.97 inches in Oklahoma City, Oklahoma, and 14.53 inches in Wichita Falls, Texas.  In both locations, those values represent the highest monthly totals on record.  Previously, Oklahoma City’s wettest month had been June 1989, with 14.66 inches, while Wichita Falls’ had been May 1982, with 13.22 inches.  Oklahoma City’s total was boosted by a daily-record total (3.73 inches) on May 23, part of a broad heavy rain event that led to catastrophic flash flooding in portions of the south-central U.S.  In Texas, for example, preliminary [U.S. Geological Survey] data indicated that the Blanco River at Wimberly rose more than 35 feet in less than 8 hours, cresting on May 24 at 27.21 feet above flood stage.  he preliminary high-water mark at Wimberly was 6.91 feet above the previous record set on May 28, 1929. The San Marcos River near Martinsdale, Texas, surged more than 51 feet in less than 24 hours on May 23-24, based on initial data.

Following are several government and news media sources of information about these ongoing situations.

Government Sources
National Weather Service “River Observations” Web page, at http://water.weather.gov/ahps/#.  At this page, you can view a color-coded map of the current and expected flood status at river gages across the United States, and you can click on each location for more detailed information.  Similar information is available from the NWS/Advanced Hydrologic Prediction Center’s “River Forecast Centers” page, at http://water.weather.gov/ahps/rfc/rfc.php.

Federal Emergency Management Agency (FEMA), Disaster Declarations Web page, https://www.fema.gov/disasters#.  A federal major-disaster declaration was issued for Oklahoma on May 26 and for Texas on May 29.

Louisiana’s emergency-management Web site, at http://emergency.louisiana.gov/.

Oklahoma Department of Emergency Management, situation reports for “Severe Weather Event—May 6 and Continuing,” online at http://www.ok.gov/OEM/Emergencies_&_Disasters/2015/20150506_Severe_Weather_Event/;

Texas Department of Public Safety, Situation Reports for “8 May 2015 Severe Weather Event,” online at http://www.txdps.state.tx.us/dem/sitrepindex.htm.

Louisiana State of Emergency Proclamation, 5/29/15, online at http://gohsep.la.gov/agencyrelated/85_BJ_2015_Imminent_Threat_of_Flooding.pdf.

Governor Mary Fallin Announces Federal Assistance Granted for Oklahomans Devastated by Storms, Floods; All 77 Counties Now Under a State of Emergency, Oklahoma Department of Emergency Management News Release, 5/26/15.

Governor Abbott Adds 24 Counties To Disaster Declaration, Texas Governor’s Office News Release, 5/25/15.

National Weather Service/Storm Prediction Center, daily storm reports, online at http://www.spc.noaa.gov/exper/archive/event.php?date=20150527.

News Media Sources
Shreveport Times – ongoing coverage, online at http://www.shreveporttimes.com/.

The Oklahoman – ongoing coverage, online at http://www.oklahoman.com/live.

Houston Chronicle – ongoing coverage at http://www.chron.com/news/houston-weather/.

Dallas Morning NewsFlood-control effort in Dallas area a daunting task, 5/27/15 (with links to related articles).

PBS NewsHour – More rain adds to Texas flooding, disrupts river rescue search (2 min/14 sec), 5/27/15; and Could more have been done to prepare for Texas floods? (5 min./43 sec.), 5/27/15.