**November 2007 NC Weather Review**

**Monthly Headlines**

...November 2007 was the driest on record at Raleigh-Durham...

...Extreme to exceptional drought conditions persisted...

\...Temperatures returned to near normal levels in November, after
record October heat...

**November 2007 Precipitation**

Central North Carolina slipped deeper into extreme to exceptional
drought conditions throughout the month of November. There was generally
less than an inch of rainfall across the interior of North Carolina,
which was only 10 to 20 percent of normal. Raleigh-Durham tallied only
0.48 inches the entire month, which set a record for the driest November
ever recorded in the Raleigh area. Records have been kept in the Raleigh
area since January 1887. Greensboro had nearly double the amount of
rainfall as Raleigh-Durham, yet the total of 0.84 inches still made it
the sixth driest November on record.

Elsewhere, the Mountains and the Outer Banks fared a little better this
month, with rainfall totals between one and three inches. Even these
totals were only 25 to 75 percent of normal.

The final monthly rainfall totals are depicted in figure 1, while the
observed rainfall totals and departures from normal for selected
locations are depicted in figure 2.

![](media/image1.png){width="6.989583333333333in"
height="3.2604166666666665in"}

**Figure 1. Total reported rainfall for November 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 and normal precipitation for November
2007 at selected locations across North Carolina.**

Not surprisingly, the very dry November resulted in worsening drought
conditions across the state. Much of the state slipped deeper into the
two worst possible drought categories (extreme or exceptional) at
month's end. The stream flow into main stem rivers and local reservoirs
declined to set additional historical record lows for November. The
North Carolina Drought Monitor, shown in figure 3, highlights the
continued extreme to exceptional drought conditions throughout the state
as of December 4, 2007.

![](media/image3.png){width="5.114583333333333in" height="3.5in"}**\
**

**Figure 3. N.C. Drought Monitor observed on December 4, 2007.**

**November 2007 Temperatures**

After a very warm beginning of the month, much colder air overspread the
state on October 6^th^. This cold snap brought the first hard freeze,
and effectively ended the growing season for much of the interior of the
state on November 7^th^ and 8^th^. The lowest minimum temperatures
recorded during this cold spell are depicted in Figure 4 below.

![](media/image4.png){width="6.958333333333333in"
height="3.2916666666666665in"}

**Figure 4. Lowest minimum temperatures that occurred on November 7^th^
and 8^th^.**

![](media/image5.png){width="6.947916666666667in" height="3.125in"}

**Figure 5. Monthly average temperatures for November 2007.**

The temperatures for the rest of the month alternated between warm and
cool periods that lasted generally 3 to 5 days - a typical transitional
temperature pattern for the fall season. The final monthly temperatures
averaged within a degree or so of normal at most reporting sites.
Raleigh-Durham averaged 50.7 degrees, which was 0.3 degrees below
normal. Similarly, Greensboro recorded a monthly average of 50.3, which
was 1.1 degree above normal. The average monthly temperatures for the
entire state are shown in figure 5, while figures 6 and 7 depict the
daily maximum and minimum temperatures observed throughout November 2007
at Raleigh-Durham (RDU) and Greensboro (GSO), respectively.

![](media/image6.wmf){width="5.385416666666667in"
height="3.2604166666666665in"}

**Figure 6. Daily maximum and minimum temperatures observed during
November 2007 at Raleigh-Durham (RDU).**

![](media/image7.wmf){width="5.375in" height="3.2604166666666665in"}

**Figure 7. Daily maximum and minimum temperatures observed during
November 2007 at Greensboro (GSO).**

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

After the record hot period of August, September, and October, the
November temperature departures were much closer to normal levels.
Greensboro, which averaged only 1.1 degree above normal for November,
did continue the general trend of above normal temperatures that began
in November 2006. Seven of the past eight months, and ten of the past
twelve months have been warmer than normal at Greensboro (see figure 8).
Raleigh-Durham ended a three month streak of well above normal
temperatures, averaging 0.3 of a degree below normal for November. Nine
of the past twelve months have averaged above normal (see figure 8).

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

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

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

In addition to Raleigh-Durham recording their all time driest November
on record, three of the past four, and seven of the past eleven months
have been drier than normal. The rainfall deficit at RDU during the
first eleven months of 2007 stood at 8.65 inches on November 30. At
Greensboro, six of the past seven, and ten of the past thirteen months
have been drier than normal. The rainfall deficit at Greensboro for 2007
was at 10.80 inches. Figures 9 and 10 show the monthly precipitation
versus normal at Raleigh-Durham and Greensboro, respectively, during the
past 13 months.

![](media/image9.wmf){width="5.416666666666667in" height="3.6875in"}

**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 drought of 2007 continued to worsen throughout November as a result
of the record dryness in November. Extreme to exceptional drought
conditions had overspread much of the interior section of North Carolina
by the end of November. Such drought conditions continue to impact the
major metropolitan areas of Charlotte, Winston-Salem-Greensboro-High
Point, and Raleigh-Durham.

Stream and river levels over central North Carolina declined
significantly through November after the slight improvement after the
heavy rain event October 22-27. Stream flows by the end of November also
bottomed to record low values for the month. The inflow into Jordan Lake
from the Haw River had been reduced to 5 percent of the long term
average by the end of November. Meanwhile, Falls Lake, the main water
supplier for Raleigh and surrounding municipalities, continued to
decline as well. In fact, inflow into Falls, including the Eno River
flow, became virtually zero by the end of November. The persistent
extremely low inflow into Falls had caused the lake elevation to drop to
an all-time minimum level of 241.7 feet by the middle of December.

![](media/image11.png){width="6.041666666666667in"
height="5.000694444444444in"}

**Figure 11. Falls Lake level from November 15^th^ to December 15th.**

The winter and early spring seasons are typically when streams, rivers,
and reservoirs are replenished by the cool season rains. The outlook for
this winter and early spring is not as promising as most, as La Nina
conditions over the Equitorial Pacific historically have meant less in
the way of beneficial rain events over North Carolina in the cool
season.

For the latest information concerning the drought, visit:

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

![](media/image12.png){width="6.2375in" height="3.736111111111111in"}

**Figure 12. Precipitation Outlook from the Climate Prediction Center
for December 2007 through February 2008.**

**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)

A more specific local outlook for this winter season can be found at
this web address below:

In general, the overall precipitation outlook was expected to be heavily
influenced by the ongoing moderate La Nina. The outlook for the winter
season for North Carolina indicated significantly elevated odds of below
normal precipitation. The 90 day precipitation forecast for the winter
season is depicted in Figure 12. If below normal rainfall is realized
this winter, there would be little improvement in the current drought
status. The latest Drought Outlook can be found in Figure 13.

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/image13.png){width="5.457638888888889in"
height="4.104861111111111in"}

**Figure 13. U.S. Seasonal Drought Outlook, valid through February
2008.**

**NC Weather Review Team**

Phillip Badgett

Michael Strickler