Daily Weather Forecasts Research Articles

Enhancement, implementation, and performance of an adaptive short-term load forecasting algorithm

An adaptive load forecasting algorithm that was originally developed for the one-hour time period has been extensively enhanced and implemented. The major enhancement is the ability to forecast total system hourly load as far ahead as five days. The focus is on the enhancements and implementation of the algorithm. The purpose is to describe the final form of the forecasting model and the overall forecasting procedure; the procedure for utilizing minimum/maximum daily weather forecasts made by the US Weather Bureau: the offline forecasting accuracy based on four years of historical hourly load and weather data; and the implementation of the algorithm on a desktop computer.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Weather Forecasts as a Control Input for Water Table Management in Coastal Areas

ABSTRACT FOUR water table management methods were compared in computer simulations of a controlled-drainage and subirrigation system using soils and climate conditions of the Mississippi Delta region. No significant difference in the predicted relative corn yield was obtained among the four management methods when the operation for each method was adjusted to maximize yield. However, stopping subirrigation pumping whenever the rainfall probability index (RPI) exceeded 55% reduced pumping requirements for three of the methods 12 to 21% compared to the continuous subirrigation method. The optimal management of soil-water for agricultural cropland in humid, coastal areas of the U.S. often involves complex daily control of the water table because of the erratic spatial and temporal distribution of rainfall. Periods of excess and deficit soil-water conditions are common within the same growing season. Thus, water management requires both controllable drainage and irrigation facilities. A water table management system popular in the humid region, especially in the southern coastal plains, uses a subsurface draintube system for both controlled-drainage and subirrigation. Controlled-drainage permits storage of rainfall and irrigation water in the soil profile below the depth of an overflow pipe at the drain outlet. Free'' drainage to the full depth of the drainline is often needed during periods of extended or heavy rainfall to reduce the duration of excess water in root zone. During subirrigation, the water level at the drain outlet is maintained just below the overflow pipe by pumping from an external source. A sump-type structure for controlling the water level at the drain outlet for a water table management system is illustrated in Fig. 1. The check-valve, activated by a double-float, allows fast subsurface drainage during peak flow events, functioning like the two-stage weir described by Fouss, et al. (1987b). It is often necessary to pump from a sump in level and low lying topography of the coastal plains, where subsurface drainage by gravity flow is not possible. Water table management with this type of system has a high potential for achieving maximum crop production and water use efficiency if properly controlled to compensate for changes in weather conditions. The timing of changes needed in controlled-drainage and subirrigation to manage optimally the water table depth is a major problem for farmers, especially in coastal areas with fine textured soils. In the Mississippi Delta frequent occurrences of rainfall can cause large variations in water table depth because of the small, 3 to 8%, drainable soil porosity. Results from computer simulation of four management methods for water table control are presented for soils and climate conditions of the Mississippi Delta. The primary research objective was to determine the best operational parameters that efficiently utilized rainfall during the growing season without creating periods of severe excess soil-water conditions, and which minimized the need for pumping drainage and subirrigation water. Special attention was given to the potential use of rainfall probability information from the daily weather forecast as a system control input to minimize subirrigation pumping.

Top Secret/Trade Secret: Restricting and Accessing Information

Our society could well be said to run on information. We use information so much that we tend to take it for granted. We wake up to radio broadcasts of the latest news or the daily weather forecast. During the day we need data about many things—the price of goods we intend to purchase, the technical features of a service proposed for the business we run, the schedule of appointments for next week, and so on during working hours. We may have called colleagues for data, used a library, or had a search done on a computerized database. As we return home we might peruse reports and correspondence received during the day. Before the day comes to an end we have undoubtedly read at least one newspaper and perhaps checked the television guide to find out the schedule of programs. Our waking hours are filled with accessing and evaluating information.

Comparison of Mean Cloud Cover Obtained By Satellite Photographs and Ground-Based Observations Over Europe and the Atlantic

Abstract An important field of weather observation is the statement of cloud cover of the sky. Clouds not only are significant for the daily weather forecast but also are important for energetic calculations of atmospheric processes. A milestone in monitoring of large-scale cloudiness is the application of weather satellites. With the daily pictures from ESSA 8, estimations of the cloud cover in tenths for geographical 2.5° sections have been made for a period of 3 yr (Dec. 1, 1967–Nov. 30, 1970), and the mean seasonal cloud distribution over Europe and the Atlantic has been calculated. Twenty-nine synoptic stations have been used for comparison between satellite and surface observations. A detailed discussion shows the reasons for the higher surface values of cloud cover compared to the satellite values. The mean annual differences, with values about 0.9 tenth over northern Europe and 1.5 tenths over southern Europe, are caused by geometric, synoptic, and orographic factors, there is a basic difference o...

SOME WINTER WEATHER SIGNS IN UTAH

SYNOPSIS Five storms in an average winter are of sufficient severity to concern the sheepherder or other outdoor worker in Utah: and the meteorological forerunners and advance evidences of these storms are often sufficiently well marked as to enable a careful observer, isolated from access to the daily weather forecasts, to make weather forecasts of sufficient range and accuracy as to assist in the protection of his interests. An average or typical storm over the Plateau States is described, both from the meteorologist's viewpoint, and with especial reference to the attending phenomena that can be observed in any locality within the field of the storm's influence, by the layman without instrumental equipment, or with limited apparatus. Thus the lone observer, unversed in weather lore, is enabled more intelligently to read the weather signs from day to day. A number of axioms or the more significant and reliable weather signs furnished by old-time observers in the West, are quoted: and a number of weather proverbs which have been found fairly reliable in Utah are presented, with brief explanations of their relevancy.

THE WEATHER AND DAILY STREAM FLOW FOR HYDRO-ELECTRIC PLANTS

SYNOPSIS The important part played by daily weather forecasts in the problem of water regulation for hydroelectric plants in Utah is brought out in this paper. The writer compares this work with the daily prediction of water stages on eastern rivers. As many of the hydro-electric plant reservoirs are located at least 36 hours travel (measured by stream flow) from the plants themselves, it is of great importance that weather conditions, particularly as regards precipitation, be accurately known 36 hours in advance. If, for example, rain is expected at the end of any given period of 36 hours the reservoir outlet can be closed and the precious water saved until needed. On the other hand, if a period of dry weather is expected to set in at the end of 36 hours, the outlet at the reservoir must be opened so that the plant will have an abundance of water. This conditions apply equally well to irrigation control.—H. L.

Scientific Serials

THE American Meteorological Journal for July contains the following articles:— On the appearance and progressive motion of cyclones in the Indian region, by W. L. Dallas. The object of the inquiry is to see whether the cyclones of the Indian Ocean originate from the unequal distribution of temperature over and above the earth's surface. The author favours the assumption that cyclones are a production of the upper atmosphere, and thinks that the evidence, although far from conclusive, goes to show that (1) cyclonic storms descend from and retreat to the superior layers of the atmosphere; (2) the whirl may travel along in the upper atmosphere, giving only faint indications of its presence at the earth's surface; (3) the movements of cyclones agree generally with what may be supposed to be the movements of a superior layer of the atmosphere.—S. A. Hill, a memoir, by Edna Taylor Hill.—The eye of the storm (conclusion), by S. M. Ballou. The cause of the clearness of the eye is attributed by the author to the deficiency of the air at the outer edge of the calm, owing to the deflective force of the earth's rotation and the upward and outward movements of the air before reaching the centre; the deficiency being supplied by a gradual settling of the air over the whole area, thus dissolving the cloud stratum and showing the blue sky. The author admits that the discussion of the subject shows the need of more observations concerning the phenomenon.—Recent efforts towards the improvement of daily weather forecasts, by H. Helm Clayton. Tne author states in a clear and interesting form the various rules which have hitherto been established, and draws attention to a law of averages discovered by Francis Galton, which might with advantage be used in weather forecasting, for, although only applied by Mr. Galton to heredity, it is probably universal. For example, if a storm during a given twelve hours has moved with a velocity below the average, the probability is that it will move with a velocity one-third nearer the average during the next twelve hours.—The other articles are—on the sea breeze, by W. C. Appleton, and temperature sequences, by H. A. Hazen, being an inquiry as to whether, if the temperature has been high or low for a certain period, we may anticipate the contrary condition shortly. The inquiry does not seem to have led to any result which could be turned to practical use.