Climate Summary

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

July 2009 began with dry conditions across the state. However, the last 2 weeks in July brought scattered thunderstorms and locally intense rainfall more typical of summer conditions in the southeastern United States. Locally intense storms caused flash flooding and wind damage in several locations, including Mecklenburg, Cabarrus, Stanly, Union, Gaston, New Hanover, Guilford, Davidson, and Rowan Counties.

But the big climate story for July 2009 is the cool temperatures across the state. Most long-term monitoring gages reported temperatures that were below normal. Statewide average temperature for July 2009 ranks as the 6th coldest July on record since modern records began in 1895. July 2009 was the coldest July since 2001, and for the past 3 years the month of July has been cooler than normal.

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

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

Impacts to Agriculture and Water Resources

Dry conditions in late June and early July began to stress crops across the state, especially corn and soybeans that were planted late due to wet conditions in the spring. While scattered showers and storms brought relief to some locations in the second half of July, many areas are still in need of regular precipitation to relieve crop stress. Overall, most crops are reported as in fair to good condition.

Despite scattered storms in recent weeks, dry conditions have led to increased risk of drought across the state. As of the last week in July, most of eastern NC is designated as D0 (Abnormally Dry) by the US Drought Monitor. Low streams were observed in the upper Tar, upper Neuse, and upper Cape Fear River basins. The US Army Corps of Engineers is moving to reduce the water released from Jordan Dam according to its drought plan to manage the water quality pool. Dry conditions in the southern Mountains also resulted in lower streams in headwaters of the Broad, French Broad and Little Tennessee Rivers. The NC Drought Management Advisory Council is closely monitoring eastern and southwestern North Carolina for any impacts.

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

El Niño Returns, Impacts for Tropical Cyclones and Winter Precipitation

The warm phase of the El Niño / Southern Oscillation has returned to the tropical Pacific Ocean. Often referred to as simply "El Niño", ocean temperatures in the tropical Pacific have increased rapidly over the past several weeks, and the El Niño is forecasted to intensify over the coming months before weakening next spring. What does this mean for NC? There are 2 impacts likely, based on historical climate conditions during El Niño events.

Courtesy of IRI, Columbia University

First, we're likely to see fewer tropical cyclones develop in the Atlantic Ocean than originally expected. Historically, fewer tropical storms form during El Niño due to stronger winds in the upper atmosphere. However, ocean temperatures are still warmer than the long-term average, and western African has been relatively wet. These 2 factors may compensate for stronger upper level winds. And while we may see fewer storms in the entire Atlantic Ocean, there is still a good chance one will affect North Carolina.

NC is also more likely to have a wetter winter than typical. Rainfall amounts during the winter season are generally above-normal during El Niño events. The El Niño event in the winter of 2001-2002 was largely accredited for eliminating drought conditions in the western half of the state.

One key point here - we're intentionally using terms such as "likely" and "generally". El Niño events shift the odds that a specific climate pattern will occur. But there have been El Niño years with active tropical cyclone patterns and dry winters in NC. Overall, the odds are shifted to favor fewer tropical cyclones and a wetter winter, but the science has not get progressed to where we can provide guaranteed climate forecasts. Trust us - we'll let you know when we get to that point.

AgroClimate: Climate-based Decision Support Tools for the Agricultural Community

The Southeast Climate Consortium (SECC) is a partnership of seven universities across the southeastern US aimed at integrating climate information with agricultural needs. The SECC provides decision support tools for the agricultural community on their website, AgroClimate, which is accessible at http://agroclimate.org. Currently, these tools are being adapted and developed for North Carolina.

This site provides decision tools based on climate information and seasonal climate patterns for growers, extension agents, and researchers. Important features on the home page include the current climate phase shown in the top right corner, an option to join the SECC mailing list (top left corner), and an option to contact SECC with any questions, comments, or suggestions (top left corner). The newest feature available on AgroClimate is the option to view the page in Spanish which is also located in the top left corner. In addition, the home page features recent news related to agriculture as well as several climate and commodity-specific agricultural outlooks such as spring crop progress and outlook, climate phase forecast, and summer climate outlook.

Decision support tools currently available for North Carolina include the following:

• Climate risk tool
• Cooling / heating degree days
• County yield database
• Growing degree day guidance
• Chill accumulation tool
• Monthly climate summary

Other tools being implemented include freeze risk maps, KBDI maps, lawn and garden moisture maps, regional yield maps, yield risk tool, and irrigation tool. New products and services are being incorporated to AgroClimate which are targeted to the needs of NC growers and extension personnel. Among these new applications are tools to help forecast and manage diseases as well as other pest risks.