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Collection of precipitation in a raingage located in Lake Michigan near Chicago over an 11-yr period has permitted a study of the average monthly, seasonal and annual precipitation received off the southwestern shore of the lake. These values are compared with average precipitation occurring in the Chicago urban area and with amounts from other nearby rural and shore stations. From these comparisons, the effects of lake and urban influences on the precipitation pattern are evaluated.
The results of this study compare favorably with results from similar lake-precipitation studies performed by the Corps of Engineers. The precipitation data from this station in the lake indicate that precipitation over southern Lake Michigan may be considerably less than previously estimated from data of stations along the shore. The effect of precipitation on lake levels may be better evaluated now that additional information on lake precipitation is available.
Collection of precipitation in a raingage located in Lake Michigan near Chicago over an 11-yr period has permitted a study of the average monthly, seasonal and annual precipitation received off the southwestern shore of the lake. These values are compared with average precipitation occurring in the Chicago urban area and with amounts from other nearby rural and shore stations. From these comparisons, the effects of lake and urban influences on the precipitation pattern are evaluated.
The results of this study compare favorably with results from similar lake-precipitation studies performed by the Corps of Engineers. The precipitation data from this station in the lake indicate that precipitation over southern Lake Michigan may be considerably less than previously estimated from data of stations along the shore. The effect of precipitation on lake levels may be better evaluated now that additional information on lake precipitation is available.
Climate fluctuations and their impacts exist on all scales, from the local to the global, but often both are most easily measured and understood on the state scale. Illinois, located in a humid continental climate and with a north-south extent of 640 km, experienced a diversity of climate fluctuations in the period from 1901 to 1980. Illinois records for a variety of climate conditions reveal several recent fluctuations that have had major impacts on energy, agriculture, water resources, transportation, and government sectors. Analyses indicate recent changes to wetter and cooler conditions (1961–80 compared with 1901–60). In the last 20 years, there has been more rain and snow and fewer droughts; decreases in temperatures, especially in summer and winter, with fewer extremely warm days and many more extremely cold days; increases in cloudiness, especially in summer; and increases in storminess. These trends are more marked in the extreme seasons of summer and winter than in the transition seasons. The recent conditions have been generally beneficial to agricultural activities and water resources but detrimental to transportation, energy consumers, and local and state government.
Climate fluctuations and their impacts exist on all scales, from the local to the global, but often both are most easily measured and understood on the state scale. Illinois, located in a humid continental climate and with a north-south extent of 640 km, experienced a diversity of climate fluctuations in the period from 1901 to 1980. Illinois records for a variety of climate conditions reveal several recent fluctuations that have had major impacts on energy, agriculture, water resources, transportation, and government sectors. Analyses indicate recent changes to wetter and cooler conditions (1961–80 compared with 1901–60). In the last 20 years, there has been more rain and snow and fewer droughts; decreases in temperatures, especially in summer and winter, with fewer extremely warm days and many more extremely cold days; increases in cloudiness, especially in summer; and increases in storminess. These trends are more marked in the extreme seasons of summer and winter than in the transition seasons. The recent conditions have been generally beneficial to agricultural activities and water resources but detrimental to transportation, energy consumers, and local and state government.
Lake Michigan reached record-high levels during 1985 and 1986 just 10 years after attaining its previous record highs of this century. The climate of the basin has become cloudier and cooler over the past 40 years, leading to decreased evaporation and transpiration, but the principal factor for the increased water in the basin is extremely heavy precipitation in the most recent 15 years. Precipitation in this 15-year period averaged 107 percent above the 90-year average, and since 1970 only two years have been dry and 10 have been classified as wet, or much above normal. No other prior period has experienced comparably wet conditions since quality basin-wide records began in 1895. The current record-high levels on Lake Michigan and all other Great Lakes are producing a mixture of impacts including advantages to shipping and hydropower generation and disadvantages to shorelines. Most of the impacts on Lake Michigan have been disastrous with beaches destroyed, shorelines eroded, and near-shore structures badly damaged. Illinois, with its high-valued 101-km shoreline, is involved in a myriad of very costly adjustments being performed by individuals, lakeside communities, and state agencies. The federal government is reacting and attempting solutions, such as altered flows between the lakes and increased diversions. However, outlooks call for sustained high levels for at least the next six years and with no major means to sizably reduce levels in sight, damages and costly adjustments will continue into the foreseeable future. The situation illustrates how our complex society has become vulnerable to climate fluctuations. In such a regional case where any extreme has advantages and disadvantages to different economic interests, isolated solutions to ameliorate losses are difficult to achieve and often ineffectual, with resolution most likely needed at the regional policy level.
Lake Michigan reached record-high levels during 1985 and 1986 just 10 years after attaining its previous record highs of this century. The climate of the basin has become cloudier and cooler over the past 40 years, leading to decreased evaporation and transpiration, but the principal factor for the increased water in the basin is extremely heavy precipitation in the most recent 15 years. Precipitation in this 15-year period averaged 107 percent above the 90-year average, and since 1970 only two years have been dry and 10 have been classified as wet, or much above normal. No other prior period has experienced comparably wet conditions since quality basin-wide records began in 1895. The current record-high levels on Lake Michigan and all other Great Lakes are producing a mixture of impacts including advantages to shipping and hydropower generation and disadvantages to shorelines. Most of the impacts on Lake Michigan have been disastrous with beaches destroyed, shorelines eroded, and near-shore structures badly damaged. Illinois, with its high-valued 101-km shoreline, is involved in a myriad of very costly adjustments being performed by individuals, lakeside communities, and state agencies. The federal government is reacting and attempting solutions, such as altered flows between the lakes and increased diversions. However, outlooks call for sustained high levels for at least the next six years and with no major means to sizably reduce levels in sight, damages and costly adjustments will continue into the foreseeable future. The situation illustrates how our complex society has become vulnerable to climate fluctuations. In such a regional case where any extreme has advantages and disadvantages to different economic interests, isolated solutions to ameliorate losses are difficult to achieve and often ineffectual, with resolution most likely needed at the regional policy level.
The anomalous behavior of the precipitation in northwestern Indiana (the La Porte anomaly) since the late 1930s has been extensively studied and debated. Local records suggested an upward shift in warm season rainfall, thunderstorms, and hail during the 1935–65 period. The possible causes for this included changed station exposure, a poor observer, urban influences on the atmosphere due to nearby Chicago, and/or shifts in the general circulation patterns. Most debate has centered on the observer error versus urban effects explanation, but the La Porte anomaly has become a cause célèbre in the interwoven areas of climate change, air pollution, weather modification, and the quality of climatic records. A variety of recent studies of rainfall conditions and their areas of impact (streamflow, crop yields, and hail losses) show that the anomaly in the La Porte area began to shift locale in the 1950s and then disappeared in the 1960s. Taken in totality, it seems likely that the anomalous precipitation at La Porte was due to urban influences on the atmosphere, but the anomaly either ended or shifted into Lake Michigan (where it cannot now be detected) as the general circulation pattern changed, leading to fewer cyclonic passages and a more southward position of the Polar Front in the Midwest since 1960.
The anomalous behavior of the precipitation in northwestern Indiana (the La Porte anomaly) since the late 1930s has been extensively studied and debated. Local records suggested an upward shift in warm season rainfall, thunderstorms, and hail during the 1935–65 period. The possible causes for this included changed station exposure, a poor observer, urban influences on the atmosphere due to nearby Chicago, and/or shifts in the general circulation patterns. Most debate has centered on the observer error versus urban effects explanation, but the La Porte anomaly has become a cause célèbre in the interwoven areas of climate change, air pollution, weather modification, and the quality of climatic records. A variety of recent studies of rainfall conditions and their areas of impact (streamflow, crop yields, and hail losses) show that the anomaly in the La Porte area began to shift locale in the 1950s and then disappeared in the 1960s. Taken in totality, it seems likely that the anomalous precipitation at La Porte was due to urban influences on the atmosphere, but the anomaly either ended or shifted into Lake Michigan (where it cannot now be detected) as the general circulation pattern changed, leading to fewer cyclonic passages and a more southward position of the Polar Front in the Midwest since 1960.
A paradox has developed involving on one hand sizeable reductions during the last two years in federal support of weather modification, as opposed to major scientific-technical advances in the field plus strong recommendations for increased federal support from the scientific community. The major recent advances include the capability to operationally dissipate cold fogs, to enhance snow from orographic clouds, and to increase rain from tropical clouds, plus the discovery of sizeable urban-related increases in rainfall. Other advances include special weather radars, aircraft with new cloud sensors and the capability to penetrate thunderstorms, new seeding materials and delivery systems, and new techniques for evaluation of projects. These have been coupled with the spread of weather modification around the world and with the initiation of major seeding projects in Colorado (NHRE, HIPLEX, and San Juan Project), Florida, South Dakota, and Illinois-Missouri (METROMEX). Several groups (NACOA, NAS, ICAS, NWC, AMS) all made a series of positive recommendations for advancing the field through more federal support and reorganization. Yet, beginning in FY74, federal support for weather modification dropped 21% when other R&D increased 11%. Many possible causes for the paradox appear, including fear of weather changes, lack of scientific commitment, and a series of public, scientific, political, and military controversies. The three basic issues are that weather modification is still an immature technology; the socio-economic impacts are ill defined; and its management has been uncertain. Proper resolution of the paradox is more apt to occur either because of a dramatic scientific breakthrough or from growing concerns about weather and climate-related environmental changes.
A paradox has developed involving on one hand sizeable reductions during the last two years in federal support of weather modification, as opposed to major scientific-technical advances in the field plus strong recommendations for increased federal support from the scientific community. The major recent advances include the capability to operationally dissipate cold fogs, to enhance snow from orographic clouds, and to increase rain from tropical clouds, plus the discovery of sizeable urban-related increases in rainfall. Other advances include special weather radars, aircraft with new cloud sensors and the capability to penetrate thunderstorms, new seeding materials and delivery systems, and new techniques for evaluation of projects. These have been coupled with the spread of weather modification around the world and with the initiation of major seeding projects in Colorado (NHRE, HIPLEX, and San Juan Project), Florida, South Dakota, and Illinois-Missouri (METROMEX). Several groups (NACOA, NAS, ICAS, NWC, AMS) all made a series of positive recommendations for advancing the field through more federal support and reorganization. Yet, beginning in FY74, federal support for weather modification dropped 21% when other R&D increased 11%. Many possible causes for the paradox appear, including fear of weather changes, lack of scientific commitment, and a series of public, scientific, political, and military controversies. The three basic issues are that weather modification is still an immature technology; the socio-economic impacts are ill defined; and its management has been uncertain. Proper resolution of the paradox is more apt to occur either because of a dramatic scientific breakthrough or from growing concerns about weather and climate-related environmental changes.
Weather modification activities in 1972 are reviewed to identify the major new projects, the major new findings, the major problems, and what these all mean for this exciting, often controversial science. The major new projects revealed a decided increase in interest and funding at the state and local levels, as well as new thrusts in federal programs. Non-governmental support of weather modification research and operations performed by American commercial firms exceeded $8 million, representing about 25% of the total expenditure on weather modification in the United States in 1972. Major new findings related to a variety of laboratory, instrumental, and field activities concerning planned modification of precipitation, hail, and warm fog, and also to inadvertent modification of clouds and rainfall. Several controversies regarding weather modification arose in 1972, but they all revolved more around the questions of its desirability or methodology, rather than whether it could be done. In general, 1972 was a year of 1) growing public acceptance and concern over weather modification as a technology, 2) growing local-state support of weather modification, and 3) federal reassessment of the thrust of their programs.
Weather modification activities in 1972 are reviewed to identify the major new projects, the major new findings, the major problems, and what these all mean for this exciting, often controversial science. The major new projects revealed a decided increase in interest and funding at the state and local levels, as well as new thrusts in federal programs. Non-governmental support of weather modification research and operations performed by American commercial firms exceeded $8 million, representing about 25% of the total expenditure on weather modification in the United States in 1972. Major new findings related to a variety of laboratory, instrumental, and field activities concerning planned modification of precipitation, hail, and warm fog, and also to inadvertent modification of clouds and rainfall. Several controversies regarding weather modification arose in 1972, but they all revolved more around the questions of its desirability or methodology, rather than whether it could be done. In general, 1972 was a year of 1) growing public acceptance and concern over weather modification as a technology, 2) growing local-state support of weather modification, and 3) federal reassessment of the thrust of their programs.
A technology assessment of the future potential of hail suppression and all its possible ramifications in the United States in future years has included an attempt to define the current status of hail suppression. Hail suppression is at a stage in which the socioeconomic impacts of its use and the means to optimize its future utilization can be adequately treated. The estimation of a wide range of future suppression capabilities was based on the current status, which was defined after inspecting three sources of information: 1) results from preliminary evaluations of six recent projects, 2) findings on four published assessments of weather modification, and 3) results from two opinion surveys. This investigation indicates: 1) scientific beliefs about existing capabilities are widely different, with the majority of experts believing there is no capability; 2) the published reviews are optimistic but largely nondefinitive; and 3) the results of five of six recent suppression projects show suppression levels of 20–50%, but the results are largely not significant at the 5% level. This difference between average beliefs of experts and the results of recent projects suggests the need for an extensive investigation of the data and results of these recent projects.
A technology assessment of the future potential of hail suppression and all its possible ramifications in the United States in future years has included an attempt to define the current status of hail suppression. Hail suppression is at a stage in which the socioeconomic impacts of its use and the means to optimize its future utilization can be adequately treated. The estimation of a wide range of future suppression capabilities was based on the current status, which was defined after inspecting three sources of information: 1) results from preliminary evaluations of six recent projects, 2) findings on four published assessments of weather modification, and 3) results from two opinion surveys. This investigation indicates: 1) scientific beliefs about existing capabilities are widely different, with the majority of experts believing there is no capability; 2) the published reviews are optimistic but largely nondefinitive; and 3) the results of five of six recent suppression projects show suppression levels of 20–50%, but the results are largely not significant at the 5% level. This difference between average beliefs of experts and the results of recent projects suggests the need for an extensive investigation of the data and results of these recent projects.
Changes for JAM and JAS
New Editors and Editorial Policy of the Journal of Applied Meteorology
Mesoscale networks are designed and used to serve various specific purposes. Experience in the operation of several meso-networks has been used to describe those factors to be considered in their design, installation, and operations. Successful operation of networks depends on good management that can optimize project goals and available resources. The primary factors involved include network planning, procurement of facilities and staff, instrument siting, data collection, maintenance, calibration, data processing, and the eventual data bank. Long-term data retention is useful since network data frequently get re-used in subsequent, unforseen research. METROMEX, an on-going program studying urban effects on weather, has 15 sub-networks, and their designs and operations are used as illustrations. Public relations, unexpected problems, and data processing are high-lighted for the rainfall and severe storm networks.
Mesoscale networks are designed and used to serve various specific purposes. Experience in the operation of several meso-networks has been used to describe those factors to be considered in their design, installation, and operations. Successful operation of networks depends on good management that can optimize project goals and available resources. The primary factors involved include network planning, procurement of facilities and staff, instrument siting, data collection, maintenance, calibration, data processing, and the eventual data bank. Long-term data retention is useful since network data frequently get re-used in subsequent, unforseen research. METROMEX, an on-going program studying urban effects on weather, has 15 sub-networks, and their designs and operations are used as illustrations. Public relations, unexpected problems, and data processing are high-lighted for the rainfall and severe storm networks.
