SEASONAL CLIMATE SUMMARY FROM JUNE THROUGH AUGUST 2009

by Robert Stonefield

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.


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

Overall, the temperatures this past summer (June through August) averaged near normal. Figure 2 shows all of the Blacksburg County Warning Area within a degree of normal. Looking specifically at Blacksburg's five climatic sites (Tables 1-5), each were within about a half of a degree of normal for the 2009 summer season.


Figure 2. Departure of Average Temperature (°F) from Normal (June through August 2009)
Figure 2. Departure of Average Temperature (°F) from Normal (June through August 2009), Climate Prediction Center.

Although the three month average temperature was near normal, this summer was still the coolest in the past 5 years. Also, this summer may have seemed below normal because there were not very many hot days (>90F). In this aspect, the area was below normal as Danville had 30 days of 90F or warmer (normal is 42.6 days), Lynchburg had 12 days (normal is 20.6 days), and Roanoke had 8 days (normal is 24.1). Blacksburg and Bluefield had no 90F or warmer days and they typically average 5.7 and 1.6 days respectively.


However, a break down by month (Tables 1-5) at each site shows a roller coaster of a summer with June being above normal, July being below normal and August being above normal. July was a very cool month across the area; the 4th coolest on record at both Lynchburg and Blacksburg, 7th coolest at Roanoke and 8th at Danville.  


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 summer period.


Blacksburg, VA Summer graph
Graph 1: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from June 1 to August 31, 2009 for Blacksburg (RNK), VA.

June-August 2009 Monthly and
Summer Season Temperature (F) Summary

Blacksburg, VA

June

July

Aug

Summer

Mean Temperature

69.4

66.9

71.4

69.7

Normal Temperature

66.9

71.1

69.6

69.2

Departure from Normal

+2.5

-2.7

+1.8

+0.5

Table 1. Blacksburg, VA monthly (June through August 2009) and 2009 Summer season temperature summary.


Roanoke, VA Summer graph
Graph 2: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from June 1 to August 31, 2009 for Roanoke (ROA), VA.

June-August 2009 Monthly and
Summer Season Temperature (F) Summary

Roanoke, VA

June

July

Aug

Summer

Mean Temperature

74.1

73.3

76.1

74.5

Normal Temperature

71.9

76.2

74.7

74.3

Departure from Normal

+2.2

-2.9

+1.4

+0.2

Table 2. Roanoke, VA monthly (June through August 2009) and 2009 Summer season temperature summary.


Lynchburg, VA Summer graph
Graph 3: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from June 1 to August 31, 2009 for Lynchburg (LYH), VA.

June-August 2009 Monthly and
Summer Season Temperature (F) Summary

Lynchburg, VA

June

July

Aug

Summer

Mean Temperature

72.3

72.6

75.6

73.5

Normal Temperature

71.0

75.1

73.8

73.3

Departure from Normal

+1.3

-2.5

+1.8

+0.2

Table 3. Lynchburg, VA monthly (June through August 2009) and 2009 Summer season temperature summary.


Danville, VA Summer graph
Graph 4: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from June 1 to August 31, 2009 for Danville (DAN), VA.

June-August 2009 Monthly and
Summer Season Temperature (F) Summary

Danville, VA

June

July

Aug

Summer

Mean Temperature

74.9

76.0

78.5

76.4

Normal Temperature

74.4

78.8

77.1

76.8

Departure from Normal

+0.5

-2.8

+1.4

-0.4

Table 4. Danville, VA monthly (June through August 2009) and 2009 Summer season temperature summary.


Bluefield, wv Summer graph
Graph 5: Daily Highs, Lows, Normal Highs, Normal Lows, and Precipitation amounts
from June 1 to August 31, 2009 for Bluefield (BLF), WV.

June-August 2009 Monthly and
Summer Season Temperature (F) Summary

Bluefield, WV

June

July

Aug

Summer

Mean Temperature

70.8

69.3

72.3

70.8

Normal Temperature

68.0

71.6

70.8

70.2

Departure from Normal

+2.8

-2.3

+1.5

+0.6

Table 5. Bluefield, WV monthly (June through August 2009) and 2009 Summer season temperature summary.
 

Rainfall amounts for the summer of 2009 across the entire county warning area was around normal (Fig. 3). At Blacksburg’s climatic sites, rainfall amounts for the summer were above normal with the exception of Lynchburg. Below are tables (6-10) which break down rainfall by month and season. Most climatic sites had a surplus of rain during the month of June. As the summer progressed, convection became more scattered in July and August and some areas were above normal while others were below normal. Bluefield's monthly rainfall total for August of 5.88 inches was a new record. The old record was 5.77 inches set in 2006.

Figure 3. Percent of Normal Precipitation (June through August 2009)
Figure 3. Percent of Normal Precipitation (June through August 2009), Climate Prediction Center.


Despite the area not seeing any tropical systems this summer, on occasion, a tropical-like atmosphere was over the region and when storms developed, heavy rain fell. Looking at days where 1.00 inch of rain fell at a climatic site, Roanoke had 6 (normal is 2.6), Danville had 4 (normal is 3.2) and Lynchburg had 1 (normal is 3.2 days). Both Blacksburg and Bluefield had 3 days of an inch or more which is near average (2.6 and 2.3 days respectfully).

June-August 2009 Monthly and Summer Precipitation (inches) Summary

Blacksburg, VA

June

July

August

Summer

Precipitation (type)

Rain

Rain

Rain

Rain

Total Precipitation

4.06

6.44

3.25

13.75

Normal Precipitation

3.93

4.17

3.68

11.78

Departure from Normal

+0.13

+2.27

-0.43

+1.97

Table 6. Blacksburg , VA monthly (June-August 2009) and 2009 Summer season precipitation summary.
 

June-August 2009 Monthly and Summer Precipitation (inches) Summary

Roanoke, VA

June

July

August

Summer

Precipitation (type)

Rain

Rain

Rain

Rain

Total Precipitation

4.54

5.84

4.43

14.81

Normal Precipitation

3.68

4.00

3.74

11.42

Departure from Normal

+0.86

+1.84

+0.69

+3.39

Table 7. Roanoke, VA monthly (June-August 2009) and 2009 Summer season precipitation summary.

June-August 2009 Monthly and Summer Precipitation (inches) Summary

Lynchburg, VA

June

July

August

Summer

Precipitation (type)

Rain

Rain

Rain

Rain

Total Precipitation

3.71

3.09

2.37

9.17

Normal Precipitation

3.79

4.39

3.41

11.59

Departure from Normal

-0.08

-1.30

-1.04

-2.42

Table 8. Lynchburg, VA monthly (June-August 2009) and 2009 Summer season precipitation summary.
 

June-August 2009 Monthly and Summer Precipitation (inches) Summary

Danville, VA

June

July

August

Summer

Precipitation (type)

Rain

Rain

Rain

Rain

Total Precipitation

4.83

3.57

3.35

11.75

Normal Precipitation

3.50

4.44

3.54

11.48

Departure from Normal

+1.33

-0.87

-0.19

+0.27

Table 9. Danville , VA monthly (June-August 2009) and 2009 Summer season precipitation summary.
 

June-August 2009 Monthly and Summer Precipitation (inches) Summary

Bluefield, WV

June

July

August

Summer

Precipitation (type)

Rain

Rain

Rain

Rain

Total Precipitation

4.04

3.81

5.88

13.73

Normal Precipitation

3.85

4.01

3.20

11.06

Departure from Normal

+0.19

-0.20

+2.68

+2.67

Table 10. Bluefield , WV monthly(June-August 2009) and 2009 Summer season precipitation summary.