20051457 Ver 1_Re USGS streamflow and ground-water conditions in NC through Monday October 24.msg_20111025

Strickland, Bev
From:
Rick Neuherz [Richard. [e-mail]]
Sent:
Tuesday, October 25, 2011 11:23 AM
To:
John C Weaver
Cc:
Linwood Peele; Ashley. E.Hatchell @usace. army. miI; Brian. Cullen @noaa.gov; Brian. Hai nes @ncdenr.gov;
david.lane @ncdenr.gov; debra.owen @ncdenr.gov; eric.seymour @noaa.gov; gagalleh @duke -
energy.com; garry_grabow @ncsu.edu; George. Mathews @noaa.gov; harold.m.brady @ncdenr.gov;
jamie.kritzer @ncdenr.gov; jeff.orrock @noaa.gov; jim.prevette @ncdenr.gov;
jucilene.hoffmann @ncdenr.gov; Lara.Pagano @noaa.gov; Michael .A.Young @saw02.usace. army. miI;
Michael. Moneypenny @noaa.gov; mike.orbon @ncdenr.gov; neelufa.sarwar @ncdenr.gov;
Patricia. Tanner @noaa.gov; Peter. Corrigan @noaa.gov; rwall @ncem.org; ryan_boyles @ncsu.edu;
sarah.young @ncdenr.gov; Todd. Hamill @noaa.gov; Tom.Fransen @ncdenr.gov; tom.reeder @ncdenr.gov;
tony_dorn @nass.usda.gov; Torey_Lawrence @nass.usda.gov; Vernon.Cox @ncagr.gov-
Wayne.Munden @ncdenr.gov; woody. yonts @ncdenr.gov; Brian Fuchs; Allison.Wash @va.usda.gov;
Kathleen Carroll; Darin Figurskey; Glenn Carrin
Subject:
Re: USGS streamflow and ground -water conditions in NC through Monday, October 24
Everyone,
I won't be on the call today. I am in agreement with status quo over eastern NC (ILM and MHX areas) for this
week's DM.
Rick
On 10/25/2011 11:08 AM, John C Weaver wrote:
NC Drought advisory group,
The precipitation totals maps ( http : / /water.weather.gov /precip /) indicate widespread 0.5+ -inch totals across most all North
Carolina with exception of some areas in the northwest Piedmont and northern mountains. Higher totals exceeding 1 and
2 inches are indicated in a line running from Union County northeast towards Granville County. Even higher totals
exceeding 3 and 4 inches are indicated for most of the Outer Banks.
The mix of streamflow conditions noted in the past few weeks continues to be the situation for North Carolina as shown on
the current real -time streamflow map (http: / /waterwatch.usgs.gov/ new / ?m= real &r =nc &w= real %2Cmap). Areas that
continue to bear close monitoring are along a line running from the Broad River and upper Catawba River basins, then
eastward along the northern tier from the upper Cape Fear into the upper Tar River basin, then southwest towards the
Sand Hills region. As of this morning, there are 14 USGS streamgages along this line with streamflow conditions in the
"less than 10th percentile" range, including two at record low for the calendar date (Reedy Fork near Oak Ridge in
Guilford County and Flat River below dam near Bahama in Durham County). An additional area needing continued
monitoring is extreme southern mountains where streamflow conditions for two gages are indicated in the "less than 10th
percentile" range.
As of October 23 (Sunday), streamflow conditions indicate 21 percent of sites across North Carolina have percentiles for
7 -day average flows falling below the 25th percentile for the calendar date (see graph below). This percentage suggests
some improvements in overall streamflow relative to 51 percent just a week ago.
Over the past month, there appears to have been very little change in the groundwater depictions shown on the Climate
Response Network in North Carolina (http: / /ogw01.er.usgs.gov /crn /StateMaps /NC.html). Water levels at the 10 Blue
Ridge, Piedmont, and Sand Hills observations wells in the continue to be depicted in the normal range for 8 wells and
much below normal for 2 wells: one near Marston in Scotland County
(http: // groundwaterwatch .usgs.gov /AWLSites.asp ?S= 345812079313401 &ncd =crn) and the well at Chapel Hill in Orange
County (http: // groundwaterwatch .usgs.gov /AWLSites. asp ?S = 355522079043001 &ncd =crn).
As of October 24, the water level at the Chapel Hill well is currently 46.33 feet below land surface, very close to the record
low water level for October at 46.58 ft and likewise close to the POR low of 46.77 ft set in December 1956. The current

water level is also about 2.5 feet below the level this time last year.
As noted in previous weeks, the water levels for the 6 wells in the Coastal Plain continue to be depicted in the normal
range for 4 wells, above normal for 1 well, and below normal for 1 well near Grantham in Wayne County
(http: // groundwaterwatch .usgs.gov /AWLSites.asp ?S= 353219077153801 &ncd =crn).
Draft 1 for this week's release was not available as of Tuesday morning. Changes to the NC depictions in last week's
USDM included some trimming of the DO northern extent from the mountains region into the Piedmont, the biggest
changes being in the central Piedmont. Some trimming of the D1 and D2 in the Broad River basin within the southwest
Piedmont also occurred in last week's version.
Given the rainfall pattern noted for last week, the initial tendency is to refrain from any substantial changes and use
"status quo" for this week's release. The challenge in deciding the appropriate depictions is that streamflows are mixed,
particularly across the Piedmont region. However, a close inspection of the 30 -day percent of normal precipitation may
provide some guidance. Widespread 30 -day percent of normal in the 25 to 50 percent range is visible for much of the
southern mountains and western Piedmont. Some deterioration may be warranted this area. Likewise for parts of the
southern Coastal Plain where 30 -day values in the 25 -50 percent range are noted( ?). One advantage being gained as we
transition towards the cooler months is the reduction in evaporation amounts.
Comments and opinions welcome...
Thanks.
JCWeaver
****************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * **
J. Curtis Weaver, Hydrologist, PE
USGS North Carolina Water Science Center
3916 Sunset Ridge Road
Raleigh, NC 27607
Phone: [phone] H Fax: [phone]
Mobile: [phone]
E -mail address -- Icweaver(c�usgs.gov
Internet address -- http: / /nc.water.usgs.gov/
****************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * **
-- USDM draft (if available) --
As of Tuesday morning, draft 1 for this week's version was not available. David Miskus, meteorologist with the Climate
Prediction Center in Camp Springs, Maryland, is again the USDM author for this week's release. In his "preliminary
thoughts" email issued late Tuesday morning, he made the following comments concerning the Southeast region.
Southeast: Scattered showers & T- storms dropped some locally heavy amounts on drought areas (e.g. eastern
Panhandle FL) and across sections of the northern drought boundary (nGA, seTN, and the Carolinas), but I'll have to
check if it was enough to remove large or small areas of the drought. Where little or no rain fell, will need to expand the
drought a bit, although much cooler weather accompanied the dryness. Short -term dryness (30 -days) in AL & MS is
beginning to offset the heavy rains from TS Lee as the 'no drought gap' between the 2 major drought areas (s &cPlains
and the Southeast) is starting to close. Also expect an eastward drought creep to continue in the lower Delta (sLA, sMS)
as little or no rain fell there again.
USDM archive (you can select North Carolina from the drop -down box near the top, a quick way to see the last two USDM

releases):
httD:Hdrouaht.un1.edu /dm /archive.html
-- Observed precipitation --
Sources of precipitation totals are available from the following:
(1) USGS rainfall totals (sorted by county) for the last 7 days at
http: / /waterdata.usgs.gov /nc /nwis /current ?tvpe = precip &group kev= county cd
(2) State Climate Office of North Carolina at http : / /www.nc - climate.ncsu.edu /mpe departure/
(3) NOAA NWS's Advanced Hydrologic Prediction Service at http://water.weather.gov/preci
shown below pulled from the NOAA NWS's Advanced Hydrologic Prediction Service at
http: / /water.weather.gov /precip/
-- Streamflow --
Current conditions are depicted as real -time, 7 -day, 14 -day, and 28 -day flows available in the WaterWatch series of maps
at:
http://waterwatch.usgs.gov/classic/?m=real&r=nc&w=real%2Cmap
Current conditions...
Last week's conditions...
When viewing the USGS WaterWatch streamflow information, you can hover your cursor over a site and a pop -up box
appears with various pieces of information, including the percentile for the current streamflow AND the current percentage
of mean and median for the calendar date.
Highlighting current flows (October 25 morning) at some selected gaging stations (obtained from
http: / /waterdata.usgs.gov /nc /nwis /current / ?type =flow ):
Site number Site name (and County) Flow Oct 18 Current flow
(% of) Median Oct 25
02053200 Potecasi Creek near Union (Hertford) -- 17 cfs 90 cfs
5290 17 cfs
3

02106500
Black River near Tomahawk (Sampson) --
118
cfs
132
cfs
55%
239 cfs
02085500
Flat River at Bahama (Durham) --
3.7
cfs
2.4
cfs
20%
12 cfs
02096960
Haw River near Bynum (Chatham) --
186
cfs
271
cfs
1050
259 cfs
02115360
Yadkin River at Enon (Yadkin) --
1,010
cfs
1,170
cfs
85%
1,370 cfs
02152100
First Broad River near Casar (Cleveland) --
21
cfs
22
cfs
490
45 cfs
03451500
French Broad River at Asheville (Buncombe) --
696
cfs
780
cfs
700
1,110 cfs
03550000
Valley River at Tomotla (Cherokee) --
47
cfs
54
cfs
730
74 cfs
Focusing on the 7-day average flows...
Visit the WaterWatch pages at http: / /waterwatch.usgs.gov /classic / ?r =nc to get the most recent data for sites of interest.
Durations plots for selected individual USGS stations can be accessed at http: / /nc.water.usgs.gov /drought /duration.html
The OVERALL 7 -day average flows by HUC map
(http:Hwaterwatch.usgs.gov /classic / ?m= pa07d &r= nc &w =pa07d nwc %2Cmap) are depicted in the image below:
To help provide more detail by major basin, the BELOW NORMAL 7 -day average flows by HUC map
(http: / /waterwatch.usgs.gov /classic /index.php ?map type =drvw &state =nc) are depicted in the image below:
As of October 23 (Sunday), the graph of 7 -day flow percentiles shown below indicates 21 percent of sites across North
Carolina have percentiles for 7 -day average flows falling below the 25th percentile for the calendar date. And 2 percent
of sites across North Carolina are shown as having 7 -day average flows below the 10th percentile or reaching new
minimum for calendar date.
Compared to October 16 (Sunday), the current values indicate some improvements in overall streamflow conditions
during course of the past week, considering 26% of sites across the state were below the 25th percentile and 7% of sites
were below 10th percentile and /or reaching new minimum for the calendar date.
Below is a graph developed from the 7 -day average flow summary table available at:
http: / /waterwater.usgs.gov/ classic / ?m= pa07d &r= nc &w= pa07d %2Ctable
Another measure of the streamflow conditions is available from maps of median percentiles for 7 -day average flows for
the previous 7 -, 14- 30 -, 60 -, and 90 -day periods updated through October 24 (Monday). These maps are intended to
provide some kind of "long-term" index of the streamflow conditions (not available through the USGS WaterWatch pages)
that is mapped according to the classification scheme for streamflow used by the U.S. Drought Monitor. Map images (via
the above URL) showing the median percentiles for 7 -day average flows for previous 7 and 30 days are shown below.
http: / /nc.water.usgs.gov /drought/dm- streamflow.html
4

Explanation
No - No Drought ( >30 percentile)
DO - Abnormally Dry (21 to 30 percentile)
D1 - Moderate Drought (11 to 20 percentile)
D2 - Severe Drought (6 to 10 percentile)
D3 - Extreme Drought (3 to 5 percentile)
D4 - Exceptional Drought (0 to 2 percentile)
n/d - Not determined
Unregulated Regulated
The following ArcMap screenshot shows the change in the median percentiles of 7 -day average flows for 7 -day period
from last week (with last week's U.S. Drought Monitor in the Background). In other words, at a given site, take last
week's median percentile and compare it to this week's median percentile. Sites in red indicate a decrease in the median
percentile from last week to this week (suggesting a decline in streamflow). Sites in blue indicate an increase in the
median percentile from last week to this week (suggesting an improvement decline in streamflow). The size of the circles
indicates the general range in percentile increase or decrease (note legend to left of the map).
-- Ground Water --
Please visit the Climate Response Network page at
http: / /groundwaterwatch. usqs. gov /StateMapsNet.asp ?ncd= crn &sc =37 (map shown below) for more information on
ground -water conditions at selected USGS observation wells in North Carolina.
Explanation - Percentile class
�.
......ee __
New <10 1024 25-75 75-90 >90 New Not
Low hrluGh Below Below Plartnal ¢ve hrluGl l ive' High Ranked
Shown below are the hydrographs at four selected wells across North Carolina... real -time page for USGS ground water
data in NC is available at http: / /waterdata.usgs.gov /nc /nwis /current ?tvpe =qw
(MOUNTAINS) NC -144 at Blantyre in Transylvania County
(http: / /waterdata.usgs.gov /nc /nwis /dv / ?site no= 351808082374302 &agency cd =USGS &referred module =sw)
(WESTERN 1 T) NC -193, Piedmont RS near Barber in Rowan County
5
0
❑
Em
The following ArcMap screenshot shows the change in the median percentiles of 7 -day average flows for 7 -day period
from last week (with last week's U.S. Drought Monitor in the Background). In other words, at a given site, take last
week's median percentile and compare it to this week's median percentile. Sites in red indicate a decrease in the median
percentile from last week to this week (suggesting a decline in streamflow). Sites in blue indicate an increase in the
median percentile from last week to this week (suggesting an improvement decline in streamflow). The size of the circles
indicates the general range in percentile increase or decrease (note legend to left of the map).
-- Ground Water --
Please visit the Climate Response Network page at
http: / /groundwaterwatch. usqs. gov /StateMapsNet.asp ?ncd= crn &sc =37 (map shown below) for more information on
ground -water conditions at selected USGS observation wells in North Carolina.
Explanation - Percentile class
�.
......ee __
New <10 1024 25-75 75-90 >90 New Not
Low hrluGh Below Below Plartnal ¢ve hrluGl l ive' High Ranked
Shown below are the hydrographs at four selected wells across North Carolina... real -time page for USGS ground water
data in NC is available at http: / /waterdata.usgs.gov /nc /nwis /current ?tvpe =qw
(MOUNTAINS) NC -144 at Blantyre in Transylvania County
(http: / /waterdata.usgs.gov /nc /nwis /dv / ?site no= 351808082374302 &agency cd =USGS &referred module =sw)
(WESTERN 1 T) NC -193, Piedmont RS near Barber in Rowan County
5

(http: / /waterdata.usgs.gov /nc /nwis /dv / ?dd cd =01 72019 00003 &format =imq default &site no= 354057080362601 &set to
qscale y =0 &begin date = 20070319)
(EASTERN PIEDMONT) NC -126 at Chapel Hill in Orange County
(http: / /waterdata.usgs.gov /nc /nwis /dv / ?site no= 355522079043001 &agency cd =USGS &referred module =sw)
(COASTAL PLAIN) NC -160 near Simpson in Pitt County
(htto:Hwaterdata.usas.aov /nc /nwis /dv / ?site no= 353219077153801 &aaencv cd =USGS &referred module =sw