**Status of Drought across Central NC**

**Updated October 11, 2007**

Recent Rainfall has been quite sparse, and there have only been 2 days
with measurable rain thus far in October. An isolated thunderstorm
produced a narrow swath of 1 to 3 inches of rain across northern
Davidson and Forsyth counties on the 4^th.^ Otherwise, the only
significant rain fell along the interstate 95 corridor, where rainfall
has ranged up to an inch. Rainfall deficits for the year thus far
generally range from 12 to 15 inches

![](media/image1.jpeg){width="5.747222222222222in"
height="3.1416666666666666in"}

![](media/image2.jpeg){width="5.624305555555556in"
height="3.2645833333333334in"}

The images below provide a quick series of drought status maps showing
the progression of drought as the summer progressed, culminating at the
current D4 (exceptional drought) status across most of central NC.

![](media/image3.jpeg){width="5.992361111111111in"
height="1.832638888888889in"}

![](media/image4.jpeg){width="2.6354166666666665in"
height="0.7708333333333334in"}
![](media/image5.jpeg){width="2.998611111111111in" height="1.4625in"}

**Streamflow and Lake Levels**

Currently, river and stream levels are less than 25 percent of normal at
90 percent of the gaging sites across North Carolina. Some exceptionally
low flows are being recorded in the headwaters of the Tar and Neuse
River basins, where the Flat River at Bahama and the Tar River at Tar
River (Granville County) are at less than 2 percent of normal. Below are
the current lake levels and departure from the target pool elevations:

![](media/image6.jpeg){width="3.4409722222222223in"
height="2.6118055555555557in"}

Falls Lake, which of if particular concern to the city of Raleigh, is at
39 percent of its water supply pool, while Lake Jordan is at 91 percent
of its water supply. It's important to note that Falls Lake does not go
dry when the water supply pool has been reached; the lake will still be
36 feet deep, but that remaining water would be heavily sedimented and
require additional treatments.

Below are some water supply lake levels of concern further up the Neuse
River basin. Note that these smaller lakes are more than 15 feet below
normal. Going back to our rainfall graphic above, virtually no rain has
fallen over the upper Tar, Neuse, and Cape Fear River basins since the
remnants of Hurricane Humberto, nearly month ago (Sep 14^th^).

![](media/image7.jpeg){width="4.877777777777778in"
height="3.036111111111111in"}

The figure below shows the monthly inflow to Falls Lake for this year
(purple) and the 80 year mean value (blue). The Falls Lake inflow has
been negative since June and monthly inflows have ranked within the top
10 lowest for that particular month since April.

![](media/image8.jpeg){width="4.402083333333334in"
height="3.3409722222222222in"}

The figure below compares the level of Falls Lake with several prior
years along with the level from this year which is shown in red. The
forecast level of Falls Lake, assuming no rainfall is shown in the
dashed red line. The water supply would run out around mid January, but
keep in mind that, as noted above, the lake would not be depleted.

![](media/image9.jpeg){width="4.411111111111111in"
height="3.1444444444444444in"}

This is a lateral profile of Falls Dam and Lake, which has been included
to give some perspective on the various pool elevations.

![](media/image10.jpeg){width="4.345138888888889in"
height="3.2729166666666667in"}

The figure below shows the monthly inflow to Lake Jordan for this year
(blue) and the 78 year mean value (purple).

![](media/image11.jpeg){width="5.0in" height="3.5340277777777778in"}

The figure below compares the level of Lake Jordan with several prior
years along with the level from this year which is shown in blue. The
forecast level of Lake Jordan, assuming no rainfall is shown in the
dashed brown line.

![](media/image12.jpeg){width="4.563194444444444in" height="3.50625in"}

This is a lateral profile of the B. Everett Jordan Lake and Dam, which
has been included to give some perspective on the various pool
elevations.

![](media/image13.jpeg){width="4.34375in" height="3.2444444444444445in"}

**Weather Outlook**

High pressure will be dominant across the central Plains through later
this month. That's not good new, as this high will effectively block the
flow of significant moisture off the gulf or Atlantic into the area. The
6-10 day outlook shows a strong likelihood of below normal rainfall
through October 20^th.^

![](media/image14.png){width="5.067361111111111in" height="3.13125in"}

Meanwhile, the 8-14 day outlook offers little hope for significant rain
through the 25^th^.

![](media/image15.png){width="4.680555555555555in"
height="3.4034722222222222in"}

At this point, the growing season is over and cooler days will lead to
less evaporation. Runoff will thus be increased and it would take less
rain to replenish the water supply reservoirs. Despite the favorable
conditions for drought amelioration, a weak La Nina is developing this
Fall, and is forecast to linger at least through the remainder of the
year. La Nina is not a particularly strong signal for climatological
anomalies over central North Carolina, but there will be an increased
chance for below normal rainfall through late Winter.

![](media/image16.png){width="7.000694444444444in" height="2.475in"}

**Credits**

The streamflow and lake level diagrams are provided by the U.S. Army
Corps of Engineers.

The weather outlook diagrams are courtesy of the Climate Prediction
Center