bluuebunny/crossref_metadata_2025 huggingface dataset:
A Fast Response Anemometer for Micrometeorological Investigations*
Authors: Gill Gerald C.
Published: August 2018

There has been relatively little study of the fine structure of turbulent flow near the ground due, in no small part, to the scarcity of suitable instrumentation to measure and record the rapid fluctuations of the wind. The present paper describes a simple heated-thermocouple type of hot-wire anemometer that in a wind averaging 5 m sec−1 is capable of recording sinusoidal wind fluctuations of 10 per sec with an accuracy of better than 90 percent, and of 40 per sec with an accuracy of 50 percent.
Some Experiments on the Speed of Response of the Electrolytic Hygrometer
Authors: Morris Vernon B. , Sobel Frederick
Published: August 2018

A simplified theory of the speed of response of electrolytic humidity sensing elements is proposed and experimental measurements which support the theory are presented. Some methods are suggested for obtaining maximum speed of response with sorption hygrometers.
Corrections of Upper-Level Wind Computations for Effect of Earth's Curvature*
Authors: Clem Leroy H. , Colson Dever , Harrison Louis P .
Published: August 2018

The conventional method of upper-wind evaluation involves projection of the sounding balloon's trajectory on the surface of a horizontal plane, tangent to the earth at the observation point. This method which fails to allow for the curvature of the earth is shown to be seriously in error in situations where the balloon is tracked by new electronic equipment to large horizontal distances. This is particularly significant under jet-stream conditions. By projecting the balloon's path on an appropriate spherical surface corresponding arc distances are obtained. Thus the effect of the earth's curvature is taken into account and more accurate wind evaluations result.

Two methods of upper-level wind computations, making proper allowance for the earth's curvature, are given. The first method involves the determination of a correction (ΔE)to one of the observed parameters (elevation angle, E) as an intermediate step to calculation of the required arc distances. The second method gives the corrected arc distances directly.

Examples are shown illustrating the effect of neglecting the curvature of the earth in computing upper-level wind speeds; positive errors of as much as 20 percent being possible under the conventional method.
The Effects of Air Temperature and Pressure on the Decay of Silver Iodide
Authors: Bolton J. G. , Qureshi N. A.
Published: August 2018

This paper describes some experiments on the deterioration of silver iodide freezing nuclei produced with a kerosene burner. It is found that the number of particles effective as freezing nuclei decreases with time as does the rate of decay itself. The decay rate is critically dependent on the ambient air temperature and to a lesser extent on the air pressure. The results suggest that for artificial rainmaking, silver iodide smoke released from the ground in warm climates is of little use but it may be very effective when released from high mountains or aircraft.
A Study of the Movement of Arctic Sea Ice in the Canadian Arctic in Relation to Meteorological, Geographical, and Oceanographic Parameters *
Authors: Winchester James W.
Published: August 2018

The movement of Arctic sea ice appears to be very erratic, and at first it seems to be a phenomenon that is impossible to forecast. This study shows that there is a relationship between ice movement and the known meteorological, geographical, and oceanographic parameters.
An Indirect Method for Estimating the Weight of Glaze on Wires
Authors: Lenhard Robert W.
Published: August 2018

The relationship between the weight of glaze on power lines and common meteorological variables is examined. The icing data used are those collected by the Pennsylvania Electric Association; the meteorological data are those available in third-order climatological station records. A graphical correlation between ice weight, daily precipitation total and a derived temperature variable is obtained. In addition, the regression of ice weight on daily precipitation is explored and the probability of occurrence of daily maximum and minimum temperatures associated with glaze storms is given. These two relations are suggested as alternative estimating tools.
The Rotary Rain Indicator, an Electrical Precipitation Time Recorder*
Authors: Raynor Gilbert S.
Published: August 2018

The rotary rain indicator, an electrical device for recording the time of beginning and ending of periods of precipitation, was developed at the Brookhaven National Laboratory Meteorology Group and has operated successfully for eight months. Its sensitive element consists of a rotating grid whose circuit may be completed by a drop of water.
Notes on Warm-Cloud Rainfall
Authors: Alpert Leo
Published: August 2018

Warm-cloud rainfall characteristics observed during field work in Puerto Rico in November 1953 as a consultant for the Puerto Rico Water Resources Authority to investigate the possibilities of stimulating rainfall through cloud seeding are reported. A map and list of 52 references of observations of warm-cloud rainfall over the Earth are presented.
An Automatic Water Drop Collector for Field Use
Authors: Wittman John P. , Goodale T. C.
Published: August 2018

A self-powered instrument for collecting rain drops is described. The rain drops are collected in flour filled trays and retained as flour pellets. The collector is triggered by the rain drops and its sampling rate varies with intensity of the rain. It operates remotely and once started samples automatically.
Fire Whirlwinds
Authors: Graham Howard E.
Published: August 2018

Description and general behavior of fire whirlwinds in the Pacific Northwest are outlined, field data are presented and conclusions are drawn as to favorable conditions. The behavior of observed fire whirlwinds agrees well with related aerodynamic theory.
Westerly Flow Past an Obstacle in a Rotating Hemispherical Shell*
Authors: Frenzen Paul
Published: August 2018

Further results obtained in the model experiments originally discussed by Long and Fultz are described including the details of wave-number changes and the characteristic types of wave patterns associated with certain latitudes of the obstacle. Possible analogies between circulations in the model and in the atmosphere are drawn.
The Thermal Influence on the Daily Pressure Wave
Authors: Haurwitz B.
Published: August 2018

The effect of clear and cloudy days, and of days with large and small temperature ranges on the daily pressure variation at Bermuda is investigated. It is shown that the various harmonic components are not significantly affected by the different weather conditions contrary to what has been found for continental stations. Such an independence from the local weather situation is to be expected over the oceans, especially in the case of the semidiurnal pressure oscillation. The results strengthen the explanation given by Chapman for the occurrence of the semidiurnal pressure maximum two hours before solar transit through the meridian.
Synoptic Climatology of the Arizona Summer Precipitation Singularity *, #
Authors: Bryson Reid A. , Lowry William P.
Published: August 2018

Using the percent of climatological stations reporting rain as a measure of the raininess of a particular day in Arizona, a large increase in rainfall within a few days is found to occur about July 1 in most Arizona summers. By means of flow charts, upper air sequences, mean soundings, and diurnal temperature ranges, this increase is shown to be the result of a rather sharp transition from one dominant air mass to another over the state. The occurrence appears to be related to index, and a hemispherical singularity also appears to be related to the phenomenon.
Hurricane Squall Lines
Authors: Ligda Myron G. H.
Published: August 2018

Are the outer precipitation bands of hurricanes and typhoons important phenomena? In suggesting that the answer to this question is “yes” several features of these bands are described or postulated. Methods of estimating the severity of attendant weather conditions by radar observation are offered.
Analysis of Some “Project Jet Stream” Data
Authors: Landers Holbrook
Published: August 2018

Wind and temperature observations made by a specially equipped B-29 aircraft are compared with the conventional upper wind and temperature observations. Analyses of the two sets of data are compared in vertical and horizontal planes, and some wind field derivatives are compared and discussed. In one case strong vorticity fields of opposite sign are found to occupy ] the same region when computations are made from the two different sets of data. Two corrections to the wind speeds measured by pibal and rawin methods are discussed and applied to the data. These are the correction for the earth's curvature and a correction of the opposite sign which is caused by the graphical method of taking two minute* averages. It is suggested that perhaps the latter correction is large enough at low speeds to warrant applying it to upper wind data.
A Discontinuity Surface Produced by Topographic Winds Over the Upper Snake River Plain, Idaho *
Authors: Wilkins Eugene M.
Published: August 2018

Eastern Idaho's Snake River Plain and that portion of the Continental Divide bordering it to the north comprise a topographic feature that provides an interesting local wind phenomenon. A sloping discontinuity surface is produced in a zone of conflict between slope ** and valley winds. The incursions of the front at the National Reactor Testing Station have become the subject of investigation because of their effect on the dispersion of stack effluents*

Photographs are presented showing the effect of the frontal shear on a stack plume, smoke released at the ground, and a debris cloud from an experimental explosion. These photographs give an indication of the circulation pattern in the vicinity of the front. In addition, data from a network of recording stations, instruments on a 250-ft tower, and low-level wind and temperature soundings have been used to establish the circulation model.

Information is presented to show seasonal and diurnal effects, and also the influence of major pressure systems on the front phenomenon.
A Possible Relationship Between the Solar Corona and Weather Conditions in the Central Midwest
Authors: Farthing E. D.
Published: August 2018

Evidence strongly indicates that terrestrial weather conditions are closely related to changes in solar emission at certain wave lengths. Although this work is confined to weather conditions at one specific location (Kansas City, Missouri), there is reason to believe that similar correlations, with probable changes in phasing and/or timing, may be noted in other areas. Correlations of the type noted should be of considerable value to agriculture and to other interests depending on general forecasting. The results, if valid, are of great theoretical importance and promise improved forecasting methods applicable to both daily and longer term forecasting.
Meteorological Problems in the Forecasting of Citrus Insect Infestations *
Authors: Pratt Robert M.
Published: August 2018

As a basis for forecasting infestations, data on insect and mite populations have been collected from 130 representative central Florida citrus groves at monthly intervals during a four year period. To some extent, forecasts can be based on recurring annual cycles, but to obtain a higher degree of precision, information must be obtained on the factors which regulate populations. Weather conditions affect the life span and mortality of insects and mites directly, and also indirectly through effects on the abundance and efficiency of parasites, predators and diseases. December temperatures have been found to be a factor in the abundance of six-spotted mites in succeeding months through June. The populations of this and the citrus red mite are inversely correlated with rainfall. Other temperature and moisture relations have been established but extensive further microclimatological studies are needed.
Project Jet Stream Observation of a Small-Scale, High-Level Vortex
Authors: McLean George S. , Rados Robert M .
Published: August 2018

An intense cyclonic vortex over Florida at 36,000 feet is evidenced by Project Jet Stream's B-47 flight observations. Aircraft winds, temperatures, and cloud observations are presented with an analysis of synoptic charts. A weak jet stream on the west side of the vortex and strong horizontal shear are obvious. The scarcity of upper-air observations could cause an oversight of similar situations which are not reflected at the surface level.
Integrating Facsimile into a Weather Service*
Authors: McTaggart-Cowan P. D.
Published: August 2018

To make maximum use of facsimile in a weather service it is necessary to examine practically all organizational aspects of the forecast services. This paper attempts to set forth the fundamental questions that must be considered by a weather service embarking on the operational use of facsimile, and presents suggestions on how to integrate weatherfax into an economical and efficient weather service.
A Severe Weather Service for Industry *
Authors: Collins George F.
Published: August 2018

The du Pont Company has recently set up a weather advisory service to supplement United States Weather Bureau services. Installation of weather teletype-writers and instrument facilities enables special forecasts to be made for maintenance shutdowns, equipment testing, barging operations, shipment of commodities subject to damage by weather extremes, and the issuing of severe weather warnings for company operations which might be affected.
A Study of Easterly Waves in the Gulf of Mexico
Authors: Hosler Charles R.
Published: August 2018

This report presents the results of synoptic analyses of thirty-five easterly waves in the Gulf of Mexico in the period 1946 through 1954. The findings are presented in a synoptic manner.
The Effects of Air Temperature and Pressure on the Decay of Silver Iodide
Authors: Warner J. , Bigg E. K.
Published: August 2018

Bolton and Qureshi's laboratory experiments on the decay of silver iodide smokes were repeated and it was shown that for dilute smokes the deterioration was very slight and there was no important temperature effect. It is concluded that the coagulation of concentrated smokes used was responsible for the high rates of decay they observed at warm temperatures.
A Spot Climate Recorder
Authors: Schultz Herbert B. , Brooks Frederick A.
Published: August 2018

In agricultural research as well as in applied climatology as a whole, there is an increasing demand for portable meteorological field equipment capable of recording continuously more environmental factors than the conventional hygro-thermograph. The spot climate recorder described can register dry bulb, wet bulb, soil, and black globe temperatures, and wind direction and velocity on either daily or weekly charts, whichever is best for the climate survey. If desired, all these elements can be registered on one chart, but a set of two recorders has been found to be no more expensive and gives the economic advantage of making each useable separately. This is desirable for instance when a network of wind registering stations is needed (including 1 temperature each) but the complete record of moisture, radiation, etc. is sufficient at one station. The wind-recording circuits are designed for low-current drain on a 6-volt storage battery. Rather than draw on this battery to provide aspiration for the dry and wet-bulb thermometers, the wind velocity record is used to determine at which few hours the wet-bulb record may be unreliable.
Tropopause Analysis and Surface Forecasting
Authors: Culkowski Walter M.
Published: August 2018

Few forecasters in the field realize the value of tropopause analysis. This article, though general in nature, may serve as an introduction to a few of the theoretical aspects of such analysis as applied to the “Ft. Scott Blizzard” of 1954. Since the tropopause defines the upper limit of tropospheric dynamics, and since elementary tropopause analysis is faster, easier and sometimes more rewarding than the more familiar constant pressure charts, a brief description of the writer's investigations may stimulate some much needed interest in the field.
Microwave Refractive Index Fluctuations Associated with Convective Activity in the Atmosphere *
Authors: Gerhardt J. R. , Crain C. M. , Chapman H.
Published: August 2018

The study of tropospheric refractive index distributions which began in 1951 using an airborne microwave refractometer has been continued during the past year with emphasis being placed on obtaining data on the microstructure of the atmosphere. Refractometers sufficiently sensitive to observe refractive index or equivalent moisture content variations having frequencies up to 100 cycles per second and amplitudes as small as 0.01 N-unit have been used in aircraft over New England, Florida, Ohio and Colorado areas to measure refractive index fluctuations from near the surface to up to 20,000 feet. Special efforts have been made to obtain data on free air and air to cloud index changes and a summary of certain of these data is presented. Preliminary analyses are made of data showing flights through clouds, convective thermals and frontal systems.
Preliminary Report on the Relationship Between the Jet at the 200-mb Level and Tornado Occurrence
Authors: Lee Jean T. , Galway Joseph G.
Published: August 2018

In a study of the 200-mb Height Chart and associated jet to determine their usefulness in tornado forecasting, a consistent phenomenon was observed, namely, that the majority of tornadoes investigated occurred along or near the −60°C isotherm at 200-mb. More precisely, the western and southern portions of the −60°C isotherm of the cold “pool” it circumscribed were the favored area. The jet at 200-mb in most cases delineated that portion of the −60°C isotherm under which tornadoes occurred. Further, certain consistencies appeared on the tropopause chart that might be related with tornado occurrence.
The Microbarographic Oscillations Produced by the Explosions of Hydrogen Bombs in the Marshall Islands *
Authors: Yamamoto Ryōzaburō
Published: August 2018

Concerning the pressure oscillations due to the hydrogen-bomb explosions in the Marshall Islands, the records of routine barographs at the fourteen stations in the Pacific territory were examined and the following facts were found: (1) No trace of the oscillation could be detected on the barograms at the stations located nearly to the west of the explosion site in spite of the comparatively close distance. (2) Speed of the wave propagating eastwards was higher than that of the westward wave by about 50 m/sec.
Sea Surface Temperature Anomalies and Hurricanes *
Authors: Riehl Herbert
Published: August 2018

Monthly and annual sea surface temperature anomalies have been computed for a large portion of the North Atlantic Ocean for the period 1887–1936. Correlations with hurricane frequencies and tracks become evident only when periods of five years and more are considered.
The Variability of Cold Front Precipitation
Authors: Austin James M. , Blackmer R. H.
Published: August 2018

Radar data are utilized to describe the precipitation patterns with 30 summertime cold fronts in the vicinity of Cambridge, Massachusetts. An attempt to relate the precipitation type and coverage to synoptic parameters which can be obtained from the conventional meteorological charts yielded essentially negative results. Possible causes of the precipitation variability are discussed.
Experiments Using Window to Measure High-Altitude Winds
Authors: Anderson Albert D. , Hoehne Walter E.
Published: August 2018

Strips of metal foil (window), dispersed by balloon and aircraft, have been tracked by radar to measure wind velocities at altitudes up to 74,000 feet. These wind velocities have been compared with those measured over the same altitude range by GMD-1A equipment and radar-target tracking. The results indicate promise for obtaining high-altitude winds by this new technique. Further experiments envisioned for the 100,000 to 200,000 foot altitude range will necessitate the use of rockets to carry and eject the window.
Turbulence Measurements in a Young Cyclone Over the Ocean1
Authors: Bunker Andrew F.
Published: August 2018

A flight was made through a young coastal storm with a PBY-6A aircraft equipped to measure both mean temperatures and rapid variations of the temperature and turbulent gust velocities. Low level observations were obtained which show the thermal structure of the cyclone and the magnitude of the turbulence, the shearing stresses and the heat flows. Particularly strong turbulence was noted in the transition zone between the cool air of the anticyclone and the faster moving air of the warm sector. Stable air and downward heat flow was observed in the cold air mass.
A Simple Analog Computer for Determination of the LaPlacian of a Mapped Quantity
Authors: Hess Seymour L.
Published: August 2018

The determination of the LaPlacian of a mapped quantity, such as the geostrophic vorticity, is an important but a time consuming process. The common procedure involves a number of interpolations and an algebraic computation for each point at which the evaluation is made. A device is presented in which the slow process of interpolation is replaced by the faster and more reliable process of measurement of distance between isopleths of the mapped quantity, and the algebraic calculation is replaced by the rapid, automatic operation of a DC analog computer. The numerical result is presented as the deflection of a millivoltmeter.

In practice the use of this computer proves to be a rapid, reproducible, sufficiently accurate means of determining the geostrophic vorticity from an analysis of the contours of an isobaric surface.
Weather Reconnaissance by Airborne Time Lapse Camera
Authors: Schaefer Vincent J. , Taylor Wallace M.
Published: August 2018

The operation, in a high flying airplane, of a simple 16 mm time lapse motion picture camera produces an excellent record of the cloud systems and other visual atmospheric patterns existing over large areas of continent and ocean.

Over the past several years such records were obtained from both jet and propeller driven planes through the cooperation of the Boeing Airplane Company and the Air Weather Service, U.S.A.F. with the Munitalp Foundation.

For best results it was found that the camera should be mounted at right angles or at 45 degrees with respect to the flight path and with a downward tilt of from five to twenty degrees depending on the cruising height of the plane. A two second interval was found to be suitable for good results with planes with an average speed in the range of 300–600 mph. Intervals of four to even ten seconds are permissible at these speeds for economy or convenience. When such a sequence is viewed as a movie, near clouds move by at a different rate from those in the middle or far distance thus giving an excellent illusion of three dimensions. Successive frames may be selected from a sequence and viewed in a stereoscope to get a three dimensional view of the area photographed. When projcted at sound speed in a movie projector, a film made with a two second interval sequence presents the illusion that the viewer is travelling through the sky at a speed of nearly 29,000 mph.
An Application of Long-Wave Principles to a Cold Outbreak
Authors: Hughes Lawrence A. , Saxton David W.
Published: August 2018

An incipient severe polar outbreak that eventually affected practically all of the United States is considerably delayed by retrogression of a major trough in the westerlies. An investigation of this retrogression shows how long-wave principles aid in the prediction of such outbreaks.
Detailed Wind Structure in an Intense Frontal Zone *
Authors: Reed Richard J.
Published: August 2018

Measurements of elevation and azimuth angles, taken every six seconds by an AN/GMD-1 rawin set, are used to compute the detailed wind structure in an intense frontal zone. It is found that the vertical wind shear is discontinuous at the frontal boundaries as anticipated from the thermal wind equation.
A Fast-Response Resistance Thermometer System for Simultaneous Recording of Air Temperatures at a Number of Separated Points1
Authors: Mason George L.
Published: August 2018

A resistance-thermometer system is described which permits simultaneous and continuous recording of air temperatures at a number of separated points. Unbalance current in a Wheatstone bridge network is used as the measure of temperature, and is recorded by a multichannel light-beam oscillograph. The lag coefficient of the system is approximately 0.1 second.
Incipient Wind-Generation of Ocean Waves by a Norther1
Authors: Wilson Basil W.
Published: August 2018

Details are presented of observations and photographs of the sea surface in the Gulf of Mexico, near Galveston, obtained during a south-north run on a formal cruise of the A. A. Jakkula, oceanographic vessel of the Texas A. & M. Research Foundation. The occasion was highlighted by the advent of a norther which provided an example of incipient wind-generation of waves from ripples. The first stage of the run had following winds and swells from the south. After a period of calm the wind backed to the north and wavelets from the north developed against the southerly swell. Good agreement is obtained between the observed heights and periods of waves and those determind by forecasting procedures which make suitable allowance for the moving fetch and the variability of the wind within it.
Hay Fever Pollen Counts and Some Weather Effects
Authors: Dingle A. Nelson
Published: August 2018

The standard gravity slide method of obtaining hay fever pollen counts is examined in relation to the volumetric method. Scrutiny of calibration data in the light of weather information reveals three interesting weather-related sequences of pollen concentrations. The gravity slide counts appear to represent the pollen concentrations quite poorly.
Utilization of Satellite Observations in Weather Analysis and Forecasting
Authors: Widger William K. , Touart C. N.
Published: August 2018

The meteorological data which can be expected from artificial satellites of relatively sophisticated types are discussed, as are the problems associated with the observing and handling of such data. The deductions which seem possible from such data and a simplified example of how they might be used are presented. An appraisal of the probable meteorological value of such data is included.
Microbarographic Oscillation Produced by the Soviet Explosion of a Hydrogen Bomb on 22 November, 1955
Authors: Yamamoto Ryōzaburō
Published: August 2018

The propagative natures and the modes of the microbarographic oscillation of the Soviet nuclear explosion are discussed, and a method of rough estimation of the distance from the explosion site in western Japan is suggested by taking account of the dispersive natures of the observed wave.
A Systematic Approach to Local Objective Forecast Studies
Authors: Sartor J. Doyne
Published: August 2018

Problems in the design, preparation, and use of local objective forecasting studies have been evaluated while specific local objective forecasting studies were being made. As a result, a systematic procedure that may be used as a guide in designing and preparing local objective forecasting studies was developed and tested in a number of seminar-workshop groups. The systematic procedure is outlined and discussed with illustrations from several local objective forecasting studies. The procedure consists of defining the local forecasting problem in terms consistent with observing and forecasting capabilities, resolving the variability of the forecast element into its cyclic (seasonal and diurnal) and “synoptic” components, and finally, reassembling the components into a forecast scheme that allows the forecaster to exercise his training as a meteorologist.
Large-Scale Vertical Motion and Weather in January, 19531
Authors: Miller Albert , Panofsky Hans A.
Published: August 2018

This paper summarizes the relationships between weather, moisture and large-scale vertical motion for January, 1953. The moisture parameter was the dew point depression at 850 mb, and vertical velocities at 700 mb were available as computed by three different methods. The probability of clear sky at an individual station varies from five percent for moist, ascending air to 93 percent for dry, descending air. The probability of precipitation for the same conditions varies from 67 percent to 0 percent.

Incidentally, comparison of vertical velocities of various types indicates that nonadiabatic warming at 700 mb is important only for rapid flow from north to south, then averaging 1.3C in 12 hours.

The standard errors of the different techniques of computing vertical motion are estimated to vary from 0.9 to 1.4 cm sec−1.
The Relation Between Large-Scale Vertical Motion and Weather in Summer
Authors: Curtis R. C. , Panofsky H. A.
Published: August 2018

Large-scale vertical velocities are shown to be closely related to the probabilities of convective precipitation and fair weather in the eastern United States during July 1955. In the daytime the mean relative humidity of the 900 to 700 mb layer is better related to the probability of convective precipitation than the vertical velocity. At night, however, vertical velocity is the best single predictor of convective precipitation, with a modified Showalter Index being a very useful additional criterion.

The large-scale vertical velocities that occur in normal summer synoptic situations appear to be produced by a diurnal variation in the momentum exchange between the ground and the air.
Ulcers and Temperature Changes
Authors: Davis Francis K.
Published: August 2018

A comparison of the number of duodenal ulcer cases admitted to the Philadelphia General Hospital over a 5-year period with the temperature-change curve over the same period shows close agreement, indicating that hemorrhages from duodenal ulcers may be brought on by marked variations in temperature and the stress that such variations put on the body as it is forced to adjust. This suggests that a warm climate with relatively little daily and seasonal change in temperature would afford the most suitable residence for those prone to suffer from duodenal ulcers.
Nuclei in the Exhaust of a Jet Engine
Authors: Poppoff I. G. , Robbins R . C. , Goettelman R. C.
Published: August 2018

Surveys were made of condensation nuclei, freezing nuclei, and water vapor concentrations in the exhaust wake of an F80 jet aircraft.

Condensation nuclei concentrations were found to be maximum in a region of 50 to 75 ft aft of the tailpipe, with secondary maxima appearing at approximately 150 ft. No freezing nuclei were found, although observations indicated the possibility that they were present but inhibited by exhaust constituents.
A Practical Method for Estimating Rainfall Rate Frequencies Directly from Climatic Data
Authors: Russak S. L. , Easley J. W.
Published: August 2018

In evaluating the environmental limitations on microwave signal transmission, it was necessary to determine the occurrence of rainfall rates for a number of regions in different parts of the world. Clock-hourly precipitation data were used where available. Where these data were not available, a known empirical technique was employed which correlates clock-hourly rainfall at individual rates to a climatological index. This index uses parameters which are almost universally obtainable—namely, mean annual rainfall and number of days with measurable rain. In the course of this work, the authors found a more general relation between clock-hourly rainfall rate frequencies and the climatological index. Using this relation, rainfall frequencies at any rate are obtained directly from a linear equation and two nomograms. It is also possible to synthesize the complete frequency distribution of rainfall rates and obtain, as a check, the mean annual rainfall. Examples, supplemented by illustrations, are given in the development of this technique and its utilization.
Observed Winds at High Levels
Authors: Woodbridge David D.
Published: August 2018

Very-high-level winds have been observed as a result of smoke drifts from rocket flashes. These smoke drifts have been observed visually on the ground under full-moon conditions. The drifts have also been photographed with tracking cameras and the directions and shears measured. It appears that considerable shear occurs at some levels.
An Outdoor Weather-Comfort Index for the Summer Season in Hartford, Connecticut
Authors: Hendrick Robert L.
Published: August 2018

Temperature, relative humidity, wind speed, and solar radiation are combined into a single numerical expression for outdoor weather comfort in Hartford. The use of this “Comfort Index” in radio weather broadcasts is discussed.
History and Measurement of the Two Major Scottsbluff Tornadoes of 27 June 1955
Authors: Hoecker Walter H.
Published: August 2018

Fairly complete tornado life histories have been synthesized from over 100 still photographs and eight strips of color movie film taken of two tornadoes near Scottsbluff, Nebraska, in June 1955. Funnel height and width measurements have been made from the still photographs, and translational speed has been determined at a few points and rotational speed at one point from the movies.

Evidence of downward air motion in the vicinity of the second tornado was found, and in one instance cloud elements acting as air parcel tracers demonstrated the downward motion.

Outline tracings of photographs illustrating significant size- and shape-changes are presented and measurements of interest are attached. All drawings are scaled to give the effect of observing the tornadoes from the same distance. Time lapse between the significant stages of each tornado has been estimated.

Some definite relationships are shown to exist between the tornado height and width, and differences between the two tornadoes in time trends of the several dimensions are also shown.

A model of tornado evolution is proposed.
Observations on a Wind Anomaly near the Earth's Surface
Authors: Longley Richmond W.
Published: August 2018

The results of the observations by double theodolites on 10 pairs of pilot balloons released during an 80-min period are described. These showed variations of the wind speed and direction below 3000 ft, both with height and time. The results are not related to the nocturnal inversion as are those of other observers of the same phenomenon but can be attributed only to the lack of uniformity of the wind field under certain conditions.
An Operational Technique for the Forecasting of Flow Patterns in the Upper Troposphere
Authors: Vederman Joseph , Dubofsky Bernard
Published: August 2018

Forecasting procedures are given so that a rapid 300-mb or 200-mb prognostic chart can be made from any valid 500-mb prognosis. Height relationships are given between the 500- and 300-mb levels and the 500- and 200-mb levels.

The 500-mb relative vorticity is also utilized to adjust for variations in tropopause height.
A Comparison of Rainfall Data Obtained from Rain-Gage Measurements and Changes in Lake Levels
Authors: Harbeck G. Earl , Coffay Ethel W.
Published: August 2018

During the Lake Hefner evaporation studies of 1950-1951, changes in lake stage were measured with great accuracy. Rainfall records were obtained using a network of 22 standard 8-in rain gages. In the present study, the lake was considered to be an immense rain gage, and the changes in lake stage were used as a measure of the rainfall. A comparison was then made with the average catch of the 22 rain gages around and on the lake. This catch was 10 per cent less than the rise in stage on the lake. The data indicate that strong winds reduce the catch in the rain gages.
Tornado-Producing Synoptic Patterns
Authors: Miller Robert C.
Published: August 2018

Three basic Fawbush-Miller tornado-forecast rules are discussed in the light of experience gained during nine years operation of the USAF Severe Weather Warning Center. These three rules are then related to five tornado-producing synoptic patterns and the suggestion made that the latter are suitable to serve as a basis for an analog system. The discussion is sufficiently detailed to be of operational value to the field forecaster.
The Pulsed-Light Theodolite
Authors: Jay Lee A.
Published: August 2018

The U. S. Army Electronic Proving Ground at Fort Huachuca, Arizona has tested a new type of theodolite using pulsed light for ranging and tracking of meteorological balloons. The pulsed-light theodolite (PLT) electronically computes the slant range to an airborne free balloon. The time required for a pulse of light to go to the balloon and back determines the range. By using the slant range and azimuth and elevation angles, the equipment computes the elevation, wind speed and wind direction and automatically prints the data on paper tape. The tests indicate that the PLT system is an accurate and fast method of measuring low-level winds. It could provide wind data without delay to such activities as rocket launchings.
Distribution of Precipitable Water Vapor over the Continental United States 1
Authors: Reitan Clayton H.
Published: August 2018

Mean monthly values of precipitable water for about 50 stations in the United States are used to describe the amount and variation of moisture over the area. The average precipitable water over the United States is found to be 1.75 cm and to range from 0.94 cm in February to 2.99 cm in July. Monthly and yearly averages for the period 1946 to 1956 indicate that there is considerable variation on a monthly and sectional basis but that the yearly and overall area amounts of precipitable water are rather stable.
A Method in Regression Equations for Forecasting the Movement of Typhoons
Authors: Wang Griffith
Published: August 2018

Based on six years (1950 through 1955) of typhoon data, three equations are formulated for the purpose of forecasting the movement of typhoons. In these equations, the following criteria at the 700-mb level are accounted for:(1) the contour height and its tendency at a point 10 deg of lat north of the typhoon center,(2) the contour height and its tendency at a point 10 deg of lat from the typhoon center and 90 deg to the right of its direction of motion,(3) the contour height and its tendency at a point 10 deg of lat from the typhoon center and 90 deg to the left of its direction of motion, and(4) the intensity and orientation of the major axis of a subtropical high cell which plays the role of steering the movement of the typhoon.

Typhoon data collected during the years 1956 through 1958 are used for verification. With use of these equations, results of forecasting a 24-hr typhoon movement are found to be of practical value.
An Objective Application of Vorticity Principles to Precipitation Forecasting
Authors: Jenrette James P.
Published: August 2018

An objective method is developed for forecasting the occurrence and intensity of showers. A composite moisture-stability parameter is designed which approximates the current structure of the atmosphere. This parameter is then combined with a vorticity-advection parameter which dictates the changes of the current structure. The system is designed for the summer season and is tested for Chanute Air Force Base, Illinois with a resultant skill score and per cent correct of 0.74 and 90 respectively.
A Rational Approach to the Mapping of Freeze Dates1,2
Authors: Caprio Joseph M.
Published: August 2018

Two methods of estimating average last-freeze dates as applied in Montana are described. Both methods are based on the observation that day-time-temperature differences between Weather Bureau climatological stations in close proximity and at the same elevation are much less than night-time differences in temperature. A procedure for drawing 100-ft-elevation-interval maps of the date when the mean maximum temperature reaches 70F in the spring is described. The first method of estimating freeze dates is based on the statistical relation between average date of last spring freeze, the date when the mean maximum temperature reaches 70F and average diurnal temperature range at the time. The second method incorporates the same general parameters but is based entirely on mapping procedures. A method of mapping average last-freeze dates is described employing the unit area concept, which can be applied in connection with either method of estimating average last-freeze dates.
Some Measurements of Diffusion Parameters from Smoke Plumes1
Authors: Bowne Norman E.
Published: August 2018

A new technique for the use of smoke as a visible quantitative tracer for diffusion measurements was applied to aerial photographs of smoke plumes. The turbulence measurements obtained from the smoke plumes are compared with turbulence measurements from a wind vane.
A Graphical Technique of Forecasting Overcast Skies and Precipitation with Central Weather Facility Products
Authors: Jenrette James P.
Published: August 2018

Practical procedures for forecasting areas of overcast skies and precipitation are presented. The forecast thickness field is relabeled as a forecast maximum precipitable water field. A forecast actual precepitable water field is then graphically subtracted from this field to derive a forecast saturation chart. The forecast saturation chart is then adjusted with the forecast vertical-motion field. Isopleths of critical values on the adjusted saturation chart outline forecast areas of overcast skies and areas of probable precipitation.
Cloud Structure of an Occluded Cyclone Over the Gulf of Alaska as Viewed by TIROS I1
Authors: Winston Jay S. , Tourville Lloyd
Published: August 2018

The cloud structure of an occluded cyclone and its environs over the Gulf of Alaska is revealed in detail by a series of TIROS pictures. The pictures clearly portray:(1) the nature and extent of dense cloudiness around the inner core of the cyclone;(2) a broad band of cloudiness associated with the main polar front;(3) the pattern of overrunning cloudiness marking a newly developing wave south of the main storm;(4) a previously undetected, old cyclonic vortex in mid-troposphere; and(5) the striking cellular arrangement of cumuliform clouds in the cyclonic flow to the rear of the storm.

These features are related to the conventional meteorological data and analyses over this area and are found in many places to corroborate them rather well. On the other hand, there are several places, particularly in view of the sparsity of conventional data, where the cloud pictures suggest that improvements could be made in the map analyses and numerically computed vertical motions on the basis of the TIROS cloud information.
A Modification of the Standard Weather Bureau Rain Gage for Summer and Winter Use 1
Authors: Gomm F. B.
Published: August 2018

This article describes a modified collection unit for the standard Weather Bureau-type rain gage. The described unit, consisting of a polyethylene bottle, rubber stopper, vent tube and adapter funnel, replaces the metal collection tube of the standard gage.

In a laboratory test, evaporation from the modified system was not great enough in a 30-day period to measure with a standard measuring tube. Field tests showed the described unit superior to the standard collection unit and equal to the standard unit with a 0.20-inch oil film in the reduction of evaporation. The described unit, which eliminates recharging with oil or antifreeze after each reading, has been in field use for two years without damage from freezing.
The Problem of Forecasting Hail Encounters During Flights through Thunderstorms 1
Authors: Lehr Paul E.
Published: August 2018

Although it is known that hail is formed in thunderstorms, relatively little is known about positive means of forecasting the probability of encountering hail during flights through thunderstorms.

To provide guidance toward a solution of this problem, characteristics of thunderstorm-hail occurrences in the Alberta Province of Canada and the continental United States, exclusive of Alaska, are discussed.
Hailfall of 10 September 1959 Near Medford, Oregon
Authors: Decker Fred W. , Calvin Lyle D.
Published: August 2018

A system for observing hailfalls at Medford, Oregon includes a network of hail recorders and a number of volunteers who collect hail. This paper reports the area affected and the kind of stones collected in one typical hailfall of 1959. Conclusions call for more comprehensive observations in 1960.
Prediction of Upper-Air Winds over Cape Canaveral1
Authors: Striebel C. T. , Bieber R. E.
Published: August 2018

The prediction-error variance has been obtained by linear-regression methods for various 12-hr and 24-hr predictions of winter-season winds over Cape Canaveral, Florida. The prediction schemes employed include the most sophisticated which utilizes all of the wind measurements at all of the altitude levels as well as the simplest which utilizes only the measurements at the same altitude level. The results show that very little is gained by considering the most sophisticated or “Best Linear Prediction” as opposed to the simplest. Also, very little is gained by taking more than one sounding in advance of the prediction. An appreciable decrease in the error variance, especially in the region just below the jet-stream altitude, is realized for the 12-hr as compared to the 24-hr prediction.
Vertical Temperature Difference Observed over an Urban Area
Authors: DeMarrais Gerard A.
Published: August 2018

Temperature differences recorded from thermohms at the 60-, 170-, and 524-ft levels on the WHAS-TV tower in Louisville are analyzed. The data indicate that the heat island of an urban area has considerable effect on the vertical temperature differences observed at night so that the normal diurnal range of stability conditions encountered over an urban area is much smaller than that over open country.
Meteorological Factors Affecting Particulate Air Pollution of a City
Authors: Dickson R. R.
Published: August 2018

Due to its utility in handling joint functions, the method of coaxial graphical correlation is used to relate particulate air pollution at Nashville, Tennessee to various meteorological factors. The derived relationship applied to test data yielded an average absolute error of 38.3 micrograms per cubic meter and root-mean-square error of 59.3; these results are clearly superior to a climatological control forecast using seasonal average concentrations. Graphical analysis and supporting correlation-ratio computations suggest that small amounts of precipitation may be very effective in cleansing particulate matter from the atmosphere, rendering further precipitation of little consequence. The analysis emphasizes the importance of wind direction in governing air-pollution concentrations at a point, suggesting that point measurement of particulate concentrations may have little representativeness when applied to an area the size of a city. Particulate-matter concentration is found significantly correlated with day of the week (weekday-weekend groupings), offering an avenue for improvement of results.
The San Fernando Convergence Zone 1
Authors: Edinger James G. , Helvey Roger A.
Published: August 2018

The vertical structure of a zone of converging winds in the San Fernando Valley is examined by using stadia pibal observations and a network of continuously recording surface wind stations. This zone of convergence, marking the location where two sea breezes of different points of origin along the southern California coast meet each other, apparently produces rising motions. The pattern of flow in the vertical plane normal to the convergence line is constructed by applying the continuity equation to the wind data. This pattern prescribes a redistribution of a ground-based layer of pollution on the Los Angeles side of the zone of convergence. This redistribution is compared with the actual distribution as observed from aircraft.