Category Archives: Weather

Weather, Climate, and Virginia’s Hampton Roads Area to be the Focus of a Two-part Workshop Series, Jan. 27-28, 2015 and Feb. 24, 2015.

In January and February 2015, several federal, state, and private entitites are organizing a Weather and Climate Workshop Series at two locations in the Hampton Roads, Va., area.

Session 1, “Weather-Ready Hampton Roads,” will be January 27-28, at the Nauticus science and technology center in Norfolk (http://www.nauticus.org/).

Session 2, “Climate Change in Virginia, will be February 24 at the Virginia Institute of Marine Science (VIMS) in Gloucester Point (http://www.vims.edu/).

The workshop series aims to bring together educators and scientists to explore the science that drives our understanding of weather and climate, talk about ways weather and climate affect the Hampton Roads region, and discuss ways to incorporate that science into education programming for students, teachers, and the general public.

The workshop series is organized by the National Oceanic and Atmospheric Administration (NOAA) Chesapeake Bay Office’s Environmental Science Training Center (http://chesapeakebay.noaa.gov/environmental-science-training-center), along with the National Weather Service, Nauticus, the Virginia Department of Environmental Quality, the Virginia Chesapeake Bay National Estuarine Research Reserve (CBNERR), and VIMS.

More information and registration are available at this link.

Thanks to the Virginia Water Monitoring Council for providing some of the information in this post.

Virginia Precipitation and Stream Flow for the 7-day Period Ending December 16, 2014, 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 December 16, 2014.  Also below is a map showing the status of drought indicators in Virginia as of December 17, 2014.  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: http://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 December 16, 2014.   The maps were accessed on 12/17/14 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.  As of 12/17/14, these data are provisional (needing to be verified for accuracy and subject to possible revision).

Precip Dec16

PrecippercDec16

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. As an example, shown below is the map of one-day precipitation ending at 7 a.m. EST on December 17, 2014. (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 National Dec17

 

 

Stream Flow

Average Virginia stream flow over week ending December 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 12/17/14).  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 (higher the percentile and the “bluer” the color, the higher the flow):

KEEP ON DESK _ Stream Flow ChartStreams Dec 16

 

 

 

 

Drought Update

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on December 16, 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.

Here is the first paragraph of the December 16 report, summarizing statewide conditions: “The dry conditions across parts of central and eastern Virginia that have persisted for several months were moderated by precipitation events during late November and early December. Consequently, streamflows at some gaging stations in these regions are now within normal ranges. Below normal streamflows still persist in parts of eastern Virginia, however. Below normal groundwater levels also persist in several climate-response observation wells in these areas. A significant continuation of dry conditions through the winter months will negatively affect the normal ground water recharge pattern.”

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.” Shown below is the December 8, 2014, map (the most recent one available on 12/17/14). A given day’s current map and more information on the ratings are available the Task Force Web site listed above.

Drought VA Dec8

Virginia Precipitation and Stream Flow for the 7-day Period Ending December 9, 2014

Below are images showing precipitation in Virginia and other parts of the southeastern United States, and stream flow in Virginia, over the seven-day period ending December 9, 2014.  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: http://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 over the past seven days (top map), and the percent of normal precipitation for the given location at this time of year (bottom map).   The maps were accessed on 12/10/14 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.  As of 12/10/14, these data are provisional (needing to be verified for accuracy and subject to possible revision).

Precip Dec9Precip perc Dec9

 

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. As an example, shown below is the map of one-day precipitation ending at 7 a.m. EST on December 10, 2014. (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 map Dec 10

 

Stream Flow

Average Virginia stream flow over week ending December 9, 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 12/10/14).  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 (higher the percentile and the “bluer” the color, the higher the flow):

KEEP ON DESK _ Stream Flow ChartStreams Dec 9

 

Virginia Water Status Report as of the End of November 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 November 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 November 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 2.7 -0.1
Bluefield (Va.-W.Va. state line) 2.5 -0.2
Bristol (Tri-Cities Airport in Tenn., about 20 miles from Bristol, Va.-Tenn.) 2.4 -0.7
Charlottesville 2.8 -1.0
Danville 2.7 -0.6
Dulles Airport (Loudoun County) 2.7 -0.8
Lynchburg 2.4 -1.0
Norfolk 3.4 +0.3
Richmond 3.0 -0.3
Roanoke 3.5 +0.1
Wallops Island (Accomack County) 3.1 +0.3

Precipitation sources are the 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/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 November 30, 2014.

Precip 60 days Nov30Precip 60 days Nov30Precip 90 day Nov 30

 

Next, in stream flow: According to the U.S. Geological Survey WaterWatch for Virginia, average stream flow values for November 2014 at 150 stream gages in Virginia and just beyond the state border were in the normal range at about 75 percent of gages; below normal at about 17 percent; above normal at about 8 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 ChartStreams Nov 2014

Finally, our drought watch:
The weekly National Drought Monitor map from the University of Nebraska-Lincoln (http://droughtmonitor.unl.edu/) on December 2, 2014, categorized about 32 percent of Virginia as being abnormally dry.  That area covered an arc from the central Shenandoah Valley across the Blue Ridge to the tidal Potomac River basin; all of the Rappahannock River basin, most of the non-tidal York River basin; all or parts of several south-central counties, particularly around Danville and Martinsville; the southern part of the Hampton Roads area; and Accomack County on the Eastern Shore.

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:
10/28/14 – 23 percent abnormally dry;
9/30/14 – 48 percent abnormally dry;
9/2/14 – 11 percent abnormally dry;
12/3/13 – 11 percent abnormally dry.

The Virginia Drought Monitoring Task Force, a collaboration of state and federal agencies, issued its most recent Drought Status Report on November 17, 2014. 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 December 2, 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 Dec2Looking beyond Virginia: The December 2, 2014, U.S. Drought Monitor rated 39.9 percent of the United States (including all or parts of 41 states) as being abnormally dry or worse, and it rated 14.1 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:
10/28/14 – 36.4 percent abnormally dry or worse; 15.1 percent severe drought or worse;
9/30/14 – 40.1 percent abnormally dry or worse; 15.6 percent severe drought or worse;
9/2/14 – 39.2 percent abnormally dry or worse; 17.5 percent severe drought or worse;
12/3/13 – 48.9 percent abnormally dry or worse; 13.8 percent severe drought or worse;

In the following states, over 50 percent of the state was categorized by the December 2 report as being in severe-or-worse drought:

California – 94% (with 80% 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 – 68% (with 48% in extreme or exceptional drought);

Oregon – 54% (with 35% 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 12/4/14.

Drought outlook national

For previous monthly water-status reports, please see this link: http://vawatercentralnewsgrouper.wordpress.com/?s=Water+Status.

Atlantic Tropical Storm Season-end Report Issued Nov. 30, 2014, by National Hurricane Center

On November 30, 2014, the National Hurricane Center in Miami, Florida, published its final monthly summary and its season-end report for the 2014 tropical storm season in the Atlantic Basin (North Atlantic, Caribbean Sea, and Gulf of Mexico).  The Atlantic season runs June 1-November 30.  The report is available online at http://www.nhc.noaa.gov/text/MIATWSAT.shtml.

No tropical storms formed during November 2014.  The Hurricane Center’s report noted that during the period 1981-2010, a named tropical storm has formed in November in about 7 out of every 10 years, and a hurricane has formed about every other year.

Overall during 2014, eight named storms occurred, six of which became hurricanes and two of those became “major” hurricanes (Category 3 or above).  The annual average seen during the 30-year period 1981-2010 is 12 named storms, six hurricanes, and three major hurricane.  The report also noted that the “accumulated cyclone energy” for 2013—combining strength and duration of storms—was about 63 percent below the 1981-2010 average.

Below is the Hurricane Center’s list of all tropical depressions, tropical storms, and hurricanes in the Atlantic basin in 2014, 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
TS Dolly – Sep. 1-3 – 50 mph
MH Edouard – Sep. 11-19 – 115 mph
H Fay – Oct. 10-13 – 75 mph
MH Gonzalo – Oct. 12-19 – 145 mph
TS Hanna – Oct 22-28 – 40 mph

When completed, reports on individual 2014 storms (including tracks) will be available online at http://www.nhc.noaa.gov/2014atlan.shtml.  The archive of Hurricane Center advisories on these storms is available online at http://www.nhc.noaa.gov/archive/2014/.

Below is the Hurricane Center’s graph of preliminary (subject to verification) tracks of Atlantic tropical storms and hurricanes in 2014, as of 12-2-14.
Tropoical storm tracks 2014
A November 24, 2014, National Oceanic and Atmospheric Administration (NOAA) news release on the 2013 tropical storm season (available online at http://www.noaanews.noaa.gov/stories2014/20141124_hurricaneseasonwrapup_2014.html) noted the following about the Atlantic and Pacific tropical storm seasons:

“The Atlantic hurricane season…will be remembered as a relatively quiet season as was predicted.  … Fortunately, much of the U.S. coastline was spared this year with only one land-falling hurricane along the East Coast. …   Meanwhile, the eastern North Pacific hurricane season [May 15-November 30] met or exceeded expectations with 20 named storms – the busiest since 1992.  Of those, 14 became hurricanes and eight were major hurricanes. …  Two hurricanes (Odile and Simon) brought much-needed moisture to the parts of the southwestern U.S., with very heavy rain from Simon causing flooding in some areas. …  In the central North Pacific hurricane basin [June 1-November 30 season], there were five named storms (four hurricanes, including a major hurricane, and one tropical storm). …  The most notable storm was major Hurricane Iselle, which hit the Big Island of Hawaii in early August as a tropical storm, and was the first tropical cyclone to make landfall in the main Hawaiian Islands since Hurricane Iniki in 1992.  Hurricane Ana was also notable in that it was the longest-lived tropical cyclone (13 days) of the season and the longest-lived central Pacific storm of the satellite era.”

Below is an October 16, 2014 (11:45 a.m. EDT) satellite photo of Hurricane Gonzalo (category 4 at the time), southwest of Bermuda.  Gonzalo reached the highest wind speed (145 mph) of any Atlantic basin storm in 2014.  (Photo taken from the National Oceanic and Atmospheric Administration Web site at http://www.goes.noaa.gov/browsh.html, on 10/16/14, 12:30 p.m. EDT.)

Gonazalo

On Virginia Water Radio for 12-1-14: Virginia’s Winter Preparedness Week (Nov. 30-Dec. 1)

This week, with “Cold World” by Blacksburg, Va., musician Kat Mills, Virginia Water Radio gives a musical spin to our annual episode on Virginia’s Winter Preparedness Week.   Click here to have a listen (3 min./33 sec.)

Snow falling 7am Nov26 2014 SLV on phone camera

Snow falling in Blacksburg, Va., in the early morning of November 26, 2014.

Virginia Water Radio, online at http://www.virginiawaterradio.org, is the Virginia Water Resources Research Center’s weekly podcast using sounds and music to focus on issues, events, people, and creatures connected to Virginia’s waters.

Virginia Snowfall Prediction and Accumulation Information and Map Sources – November 2014

For the next predicted winter storm in Virginia, you can find National Weather Service maps of predicted amounts from the NWS forecast offices serving Virginia, online as follows:
Blacksburg, Va., forecast office: http://www.erh.noaa.gov/er/rnk/emer/emer_winter.php;

Morristown, Tenn., forecast office (serves far southwestern Virginia): http://graphical.weather.gov/sectors/mrx.php#tabs;

Sterling, Va., forecast office: http://www.erh.noaa.gov/lwx/winter/;

Wakefield, Va., forecast office: http://www.erh.noaa.gov/akq/wntr_grp.php.

During and after snow events in Virginia, preliminary (not official) snowfall totals (and total precipitation amounts) at many locations are available online at the “Virginia Daily Precipitation Reports” link of the Web site of the Community Collaborative Rain, Hail, and Snow Network (CoCoRaHS), at http://www.cocorahs.org/ViewData/StateDailyPrecipReports.aspx?state=VA.

A National Weather Service (NWS) color-coded map of snowfall amounts (preliminary reports for the previous 24 hours, 48 hours, and 72 hours) is available at http://www.srh.noaa.gov/ridge2/snow/.  This interactive page allows you to zoom into your area of interest.  A snowfall map (preliminary reports) for the area served by the Sterling, Va., NWS Forecast Office is available at  http://www.erh.noaa.gov/lwx/events/snowmaps/index.php.