Category Archives: Weather

Virginia Precipitation and Stream Flow for the 7-day Period Ending July 28, 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 July 28, 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 July 28, 2015.  The maps were accessed 7/29/15 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).
PrecipJul28PrecippercJul28

Another source of precipitation data is 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 precipitation and percent of normal precipitation for the 7-day precipitation ending at 8 a.m. Eastern Daylight Time on July 29, 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.)
PrecipUSJul29PrecippercUSJul29

Stream Flow

Average Virginia stream flow over the seven-day period ending July 28, 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 7/29/15).  For about 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 “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 Jul28

KEEP on deskto - Stream flow code graph

Virginia Precipitation and Stream Flow for the 7-day Period Ending July 21, 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 July 21, 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 July 21, 2015.  The maps were accessed 7/22/15 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).
PrecipJul21

Precip perc Jul21

Another source of precipitation data is the National Weather Service’s Advanced Hydrologic Prediction Service, http://water.weather.gov/precip/, which 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 precipitation and percent of normal precipitation for the 7-day precipitation ending at 8 a.m. Eastern Daylight Time on July 22, 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 Jul22

PrecippercUS Jul22

Stream Flow

Average Virginia stream flow over the seven-day period ending July 21, 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 7/22/15).  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 “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 Jul21

KEEP on deskto - Stream flow code graph

Virginia Precipitation and Stream Flow for the First Half of July 2014, Plus a Mid-Month Drought Assessment

Below are images showing precipitation in Virginia and the rest of the continental United States, and stream flow in Virginia, over the 14-day period ending July 14, 2015.  Also below is a map showing the status of several drought indicators in different Virginia regions, as of July 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 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 precipitation and percent of normal precipitation for the 14-day precipitation ending at 8 a.m. Eastern Daylight Time on July 15, 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 July 15Precip perc US July 15

Stream Flow

Average Virginia stream flow over the 14-day period ending July 14, 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=pa14d&r=va&w=pa07d%2Cmap, accessed 7/15/15).  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 July 15

KEEP on deskto - Stream flow code graph

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 July 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.  or 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.

Drougth VA July 15

June 2015 Atlantic Tropical Storm Summary from the National Hurricane Center; Issued July 1, 2015

On July 1, 2015, the National Hurricane Center (NHC) issued its monthly tropical weather summary for the North Atlantic, Caribbean Sea, and Gulf of Mexico; the report is available online at http://www.nhc.noaa.gov/text/MIATWSAT.shtml (as of 7/7/15).  One tropical cyclone, Tropical Storm Bill, formed in the basin in June.  The 2015 season’s first named storm, Tropical Storm Ana, occurred in May.  According to the NHC’s July 1 report, records from 1981—2010 indicated that, on average, a named storm forms in the Atlantic basin in June about every other year, and a hurricane forms in June about once every 7 or 8 years.

Below is the NHC’s list of all tropical depressions, tropical storms, and hurricanes this year through June, with their dates of occurrence and maximum wind speeds, and the Center’s graph of preliminary (subject to verification) tracks of Atlantic tropical storms and hurricanes in 2015, as of 7-7-15 (H = hurricane; MH = major hurricane; TD = tropical depression; TS = tropical storm):

TS Ana – May 8-11 – 60 mph
TS Bill – June 16-20 – 60 mph

Tropical storms May-June 2015

When NHC reports on individual storms in 2015 are completed, the reports (including maps of tracks) will be available online at http://www.nhc.noaa.gov/data/tcr/index.php?season=2015&basin=atl.

For previous News Grouper posts on tropical storm monthly and yearly reports from the NHC, please go to this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Monthly+Tropical+Storm.

Tropical Storm Bill

Tropical Storm Bill nearing the Texas Gulf coast, June 16, 2015, 1:45 p.m. EDT.   Photo taken from the National Oceanic and Atmospheric Administration (NOAA) Web site, http://www.nhc.noaa.gov/satellite.php, on 6/16/15, 2:45 p.m. EDT.

Virginia Water Status Report as of the End of June 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 June 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 June 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 June 2015

Precipitation

 

Normal for Month July 2014-June 2015 Precipitation

 

Normal Annual Precipitation
Blacksburg 3.48 4.00 40.41 40.89
Bluefield (Merc. Co. airport, near Va.-W.Va. state line) 3.23 4.14 41.01 39.63
Bristol (Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va.-Tenn.) 2.45 3.90 39.91 41.01
Charlottesville (Char.-Albemarle Airport) 8.23 3.73 38.44 42.71
Danville 8.12 3.85 41.36 44.41
Lynchburg 5.59 3.63 40.25 41.57
Norfolk 8.34 4.26 52.10 46.53
Richmond 6.05 3.93 40.34 43.60
Roanoke 9.07 3.83 44.83 41.25
Wallops Island (Accomack County) 4.31 3.29 42.27 40.84
Washington-Dulles Airport (Loudoun County) 7.44 3.98 38.40 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 June 30, 2015.

Precip perc 30 dayPrecip perc 60 dayPrecip perc 90 day 

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), monthly average stream flow values for June 2015 at 152 stream gages in Virginia and just beyond the state border were in the normal range at about 71 percent of gages, below normal at about 11 percent, and above normal at about 18 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.

StreamsKEEP 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 June 30, 2015, showed about 13 percent of Virginia as abnormally dry, covering parts of far southwestern Virginia and some areas of the New River and Roanoke River basins between Montgomery County and Danville.  The Drought Monitors for June 16 and June 30 had categorized about 4 percent of Virginia in moderate drought (covering parts of several counties in far southwestern Virginia).

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:
5/26/15 – 32 percent abnormally dry;
4/28/15 – drought-free;
3/31/15 – 14 percent abnormally dry;
7/1/14 – 10 percent abnormally dry or worse; and 2 percent in moderate drought.

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on June 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 next report is scheduled for July 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.

Following is an excerpt from the beginning of the June 17, 2015, report, summarizing statewide conditions at that time: “…While precipitation has continued the typical uneven summer pattern due to scattered thunderstorms, some areas, mainly within south-central and southwestern Virginia, are continuing to experience less than normal rainfall.  Stream discharge rates in these areas have been fluctuating between above and slightly below normal ranges, depending upon local rainfall amounts.  Groundwater levels have continued the normal summer decline in nearly all of the observation wells in the Virginia Climate Response Network.

The Drought Monitoring Task Force also produces a daily map rating drought-status indicators.  Shown below is the July 1, 2015.  The status-indicator abbreviations on that map are as follows: GW = groundwater levels, Prcp = precipitation deficits, Res – reservoir storage, and Flow = stream flow conditions. F or 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 VA June 1MORE 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 June 30, 2015, U.S. Drought Monitor rated 41.7 percent of the United States (including all or parts of 42 states) as being abnormally dry or worse, and it rated about 13 percent of the country (including all or parts of 12 states), as being in severe drought or worse (categories D2, D3, and D4).

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:
5/26/15 – 46.4 percent abnormally dry or worse; 11.9 percent severe drought or worse;
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;
7/1/14 – 37.3 percent abnormally dry or worse; 20.9 percent severe drought or worse.

In the following states, over 50 percent of the state was categorized by the June 30 report as being in severe-or-worse drought.

California – 95% (with 71% in extreme or exceptional drought).  California has had over 80 percent of its area categorized in severe-or-worse drought every week since June 25, 2013, and the Golden State had 100 percent in those categories from May 13—July 29, 2014. C alifornia’s current drought began in late 2011 and early 2012.

Nevada – 87% (with 48% in extreme or exceptional drought).

Oregon – 84% (with 34% in extreme drought).

7/14/15 addition: On the other hand, here are some comments from the July 14, 2015 Drought Monitor on near-record wet conditions in June 2015 in several parts of the United States, including areas of  Virginia:

“According to the NOAA National Centers for Environmental Information (NCEI) statewide precipitation rankings, both Virginia and West Virginia experienced near-record precipitation totals for the month of June as well as near-record heat across most of the region.

“According to the NOAA NCEI statewide precipitation rankings (based on the last 121 years) for the period of April through June, portions of the Midwest experienced near record wettest with the following rankings: Illinois (118/121), Indiana (117/121), and Ohio (116/121).

“According to the …NCEI, the Northeast region experienced one of its wettest Junes for the period of record from 1895 to 2015.

“According to the [National Weather Service] in San Angelo (TX), …Texas experienced the wettest January through June period on record (1895–2015), according to NOAA NCEI.”

7/27/15 addition: As for temperatures in June 2015, here’s a comment from the July 21, 2105, Drought Monitor on near-record average temperature nationwide, and record high average temperature in several states, for June 2015:
“According to the National Centers for Environmental Information (NCEI) climatological rankings, the contiguous U.S. average temperature for June was the second hottest in the observational record (1895–2015). On a state level, California, Idaho, Oregon, Utah, and Washington all experienced their hottest average-temperature Junes on record since 1895.”

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 July 1, 2015.

Drought Outlook US


PREVIOUS MONTHLY WATER-STATUS REPORTS

For previous Water Central News Grouper monthly posts on water status in Virginia, Please see this link: https://vawatercentralnewsgrouper.wordpress.com/?s=Water+Status.

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!

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.