bluuebunny/crossref_metadata_2025 huggingface dataset:
Results of Rocket and Meteor Research *
Authors: Whipple Fred L.
Published: August 2018

Results are presented of rocket and meteor research in the upper atmosphere during the past three years. Both methods have been valuable in determining the pressures, densities and temperatures in the upper atmosphere and variations with time and place above an altitude of 30 km. The basic atmospheric data are now rather well determined to 130 km over New Mexico. Knowledge of the composition of the atmosphere to 72 km depends solely upon rocket sampling techniques. A great deal of information has been obtained from the rocket measures concerning radiation from the sun in the far ultraviolet to wavelength about 800 Å and in the soft X-ray region below 20 Å.

A considerable section of the paper is devoted to the question of micro-meteorites, their existence and effect on the upper atmosphere. In addition, three Appendixes include some more recent information concerning temperatures and composition of the upper atmosphere and concerning high-frequency solar radiation.
Some Measurements of Velocity of High Altitude Winds at Sydney, NSW
Authors: Edwardes H. N.
Published: August 2018

A technique is described of measuring wind velocities at high altitudes by observing with radar the course of an ascending balloon. The results of high altitude windfinding experiments conducted at Sydney during the winter months of 1949 showed a maximum velocity at 40,000 feet and a minimum at about 70,000 feet. The flow near and above the maximum was generally from the west. At higher altitudes, near the minimum, the wind was also from the west but showed a tendency to change to the east during July and August.
Some Air Pollution Aspects of the Los Angeles Temperature Inversion
Authors: Robinson Elmer
Published: August 2018

During research on air pollution in Los Angeles, various meteorological aspects of the problem have been studied. One of these was the derivation of a mathematical formula which combines measures of the stability, height, and thickness of the inversion layer to give an overall value for its intensity. This formula has been useful in describing inversions and in various correlation studies. A file of data on inversion conditions in the Los Angeles area has been accumulated in the course of the smog program. These data, which apply to mean inversion conditions from May through November, are interesting not only for the smog problem but also in evaluating the climate of the area. They should prove useful in other studies where an appreciation of the climatic nature of the inversion surface is required. The cycle of the inversion indicates that the base gradually lowers during the summer and early fall and that as early as June, inversions are present 90% of the time. The “smog season” generally coincides with the latter part of the inversion cycle.
A Numerical Prediction Experiment
Authors: Berkofsky Louis
Published: August 2018

An experiment was conducted, under simulated routine operating conditions, to determine the feasibility of preparing forecasts of the 500-mb surface by business machine methods. It was found that a 24-hour forecast could be prepared in about 11% hours. It appears that this time may eventually be reduced to about 7 hours.
The Annual Course of Month-to-Month Persistence in Climatic Anomalies*
Authors: Namias Jerome
Published: August 2018

The annual march of month-to-month persistence in anomaly of temperature, precipitation, and mid-tropospheric flow pattern over the United States is examined for approximately the past decade. The data indicate a tendency for persistence in all three elements during all adjacent pairs of months except from April to May and from October to November when great and often abrupt transitions of long period regimes occur. These empirical findings are related to a “self-developmental” hypothesis presented by the author in a recent paper and designed to explain the evolution of climatic anomalies. An analysis of the year-to-year behavior of persistence suggests possible gradual secular trends which might be related to sunspots, but the evidence is inconclusive. Finally, persistence is related to zonal index, and here there is a suggestion that during the colder parts of the year low index periods are more persistent than high.
Unusual Vertical Air Currents in the Vicinity of Warm Springs, California, October 29, 1950
Authors: Smalley Clarence L.
Published: August 2018

A description of unusual vertical air currents encountered by sailplane pilots near Warm Springs, California. Certain formulae developed for computation of wave characteristics are applied. Reasonable agreement is found between the results of these formulae and observed conditions.
A Mean Sounding Representative of the Tornadic Airmass Environment
Authors: Fawbush W. J. , Miller R. C.
Published: August 2018

Utilizing more than 72 soundings representative of the airmass structure favorable for tornadic activity, a mean sounding is constructed. Data pertaining to moisture depth, temperature inversions and relative humidity within the airmass structure are indicated and discussed.
Squall Lines *
Authors: Brunk Ivan W.
Published: August 2018

Squall lines are among the most severe but least understood weather phenomena. They are difficult to identify on the usual synoptic charts, and there has been some confusion concerning the definition of the terms “squall line” and “instability line.” The primary purpose of this paper is to show that squall lines can be defined and identified by the surface windshift, and that the surface windshift is highly informative as to the location of areas of severe turbulence. Characteristies of squall lines and synoptic conditions favorable for their development are discussed.
A Statistical Study of Precipitation Distribution as Related to Various Types of Mean Zonal Motion
Authors: Jenista C. O.
Published: August 2018

A study is made of precipitation occurrence as related to types of mean zonal motion. It is found that strikingly different patterns result.
The Tornado Situation of 17 March 1951 *
Authors: Fawbush Ernest J. , Miller Robert C.
Published: August 2018

The authors' method of forecasting severe storms is applied to the tornado development in Arkansas, 17 March 1951. The forecast of that storm is quoted and the considerations on which it was based are described. Since the method is entirely empirical, no attempt is made to explain why it works, but rather to describe how the practical forecaster's mind works as he uses commonly accessible data in an uncommon way. The forecast described was transmitted over Air Force teletype circuits eight hours before the first known tornado struck and four hours before the first known damaging hail fell. Verification shows one tornado reported within the forecast area and another 50 miles north, both well within the forecast time period, which was six hours in length. Related hailstorms are also shown.
An Improved Bimetallic Actinograph *
Authors: Fowler J. R.
Published: August 2018

A bimetallic actinograph has been developed by the Canadian Meteorological Division. It is proposed to equip a network of radiation stations with this instrument to supplement the existing network provided with Eppley pyrheliometers. Calibration agreement between the new actinograph and Eppley records for total daily radiation values is within ± 5%. This divergence includes errors of the Eppley and its recorder and scaling errors in both records as well as the strictly instrumental errors of the actinograph. The instrument therefore approaches the limit of practical accuracy for field use by non-technical personnel. Further development will be devoted mainly to increasing pen control (Span) and reducing cost and maintenance of the instrument.
The Cause and Forecasting of Ice Fogs *
Authors: Appleman H.
Published: August 2018

Studies carried out in Alaska and Canada have shown that fog is a relatively rare phenomenon at temperatures between 0° and − 30°F, with a minimum frequency between − 20° and −30°. At still lower temperatures, however, the frequency of fog increases rapidly. This effect is noted only in the immediate vicinity of inhabited areas, such as towns and airfields. The reason for the sudden increase in fog frequency at these temperatures, and the rarity or lack of fog at the higher temperatures, has not been heretofore explained. In a recent study on aircraft condensation trails, it was shown that if the temperature is sufficiently low (between − 20 and − 40°F, depending on the relative humidity), the burning of hydrocarbon fuels, such as would occur in towns and at airfields, easily results in supersaturation of the air and a “surface contrail” or ice fog. At higher temperatures, on the other hand, combustion actually reduces the relative humidity of the atmosphere, hindering the formation of fog. In this paper it is shown that low-temperature (ice) fogs form as a result of the combustion process, and curves are presented showing the temperature-dew-point relationship necessary for the formation of such fogs.
Recent Advances in the Study of Ionospheric Winds
Authors: Manning Laurence A.
Published: August 2018

Two new ways of finding the speed of ionosperic winds are reviewed. The first depends on the fading of radio signals reflected from the ionosphere. The second depends on the Doppler frequency shift of radio signals returned from drifting meteoric ionization trails. Use of these methods is adding greatly to what we know of the winds above the stratosphere.
The Relation Between the Temperature Differences Between the 700-Mb and 500-Mb Levels and Thunderstorm Rainfall
Authors: Buell C. Eugene
Published: August 2018

In establishing a relation between the amount of thunderstorm rainfall and certain upper-air parameters for use in New Mexico, it was found that the rainfall and the temperature difference between the 700-mb and 500-mb levels are negatively correlated. A similar relation was verified for summer thunderstorms in southern Florida. It is suggested that this may be characteristic of some non-frontal thunderstorms.
The Spontaneous Freezing Temperatures of Melted Snow and of Small Water Drops
Authors: Vaughan Harry C.
Published: August 2018

The spontaneous freezing temperatures of samples of melted snow collected at hourly intervals during several storms are reported. The freezing temperatures were found to range from −8.3 to −16.8°C. In most cases the freezing temperature remained fairly constant over periods of several hours. Gross variations in the pollution of the lower atmosphere caused no obvious effect on the observed freezing temperatures. It is suggested that the observed freezing temperatures represent the temperatures of initial formation of the snow crystals. A few experiments on the freezing temperatures of small drops were made with a technique such that all drops were formed from the same bulk sample without any danger of contamination. In all cases the freezing temperatures of the drops were well below that of the bulk water. The freezing temperature decreased with decreasing drop size but there was a relatively large variation for a given drop size.
A Study of Some of the Meteorological Effects on Radio Propagation at 96.3 Mc between Richmond, Va. and Washington, D. C.
Authors: Randall D. L.
Published: August 2018

This study was made to investigate the relationship of surface meteorological data and corresponding surface refractive indices to radio field strengths in the FM frequency band. For meteorological observations during which the wind speeds were equal to or greater than 10 mph, and when fronts, low overcast clouds (less than 5000 ft), rain, thunderstorms and fogs were excluded, a 0.70 correlation coefficient was found between hourly surface refractive index and hourly median field strength over a Washington-Richmond path at a frequency of 96.3 Mc.
Project Jet Stream
Authors: Endlich R. M. , Harney Patrick , McLean G. S. , Rados Robert M. , Tibbets Maj. O. J. , Widger W. K.
Published: August 2018

The importance of “jet streams” and other near-tropopause phenomena to aircraft operations led to the establishment by the Air Force of a project for probing these regions. Two specially instrumented aircraft, a B-47 jet bomber and a B-29, are the data gathering vehicles. Their instrumentation is discussed and examples of the data gathered thus far are given. These data show that significant maxima and minima of wind speed can occur between reporting stations and indicate that at jet stream levels, the gradient wind is a much better approximation to observed space-averaged winds than the geostrophic.
The Types of Airmasses in Which North American Tornadoes Form
Authors: Fawbush Ernest J. , Miller Robert C.
Published: August 2018

Three types of airmasses in which tornadoes form are identified from consideration of 286 representative soundings and a median sounding for each type presented and discussed. Previously published descriptions of tornadic airmasses are identified as being of TYPE I, the most common TYPE, and some refinement is given. Two other TYPES are described and it is contended that all tornadoes and water spouts of the continental United States and adjacent waters form in airmasses that fit one of the three classifications. Finally, the weather phenomena that most commonly accompany tornadoes in each TYPE of airmass are described and related to the height of the wet-bulb freezing level above the terrain.
The Error in Rawin Computations Due to Neglecting the Earth's Curvature *
Authors: Gustafson A. F.
Published: August 2018

General expressions giving the error in rawin computations arising from the neglect of the earth's curvature are derived. The error is found to be a function of the height of the balloon, the elevation angle, the wind speed, and the balloon ascent rate. The results are presented in the form of a graph which can be used by researchers to correct wind observations made without taking the earth's curvature into account. The nature of the curvature errors is such that maximum values of both wind speeds and wind shears tend to be exaggerated.
A Procedure For Studying Mountain Effects at Low Levels
Authors: Radok Uwe
Published: August 2018

A representative picture, from the aeronautical point of view, of vertical currents above mountainous country is obtained by letting these currents act on an aircraft set to fly horizontally in still air. Pressure and temperature traces recorded by such an aircraft give the effective vertical velocities and some idea of the temperature lapse rate in the undisturbed stream. Two sets of results are given for illustration. One shows low-level lee waves which were caused presumably by a temperature inversion; the other is a case of strong turbulence side by side with a smooth wave, in which downdrafts reached 1600 ft/min in an 18-knot wind.
An Evaluation of the Results of Cloud Seeding in Western New Mexico and Southeastern Arizona During July and August, 1951 and 1952
Authors: Buell C. Eugene
Published: August 2018

An attempt is made to determine whether or not the effectiveness of cloud seeding in increasing the amount of natural rainfall during the years 1951 and 1952 over western New Mexico and southeastern Arizona can be established. Only the months of July and August are considered since these are the months during which the rainfall is greatest and is mostly from non-frontal convective thunderstorms or showers.

The method used consists of estimating the amount of natural rainfall that might be expected from the mixing ratios at the 700-mb and 500-mb levels and the temperature difference between these levels, the difference between the estimate of the natural rainfall and the actual rainfall containing the part that might be attributed to the effectiveness of cloud seeding.

It is found that the effectiveness of cloud seeding cannot be established by this method on the basis of the data accumulated to date at an acceptable level of significance (1% or at most 5%). An interesting dilemma develops in that if effectiveness is acceptable at the 9% level for only those days on which seeding occurred, it is not possible to escape the conclusion that since seeding did not occur on all days, the suspension of operations on these few days reduces the effectiveness of the whole operation to nearly zero.

It seems evident from the data analyzed that if there is additional rainfall due to cloud seeding it can, at most, not exceed an amount of about 10%. Statistical methods to establish so small an amount must be very refined.
The Atmospheric Solitary Wave
Authors: Abdullah Abdul Jabbar
Published: August 2018

Solitary waves have been observed in shallow water. In the present paper some evidence is presented for the existence of similar phenomena in the atmosphere. A possible mechanism for the formation of atmospheric solitary waves is described, and a case study is discussed in support of this mechanism. Some speculations are made about some possible effects of these disturbances on the local weather.
Hurricane Hazel and a Long-Wave Outlook
Authors: Hughes Lawrence A. , Baer Ferdinand , Birchfield Gene E. , Kaylor Robert E.
Published: August 2018

It is believed that the severity of the storm hitting Canada on October 15, 1954 was due to the addition of an independent development to the dying hurricane Hazel. The problem of forecasting this event is discussed in the light of forecasts made at the time. The presence of a secondary development is verified.
A Study of Reference Citations in the Journal of Meteorology and the Quarterly Journal of the Royal Meteorological Society
Authors: Baum Werner A.
Published: August 2018

References cited in ten volumes (1944–1953) of the Journal of Meteorology and the Quarterly Journal of the Royal Meteorological Society were analyzed for country and year of publication of the references. American and British authors are found to have remarkably similar referencing patterns. Both rely primarily on the literature of their own nation and on quite recent literature. They rely to almost the same extent on the literature of various foreign nations, and both display very little utilization of the available Soviet publications.

A proposal is made for annual publication of a survey of significant advances in Soviet meteorology.
An Objective Method of Forecasting the Occurrence of Low Clouds in the McChord-Seattle Area During the Summer Months
Authors: Kinzebach R. M.
Published: August 2018

This paper presents an objective method of forecasting advective stratus and other low clouds during the summer months in the McChord-Seattle area. A relationship is shown between the 1630P pressure at North Bend, Oregon and Seattle, Washington, and the inland movement of stratus and the occurrence of other low clouds. Higher 1630P pressure at North Bend, beginning at a critical positive difference, favors the occurrence of low clouds the following day; higher 1630P pressure at Seattle, at a critical negative difference, favors clear skies or fog formation, with higher values reaching 100% verification.
On the Dispersal of Large Particles in the Atmosphere*
Authors: Edinger James G.
Published: August 2018

The process by which large airborne particles move farther apart with time in our atmosphere is investigated by means of simple examples and arguments.
Diurnal Temperature Variations in the Middle Atmosphere
Authors: Pressman Jerome
Published: August 2018

A computation has been made of the seasonal and latitudinal variation of the diurnal temperature changes in the ozonosphere. There was assumed a uniform cooling rate over a twenty-four hour period which exactly balanced the heating due to absorption by ozone of solar energy. The computations indicate that the diurnal temperature variation curve is relatively constant with latitude up to about 75 °N Latitude. The maximum diurnal temperature variation is at about 45 km.
A Radio-Command-Control Puffer for Studying Airflow*
Authors: Randall D. L. , Clark A. B. J.
Published: August 2018

A system is described with which air flow in the lower one or two thousand feet of the atmosphere can be studied by the use of a radio-command-control smoke puffer. Several applications of this system are proposed in connection with balloon sounding techniques.
Composite 200-mb Temperature Fields over Extratropical Cyclones 1
Authors: Ballenzweig Emanuel M.
Published: August 2018

The composite-map technique has been employed to construct some pictures of the average horizontal temperature distribution in the lower stratosphere over cyclones which do and cyclones which do not produce secondary Lows along the east coast of the United States. This study in comparative analysis verified that a characteristic anomaly exists in the 200-mb temperature field twelve hours prior to the development of the type of east-coastal secondary cyclones studied.
A Technique for Predicting Extreme Turbulence Related to Thunderstorms
Authors: Bates Ferdinand C.
Published: August 2018

A procedure for the prediction of extreme turbulence within and in the vicinity of thunderstorms is proposed and developed. The objective of the technique, within the limits of accuracy attainable, is the prediction of turbulence characterized by effective gusts of a given magnitude. The technique is basically similar to current techniques in the use of indices to potential energy of hydrostatic instability. Since the technique is developed upon a physical basis with statistical links, there exists a possibility of further refinement through a consideration by parts when further necessary basic data become available.
Frictional Filling of Hurricanes
Authors: Hubert Lester F.
Published: August 2018

As a hurricane moves from ocean to land, the surface roughness and the wind stress increase, which in turn causes the surface wind to blow across the isobars at an increased angle.

The resulting increase in mass convergence in the surface friction layer is examined in the light of the Rossby-Montgomery theory on the influence of friction on surface flow, and the results are compared with the analysis of fifty years of hurricanes that moved into the United States.

Those hurricanes are also analyzed to study the rate of pressure gradient decrease in the maximum wind zone. The results of this study indicate that frictional effect alone cannot dissipate the dangerous winds of a mature hurricane within the first eight to ten hours after moving onshore, but that dissipation is controlled essentially by the energy budget.
The Comparative Accuracy of Certain Statistical and Synoptic Forecasting Techniques
Authors: White Robert M. , Galligan Agnes M.
Published: August 2018

Forecasts of the pressure-height variations at eight stations in the eastern United States are prepared by a statistical technique employing empirical influence functions. The accuracy of such forecasts is found to be comparable with that attained by synoptic techniques.
Representative Winds Aloft
Authors: Arnold A.
Published: August 2018

A knowledge of the scale of a wind value that is desired for a particular application determines one important aspect of the wind. The scale of winds measured by conventional methods generally differs from the scale required. Therefore, errors exist when measured wind values are used. Data are presented giving the standard deviation of the winds aloft values as measured with a balloon from winds of larger scale. The importance of these considerations in some fields of activity is discussed.
Daily Wind Flow at the 50- and 25-MB Levels*
Authors: Kochanski Adam , Wasko Peter E.
Published: August 2018

Several daily series of 100-, 50-, and 25-mb maps over North America were analyzed. The wind flow at these levels and the thermal structure in the 100- to 25-mb region of the atmosphere are discussed and certain conclusions drawn.
Some Observations and Radar Pictures of the Blackwell and Udall Tornadoes of May 25, 1955
Authors: Staats Wayne F. , Turrentine Charles M.
Published: August 2018

Some accounts of meteorological conditions along the paths of these two severe tornadoes are described. Photographs of 3 centimeter radar of the Oklahoma A. & M. College sferics project show the development of a cyclonic protuberance out of the left rear quadrant of the radar echo similar to those previously observed in Illinois, Texas, and Massachusetts. Other similarities in the development of these tornadoes to the Massachusetts tornadoes of June 9, 1953, are pointed out. The average speed of radar echoes passing through the area of the tornadoes increases from 18 to 63 knots in a little more than one hour.
Low-Level Temperature Structure under Alaskan Ice Fog Conditions *
Authors: Robinson Elmer , Bell Gordon B.
Published: August 2018

Wiresonde temperature soundings were taken during two winters at Eielson Air Force Base, near Fairbanks, Alaska, as part of an ice fog investigation. Correlations were found between the depths of the visible fog layers and the steep portions of the temperature inversions.

The steep portions of the temperature inversions were usually confined to the lowest 100 feet of the atmosphere. The frequency of occurrence of strong surface inversions was less than had previously been expected for an arctic continental area with temperatures in the vicinity of −40C. This is attributed to the modifying effect of the ice fog, which was usually present in the observation area at temperatures below −30C.
Horizontal Temperature Gradient at 200 MB and Adjacent Levels
Authors: Kochanski Adam
Published: August 2018

Horizontal temperature gradients as large as 7C° per distance of one degree latitude are observed occasionally on 200-mb maps and (with a generally opposite direction) on 500-mb maps. These values are derived from gradient measurements in the vicinity of stations with temperature observations. Aircraft reports yield still higher horizontal gradients: 9C° to 11C° per 1 deg lat. An extreme temperature difference of 13C° over a distance of % deg lat appears feasible, based on extrapolation of differences found over greater distances. The last value is equivalent geostrophically to a vertical wind shear (allegedly observed by aircraft) of 60 kts/1000 ft.
Evaluation of Techniques for Predicting The Displacement of North-Eastward-Moving Cyclones
Authors: Hering Wayne S. , Mount Wayne D.
Published: August 2018

An evaluation is made of various rules and methods to forecast the 30-hour displacement of a particular type of cyclone during the winter months in eastern United States. Lows of the class considered have had a past track from the SW and are moving under SW flow aloft. The “normal” movement of the class is defined and is used to measure the accuracy of the rules examined. Graphs are presented showing the comparative results for 30-hour speed, direction and final position forecasts.
Notes on the Horizontal Circulation of Ocean Currents
Authors: Neumann Gerhard
Published: August 2018

The effect of a variable depth of the wind driven oceanic circulation on the steady state current systems is discussed with the aid of a simple model. There is much evidence that in the Atlantic Ocean the depth of the layer of no motion increases poleward proportionally to the sine of the geographical latitude in both hemispheres. It seems not unlikely that the oceans react to the planetary vorticity effect in such a way that they rather tend to adjust the level of no motion than to displace the whole gyre of the wind driven circulation to the west.
Tornado Proximity Traces *
Authors: Tepper Morris , Eggert William E.
Published: August 2018

Pressure, temperature, and relative humidity traces obtained from regular reporting and special network surface stations in operation in Midwestern United States during the years 1951 through 1954 and located within 15 miles of a tornado are presented. It is noted from plots of the location of the stations with respect to the tornado that certain characteristics are suggested by the barograms, dependent primarily on the distance of the instrument from the tornado. Some relationships are also inferred between microcyclones and tornadoes, and between pressure jump lines and tornadoes. The available hygrothermograph traces show many instances of the drop in temperature and rise in relative humidity usually associated with the passage of a squall or pressure jump line. Plot of the pressure fall vs. distance from the tornado suggests a (Δp)2r = constant law for a “tornado-bearing microcyclone.” Finally, a suggestion is made that some tornadoes may form as a result of some interaction between a pressure jump line and a microcyclone.
A Comparison of Solar Radiation and Net Radiation 1, 2
Authors: Shaw R. H.
Published: August 2018

Daily values of solar and net radiation at Ames, Iowa were compared for the period, late June through November, 1954. It was found that by dividing the data into two groups, clear days and cloudy days, regression lines could be computed which fitted the data very well. The correlation between net radiation and solar radiation was 0.98 for clear days and 0.97 for cloudy days.
Forecast Height Changes at Various Levels Computed From the Thermotropic Model
Authors: Berkofsky Louis , Seager George B.
Published: August 2018

It is shown how to compute forecast height changes at other levels, given those at 500 mb and 1000 mb, as computed from the thermotropic model. Since this model is vertically integrated, solutions need only be obtained for 500 mb and 1000 mb flow, in order to compute changes at any other pressure levels. The promising results obtained thus far indicate that such a scheme may have important computational advantages over those in which equations have to be solved at a number of levels to obtain forecasts at those levels.
Low Latitude Vorticity Injections and the Development of Large Scale Anomalous Circulation Patterns
Authors: Elliott Robert D.
Published: August 2018

Some general characteristics of synoptic developments in the 500 mb vorticity field are discussed with particular attention devoted to sudden injections of vorticity and to changes in circulation patterns downwind therefrom. Attention is then focused on vorticity injections generated at low latitudes, but not too low to interact in an important way with the middle latitude circulation. Composite maps based upon numerous cases are shown which reveal the development of large scale anomalous patterns in the westerlies during the 3 days subsequent to low latitude vorticity injection. The forecasting implications are discussed.
A Proposed Temperature Element on the Canadian Radiosonde *
Authors: Bindon H. H.
Published: August 2018

A radiosonde temperature element consisting of two exactly similar bimetal elements, one silver plated and one blackened is described. If the two elements are mounted so that they received equal radiation and ventilation the true ambient temperature may be determined to a probable accuracy of ± 0.5° C.
Visibility Deterioration Associated with Operations of Jet Aircraft
Authors: Clodman J.
Published: August 2018

The operation of aircraft may modify cloud and precipitation parameters sufficiently to cause a significant deterioration of visibility at an airfield. The conditions conducive to this effect are (1) large number of aircraft operating simultaneously in the vicinity of the airfield, (2) low temperatures, (3) light winds. An incident at Goose Bay on December 4th, 1954, is discussed in the light of the above analysis.
The Challenge of Television Weather Programs *
Authors: Jehn K. H.
Published: August 2018

The objectives of television weather presentations are reviewed and are seen as a particular challenge to both professional meteorologists and television people. An effort is made to analyze the factors involved in the situation and to suggest possible means of realizing the objectives.
Hurricane Vectors
Authors: Smiley C. H.
Published: August 2018

A vector showing the magnitude and direction of the atmospheric pressure-gradient in a specific neighborhood is determined from simultaneous barometric pressures at the vertices of a triangle surrounding the area of interest. The changes in size and azimuth of this vector may be used to estimate whether an approaching hurricane will come to the neighborhood or will by-pass it. The results of the application of the method to recent hurricanes approaching New England are given.
Forecasting Summertime Shower Activity at Grand Junction, Colorado
Authors: Dickey Woodrow W.
Published: August 2018

Due to the lack of a dense network of reporting stations in the Grand Junction, Colorado area and the inadequate representation of shower activity by observations of rain at a single rain gage, certain arbitrary criteria were set up to define a “shower” day at Grand Junction. Relationships of a number of meteorological variables to shower activity were determined and the four variables which showed the strongest relationships were combined graphically to form an objective forecast aid for determining the probability of shower activity at Grand Junction during the 18-hour period 1130MST to 0530MST. Tests on independent data confirm the relationship found in the developmental data.
Weather Service to Agriculture in the Western Great Plains*
Authors: Palmer Wayne C.
Published: August 2018

The general purpose of this paper is to discuss the weather problems which confront those engaged in agriculture in a semiarid region such as the Western Great Plains. Some appraisal is made of the present service to agriculture with a view to the potentialities for a more adequate service.

Specifically, comments are made on the use of the daily forecasts in planning and performing the farming operations. Instances are given of problems requiring information which is now unavailable, and suggestions are made for improving the service through forecasting, climatological and observational procedures aimed at reducing the risks to the farmer due to the hazards of weather.
A Common Wind Damage Pattern in Relation to the Classical Tornado
Authors: Reynolds George W.
Published: August 2018

A wind damage pattern in which no major damage has been accomplished by winds blowing toward the direction from which the storm came can result from a classical tornado if the speed of translation is high enough relative to the maximum wind speed.

A distinct rotary damage pattern indicates that the speed of translation is a less important component of the total speed.

One might consider a wind damage pattern in which there is,An increase in damage intensity from right to left,No major damage accomplished to the left of the line of most extreme damage, andEvidence indicating that the damage in the major damage area was accomplished by winds blowing with the direction of translation of the storm,

to be a point in favor of cyclonic rotation. If the build-up were from left to right, with the break-off to the right of the line of most extreme damage, the point would be in favor of anti-cyclonic rotation.

The wind speed-wind pressure relationship is discussed briefly, and tables and graphs showing the wind speeds and pressures at points on opposite sides of a tornado, for assigned values of the speeds of rotation and translation, are included.

A table estimating the total force on a wall resulting from assumed wind speeds is also presented.
The Transmission of Analyzed Weather Charts
Authors: Lally Vincent E. , McInnis Donald H. , Myers Robert F.
Published: August 2018

Various deficiencies of facsimile transmission of analyzed weather charts are indicated. Higher speed and better definition can be obtained with facsimile techniques by using wideband transmission lines, but at an exorbitant cost. A more economical solution is the development of more efficient coding techniques for transmitting the weather charts. A code is outlined which is 50 times more efficient than facsimile, and an equipment is described which uses this code to transmit charts faster, on a larger scale, and in color.
Severe Local Storms and Mid-Tropospheric Flow Patterns
Authors: Fawbush E. J. , Miller Robert C. , Starrett Loyd G.
Published: August 2018

An attempt is made to relate the occurrences and locations of severe local storms to a large-scale feature of the atmosphere, the circulation at 500 mb. The regional and seasonal distributions of a selected list of severe local storms, which occurred over the ten-year period 1942–1951, are discussed. The association of these storms with fronts is given, along with average directions of the 500 mb flow upstream from the severe storm area. The correlations of the flow pattern at 500 mb with the occurrence and positions of severe local storms are presented.
Analysis of Cloud Seeding Efforts in the Tri-County Area,* Oregon, 1950–54
Authors: Decker Fred W. , Lincoln Russell L. , Day John A.
Published: August 2018

Using an 11-variable multiple regression equation to compute the “natural” rainfall, it is concluded that commercial cloud seeding during 1950–54 in three north central Oregon counties failed to produce departures in precipitation which are statistically significant at the 5 per cent level of acceptance.
Forecasting Ceilings at Denver, Colorado
Authors: Brown Merle J. , Tillotson Kenneth C.
Published: August 2018

Objective forecasting techniques are established for the average value of the ceiling at Denver of duration of three consecutive hourly observations or longer during the 6-hour period beginning 6 hours after the surface map used. Due to marked diurnal effects on ceilings and forecast variables, the study is divided into two parts: one for the forecast period 1130–1730M from the 0530M map, and the other for the forecast period 2330–0530M from the 1730M map. Persistence of ceiling at forecast preparation time (0830M and 2030M) shows such a strong relationship to subsequent ceiling occurrences that rather extreme stratification is necessary to improve upon a simple “persistence” forecast.
An Objective Method for Forecasting Winds at an Inter-Mountain Station
Authors: Simpson C. L. , Thorp J. M.
Published: August 2018

An empirical method for forecasting surface winds at an inter-mountain station, based on the differences in sea-level pressure between Hanford and five other stations, is developed. Nomograms relating the ten-hour velocity trend to the pressure gradient are presented. The method is discussed in relation to conventional methods of wind forecasting as pertaining to apparent counter-gradient winds, cyclic features of the surface winds, and variations in wind speed.
Cumuloform Shower Forecast Technique for Southern Arizona1
Authors: Reynolds Ralph D.
Published: August 2018

A procedure for using the 700-mb dew point temperature as an objective aid for forecasting the occurrence or nonoccurrence of cumuloform showers in southern Arizona is presented with verification data.
Engineering Meteorology: Weather Influences on Electrical Utility Load Dispatching1
Authors: Benner William
Published: August 2018

The problem of lead dispatching of electric utilities is discussed to show the part that weather plays in typical load dispatching techniques, both long range and short range. An effort is made to evaluate the significance of various meteorological parameters and to show the overall importance of taking weather effects into consideration from the viewpoint of improving operating efficiency and economy of utilities. Finally, consideration is given to bring out the regions where the activities of meteorologists are most desired by the utilities.
Surface Thermal Patterns as a Tornado Forecast Aid1
Authors: Darkow G. L. , Suomi V. E. , Kuhn P. M.
Published: August 2018

A tornado-forecast tool based on surface thermal patterns is presented. The procedures and results of an operational test of this forecast tool are presented. The results of this test are evaluated and suggestions made for using this additional simple tool in conjunction with existing tornado forecasting techniques.
A Pneumatically Actuated Icing Detector for Stationary Operation
Authors: Goettelman R. C. , Poppoff I. G.
Published: August 2018

An icing detector which operates on a pressurized air system and utilizes the pressure drop produced across a Venturi tube as an indication of icing conditions is described in this paper. Since the rate of ice formation on a surface is a function of the configuration of the surface, this detector has the unique advantage of being adaptable to conform with the shape of any structure on which it is mounted. Previously developed icing detectors require either a high velocity air stream, as in aircraft operation, or moving parts subject to possible mechanical failure during severe icing conditions. A pneumatically actuated icing detector designed specifically for stationary operation would be capable of icing measurements without either of these restrictions. Preliminary experiments indicate that this technique is feasible and capable of furnishing quantitative measurements of icing severity.
A Solar Time Classification for Meteorological Use
Authors: Singer Irving A. , Raynor Gilbert S.
Published: August 2018

In order to effect a more consistent grouping of hourly meteorological data influenced by the diurnal cycle, a chronology based on the time of sunrise and sunset was devised. A code classified all hours within each bi-weekly period by this time system. The classification was further extended by dividing the year into solar seasons, defined as periods of time during which the distribution of solar hours is uniform.

The use of solar time as a major classification in the analysis of two years of hourly wind and temperature data obtained from six levels on the 420-ft meteorological tower at Brookhaven National Laboratory resulted in a better understanding of the relationships between the variables than could have been obtained by the use of standard time. Results of several lapse-rate and wind-profile studies made using both standard and solar time demonstrated the advantage of the latter system. Application of this method to other problems and regions is discussed.
Typhoon Sarah, 19561
Authors: Fortner Limon E.
Published: August 2018

Typhoon Sarah, 1956, the first of the season, was unusual in several respects. First, Sarah formed in a tropical depression that first became a closed circulation less than a hundred miles from the equator. Second, Sarah showed a marked diurnal variation in intensity after reaching a maximum of intensity on the second day as a typhoon. Third, besides the diurnal variation there were two periods of intensification and weakening. Fourth, the cyclone retrograded to the east-southeast several hundred miles parallel to its previous track.

The diurnal variation of Typhoon Sarah appears to have its origin in the arrival of short intense lines of convergence at the eye. The arrival of these lines of convergence at the eye furnished the energy that gave the typhoon a pulsating characteristic.
An Empirical Basis for Forecasting Storm Tides
Authors: Donn William L.
Published: August 2018

The storm tides at six coastal stations along northeastern United States produced by eight coastal storms from 1952 to 1956 are compared with significant storm parameters. Tentative forecast graphs of tide versus wind velocity have been developed which indicate that operational usefulness can be achieved by the methods described. The storm tide appears to be a very local phenomenon, dependent primarily upon wind velocity. The problem of storm-tide lag is also examined.
High-Altitude Nighttime Balloons
Authors: Sharenow Moses
Published: August 2018

An experimental high-altitude balloon suitable for nighttime use was recently developed and tested in both tropic and temperate latitudes. Results of tests indicate the balloon is capable of attaining a bursting altitude in excess of 100,000 ft with slightly more hydrogen than that required by existing night balloons now used to attain an altitude of 80,000 ft. Some reduction in the size of the balloon will be required to make it suitable for inflation in existing shelters.
Air Mass Modification and Upper-Level Divergence
Authors: House Donald C.
Published: August 2018

A procedure for estimating the degree of modification of air mass structure as a result of favorable divergence-convergence patterns is discussed. Its application to the forecasting of severe local storms is discussed.
An Objective Method of Forecasting Maximum Temperatures at Salt Lake City, Utah
Authors: Williams Philip
Published: August 2018

An objective method is developed for forecasting the current day's maximum temperature at Salt Lake City during the warm season, May–October. Good results are obtained by using either the height of the freezing level or the 700-mb temperature at 0800 MST at Salt Lake City combined with the 0830 MST surface temperature and the 0530–0830 MST surface temperature change. Results are compared with subjective forecasts.
A Note on Early Meteorological Observations in the United States with Reference to the Germantown Temperature Record of 1731–32
Authors: Havens James M.
Published: August 2018

Following an historical sketch of meteorological records known to have been kept in Colonial America prior to 1740, the earliest instrumental readings of temperature in North America capable of approximate reduction to present-day standards, those recorded at Germantown, Pennsylvania, are examined in detail. A scale correction for the primitive Fahrenheit thermometer used is derived from two independent methods; when uniformly applied to the observed readings, reasonable values of monthly mean temperatures are shown for December 1731 to October 1732.
Climatology of the Trade-Wind Inversion in the Caribbean
Authors: Gutnick Murray
Published: August 2018

Three years of twice-daily raobs for the midseason months at six stations on the Caribbean were analyzed for evidence of the trade-wind inversion. The seasonal, spatial, or diurnal variation of the various parameters which constitute the inversion regime (frequency, height of the base, strength, thickness, and moisture budget) is discussed. It was found that most of the parameters showed a distinct seasonal variation but little or no spatial or diurnal variations.
Air Chemistry
Authors: Junge Christian E.
Published: August 2018

The field of atmospheric chemistry, which is defined as the chemistry of trace substances in the troposphere, is reviewed. Trace substances can be present as aerosols or as gases. Major sources of aerosols are the ocean and industrial activities. The chemical composition of the aerosol particles is not only determined by their source but also by various processes in the atmosphere—notably, reactions with gas traces.

Only little is known about trace gases like SO2, H2S, NH3 or NO2. Of special importance for meteorology is CO2 and its long-term fluctuations. The facts and possible reasons for its 10 per cent increase during this century are discussed.

The last part of the discussion is concerned with the physical processes by which the trace substances are removed from the atmosphere, primarily the role of precipitation.
Mesoanalysis: Some Operational Analysis Techniques Utilized in Tornado Forecasting
Authors: Magor Bernard W.
Published: August 2018

The tornado forecast becomes a small-scale problem as the tornado-generating severe-thunderstorm area approaches a particular locality. Consequently, much of this problem can be solved by the best possible analysis of surface synoptic weather data. Various tornado occurrences were investigated and found to be associated with meso-lows. These meso-lows were depicted either by the intersection of two instability lines or by the intersection of a squall line with a northeastern boundary of rain-cooled air. An explanation is given for the formation of tornadoes along this intersection.
New Developments in Observations and Instrumentation in the Weather Bureau
Authors: Rockney Vaughn D.
Published: August 2018

A review is made of programs for the development, procurement, and installation of new observing instruments by the Weather Bureau. Some new observational techniques which will be used with the new instruments are also described. The article deals with four main fields of observations—surface, upper-air, radar, and marine.