**September 2007 NC Weather Review**

**Monthly Headlines**

...Extreme to exceptional drought conditions spread across North
Carolina...

...September 2007 was one of the hottest and driest September's on
record...

**September 2007 Precipitation**

Rainfall became scarcer in September than in the previous months, which
increased the severity of the ongoing drought. Many reporting stations
from Elizabeth City and Roanoke Rapids, to Roxboro, Asheboro, and
Albemarle recorded an inch or less of rain. In fact, a large majority of
the Piedmont and northern Coastal Plain recorded less than 20 percent of
their normal rainfall, as depicted in figure 2. The spatial distribution
of monthly rainfall amounts from official National Weather Service sites
and local cooperative observers is shown in figure 1.

Drought conditions continued to worsen as a result of the extremely dry
and hot weather experienced across North Carolina during September. In
fact, the drought status across North Carolina fell into the two worst
categories possible by the end of the month. The crops, plants, and
water supplies continued to wither away, which resulted in substantial
agricultural losses statewide. Meanwhile, the stream flow along main
stem rivers and into local reservoirs continued to decline. The North
Carolina Drought Monitor released October 2, 2007 (see figure 3), shows
the extreme to exceptional drought conditions that had rapidly expanded
across the state.

![](media/image1.png){width="7.09375in" height="3.5104166666666665in"}

**Figure 1. Total reported rainfall for September 2007. Plotted data was
recorded by National Weather Service observation systems or cooperative
observers.**

![](media/image2.wmf){width="5.583333333333333in"
height="3.8020833333333335in"}

**Figure 2. Comparison of observed precipitation and normal
precipitation for September 2007, at selected locations across North
Carolina.**

![](media/image3.png){width="5.21875in" height="3.2708333333333335in"}

**Figure 3. N.C. Drought Monitor as observed on October 2, 2007.**

**September 2007 Temperatures**

The monthly temperatures across the state, depicted in figure 4,
averaged well above normal (generally by 2 to 4 degrees). Indeed, many
areas recorded one of their hottest September's on record. For example,
Greensboro averaged 73.9 degrees (4.1 degrees above normal), which was
the third hottest average monthly temperature on record for September.
Similarly, Raleigh-Durham recorded an average of 75.0 degrees (3.8
degrees above normal), which was the second hottest average monthly
temperature on record for September. The daily maximum and minimum
temperatures observed at Raleigh-Durham (RDU) and Greensboro (GSO) are
depicted in figures 5 and 6, respectively.

![](media/image4.png){width="7.052083333333333in" height="3.25in"}

**Figure 4. Average Monthly Temperatures for September.**

![](media/image5.wmf){width="5.375in" height="3.1979166666666665in"}

**Figure 5. Daily maximum and minimum temperatures observed during
September 2007 at Raleigh-Durham (RDU).**

![](media/image6.wmf){width="5.333333333333333in"
height="3.1979166666666665in"}

**Figure 6. Daily maximum and minimum temperatures observed during
September 2007 at Greensboro (GSO).**

The dry and hot conditions this spring and summer have led to a dramatic
increase in the number of 90 degree days, plotted in figure 7.
Raleigh-Durham averages about 37 days per year that the temperature
reaches or surpasses 90 degrees. A staggering total of 83 had been
recorded by the end of September, which set a new record for the number
of 90 degree days recorded in any year at RDU. The previous record was
82 days, set in 1953. Interestingly, the number of 90 degree days at
Raleigh exceeded those recorded at both Fayetteville and Lumberton.

![](media/image7.wmf){width="5.15625in" height="3.2708333333333335in"}

**Figure 7. The number of days in which the temperature has reached or
exceeded 90 degrees.**

**(January 1-September 30, 2007).**

**Current, Semi-Annual and Annual Temperature Trends**

The heat in September at both Greensboro and Raleigh continued the
general trend of above normal temperatures in the past 12 months. Six of
the past seven months, and nine of the past eleven months have been
warmer than normal at both Greensboro and Raleigh-Durham.

![](media/image8.wmf){width="5.59375in" height="3.59375in"}

**Figure 8. Monthly temperature departures from normal at Raleigh-Durham
and Greensboro from September 2006 through September 2007.**

**Current, Semi-Annual, and Annual Precipitation Trends**

The well below normal rainfall totals recorded at Greensboro and
Raleigh-Durham in September continued the very dry trend of 2007. Seven
of the nine months this year have been drier than normal. The rainfall
deficit at Greensboro for 2007 reached 12.02 inches. The drier than
normal September at Raleigh-Durham made it the sixth month in nine this
year with sub par rainfall. The rainfall deficit at RDU during the first
nine months of the year was at 7.64 inches. Figures 9 and 10 depict the
monthly precipitation versus the normal precipitation at both
Raleigh-Durham and Greensboro in the past 13 months.

![](media/image9.wmf){width="5.416666666666667in"
height="3.5104166666666665in"}

**Figure 9. Semi-annual and annual precipitation trends at
Raleigh-Durham (RDU).**

![](media/image10.wmf){width="5.447916666666667in"
height="3.3645833333333335in"}

**Figure 10. Semi-annual and annual precipitation trends at Greensboro
(GSO).**

**North Carolina Water Resources Information and Outlook**

The general lack of any significant rain during September pushed most of
the state into the extreme to exceptional drought category. Such drought
conditions have negatively affected the major metropolitan areas of
Charlotte, Winston-Salem-Greensboro-High Point, and Raleigh-Durham.
Stream and river levels over central North Carolina declined to as low
as 5 percent of long term average. Falls Lake, the main water supplier
for Raleigh and surrounding municipalities, continued well below
targeted levels. Inflow into Falls Lake, including the Eno River flow,
fell to less than 5 percent of the long term average. The inflow into
Jordan Lake from the Haw River fell to 5 percent of the long term
average. The drought severity was worst over the southwest part of the
state, where many mountain locals were running yearly rainfall deficits
of 20 to 25 inches.

For the latest information concerning the drought, visit:

<http://www.ncwater.org/drought/> or

<http://www.erh.noaa.gov/rah/drought>

**Climate Outlook for the winter season**

The Climate Prediction Center recently released the winter outlook.
Details concerning this forecast can be found at the web address below:

[http://www.cpc.ncep.noaa.gov/products/predictions/](http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/page2.gif)

The rainfall outlook for the winter season indicated increased odds of
below normal precipitation. The 90 day precipitation forecast for the
winter season is depicted in Figure 11. If below normal rainfall is
realized this winter, there is a distinct possibility of very little in
the way of drought relief as depicted in Figure 12.

You can keep up with latest monthly and seasonal forecasts by visiting
the Climate Prediction Center website at
<http://www.cpc.ncep.noaa.gov/>.

Enhanced local three month temperature outlooks are now available at
<http://www.weather.gov/climate/calendar_outlook.php?wfo=rah>

![](media/image11.png){width="5.603472222222222in" height="3.45625in"}

**Figure 11. Precipitation Outlook from the Climate Prediction Center
for November 2007 through January 2008.**

![](media/image12.png){width="5.601388888888889in"
height="4.347222222222222in"}

**Figure 12. U.S. Seasonal Drought Outlook valid through January 2008,
released on October 18, 2007.**

**NC Weather Review Team**

Phillip Badgett

Michael Strickler