**January 2007 NC Weather Review**

**Overview**

January 2007 was much warmer and slightly drier than normal. The first
two weeks of January felt more like April than the middle of winter. The
temperatures soared into the 70s on several days, which tied or set
several daily record highs. There were also days in which the average
temperatures were as much as 25 to 27 degrees above normal, namely
January 5^th^ and 15^th^. During the first 16 days of the month,
Raleigh-Durham averaged 13.4 degrees above normal, while Greensboro
averaged 13 degrees above normal. Both sites were on pace to set the all
time warmest January on record. Then, like a flip of a switch, there was
an abrupt pattern change from warm to cold. The temperatures during the
last two weeks of the month averaged 2 to 3 degrees below normal. The
colder temperatures during the latter half of the month were not cold
enough to offset the excessive warmth during the early part of the
month, however. Overall, the temperatures finished the month averaging 2
to 6 degrees above normal across the state. The January monthly average
temperature for selected locations is depicted in figure 1. It was even
warmer over regions of the United States and around the world in January
2007. For a review of global temperatures experienced in January 2007,
click on the following link:
<http://www.noaanews.noaa.gov/stories2007/s2798.htm>.

There were several wintry precipitation events that accompanied the
colder temperatures, including events on January 18^th^ and January
21^st^. Despite the wintry precipitation events, the month of January
was slightly drier than the 30 year average at the majority of the
reporting sites. Rainfall amounts generally averaged between 0.50 and 2
inches below normal across the state. The January monthly precipitation
totals for selected stations across the state is plotted in figure 2.

![](media/image1.png){width="6.989583333333333in" height="3.21875in"}

**Figure 1. Average monthly temperatures during January 2007 across
North Carolina.**

![](media/image2.png){width="6.9375in" height="3.3645833333333335in"}

**Figure 2. Estimated rainfall for January 2007. Plotted data was
recorded by National Weather Service observation systems or cooperative
observers.**

**Details**

**January 2007 Temperatures**

January is typically the coldest month of the year throughout North
Carolina. However, January 2007 began with spring-like temperatures that
persisted through the middle of the month. At locations such as
Greensboro and Raleigh-Durham, the temperatures averaged 23 to 27
degrees above normal on January 5^th^ and again on the 14^th^ and
15^th^. The extreme warmth peaked on January 15^th^ when Raleigh-Durham
recorded a daily average temperature of 66 degrees, 27 degrees above
normal. Average daily temperatures in the mid 60s are typically found in
the middle of April. Daily record highs were recorded at Greensboro on
January 14^th^ (71 degrees) and at Raleigh-Durham on the 15^th^ (74
degrees). Many locations were on target to establish their warmest
January on record by January 15^th^, when a pattern change occurred.
Figure 3 depicts the 500 hPa height anomalies from the Pacific Ocean
across North America during the first two weeks of January. Note the
large positive anomalies (120 to 150 meters) centered along the east
coast, which resulted in the record warm period. Figure 4 depicts the
pattern change to below normal 500 hPa anomalies during the latter half
of the month.

![](media/image3.png){width="5.885416666666667in"
height="4.552083333333333in"}

**Figure 3. 500 hPa Height Anomalies (in meters) over North American
during the record warm spell of January 1-15, 2007.**

![](media/image4.png){width="5.885416666666667in"
height="4.552083333333333in"}

**Figure 4. 500 hPa Height Anomalies (in meters) over North America
January 19-31, 2007.**

Figures 5 and 6 depict the daily maximum and minimum temperatures
observed at Raleigh-Durham (RDU) and Greensboro (GSO) during January
2007. The dashed lines represent the normal maximum temperature (red)
and the normal minimum temperature (blue). Note the first half of the
month was excessively warm followed by the turn to more seasonable
temperatures during the latter part of the month.

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

**Figure 5. Daily maximum and minimum temperatures observed during
January 2007**

**at Raleigh-Durham (RDU).**

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

**Figure 6. Daily maximum and minimum temperatures observed during
January 2007**

**at Greensboro (GSO).**

**January 2007 Precipitation**

There were several precipitation events that affected the state in
January. The first two events occurred January 1^st^ and again between
January 5^th^ and 8^th^. These two systems were rain events associated
with warm temperatures. Rainfall amounts during the two events generally
totaled 1 to 1.5 inches, except much higher amounts of up to 4 inches
were recorded along the southeast facing slopes of the Mountains near
Rosman.

There were a couple of wintry precipitation events during the latter
part of the month, occurring on January 18^th^, and on the 21^st^ and
22^nd^. However, snowfall was well below normal throughout North
Carolina during January. The wintry precipitation events at the middle
and end of the month only brought 1-2 inches of snow to central and
western sections of the state. Freezing rain occurred over the northwest
Piedmont and northern Foothills during the second wintry event on
January 21^st^ and 22^nd^. However, this was not a major winter storm.
The only other snow events in January occurred in the northwest upslope
snow regions of the northern Mountains after strong cold frontal passes.

The final monthly precipitation totals generally ranged from 2 to 4.5
inches, with lesser amounts reported from the southern Sandhills and
southern Coastal Plain. The maximum rainfall totals (6 to 8 inches)
occurred over the southern facing Mountains of the Blue Ridge. Figure 7
is a comparison of observed precipitation and normal precipitation for
January 2007 at selected locations across North Carolina.

![](media/image7.wmf){width="5.583333333333333in"
height="3.8020833333333335in"}

**Figure 7. Comparison of observed precipitation and normal
precipitation for January 2007 at selected locations across North
Carolina.**

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

The warmer than normal temperatures in January made it three straight
months with above normal temperatures at both Raleigh and Greensboro.
Five of the seven months have been warmer than normal at Raleigh, while
six of the past seven months have been above normal at Greensboro.

Figure 8 illustrates the monthly temperature departures from normal at
Raleigh-Durham and Greensboro during the past year. Nine of the past
twelve months have been warmer than normal at Raleigh-Durham. Ten of the
past twelve months have been warmer than normal at Greensboro.

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

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

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

The below normal precipitation recording during January marked the
second consecutive month of below normal rainfall at Raleigh-Durham.
However, the rainfall deficit during the past two months only totaled
0.94 of an inch. This marked only the 3^rd^ time in the past 7 months in
which rainfall averaged below normal at Raleigh. RDU finished 2006 with
a 12 month surplus of 10.64 inches. Figure 9 depicts the precipitation
trends at RDU during the past 12 months. The dry pattern the first half
of 2006 was replaced by wet conditions beginning in June and lasting
through November 2006.

The Greensboro precipitation also averaged slightly below normal for
January (-0.62 inches). This was the 3^rd^ month in the past 6 months
with sub par rainfall at Greensboro. Greensboro completed a dramatic
turn from a 7.50 inch rainfall deficit for 2006 at the start of June, to
an 8.55 inch 2006 rainfall surplus by November 30. Greensboro ended 2006
with a final surplus of 7.22 inches. Figure 10 depicts the monthly
precipitation totals and the departure from normal during the past 12
months at Greensboro.

![](media/image9.wmf){width="5.416666666666667in" height="3.3125in"}

**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 wet conditions that were observed across most of North Carolina
during the last 6 months of 2006 virtually eliminated residual drought
concerns. However, with the more rapid demise of the El Nino conditions
in the equatorial Pacific than expected, precipitation was generally
less than forecast during the first half of the winter season from the
Gulf Coast states northeastward across North Carolina. This was
especially true for areas along and west of the eastern continental
divide, mainly along and west of Asheville and Boone. The latest Drought
Monitor indicated that abnormally dry conditions had developed over this
region of the state, with stage one drought conditions being observed
upstream in Tennessee. East of the continental divide, the lighter
precipitation totals in the past 2 months have had little affect on
streams, rivers, lakes, or reservoirs. Most reservoirs that supply water
to the major cities in the center of the state were near normal on
January 31, 2007. The latest Drought Monitor can be viewed in Figure 11.
For the latest information concerning the drought, visit
<http://www.ncwater.org/drought/>

![](media/image11.png){width="5.625in" height="4.1875in"}

**Figure 11. U.S. Drought Monitor as observed on February 1, 2007.**

**Climate Outlook for the spring 2007**

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

<http://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/page2.gif>

The headline for the spring season was centered on the recent rapid
demise of the El Nino conditions in the equatorial Pacific. Moderate El
Nino conditions (sea surface temperatures 0.5°- 1.0° Celsius warmer than
normal) were observed in the critical regions of the Equatorial Pacific
in December. These conditions did not last as long experts felt they
would, and El Nino conditions rapidly diminished by the middle of
January. Near neutral ENSO conditions are now forecast through the
spring and summer seasons. The bottom line for North Carolina, El Nino
will no longer be a factor in the climate outlook for the spring season.
The higher probably of above normal precipitation for the southeastern
U.S. issued in earlier outlooks for February and March has been
eliminated. Instead, there are no clear signals concerning the
precipitation forecast for the upcoming spring season. Therefore, equal
chances of above normal, near normal, or below normal precipitation is
now forecast.

The temperature forecast for the spring season indicated that there is
an equal chance of above normal, near normal, or below normal
temperatures during the next 3 months as well. As is typically the case
during the spring season across North Carolina, there will likely be
large variability in temperatures and rainfall from week to week. Some
weeks will average above normal, while others will be below normal. The
temperature and precipitation outlooks for the United States during for
the spring can be viewed in Figures 12 and 13.

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/image12.png){width="6.993055555555555in"
height="3.854861111111111in"}

**Figure 12. Three-month temperature outlook from the Climate Prediction
Center for the spring 2007.**

![](media/image13.png){width="6.993055555555555in"
height="3.854861111111111in"}

**Figure 13. Three-month precipitation outlook from the Climate
Prediction Center for the spring 2007.**

**NC Weather Review Team**

Phillip Badgett

Michael Strickler