Climate Summary

Temperature and Precipitation by climate division
Departures from Normal for September 2009 - based on preliminary data.

The highlight for September 2009 in North Carolina was heavy rain that fell in western NC. Several locations in western NC experienced near-record rainfalls for the month. Damages in western NC were widespread, including flooding, tree damage, and crop damage. For much of the southern mountains, rain produced damage and flooding not experienced since the repeated tropical storm events in 2004.

In central and eastern NC, rainfall was generally below normal for the month. Parts of south-central NC experienced less than half of normal rainfall.

Temperatures in most of North Carolina were cool in September. Only western parts of NC experienced near-normal temperatures for the month.

Precipitation for September 2009
Based on estimates from NWS Radar
Data courtesy NWS/NCEP

Precipitation for September 2009: Percent of Normal
Based on estimates from NWS Radar
Data courtesy NWS/NCEP

Impacts to Agriculture and Water Resources

Despite some dry conditions in parts of central and eastern North Carolina, most crops have received timely rainfall and soil moisture conditions in September and were generally adequate across the state. Cool temperatures kept evaporation rates low, and dryer conditions helped some growers with harvest. Heavy rainfall in western NC caused damage to crops.

Drought concerns in western NC were alleviated with the heavy rainfall west of the I-77 corridor. However, the lack of rainfall in central NC has resulted in streams and reservoirs that continue to be low for this time of the year. While minimal impacts have been observed, moderate drought (D1) was expanded to include much of south-central parts of the state. The NC Drought Management Advisory Council continues to hold weekly monitoring meetings to closely monitor for drought impacts.

Change in US Drought Monitoring Status during September 2009
Provided by the NC DENR Division of Water Resources

Newly Calculated Ranges for Climate Normals

Every ten years the National Climatic Data Center (NCDC) calculates daily normal temperatures from thirty years of observed data for NWS Cooperative (COOP) Observing Network Stations around the country. Broadcast meteorologists often use the daily normals when comparing the high and low temperatures for each day. However, because of the variability of daily temperatures, nearly every day will be somewhat warmer or cooler then the daily normal for that day. This can make the daily normal temperatures misleading for many people without defining what is considered “normal”.

To answer this question, our office has released a tool to define the range of the normal temperatures, using the natural variability of daily temperature values. The Daily Normal Temperatures Tool will allow users to see the daily normal temperatures, their ranges and the daily temperature for last year for any location in their viewing area for a specific date or period of dates. This tool is linked to our Climate Normals page, which has also been updated to include information on the normal temperature ranges.

The updated Climate Normals page can be accessed through the “Data and Products” on the main menu, while the Daily Normal Temperatures Tool can be reached via the “Highlights” section on our home page:
http://www.nc-climate.ncsu.edu/normalstool.html
http://www.nc-climate.ncsu.edu/cronos/normals.php