CLIMATE SUMMARY FROM NOVEMBER 2008 THROUGH FEBUARY 2009

Note: Records and normals discussed in this article pertain to NWS Blacksburg's first order climatic sites which includes Roanoke, Lynchburg, Danville and Blacksburg, VA and Bluefield, WV. To view other station climate data that may be closer to your home, visit NWS Blacksburg's Climate web site at http://www.weather.gov/climate/xmacis.php?wfo=rnk or Southeast Regional Climate Center (SERCC) at http://www.sercc.com/climateinfo/historical/historical.html.

WFO Blacksburg Geographical Map
Figure 1. WFO Blacksburg County Warning area geographical break down.

 

Near normal temperatures for the winter of 2008/2009, and below normal precipitation.

 

Overall, the temperature this past winter (December through February), averaged near normal. Figure 2 shows all of the Blacksburg County Warning Area within a degree of normal. However, this three month average masks what were a few notable cold spells and warm spells.

Departure of average temperature above normal

Figure 2. Departure of Average Temperature (oF) from Normal (December 2008 through February 2009), Climate Prediction Center.

 

The following line graphs (graphs 1-5) and tables (table 1-5) for each of the five climate sites in Blacksburg's County Warning Area give a more in depth look at the temperature trends during the winter period. November is not part of climatological winter, but is included in these tables to show that the season got off to a cold start. All of the climate sites recorded a colder than normal November.  In contrast, all 5 climate sites recorded a warmer than normal December. However, a closer look at the temperature trends lines in each graphic shows that there was a well below normal cold spell from the end of November into the first week of December. This cold spell was then followed by a prolonged warm spell that lasted for most of the rest of December and into the first part of January. The month January averaged near normal temperatures at Blacksburg, Roanoke and Danville, while Bluefield and Lynchburg were slightly below normal. After the warm start to January, there was a sharp cold spell in the middle of the month, and then temperatures gradually modified to near normal toward the end of the month. February was warmer than normal at all climate sites, with a warm spell well above normal in the middle of the month.

Blacksburg, VA climate graph from Nov. 2008 to Feb. 2009

Graph 1: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from November 1, 2008 to March 1, 2009 for Blacksburg (RNK), VA.

November 2008-Feburary 2009 Monthly and
Winter (Dec. 2008-Feb. 2009) Temperature (F) Summary

Blacksburg, VA

Nov

Dec

Jan

Feb

Winter

Mean Temperature

40.0

37.4

30.9

35.9

34.8

Normal Temperature

42.8

34.1

30.9

33.5

33.1

Departure from Normal

-2.8

+3.3

0.0

+2.4

+1.7

Table 1. Blacksburg, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) temperature summary.

Roanoke, VA climate graph from Nov. 2008 to Feb. 2009

Graph 2: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from November 1, 2008 to March 1, 2009 for Roanoke (ROA), VA.

November 2008-Feburary 2009 Monthly and
Winter (Dec. 2008-Feb. 2009) Temperature (F) Summary

Roanoke, VA

Nov

Dec

Jan

Feb

Winter

Mean Temperature

46.0

41.8

35.9

42.2

40.0

Normal Temperature

47.3

39.1

35.8

39.1

38.3

Departure from Normal

-1.3

+2.7

+0.1

+3.1

+1.7

Table 2. Roanoke, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) temperature summary.

Lynchburg, VA climate graph from Nov. 2008 to Feb. 2009

Graph 3: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from November 1, 2008 to March 1, 2009 for Lynchburg (LYH), VA.

November 2008-Feburary 2009 Monthly and
Winter (Dec. 2008-Feb. 2009) Temperature (F) Summary

Lynchburg, VA

Nov

Dec

Jan

Feb

Winter

Mean Temperature

43.7

39.2

32.8

39.4

37.1

Normal Temperature

46.6

38.2

34.5

37.8

37.2

Departure from Normal

-2.9

+1.0

-1.7

+1.6

-0.1

Table 3. Lynchburg, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) temperature summary.

Danville, VA climate graph from Nov. 2008 to Feb. 2009

Graph 4: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from November 1, 2008 to March 1, 2009 for Danville (DAN), VA.

November 2008-Feburary 2009 Monthly and
Winter (Dec. 2008-Feb. 2009) Temperature (F) Summary

Danville, VA

Nov

Dec

Jan

Feb

Winter

Mean Temperature

46.0

43.0

36.5

43.0

40.8

Normal Temperature

48.6

40.1

36.6

39.7

39.1

Departure from Normal

-2.6

+2.9

-0.1

+3.3

+1.7

Table 4. Danville, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) temperature summary.

Bluefield, WV climate graph from Nov. 2008 to Feb. 2009

Graph 5: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from November 1, 2008 to March 1, 2009 for Bluefield (BLF), WV.

November 2008-Feburary 2009 Monthly and
Winter (Dec. 2008-Feb. 2009) Temperature (F) Summary

Bluefield, WV

Nov

Dec

Jan

Feb

Winter

Mean Temperature

42.2

39.0

31.6

37.2

35.9

Normal Temperature

45.2

36.6

32.7

36.1

35.5

Departure from Normal

-3.0

+2.4

-1.1

+1.1

+0.4

Table 5. Bluefield, WV monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) temperature summary.

 

Figure 3 shows below normal precipitation for the winter across most of Virginia and North Carolina . In Blacksburg's County Warning Area, only the southwest Virginia mountains and all of southeast West Virginia were near, or a little above normal. The driest areas were in the piedmont.

Percent of Normal Precipitation

Figure 3. Percent of Normal Precipitation (December 2008 through February 2009), Climate Prediction Center.

 

The following U.S. Drought Monitor maps (Fig. 4 and 5), which show areas with various degrees of drought, indicate that despite being a little below normal, the winter precipitation was enough to lower the severe drought depicted across most of southwest Virginia west of the Blue Ridge mountains, and the North Carolina mountains on December 2, 2008 (Fig. 4), to moderate drought by March 3, 2009 (Fig. 5).

Drought Monitor Dec 2, 2008

Figure 4: Drought Monitor ending on December 2, 2008 (http://www.drought.unl.edu/DM/monitor.html)

Drought Monitor March 3, 2009

Figure 5: Drought Monitor ending on March 3, 2009 (http://www.drought.unl.edu/DM/monitor.html)

 

For a closer look at the winter precipitation, table summaries (Tables 6-10) of each of the five climate sites are included below.  Roanoke, Lynchburg and Danville all received between two and three inches less precipitation than normal for the winter (December through February). Blacksburg was just slightly (0.27 inches) below normal, and Bluefield was slightly (0.34 inches) above normal. The month to month distribution of rainfall varied considerably across the area from November through February. Roanoke saw rainfall deficits for every month during that period. Blacksburg and Bluefield had slight surpluses in December and January, while November and December were above normal for Lynchburg and Danville. Finally, the winter snowfall was below normal for all sites. Blacksburg, Roanoke and Lynchburg were all 10 inches or more below their normal winter snowfall.

November 2008-Feburary 2009 Monthly and Winter (Dec. 2008-Feb. 2009)
Precipitation (inches) Summary

Blacksburg, VA

November

December

January

February

Winter

Precipitation (type)

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Mean Precipitation

1.95

3.2

3.43

1.3

3.60

1.4

1.96

4.2

8.99

7.2

Normal Precipitation

2.96

1.1

2.87

3.9

3.37

7.2

3.02

6.4

9.26

17.2

Departure from Normal

-1.01

+2.1

+0.56

-2.6

+0.23

-5.8

-1.06

-2.2

-0.27

-10.0

Table 6. Blacksburg, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) precipitation summary.

November 2008-Feburary 2009 Monthly and Winter (Dec. 2008-Feb. 2009)
Precipitation (inches) Summary

Roanoke, VA

November

December

January

February

Winter

Precipitation (type)

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Mean Precipitation

1.92

0.4

2.25

T

2.72

T

1.22

0.4

6.19

0.4

Normal Precipitation

3.21

1.3

2.86

3.9

3.23

6.5

3.08

7.2

9.17

17.6

Departure from Normal

-1.29

-0.9

-0.61

-3.9

-0.50

-6.5

-1.86

-6.8

-2.98

-17.2

Table 7. Roanoke, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) precipitation summary.

November 2008-Feburary 2009 Monthly and Winter (Dec. 2008-Feb. 2009)
Precipitation (inches) Summary

Lynchburg, VA

November

December

January

February

Winter

Precipitation (type)

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Mean Precipitation

3.94

0.0

3.48

0.3

3.13

T

1.14

1.2

7.75

1.5

Normal Precipitation

3.18

0.5

3.23

3.2

3.54

5.3

3.10

5.3

9.87

13.8

Departure from Normal

+0.76

-0.5

+0.25

-2.9

-0.41

-5.3

-1.96

-4.1

-2.12

-12.3

Table 8. Lynchburg, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) precipitation summary.

November 2008-Feburary 2009 Monthly and Winter (Dec. 2008-Feb. 2009)
Precipitation (inches) Summary

Danville, VA

November

December

January

February

Winter

Precipitation (type)

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Mean Precipitation

3.54

T

3.81

T

3.01

0.4

0.97

0.5

7.79

0.9

Normal Precipitation

3.07

T

3.16

1.7

4.03

3.7

3.41

2.2

10.60

5.3

Departure from Normal

+0.47

-0.1

+0.65

-1.7

-1.02

+1.3

-2.44

-1.7

-2.81

-4.4

Table 9. Danville, VA monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) precipitation summary.

November 2008-Feburary 2009 Monthly and Winter (Dec. 2008-Feb. 2009)
Precipitation (inches) Summary

Bluefield, WV

November

December

January

February

Winter

Precipitation (type)

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Rain

Snow

Mean Precipitation

1.90

2.8

3.60

2.5

3.58

4.6

1.95

11.1

9.13

20.5

Normal Precipitation

2.67

9.0

2.82

6.3

3.06

8.7

2.91

9.1

8.79

24.3

Departure from Normal

-0.77

+1.9

+0.78

-3.8

+0.52

-4.1

-0.96

+2.0

+0.34

-3.8

Table 10. Bluefield, WV monthly (Nov. 2008 through Feb. 2009) and 2009 winter season (Dec. 2008 through Feb. 2009) precipitation summary.

 

Not surprisingly, with below normal precipitation, there were only 4 winter storms that affected large portions of the County Warning Area with either significant ice or snow.  Figure 6 shows a storm total snowfall map of an early season heavy western upslope snow event. A strong cold front moved through the region November 24th and the cold air behind the front generated periods of moderate to heavy mountain snow showers into the morning of the 26th. While just the extreme western slopes areas of southeast West Virginia into Tazewell County Virginia were the only locations that saw more than 3 inches of snow, 1 to 2 inch snowfall amounts were common across the mountains of southwest Virginia and northwest North Carolina from the Blue Ridge westward. Portions of western Greenbrier County saw around a foot of snow, with Quinwood reporting 14 inches.

Nov 17-18 snow

Figure 6: Snow accumulations on November 17-18, 2008.

The second winter storm to affect the area did not occur until the end of January. Figure 7 shows accumulations from an ice storm on January 27th.  Ice storms occur when rain falls into below freezing air at the surface, and the rain freezes on contact.  The accumulations are measurements of the thickness of the glaze.  A quarter inch is considered significant because that could be enough to cause downed tree limbs and power lines. Note the large area of greater than a quarter inch of icing that extends from Bedford County VA, northeastward along the Blue Ridge into Amherst County, also including the southern Shenandoah valley, Bath County VA, and from Appomattox northeast into Buckingham. Scattered locations received around a half inch of icing. Trees and tree limbs were reported downed in Amherst, Appomattox, Bedford and Buckingham counties in VA.

Jan. 27, 2009 Ice Storm

Figure 7: Ice accumulations on January 27, 2009 Ice storm.

 

The next winter storm to affect the area arrived just a week later, when another strong cold front moved through the region on February 2nd, and the cold air behind this front produced periods of moderate to heavy snow on western slopes areas of the mountains from the afternoon of the 3rd, into the morning of the 4th. This time, the best low level moisture trajectories were further south, and the heaviest snow accumulations (Fig 8) were across the southwest mountains of Virginia and the North Carolina mountains. Widespread amounts of 5 inches or more fell from Tazewell County Virginia, southward through the Mount Rogers area, and into portions of Ashe and Watauga Counties in North Carolina along the Tennessee border. A few heavier bands set up east of the western slopes, and brought 2 to 3 inches of snow to portions of Pulaski, Montgomery, Carroll and Floyd Counties in Virginia.

Feb. 3, 2009 snow storm

Figure 8: Snow accumulations on February 3, 2009.

 

The final winter storm that affected the area brought our most widespread heavy snow of the season.  A strong low pressure system moved up along the southeast and Mid-Atlantic coasts during the day on March 1st and into the morning of the 2nd. This "Miller A" type of storm system has historically brought some of the heavier snows to our area if the air mass is cold enough. Cold air was in place across the region, and the storm brought a swatch of greater than 8 inches of snow from Boone and Jefferson in the North Carolina mountains, northeast into the southern portions of the New River Valley, and then eastward to the Smith Mountain Lake, Lynchburg and Appomattox areas. Snow accumulations (Fig. 9) of 6 to 8 inches were reported across Southside Virginia and the northwest piedmont of North Carolina.   The last "Miller A" type winter storm to bring widespread heavy snow to the Blacksburg CWA was February 27, 2005.

Mar0102_2009_snow

Figure 9: Snow accumulations from March 1-2, 2009 Snow Storm.

 

The satellite image below (Fig. 10) is a visible snapshot taken the day after the March 2nd storm which shows the swath of snow associated with it extending from parts of Georgia to New England. Most of Virginia received some snow from this system.

March 3, 2009 Satellite

Figure 10: Visible satellite on March 3, 2009.

 

 

written by: Jan Jackson and Robert Stonefield