NOAA ISSUES 2003-04 WINTER OUTLOOK FOR THE NATION

Oct. 16, 2003 — Temperatures in Alaska, the far West, Southwest and Southern Plains are expected to be above normal for the 2003-04 winter. For other parts of the nation, the winter will bring equal chances of above-, below- or near-normal temperatures, according to NOAA forecasters. The agency today released its official winter outlook, which, unlike most of the last six winters, is not expected to be influenced by a strong El Niño or La Niña. Though weak El Niño conditions are possible by the end of November, NOAA forecasters expect a minimal impact on the United States. (Click NOAA image for larger view of forecast winter temperatures for the USA. Click here for high resolution version, which is a large file. Please credit “NOAA.)

The forecast also projected the multi-year drought in the West will likely continue with limited improvement and lingering water shortages. The winter outlook will be updated on Nov. 20.

Reasons for Uncertainty
“Without a strong El Niño or La Niña signal as a guide, there is more uncertainty in our forecast, but we do expect winter to bring its typical weather variability,” said John Jones, Jr., deputy director of the NOAA National Weather Service. (Click NOAA image for larger view of forecast winter precipitation for the USA. Click here for high resolution version, which is a large file. Please credit “NOAA.)

He added that forecasters, in cases where a dominant climate feature in the Pacific Ocean is missing, rely on historical trends of temperature and precipitation averages as well as dynamical and statistical models.

Jones said researchers are studying other climatic factors that influence NOAA’s seasonal outlooks, but these influences aren’t yet routinely predictable on seasonal time scales. As examples, he cited several factors that need further study and pose significant challenges to the climate forecast, including: tropical ocean temperatures in the western Pacific and Indian Oceans, atmospheric circulation patterns in the Arctic and North Atlantic, snow cover in the high latitudes during the late fall and U.S. soil moisture conditions. (Click NOAA image for larger view of drought outlook for the USA. Click here for high resolution version, which is a large file. Please credit “NOAA.)

“There is a need to continue collaborating with the research community for improving data management and collection operations, and fine-tuning the oceanic and atmospheric models that run on the supercomputers,” Jones said. “Forecast uncertainty in low climate signal years like this can be reduced, but it will take more research and more resources to do that."

Jones said the conditions this year also highlight the value of collecting and sharing data on a global scale. NOAA is moving aggressively on that front with action that came out of the Administration-sponsored Earth Observation Summit that was held this summer in Washington, D.C. At that session, more than 34 nations plus the European Commission launched the development of a 10-year implementation plan to arrange a system of integrated space-borne, airborne and in situ observations to help understand and address global environmental and economic concerns. NOAA, NASA and the U.S. State Department hosted the summit.

Winter 2003-04 Outlook
“While ocean temperatures in the tropical Pacific are warmer than long-term averages, and may even reach the level of a weak El Niño by late November, El Niño is not expected to exert a major influence on U.S. climate this winter,” said Ed O’Lenic, senior meteorologist and lead forecaster at the NOAA Climate Prediction Center, which is part of the NOAA National Weather Service. “Our forecast tools imply large uncertainty in the northern and eastern U.S., while a clearer picture emerges elsewhere.”

Based on those tools, NOAA forecasters expect:

• In Alaska, the far West, the Southwest, and the southern Plains, temperatures will likely be warmer than the long-term averages;
• Elsewhere, there are equal chances of above, below and normal temperatures;
• The majority of the nation will have equal chances of above, below and normal precipitation, with the exception of Texas, Oklahoma and areas of western Louisiana, southwestern Arkansas and eastern New Mexico, where above normal amounts are likely.

NOAA forecasters also expect existing multi-year drought conditions in much of the West (except California) and parts of the Central Plains to continue with improvement in complex patterns predominantly in the north central plains and parts of the far west. In most other areas drought will likely persist—or improve—with many lingering, long-term water shortages.

The NOAA National Weather Service is the primary source of weather data, forecasts and warnings for the United States and its territories. The NOAA Weather Service operates the most advanced weather and flood warning and forecast system in the world, helping to protect lives and property and enhance the national economy.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation�s coastal and marine resources. NOAA is part of the U.S. Department of Commerce.

Relevant Web Sites
NOAA Climate Prediction Center

NOAA Drought Information Center

El Niño/Southern Oscillation (ENSO) Diagnostic Discussion

Weekly El Niño/Southern Oscillation (ENSO) Update

Most Recent 2 Months Sea Surface Temperature Anomaly Animation

El Niño and La Niña-related Winter Features over North America

Sea Surface Temperature Outlook

ENSO Impacts by Region

NOAA Storm Watch — Get the latest severe weather information across the USA

Media Contact:
John Leslie, NOAA National Weather Service, (301) 713-0622