DATASTREME WES WEEK THREE: 20-24 September 2004

• The Big Easy dodged another one -- Hurricane Ivan passed sufficiently far to the east of New Orleans that the Crescent City was able to survive major flooding and other storm damage. Much of the city that lies between the Mississippi River and Lake Pontchartrain is below sea level and depends upon pumps to keep the city dry. [USA Today]
• War dance attempts to stop dam expansion -- Warriors from the Winnemem Wintu tribe used the tribe's first war dance since 1887 to protest the planned expansion of the Shasta Dam in California that would destroy sites held sacred to the tribe. [ENN]
• Giant desalination plant planned -- The Israeli government has developed plans to construct a giant desalination plant along the Mediterranean coast in order to pump fresh water to the Palestinian West Bank. [New Scientist]
• Cambodian gold mining has significant environmental risks -- The Cambodian Ministry of Industry and Ofam America have recently released a report that states that the country's gold mining industry has increased its use of highly toxic chemicals that pollute the surface and ground water and, ultimately, could cause serious environmental damage and health risks in Cambodia. [US Water News Online]
• Ice core technology shared--Scientists from the University of Maine and a research institution in central China have been collaborating in the collection and analysis of ice cores from Antarctica, New Zealand and Tibet. [EurekAlert!]
• New generation European weather satellite unveiled -- The European Space Agency put their Meteosat-8 into operation last week, marking the first Meteosat Second Generation meteorological satellite, a geosynchronous satellite that has a variety of highly sophisticated sensors, to include the Geostationary Earth Radiation Budget (GERB) instrument that provides quantitative measurements of the solar and terrestrial radiation components in the planetary energy budget. [ESA]
• Riparian forests play critical role in protecting fresh water -- A team of scientists from several institutions recently reported that their study of 16 rivers in eastern North America indicates that riparian (streamside) forests appear to play a critical role in filtering pollutants to protect the fresh water in the streams. [EurekAlert!]
• Drinking water disinfection product is toxic -- A scientist at the University of Illinois at Urbana-Champaign recently discovered that a new disinfection product that would be used in US drinking water could be extremely toxic to humans. [EurekAlert!]
• Global and US Hazards/Climate Extremes -- A review and analysis of the global impacts of various weather-related events, including drought, floods, and storms during the current month. [NCDC]
• Global Water News Watch -- Other water news sources can be obtained through the SAHRA Project at the University of Arizona [SAHRA Project]
• Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Reports from the Field -- Faye McCollum, WES LIT Leader from Columbus, GA reported on the hectic weather associated with the remnants of Hurricane Ivan as it traveled across Alabama and western Georgia. She said that in the Columbus area, almost 4 inches of rain fell and winds approached 50 mph, resulting in the downing of many power lines trees and branches. Numerous tornadoes that were spawned by Ivan caused people to take cover frequently. She noted that they had just cleaned up after the remnants of Hurricane Frances had battered the region. However, the sun finally came out.

In recent years, Great Lakes water levels declined significantly to near historic lows. Lakes Superior, Michigan, Huron, and Erie experienced their lowest water levels in 35 years with serious implications for lake-based activities. Over the past year or so, however, changes in weather conditions in the Great Lakes watershed appear to have somewhat reversed the decline in water levels.

From 1997 to 2001, Lakes Michigan and Huron dropped by 104 cm (40.8 in.) and Lake Erie dropped by 96 cm (37.6 in.), encompassing the greatest three-year drop in lake levels since continuous records began in 1860. This dramatic decline in lake level was due to a combination of weather conditions in the Great Lakes watershed. Rainfall, snowfall, and air temperature during winter and spring govern water levels of the Great Lakes in spring and summer. Spring melting of the winter snow pack in the watershed is an important contributing factor as is air temperature that ultimately governs evaporation rates. During 1997, 1998, 1999, and 2000, lower than normal precipitation and higher than normal temperatures reduced the winter snow pack, decreased discharge on rivers flowing into the lakes, and accelerated lake evaporation. Although input of water into the Great Lakes was above the long-term average in Fall 2001, lake levels remained well below average because of less than the usual snow melt in the Spring of 2001 and less than normal winter ice-cover in 2001-02. (More open water translates into greater winter evaporation.)

Great Lakes water levels showed signs of recovery during 2002, but in early 2003, all the lakes were lower than the long-term average for that time of year. A cool wet summer in the eastern Lakes region, but dry summer weather across the west meant that lake levels for the upper lakes continued to remain below average, while the lower lakes had levels that returned to near average. The cool summer of 2004 was very similar to 2003, with below average precipitation across the western Lakes and above average rainfall over the eastern Lakes. By mid September 2004, Lakes Erie and Ontario had water levels that were above the long-term monthly average (0.11 m or 4 inches and 0.20 m or 8 inches, respectively). Following below average levels for the winter and spring, Lake Superior returned to average by early September. Although the water level for Lakes Michigan and Huron had increased above the level of one year ago, it remained approximately 30 cm (12 inches) below the long-term average. (The Straits of Mackinac that link Lakes Michigan and Huron are so wide and deep that the levels of these two lakes are essentially the same.)

Low lake levels adversely impact commercial navigation, marinas, recreational boaters, and electric power facilities. Shallower than usual water requires expensive and environmentally damaging dredging to keep shipping channels navigable and ports open. Even with more dredging, some channels cannot accommodate the draft of heavily laden freighters. Reduced carrying capacity impedes transport of grain, coal, ore, and other raw materials to processing facilities and markets. In 2000, Lake Carriers transported 5% to 8% less cargo, sending prices higher. If storm winds cause near-shore water levels to fall, marinas, docks, and boat ramps may be temporarily inaccessible. The Great Lakes supply most of the potable water for communities and cooling water for coal-fired and nuclear electric power plants located along their shores. A drop in water level may require costly repositioning of intake pipes. On the positive side, lower lake levels translate into broader beaches and wetland habitats and less shoreline erosion.

For more information on past, current, and anticipated Great Lakes water levels, go to http://www.glerl.noaa.gov/data/now/wlevels/, a web page maintained by the Great Lakes Environmental Research Laboratory (GLERL). Records of Great Lakes water levels constitute one of the longest high quality hydrometeorological data sets in North America, dating back to about 1860. Lake level measurements are collected and archived by NOAA's National Ocean Service.

Concept of the Week: Questions

1. With rising temperatures, the rate of evaporation of water [(increases)(decreases)].
2. A trend toward snowier and colder winters and springs is likely to cause levels of the Great Lakes to [(rise)(fall)].

• 21 September 1938...The "Great New England Hurricane" smashed into Long Island and bisected New England from New Haven, CT across Massachusetts and Vermont, causing a massive forest blowdown and widespread flooding. Winds gusted to 186 mph at Blue Hill Observatory in Milton, MA, and a storm surge of nearly 30-ft caused extensive flooding along the coast of Rhode Island. The hurricane killed over 600 persons and caused 500 million dollars damage. The hurricane, which lasted twelve days, destroyed 275 million trees. Hardest hit were Massachusetts, Connecticut, Rhode Island and Long Island NY. The "Long Island Express" produced gargantuan waves with its 150 mph winds, waves which smashed against the New England shore with such force that earthquake-recording machines on the Pacific coast clearly showed the shock of each wave. (David Ludlum) (The Weather Channel)
• 21-23 September 1992...Torrential rains deluged the south of France. As much as 17 in. fell in a 12-hr spell on the 22^nd. A 49-ft high wall of water swept through Vaison la Romaine. Whole trees penetrated houses and vehicles. At least 38 died. (Accord Weather Calendar)
• 22-23 September 1998... Hurricane Georges raked Hispaniola leaving over 580 dead in Haiti and the Dominican Republic, due mainly to flash flooding and subsequent mud slides in high terrain regions. Damage estimates from the storm exceeded $1 billion (US). (The Weather Doctor)
• 23 September 1551...The Grand Harbour at Valetta, Malta was hit by a waterspout that then moved inland and caused extensive damage. A shipping armada in the harbor about to go into battle was destroyed by the waterspout killing at least 600 people. (The Weather Doctor)
• 23 September 1815...One of the most powerful hurricanes to strike New England made landfall initially on Long Island, NY and then again at Old Saybrook, CT before crossing into Massachusetts and New Hampshire. Extensive structural damage resulted. Providence, RI was flooded and six people were killed. This "Great September Gale" was the worst tempest in nearly two hundred years, equal in strength to the Great 1938 Hurricane, and one of a series of severe summer and autumn storms to affect shipping lanes that year. (David Ludlum)
• 25 September 1939...A West Coast hurricane moved onshore south of Los Angeles bringing unprecedented rains along the southern coast of California. Nearly five and a half inches of rain drenched Los Angeles during a 24-hr period. The hurricane caused $2 million in damage, mostly to structures along the coast and to crops, and claimed 45 lives at sea. "El Cordonazo" produced 5.66 in. of rain at Los Angeles and 11.6 in. of rain at Mount Wilson, both records for the month of September. (David Ludlum) (The Weather Channel)
• 25 September 1997...While much of San Bernardino and Inyo Counties in California are desert, between 1 to 2 inches of rain from former Pacific Hurricane Nora fell across a large portion of these counties. State highway 190 was washed out between Panamint Springs and Stove Pipe in Death Valley National Park. Flooding also shut down many other park roads. (Accord Weather Calendar)
• 25-26 September 1962...Torrential rains from severe thunderstorms over the hilly regions to the west and north of Barcelona, Spain resulted in flooding and considerable property much damage. Many buildings collapsed. Tarassa was particularly hard hit with approximately 500 deaths. (Accord Weather Calendar)

Return to WES Homepage

URL: WES:/news.html
Prepared by AMS WES Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2004, The American Meteorological Society.