Category Archives: Weather

Floodplain Mapping, the National Flood Insurance Program, and Other Issues are Part of a Look Back at September 2013 Historic Flooding in Colorado

September 2014 marks the one-year anniversary of historic flash flooding in Colorado along the northern part of the Front Range of the Rocky Mountains.  Resulting from heavy rains between September  9-16, 2013, the disaster killed 10 people in the state and caused an estimated $3.4 billion in damages to residences, dams, roads, irrigation ditches, and other structures.

The Summer 2014 issue of Headwaters, from the Colorado Foundation for Water Education, provides a look back at the event, an assessment of recovery efforts as of summer 2014, and a discussion of lessons this event offers for flood prevention and response.  Of particular value for citizens outside of the Rocky Mountain State is the article “Coming Home…A Calculation of Risk, Reward, and Restitution in Flood Zones” (pages 23-27), which discusses floodplain mapping and the National Flood Insurance Program.

The magazine’s issues archive is available online at https://www.yourwatercolorado.org/cfwe-education/headwaters-magazine/archive; or contact the Foundation in Denver at (303) 377-4433 or info@cfwe.org.

 

Drought Report for Virginia and Elsewhere as of Mid-September 2014

The September 16, 2014, U.S. Drought Monitor from the University of Nebraska-Lincoln (available at http://droughtmonitor.unl.edu/) rated about 15 percent of Virginia as “abnormally dry.”

The Drought Monitor notes that it “focuses on broad-scale conditions, and local conditions may vary.” The Drought Monitor’s categories, from mildest to most severe, are as follows:
D0 = Abnormally Dry;
D1 = Moderate Drought;
D2 = Severe Drought;
D3 = Extreme Drought;
D4 = Exceptional Drought.

Virginia’s abnormally dry areas on September 16 included part of the Alleghany Highlands, part of Washington County, the Martinsville area, most of the northern Shenandoah Valley from Rockingham County to near Winchester, and a swath across the state from the northern Valley to around Richmond.

The current Virginia drought map and a link to archived maps are available at http://droughtmonitor.unl.edu/Home/StateDroughtMonitor.aspx?VA.

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on August 18, 2014. The report typically includes 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. Task Force reports and other current drought-status information are available online at http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought.aspx.

The Drought Monitoring Task Force also produces a daily map rating groundwater levels (GW), precipitation deficits (Prcp), reservoir storage (Res), and stream flow (Flow) conditions across the Commonwealth. In each area, a color code indicates “normal,” “watch,” “warning,” or “emergency conditions.” The September 18, 2014, map is shown below.  The current map and more information on the ratings are available the Task Force Web site listed above.

Drought VA 9-18-14

Elsewhere in the United States, the September 16 Drought Monitor categorized about 38 percent of the country (in 43 states) as at least abnormally dry (combined categories D0-D4), and about 17 percent (in 15 states) in at least severe drought (combined categories D2-D4). Three states—listed below—had at least 50 percent of their area rated severe drought or worse (Categories D2-D4).
California = 95%
Nevada = 81%
Oregon = 57%

The September 16 Drought Monitor noted that summer 2014 was on “the ninth wettest summer on record for the U.S. (according to the National Climatic Data Center)….” But, “[a] near-complete lack of precipitation [during the week ending 9/16/14] means drought continues largely unabated through California and along the West Coast.”

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 September 18—December 31, 2014, outlook map.

Drought outlook Sep18
For previous Virginia Water Central News Grouper mid-month drought reports, please click the following links.
Mid-August 2014
Mid-July 2014

[No reports for December 2013—June 2014]

Mid-November 2013
Mid-October 2013
Mid-September 2013
Mid-August 2013
Mid-July 2013

Hurricane Edouard in Atlantic Ocean Well Off Coast of Virginia on September 17, 2014; Northeast/East Track Predicted; Rip Currents Along U.S. East Coast Likely

As of late morning on Wednesday, September 17, 2014, the National Hurricane Center’s (NHC) public advisory #25 on Hurricane Edouard stated that the eye of Edouard was in the Atlantic Ocean off the coast of Virginia and was predicted to move toward the northeast and then the east over the next 24 to 36 hours.  The NHC advisory stated, however, the following about potential swells and rip currents from Edouard:

SWELLS FROM EDOUARD WILL AFFECT PORTIONS OF THE EAST COAST OF THE UNITED STATES NORTH OF FLORIDA BEGINNING TODAY. THESE SWELLS WILL LIKELY CAUSE LIFE-THREATENING RIP CURRENT CONDITIONS ALONG MOST OF THE UNITED STATES EAST COAST FOR THE NEXT COUPLE OF DAYS. PLEASE SEE PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE FOR MORE DETAILS.

Below are a satellite photo of Edouard as of about 2 p.m. on 9/17/14 and a chart of the possible path of the storm over the next five days (through 8 a.m., Tuesday, July 30), based on information available on September 17.  The images were accessed via the National Hurricane Center Web site, http://www.nhc.noaa.gov/, on 9/17/14.  Public advisories and other information are also available at that site.

Eduard Sep 17

Hurricane Eduard, just visible in upper right of this photograph, over the Atlantic Ocean east of Virginia, 9/17/14, 2:15 p.m. EDT.

Eduard track Sep 17

Virginia Precipitation and Stream Flow for the 7-day Period Ending September 16, 2014

Below are images showing precipitation in the southeastern United States and stream flow in Virginia over the seven-day period ending September 16, 2014. The Virginia Water Resources Research Center thanks the agencies mentioned below for providing precipitation and stream-flow information and images.

Precipitation

The following maps—accessed 9/17/14 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 — show southeastern U.S. precipitation amounts over the past seven days (top map), and the percent of normal precipitation for the given location at this time of year (bottom map).  As of 9/17/14, these data remained provisional (needing to be verified for accuracy and subject to possible revision).

Precip Sep16

Precip perc Sep 16


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.

Stream Flow

Average Virginia stream flow over week ending September 16, 2014, 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 9/17/14). The map compares the previous week’s average stream flows at about 140 stream-gaging stations (in Virginia and just beyond the state border) to the normal flow levels for that week over the historical record for each gaging station. The color codes/percentile classes used by USGS to compared flows to historical records for the month are as follows:

KEEP ON DESK _ Stream Flow Chart

Streams Sep16

 

 

 

Virginia Water Status Report as of the End of August 2014, Plus a Look at Drought Nationally

Here is the Virginia Water Central News Grouper’s monthly water-status report, as of the end of August 2014. The Virginia Water Resources Research Center thanks the agencies mentioned below for providing the data and maps used in this post.

First, in precipitation: Here are National Weather Service (NWS) preliminary precipitation totals for August 2014 at 11 Virginia or near-Virginia locations, with the amount above (+) or below (-) normal for this month of the year historically in parentheses. All values are in inches, rounded to the nearest 0.1 inch from NWS values.

Location Observed Precipitation
(inches)
Above (+) or Below (-) Normal (inches)
Blacksburg 6.0 +2.4
Bluefield (Va.-W.Va. state line) 6.4 (record high for month) +3.2
Bristol (Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va.-Tenn.) 4.2 +0.7
Charlottesville 4.3 +0.7
Danville 6.2 +2.3
Dulles Airport (Loudoun County) 5.2 +1.6
Lynchburg 4.8 +1.5
Norfolk 3.0 -2.5
Richmond 3.6 -1.1
Roanoke 6.5 +3.0
Wallops Island (Accomack County) 4.5 +0.3

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 1981-2010 period. 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/oa/climate/normals/usnormals.html.

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, as of September 8, 2014.  Please be sure to note that the scale is different for the 90-day map.

30 day precip60 day precip90 day precip

Next, in stream flow: According to the U.S. Geological Survey WaterWatch for Virginia, average stream flow values for the August 2014 at 147 stream gages in Virginia and just beyond the state border were in the normal range at about 79 percent of gages; below normal at about 3 percent; above normal at about 12 percent; and much above normal at about 6 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 as follows:

KEEP ON DESK _ Stream Flow Chart

Streams August 20124

 

Finally, our drought watch:
The weekly National Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) on September 2, 2014, categorized about 11 percent of Virginia as being abnormally dry. The areas included were Accomack County; the upper areas of the Northern Neck and Middle Peninsula; part of the Alleghany Highlands; all or parts of 5 or 6 far-southwestern counties; an area around Martinsville.

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:
7/29/14 – 27 percent abnormally dry;
7/1/14 – 10 percent abnormally dry; 2 percent in moderate drought;
6/3/14 – 9 percent abnormally dry;
9/3/13 – drought-free.

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on August 18, 2014. That report is online (as PDF) at http://www.deq.virginia.gov/Portals/0/DEQ/Water/WaterResources/VirginiaDroughtStatus/CurrentDroughtTaskForceReport.pdf; a link to the report, along with other current drought-status information, is available online at http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought.aspx. The Task Force’s reports typically include information from some or all of the following agencies: University of Virginia Climatology Office, U.S. Geological Survey (USGS), and the Virginia departments of Agriculture and Consumer Services, Health, and Environmental Quality.

The Drought Monitoring Task Force also produces a daily map rating groundwater levels (GW), precipitation deficits (Prcp), reservoir storage (Res), and stream flow (Flow) conditions across the Commonwealth. In each area, a color code indicates “normal,” “watch,” “warning,” or “emergency conditions.” The September 1, 2014, map is shown below. The current map and more information on the ratings are available the Task Force Web site listed above.

Drought Status VA Sep 1 2014
Looking beyond Virginia: The September 2, 2014, U.S. Drought Monitor rated 39.2 percent of the United States (including all or parts of 42 states) as being abnormally dry or worse, and it rated 17.5 percent of the country (including all or parts of 14 states), as being in severe drought or worse (categories D2, D3, and D4). (On August 7, 2012, 38.5 percent of the country was in the three worst categories; that was the highest percentage in these categories reported by the Drought Monitor since it began in 2000.)

The nationwide percentages for abnormally dry or worse (D0-D4) and severe or worse (D2-D4) in the previous three months and one year ago were as follows:
7/29/14 – 39.8 percent abnormally dry or worse; 19.0 percent severe drought or worse;
7/1/14 – 37.2 percent abnormally dry or worse; 20.9 percent severe drought or worse;
6/3/14 – 43.6 percent abnormally dry or worse; 22.8 percent severe drought or worse;
9/3/13 – 59.7 percent abnormally dry or worse; 27.9 percent severe drought or worse.

In the following four states, over 50 percent of the state was categorized by the September 2 report as being in severe-or-worse drought:
Arizona – 57% (with 7% in extreme drought);

California – 98% (with 82% in extreme or exceptional drought; California was rated as having 100 percent severe-or-worse drought from May 13—July 29, 2014).

Nevada – 81% (with 50% in extreme or exceptional drought);

Oregon – 56% (with 34% in extreme drought).

Here are some interesting items on high temperatures and high rainfall totals in August 2014 or summer 2014, excerpted from the September 2, 2014, Drought Monitor:

In the Mid-Atlantic
According to the NWS [National Weather Service], record high temperatures were reported earlier this week at Wallops Islands, Virginia (94° F) and New Bern, North Carolina (96° F).

In the Midwest
According to the NWS in Sioux Falls, Iowa, rainfall records were broken at the Sioux Falls Airport for the summer months (30.38 inches from June through August; breaking the previous record of 20.13 inches set in 2010) as well as for the month of August (10.12 inches).

In the Northeast
With 14.07 inches falling, the monthly total rainfall record for August was broken at Islip Macarthur Airport on Long Island, according to the NWS.

In the South
In south-central Texas, on August 12, 2014, the Edwards Aquifer Authority (serving nearly 2 million south-central residents) declared Stage 4 pumping reductions for users in the San Antonio Pool as groundwater levels dropped below threshold levels.

During this week record daily high temperatures were set at Amarillo (104° F), Borger (106°), and El Paso (100° F), according to the NWS.

In Lake Charles, Louisiana, a summer rainfall record was broken with 36.90 inches reported by the NWS in Lake Charles.

In the Southeast
In west-central Florida this week, the NWS in Tampa Bay reported record daily high temperatures at Sarasota-Bradenton (96° F) and Ft. Meyers (96° F).

For previous News Grouper monthly water status reports during the past 12 months, please click these links:
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013

August 2014 Atlantic Tropical Storm Summary from the National Hurricane Center Issued September 1, 2014

In August 2014 two tropical cyclones formed and became Hurricanes Bertha and Cristobal in the Atlantic Basin, according to the National Weather Service/National Hurricane Center’s (NHC) monthly tropical weather summary for the North Atlantic, Caribbean Sea, and Gulf of Mexico, issued by the NHC at 8 a.m. EDT on August 1, 2014.  The August 1, 2014, report and other monthly summaries, along with maps, public advisories, and links to satellite photos, and other information during the Atlantic tropical storm season (June 1-November 30) are available online at http://www.nhc.noaa.gov/index.shtml.

Here is an excerpt from the September 1, 2014, report: “Based on a 30-year (1981-2010) climatology, three or four named storms form in the basin in August, with one or two of those becoming hurricanes. A major hurricane occurs in August in about 7 out of 10 years. In terms of accumulated cyclone energy, which measures the combined strength and duration of tropical storms and hurricanes, activity in the [Atlantic] basin so far in 2014 has been about 45 percent of the 1981-2010 average.”

Also from the September 1 report, here is the NHC’s list of all tropical storms this year through July, with their dates of occurrence and maximum wind speeds:
(H = hurricane; MH = major hurricane; TD = tropical depression; TS = tropical storm):
H Arthur – Jul. 1-5 – 100 mph
TD Two – Jul. 21-23 – 35 mph
H Bertha – Aug. 1-6 – 80 mph
H Cristobal – Aug. 23-29 – 85 mph

When completed, reports on individual 2014 storms (including tracks) will be available online at http://www.nhc.noaa.gov/2014atlan.shtml.  Below is the Hurricane Center’s graph of preliminary (subject to verification) tracks of 2014 storms through August.Tropical storm tracks

Hurricane Cristobal

Hurricane Cristobal, northeast of the Bahamas, 8/26/14, 8:45 a.m. EDT. Photo taken from the National Oceanic and Atmospheric Administration (NOAA) Web site at http://www.goes.noaa.gov/browsh.html, on 8/26/14, 10 a.m. EDT.

 

Drought Report for Virginia and Elsewhere as of mid-August 2014

The August 12, 2014, U.S. Drought Monitor from the University of Nebraska-Lincoln (available at http://droughtmonitor.unl.edu/) rated about 12 percent of Virginia as “abnormally dry.”

The Drought Monitor notes that it “focuses on broad-scale conditions, and local conditions may vary.” The Drought Monitor’s categories, from mildest to most severe, are as follows:
D0 = Abnormally Dry;
D1 = Moderate Drought;
D2 = Severe Drought;
D3 = Extreme Drought;
D4 = Exceptional Drought.

Virginia’s abnormally dry areas on August 12 included parts of the far southwest, the Alleghany Highlands, and Southside.  The current Virginia drought map and a link to archived maps are available at http://droughtmonitor.unl.edu/Home/StateDroughtMonitor.aspx?VA.

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on July 11, 2014. The report typically includes 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. Task Force reports and other current drought-status information are available online at http://www.deq.virginia.gov/Programs/Water/WaterSupplyWaterQuantity/Drought.aspx.

The Drought Monitoring Task Force also produces a daily map rating groundwater levels (GW), precipitation deficits (Prcp), reservoir storage (Res), and stream flow (Flow) conditions across the Commonwealth. In each area, a color code indicates “normal,” “watch,” “warning,” or “emergency conditions.” The August 14, 2014, map is shown below. The current map and more information on the ratings are available the Task Force Web site listed above.

Va Drought Aug 14

Elsewhere in the United States, the August 14 Drought Monitor categorized about 40 percent of the country (in 43 states) as at least abnormally dry (combined categories D0-D4), and about 18 percent (in 14 states) in at least severe drought (combined categories D2-D4). Four states—listed below—had at least 50 percent of their area rated severe drought or worse (Categories D2-D4).
Arizona = 70%
California = 100%
Nevada = 87%
Oregon = 56%

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 July 17—October 31, 2014, outlook map, the latest one available as of 8/14/14.

Drought outlook

For previous Virginia Water Central News Grouper mid-month drought reports, please click the following links.

Mid-July 2014
[No reports for December 2013—June 2014]
Mid-November 2013
Mid-October 2013
Mid-September 2013
Mid-August 2013
Mid-July 2013