Showing papers on "Weather station published in 1987"

Big waves from polar lows

Abstract: A simple theoretical model is used to analyse how a polar low can produce a severe sea condition. The predictions of the model are compared to data from records of polar lows that have passed in the proximity of the weather station A.M.I. (71.5°N, 19°E) during the period (1978–82), and wave records from the same location and period. DOI: 10.1111/j.1600-0870.1987.tb00324.x

Meteorological Operations at Cape Hatt in Support of the Baffin Island Oil Spill Project

Abstract: Climatological records for Pond Inlet and Arctic Bay indicate that the climate of the northern Baffin Island area lies between the cold, dry climate of the central Arctic and the slightly milder and moister climates of the western Beaufort Sea and the southeastern Baffin Island and Hudson Strait areas. A weather station was set up at Cape Hatt in late May 1980 to provide climatological data at the site of the Baffin Island Oil Spill Project. Daily precipitation and temperatures, hourly winds, rate of rainfall and hourly global solar radiation were measured. The station operated from late May to late June and from mid-July to the end of September in 1980 and from mid-July to the end of September in 1980 and from mid-July to early September in 1981. Temperature and precipitation data from the station were compared with those from Pond Inlet for the identical periods. Six outlying stations measured winds at representative locations in the area. Hour by hour comparisons were made of the winds at five shoreline stations with those at the camp station and those on a nearby mountain. These were used as one of the tools in forecasting winds for the oil releases. The weather forecasting system utilized one meteorologist at the site using weather charts and briefings from the Atmospheric Environment Service Arctic Weather Centre at Edmonton. The forecasts provided met all requirements for timing and accuracy. Key words: climatological, Baffin Island, weather station, precipitation, temperature, winds, radiation, forecasting

The FLOWS (FAA-Lincoln Laboratory Operational Weather Studies) Automatic Weather Station Network in Operation.

Abstract: : This report describes in detail the FLOWS automatic weather station network as a wind shear data collection system, describes the post-data collection processing and analysis procedures, and presents an evaluation of the performance of the network after its first field test and an illustration of how the data are actually used in analysis. Preliminary results of an investigation into correcting wind speed measurements for the effects of anemometer site obstructions are also presented. The goal has been to describe all facets of the weather station system, data processing, and preliminary performance results in sufficient detail so as to allow current and future users to understand the experimental utility of the weather station data and the limitations, the characteristics of the meteorological sensors, and the possible improvements that could be made to the weather station system.

Wet weather exposure measures

Abstract: Accident surveillance programs require a measure of wet pavement exposure to determine whether the wet pavement accident rates of particular highway sections are higher or lower than expected. This research program used the results of laboratory and field tests, together with available weather data to construct a model for estimating the percentage of time a pavement would be wet. The laboratory and field testing program addressed (1) the minimum level of pavement surface wetness that substantially reduces tire pavement friction and (2) the time required for a pavement to dry following rainfall. A computer model, known as the wettime model, was developed in the research to estimate the monthly and annual hours of wet pavement exposure. The model can be used to estimate wet pavement exposure in the vicinity of any first order weather station from data that can be obtained from the national climatic data center in asheville, north carolina. Procedures were also developed to use the output of the wettime model to prepare isoexposure contour maps for entire states or regions. A companion volume, report no. Fhwa/rd-87/106, is a users guide for the wettime exposure estimation model.

Development of a Real Time Measurement System for Charleston Harbour

Abstract: The National Ocean Service of NOAA has developed and deployed a real-time current measuring system for verification of the accuracy of the NOAA tidal current table for Charleston Harbor. An RD Instruments acoustic Doppler current profiler on the bottom of Charleston Harbor is hard wired to a Coastal Climate weather station. The weather station transmits both the weather data and the current profiler data to a shore station for telephone interrogation from Rookville, Maryland. Although there have been several engineering evaluations of acoustic Doppler current measuring systems, this is the first application of the technology to NOS operational programs. The paper will discuss the development, integration and performance of the system as well as techniques used to assure the quality of data.

Low streamflow conditions in the western states during 1987

Abstract: Drought conditions prevailed throughout the States of California, Nevada, Idaho, Oregon, and Washington during the summer of 1987. Streamflows were the lowest since the drought of 1977. Many streams had less discharge in August-September 1987 than in August-September of 1977. At some sites flows for July, August, and September were the minimum ever recorded for those months. The reasons for the low flows, which occurred in spite of near normal precipitation for the 1987 water year (October 1, 1986 to September 30, 1987), were low winter snowpack, unseasonably early melt of that snowpack, and prolonged periods of wellabove-average temperatures. Conditions are conducive for a potentially serious drought in 1988. The low flows and a large demand for water during the summer of 1987 left many storage reservoirs at well-below-average levels. At least four cities had less than a 2-month supply of surface water at the end of September. In some areas, ground-water levels have lowered considerably, as indicated by the need to deepen irrigation wells in Oregon. Cities that used ground water did not experience serious problems in 1987 but could have extreme shortages in 1988 if groundwater supplies are not replenished. Even though the flow conditions worsened noticeably during the 1987 water year, careful management and conservative water-use practices prevented widespread critical water shortages. The U.S. Geological Survey is measuring the quantity and quality of streamflow in order to assess the extent and severity of the drought. INTRODUCTION Background In 1987, Western states experienced the lowest Streamflows since the 1977 drought. Provisional data indicate that summer flows in southern Idaho were the lowest ever recorded for that time of year and in western Washington flows were the lowest in 40 years. Low winter precipitation produced well-below average snowpack, and many Federal and State water agencies are planning for the possibility of an ensuing drought. Severe water shortages occurred only in localized areas without adequate reservoir storage. In much of the West, storage levels in reservoirs at the beginning of the 1987 water year (October 1, 1986 to September 30, 1987) equalled or exceeded the average for that time of year. The quantity of water in storage and efficient management practices provided an adequate supply of water for most uses, but some municipalities and other water suppliers instituted either voluntaryor mandatory-use restrictions. Some municipal reservoirs became critically low by the end of September. The 1987 water year may be the beginning of a severe drought in the Western states. If 1988 is another dry year, major water shortages will develop throughout the West. Conditions in 1987 are already approaching those that prevailed during the second year of the 1976-77 drought; another dry year would result in even more extreme conditions. Purpose and Scope The purpose of this report is to document the meteorologic and hydrologic conditions for the 1987 water year in order to forewarn of a potential drought and show conditions that could lead to serious water shortages. Tables and illustrations comparje precipitation and streamflow during the 1987 water year to thle average and minimum flows during the period of record and to the flows of 1977 at selected gaging stations. Hydrologic and meteorologic data for periods prior to the 1987 water year used in this report are from published records of the U.S. Geological Survey and the National Weather Service. The preliminary 1987 hydrologic and meteorologic data were obtained from 24 selected U.S. Geological Survey stream-gaging stations and 22 National Weather Service weather stations (fig. 1). Other 1987 water-supply information is from data provided by Federal and State agencies, public utilities, and the news media. METEOROLOGICAL FACTORS Precipitation and Temperature There was no consistent precipitation pattern throughout the West during 1987 water year, but generally the fall and winter precipitation was below average, with the December precipitation extremely low at most sites (fig. 2). Above average precipitation occurred in March, May, and July in some areas. The March precipitation fell largely as rain and caused snow to melt, rather than accumulate as it does in March of most years, and the May rainfall further accelerated the snowmelt. The July rain provided some relief to wilting crops but was not enough to have much impact on streamflow. For example, a 1-day rainfall of over an inch at Spokane, Washington, caused little or no increase in streamflow (R. L. Blazs, Spokane Field Office Chief, U.S. Geological Survey, oral commun., August, 1987). Total precipitation for the period October 1986 through September 1987 was near normal for most of the weather stations for which records are included in this report (table 2, at back of report). Long periods of hot dry weather separated the periods of precipitation, so that dry conditions developed by the end of summer. In the State of Washington, the Stampede Pass weather station (which is used as an index station in the State) recorded temperatures considerably above normal from February through June, with April and June averaging more than 4 degrees Fahrenheit above normal (Lee Krogh, Hydrologist, National Weather Service, oral commun., September 10, 1987), EXPLANATION WEATHER STATION 1 Eureka, California 2 Kern Reservoir, California 3 San Francisco, California 4 Tahoe City, California 5 American Falls, Idaho 6 Aver>, Idaho 7 Boise, Idaho 8 Bonners Ferry, Idaho 9 Lewiston, Idaho 10 Butte, Montana 11 Kalispell, Montana 12 Elko, Nevada 13 Detroit Dam, Oregon 14 John Day. Oregon 15 Medford, Oregon 16 Newport, Oregon 17 Colville. Washington 18 Dayton, Washington 19 Ephrata, Washington 20 Lake Wenatchee, Washington 21 Packwood, Washington 22 Snoqualmie Falls, Washington STREAM GAGING STATION 1240450

A Smart Low-Power Meteorological System

Abstract: A new low-power instrument to measure meteorological parameters has been developed. The instrument is based on an intelligent data cruncher concept: Fast sensor data rates are stored and process to yield a variety of answers for each parameter, at slower data rates, as appropriate. Special methods are used to achieve these results with an average current drain of under one mA, including sensors. Sampling rates and processing algorithms are designed to correct for swaying ocean-deployed buoys. A modular approach to design allows many types of sensors to be accommodated and permits data dissemination to a variety of destinations; data is available for real-time transmission or for internal archiving. The Weather Station's high-capacity internal data storage system, coupled with its fast data acquisition rates, enable the instrument to be used for air turbulence measurements.