NOAA 2004 Spring U.S. Outlook


March 19, 2004 — Following a highly variable winter, scientists from the NOAA National Weather Service expect drought concerns to continue in parts of the West, while less snow and warmer conditions in the upper Midwest foretell a lower than normal risk of snowmelt flooding this year. The predictions were made at a news conference held in Washington, D.C. today. (Click NOAA image for larger view of NOAA spring 2004 precipitation outlook. Click here for high resolution version, which is a large file. Please credit “NOAA.”) Expected Impacts April-June: “There is neither an El Niño nor La Niña in place; therefore, we expect a typical level of springtime variability in temperature and precipitation to occur in many areas of the nation,” said retired Navy Vice Adm. Conrad C. Lautenbacher , Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. “Specifically, NOAA meteorologists predict an enhanced likelihood for below-normal temperatures in the northern Great Plains and above-normal temperatures in Alaska, the Southwest and parts of the South for April through June. Above normal precipitation is likely in the far Northwest and below normal likely in Texas, parts of surrounding states and most of Louisiana and Florida.”

This spring NOAA scientists also expect long term precipitation deficits to decrease in parts of the northern and central Great Plains, while the hydrological drought or water supply deficits are predicted to persist over many areas in the West, especially in much of Arizona and New Mexico. Dry soils from up to five dry years will absorb snowmelt runoff and reduce recharge of reservoirs, many of which are well below normal levels as a result of this multi-year drought. (Click NOAA image for larger view of NOAA spring 2004 temperature outlook. Click here for high resolution version, which is a large file. Please credit “NOAA.”) Snowpack and snow water content have been running close to normal during this winter snow season in the Great Basin and Northwest, but continued improvement in water supplies throughout the West depends largely on snowfall continuing into spring. In many cases, the meltwater will not be enough to replenish depleted reservoirs.

Lowered Spring Flood Potential: In contrast to the gloomy water supply outlook in the West, limited snow cover both in the West and the northern tier states (near normal in many areas) makes spring snowmelt flooding less likely. There, are, however, a few areas of concern: A deep snow cover in northeastern Montana raises concern of major flooding along the Milk River. (Click NOAA image for larger view of NOAA spring 2004 flood risk. Please credit “NOAA.”) As much as 10 inches of water is stored in the snowpack in northern Wisconsin and Michigan’s upper peninsula, leaving the area at risk for flooding if warm temperatures accompany rain. Finally, thick ice on rivers in northern New York and New England could lead to ice jam flood problems. Fire Weather Outlook: Overall, the 2004 fire season is expected to be near normal in terms of the expected number of fires and acres burned. However, according to the National Interagency Fire Center in Boise, Idaho, which issues the annual National Wildland Fire Outlook, much of the interior West, and particularly the Southwest, has above normal fire potential due to the long-term drought conditions. Drought-stressed and/or insect-damaged vegetation continues to increase in the West, leading to a greater potential for large, destructive wildfires at middle to high elevations. “Accurate weather forecasts are critical to successful suppression of wildfires and can mean life or death for firefighters,” said retired Air Force Brig. Gen. David L. Johnson , director of the NOAA National Weather Service. “Particularly in the interior West and Southwest, where long-term drought conditions increase fire danger, the NOAA National Weather Service will provide meteorological support to wildland fire management agencies to protect property, and especially, lives.” Stage Set for Spring:

NOAA officials said that with the tropical Pacific Ocean featuring neither El Niño nor La Niña during this past winter, the jet stream and its associated weather conditions were highly variable. Yet, the 2003-2004 winter weather pattern did, in fact, improve drought conditions in many locations. Nevertheless, NOAA cautions that improvement does not mean total relief. (Click NOAA image for larger view of NOAA drought outlook through June 2004. Click here for high resolution version, which is a large file. Please credit “NOAA.”) As it stands today, NOAA’s U.S. Drought Monitor has very limited drought depicted east of the Mississippi River. However, it is another story for many places in the West.

“Fifty percent of U.S. states west of the Mississippi River are in some phase of dryness or drought, with the worst occurring in parts of Arizona, New Mexico, Idaho and Montana,” said Johnson. “The series of winter storms seen in the Rockies since last autumn have not made up for the substantial precipitation deficits that extend back four or five years. Snowpack in the region this spring is generally improved from last year, providing hope for limited water supply improvements and better prospects for farmers and ranchers.” (Click NOAA image for larger view of drought monitor as of March 16, 2004. Click here for high resolution version, which is a large file. Please credit “NOAA.”)

“Despite periods of record cold and warmth, as a whole, the 2003-2004 winter season (December through February) will go down in the record books as near average for the nation,” said Tom Karl , director of the NOAA National Climatic Data Center in Asheville, N.C. “The Eastern U.S. was cooler than average while warmer than average conditions affected much of the rest of the country. While there were periods of unusually heavy rain and snow in parts of the country, including above average precipitation in some parts of the West, precipitation was near average for the contiguous U.S.” (Click NOAA image for larger view of average jetstream positions during the winter of 2003-2004. Click here for high resolution version, which is a large file. Please credit “NOAA.”) NOAA’s Spring Outlook is a consolidated effort of the NOAA National Weather Service and NOAA National Climatic Data Center. The National Weather Service (including the Climate Prediction Center and the Hydrologic Services Program ) is the primary source of weather, drought and climate information, forecasts and warnings for the United States and its territories. The NOAA National 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. The NOAA National Climatic Data Center is the nation’s primary source of historical meteorological and climate data. 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 National Weather Service NOAA’s U.S. Drought Assessment NOAA Climate Prediction Center NOAA Climate Prediction Center Seasonal Outlook NOAA National Hydrologic Assessment NOAA Drought Information Center NOAA Fire Weather Page