A National Weather Service Publication In Support of The Celebration of American Weather Services...Past, Present and Future
Evolution to the Signal Service Years
The Colonial Years
The National Weather Service has its beginning in the early history of the United States. Weather always has been important to the citizenry of this country, and this was especially true during the 17th and 18th centuries. The early settlers to North America experienced the harshness of the weather of the New World. Samuel de Champlain, in the early 1600's told much about the weather of the northeast United States when he stated:
"It was difficult to know this country without having wintered there; for on arriving in summer everything is very pleasant on account of the woods, the beautiful landscapes, and the fishing for the many kinds of fish found there. There are six months of winter in that country. The cold was severe and more extreme than in France, and lasted much longer."
Samuel de Champlain's sentiments were echoed in 1600 by Governor William Bradford of Cape Cod who stated the winters to be, "...Sharp and violent, and subject to cruel and fierce storms, dangerous to travel to known places, and much more to search an unknown coast."
Weather also was important to many of the Founding Fathers. Colonial leaders who formed the path to independence of our country also were avid weather observers. Thomas Jefferson bought his first thermometer while writing the Declaration of Independence, and purchased his first barometer a few days following the signing of the document. Incidentally, he noted that the high temperature in Philadelphia, PA on July 4, 1776 was 76 degrees. Jefferson made regular observations at Monticello from 1772-78, and participated in taking the first known simultaneous weather observations in America. George Washington also took regular observations; the last weather entry in his diary was made the day before he died.
During the early and mid 1800's, weather observation networks began to grow and expand across the United States. Although most basic meteorological instruments had existed for over 100 years, it was the telegraph that was largely responsible for the advancement of operational meteorology during the 19th century. With the advent of the telegraph, weather observations from distant points could be "rapidly" collected, plotted and analyzed at one location.
When the telegraph became operational in 1845, the visionaries saw the possibility of "forecasting" storms simply by telegraphing ahead what was coming. Joseph Henry, Secretary of the new Smithsonian Institution, envisioned opportunities of the communication system and suggested that:
...a system of observation which shall extend as far as possible over the North American continent... The Citizens of the United States are now scattered over every part of the southern and western portions of North America, and the extended lines of the telegraph will furnish a ready means of warning the more northern and eastern observers to be on the watch from the first appearance of an advancing storm.
The plan was approved in 1848, and subsequently, a circular was distributed to the press to recruit volunteer observers. Henry also persuaded the telegraph companies to allot free time for the transmission of weather reports to the Smithsonian.
By the end of 1849, 150 volunteers throughout the United States were reporting weather observations to the Smithsonian regularly. By 1860, 500 of Henry's stations were furnishing daily telegraphic weather reports to the Washington Evening Star, and as Henry's network of volunteer observers grew, other existing systems were gradually absorbed, including several state weather services.
The ability to observe and display simultaneously observed weather data, through the use of the telegraph, quickly led to initial efforts toward the next logical advancement, the forecasting of weather. However, the ability to observe and forecast weather over much of the country, required considerable structure and organization--a government agency.
Formation and Evolution of The Division of Telegrams
and Reports for the Benefit of Commerce
The catalyst for the formation of the new agency was Professor Increase A. Lapham of Milwaukee, a student of meteorology. Professor Lapham supported a storm warning service for the Great Lakes and he sent frequent clippings of maritime casualties to General Halbert E. Paine, Congressman for Milwaukee. In one letter Lapham asked if it were not "...the duty of the Government to see whether anything can be done to prevent, at least, some portion of this sad loss in the future...?"
Lapham's enthusiasm for a national weather service was supported by others, including the New York Chamber of Commerce. One of the supporters was Colonel Albert J. Myer, Chief of the Signal Service. Colonel Myer used a winter storm, traced to Washington, D.C. from the Midwest, as an example of the possibilities for such a weather service.
Congressman Paine recognized the importance and practicability of Lapham's cause and, on February 2, 1870, he introduced a Joint Congressional Resolution requiring the Secretary of War "to provide for taking meteorological observations at the military stations in the interior of the continent and at other points in the States and Territories...and for giving notice on the northern (Great) lakes and on the seacoast by magnetic telegraph and marine signals, of the approach and force of storms."
The Resolution was passed by Congress and signed into law on February 9, 1870, by President Ulysses S. Grant. Little attention was given by the press to the short, seven line resolution, but an agency had been born which would affect the daily lives of most of the citizens of the United States through its forecasts and warnings.
Since considerable structure and organization was necessary, and since the operation of the new service was dependent on a reliable communication system, the new service was placed under the Secretary of War because "military discipline would probably secure the greatest promptness, regularity, and accuracy in the required observations." Within the Department of War, it was assigned to the Signal Service Corps (which was organized in 1860) under Brevet Brigadier General Albert J. Myer. General Myer gave the National Weather Service its first name: The Division of Telegrams and Reports for the Benefit of Commerce.
At 7:35 a.m. on November 1, 1870, the first systematized and synchronous meteorological reports were taken by observer-sergeants at 24 stations in the new agency. These observations, which were transmitted by telegraph to the central office in Washington, D.C., commenced the beginning of the new division of the Signal Service.
The weather service work of the new organization demanded a large number of men familiar with observations, theoretic, and practical meteorology. The commissioned officers detailed to Signal Service work were required to acquire meteorological knowledge by studying the available literature and consulting with and receiving instruction from leading meteorologists.
For the education of weather observers (enlisted men) a school of meteorology was added to the existing school of instruction in telegraphy and military signaling located at Fort Myer (then Fort Whipple), in Virginia. Instruction for the observers consisted of courses in military tactics, signaling, telegraphy, telegraphic line construction, electricity, meteorology, and practical work in meteorological observation. In 1882, a course for commissioned officers was added to the school covering meteorology, mathematics, and electricity. The training school of meteorology at Fort Myer was abolished by order of the Secretary of War in 1886.
Although most of the weather observations were taken by the military, the Signal Service turned to civilians for meteorological knowledge. On November 8, 1870, General Myer requested Professor Lapham to assume responsibility for the Great Lakes region (with a salary of $167 per month), and Lapham obliged by issuing the first storm warning the same day. The dispatch sent to observers on the Great Lakes, read:
"High wind all day yesterday at Cheyenne and Omaha; a very high wind this morning at Omaha; barometer falling with high winds at Chicago and Milwaukee today; barometer falling and thermometer rising at Chicago, Detroit, Toledo, Cleveland, Buffalo and Rochester; high winds probable along the Lakes."
In 1871, Professor Cleveland Abbe also became part of the infant agency as Special Assistant to the Chief Signal Officer. Following a month of practice, it was decided that Abbe's forecasts, covering the next 24 hours, more than filled popular expectations. The first public issuance by Abbe was entitled "Weather Synopsis and Probabilities" and was based on observations at 7:35 a.m. One of the early examples is shown below:
Synopsis for past twenty-four hours; the barometric pressure had diminished in the southern and Gulf states this morning; it has remained nearly stationary on the Lakes. A decided diminution has appeared unannounced in Missouri accompanied with a rapid rise in the thermometer which is felt as far east as Cincinnati; the barometer in Missouri is about four-tenths of an inch lower than on Erie and on the Gulf. Fresh north and west winds are prevailing in the north; southerly winds in the south. Probabilities; it is probable that the low pressure in Missouri will make itself felt decidedly tomorrow with northerly winds and clouds on the lakes, and brisk southerly winds on the Gulf.
Since the original congressional resolution covered only the Gulf and Atlantic coasts, and the Great Lakes, the early forecasts were made only for these areas. On June 10, 1872, an act of Congress extended the service throughout the United States, "for the benefit of commerce and agriculture." However, a sample forecast of 1872 reflects the lack of data west of the Mississippi River.
"Partly cloudy, but pleasant weather will prevail on Wednesday for Pennsylvania and the upper lakes southward to the Gulf. Cloudy weather will extend over New England and Canada and clearing by Wednesday night."
Early forecasts were made for eight large districts (which covered the entire United States), three times daily and the duration of the forecasts, as well as forecast elements were determined by the forecaster. However, beginning in October 1872, predictions were made regularly for 24 hours in advance for 9 districts, and in 1874, forecasts were made for 11 districts and 4 elements, namely weather, wind, pressure, and temperature. No changes occurred until 1885 when predictions were made for 32 hours in advance, and in 1886, forecasts were made for states, or parts of states, as opposed to being issued for large districts containing several states. In 1888, forecast durations were extended to 36 hours and in 1898 extended to 48 hours.
Beginning in 1873, forecasts were distributed to thousands of rural post offices (by local Signal Service offices) for display as "Farmers' Bulletins" in front of post office buildings. This dissemination method continued until 1881 when local signal flags replaced the bulletins. The flags were large (for example, the cold-wave flag measured six-by-eight feet and was white with a black center of two feet square), and were displayed over post office buildings. By the end of 1886, display flags were available at 290 cities and towns.
The Signal Service's field stations grew in number from 24 in 1870 to 284 in 1878. Three times a day (usually 7:35 a.m., 4:35 p.m., and 11:35 p.m.), each station telegraphed an observation to Washington, D.C. These observations consisted of:
- Barometric pressure and its change since the last report.
- Temperature and its 24-hour change.
- Relative humidity.
- Wind velocity.
- Pressure of the wind in pounds per square foot.
- Amount of clouds.
- State of the weather.
At Washington, D.C., forecasts were made from the telegraph reports. The forecasts subsequently were distributed back to the observers, to railroad stations and to available news media.
Although the forecasts did not always prove correct, they greatly aided in planning daily life in the United States. A noted scientist conveyed the increasing reliance on the weather service when he declared: "While scientists cannot tell at what hours to carry an umbrella, they can tell when great storms and waves of intense heat or cold are coming so as to be of great value to all the industries of the land...All the discomforts of the weather cannot be avoided but the great disasters can be anticipated and obviated."
Life in the early field stations was not dull. Signal Service personnel experienced a number of unexpected local events (the suppression of labor riots in 1873) and isolated Indian wars (including the Geronimo campaign). They also performed extra public services during emergencies, including yellow fever epidemics, plagues, and fires. In particular, a detailed account of the Chicago fire is presented by one of the weather observers in the Report of the Chief Signal Officer, 1871-1872.
The Report of the Chief Signal Officer in 1877-1878 described the duties of the enlisted men at the weather offices:
...they are required to take, put in cipher, and furnish, to be telegraphed tri-daily on each day, at different fixed times, the results of observations made at those times, and embracing, in each case, the readings of the barometer, the thermometer, the wind-velocity and direction, the rain-gauge, the relative humidity, the character, quantity and movement of upper and lower clouds, and the condition of the weather. These observations are taken at such hours, at the different stations, as to provide the three simultaneous observations, taken daily at three fixed moments of physical time (7:35 a.m., 4:35 p.m., and 11 p.m. Washington mean time) throughout the whole extent of the territory of the United States... Three other observations to be taken at the local times, 7 a.m., 2 p.m., and 9 p.m., are also taken and recorded at each station. A seventh and especial observation is taken and recorded at noon on each day. If at this observation such instrumental changes are noted as to cause anxiety, the fact is to be telegraphed to the central office at Washington.
An eighth observation is required to be taken at the exact hour of sunset at each location. This observation, embracing the appearance of the western sky, the direction of the wind, the amount of cloudiness, the readings of the barometer, thermometer, and hydrometer, and amount of rain-fall since last preceding report, is reported with the midnight report...
The average time elapsing from the time at which the readings of the instruments have been had at the stations scattered throughout the United States, to that at which the reports based on these readings have been telegraphed to the press and to the distributing-stations, has been one hour and forty minutes.
Not all reports from the Signal Service stations dealt with weather observations. For example, the following memo was concerned with another problem.
WAR DEPARTMENT, OFFICE OF THE CHIEF
DIVISION OF TELEGRAPHS AND REPORTS FOR THE
BENEFIT OF COMMERCE AND AGRICULTURE
Washington, D.C., May 17, 1877.
SERGEANT: Should the Rocky Mountain locust appear at or near your
station at any time during the present year, you will obtain all the
information possible relative to the following subjects, viz:
The date of appearance of the locusts; the direction from which
they came; the direction and velocity of wind and character of weather
at time of appearance; the length of time they remain in your neighbor-
hood, and amount of damage done by them; the direction and velocity
of flight; direction of flight when they leave your station; whether
they fly with or against the wind; whether or not they laid eggs in
great quantities in the surrounding country; what means were taken to
destroy the eggs or the locusts; any other information you can obtain
on this subject. Should the locusts have arrived at your station previous
to the receipt of this communication, you will obtain all the information
possible from the citizens residing near you and forward it without
delay to this office.
Make full notes in your daily journal in regard to locusts and
forward the same with the abstract.
Since Signal Service forecasters and observers were in the Army, rules and regulations were strict. Listed below are examples of regulations in 1883:
Clerks will keep their desks, their drawers, and file cases neat and clean. Papers taken out of the files for action will be returned as soon as the work in hand is completed, and at the close of each day's work.
The Property Officer will, each Saturday, have all rooms halls, stairways, closets, cellars, etc., carefully policed and arranged.
Drinking vessels will not be used in taking medicine; nor will the taking of medicine at water-coolers be permitted.
Discussions in reference to the business of the office at any time or place, not necessary to the proper discharge of the duties of the same, are prohibited.
The office rooms must neither be used as visiting rooms, nor for purposes of entertainment. Persons visiting the office are expected to transact their business as promptly and briefly as practicable.
Unnecessary conversations, writing of private letters, and reading of newspapers during office hours are strictly prohibited. Conversation necessary to the proper dispatch of business will be carried on in a low tone of voice.
The outfit of an inspecting officer will consist of one standard mercurial barometer, two standard thermometers, one standard compass, one jar of mercury; also the necessary blanks, stationery, barometer cisterns, clamps and screws, small screw drivers, and a tape-line.
He (the inspector) will inspect the observer and assistants in uniform, and examine them as to their knowledge of the various circulars and orders issued by the central office; and when they do not appear to understand any one, or part of one, proper instruction will be given. He will also examine them in the following text-books of the service: Loomis' Meteorology, Myer's Manual of Signals, Instructions to Observers, Pope's Telegraphy, and Hand-book for the Signal Corps. The result of the examination in each case will be reported under "general remarks" in the inspection report. He will test them in wand practice, and when there are facilities, in telegraphy, giving the number of words received and sent in each case.
All maps and bulletins issued and posted at station will be personally inspected, and their condition noted from actual observation, and not from the observer's statement. The date of the several maps and bulletins posted in the frames at the time of inspection will be observed, and if the latest issue is not found therein the observer will be called to account for neglect of duty.
Military authority is to be exercised with firmness, but with kindness and justice to inferiors. Punishments shall be strictly conformable to military law.
Superiors of every grade are forbidden to injure those under them by tyrannical or capricious conduct, or by abusive language.
During the early years (1870's and 1880's) of the national weather service, research studies were conducted at the central office in Washington, D.C. The early research was comprised mainly of topics dealing with the distribution of moisture in the air, a treatise on the laws of meteorology, a report on tornadoes from special observers in the Corps, and instructional material for Signal Service trainees. Colonel Myer, not overly interested in research, employed only one permanent, civilian professor (Cleveland Abbe); but Hazen added four senior and three junior professors after 1880. One man was in charge of investigations on atmospheric electricity and another on thermometry exposure.
The first 10 years under the Signal Service were tranquil internally. General Myer, the chief of the new agency from 1870 until his death in 1880, deserves much of the credit. Myer possessed the ability to organize the agency in a seemingly effective manner, resulting in minimal internal strife. Myer stressed public service and the personnel of the weather agency knew their job was service to others.
Under General Hazen, Myer's successor, the agency entered a period of turmoil. From 1880 to 1887, the weather service was rocked by allegations of fraud, scandals, and subsequent investigations. In 1881, information surfaced that Captain Henry W. Howgate (disbursing officer of the Signal Service) had embezzled up to $237,000 from the U.S. Government through the use of fraudulent vouchers. The Howgate scandal resulted in a number of repercussions for both the weather service and the Signal Service. Critics charged that employees of the Signal Service aided Howgate, and Hazen was pressured to reduce the expenditures of the Service by the amount of the missing funds.
Also under Hazen's administration, growing strife surfaced regarding the degree of autonomy the Signal Service should have as a component of the army. General Hazen maintained that the Service should enjoy the status of a separate corps, and therefore, more freedom in controlling its own actions, as did the Army Engineers. Although the Signal Service was able to maintain a certain degree of freedom, it was becoming apparent that the Army was not happy with the Signal Service in general, and the weather service in particular. It also was becoming clear that the War Department was not enthusiastic over having the weather service. The Signal Service had been almost completely absorbed by its new mission, and should its military services ever be needed, its personnel could not be spared from their weather duties.
In 1887, General Hazen died, and General A. W. Greely was chosen as successor. The Greely administration failed to quiet the storm of protest resulting from the previous seven years of discord. Coupled with the increasing external criticism was internal disharmony. One item surfaced when Lieutenant John C. Walshe, inspector for the Signal Service, told reporters that the man in charge of the predictions at Washington, D.C., was too much a scientist and too little a weather observer, preventing the transfer of his theories into accurate forecasts.
By 1889, General Greely became convinced of the futility of attempts to reconcile opposing factions within the organization, as well as to correct admitted shortcomings within the weather service. These admissions by the top official of the military weather service solidified adverse congressional reaction. Although Greely attempted to correct the problems which had been building for over seven years, the die was already cast and in 1889, President Benjamin Harrison recommended transfer of the national weather service to the Department of Agriculture. Congress agreed, and on October 1, 1890, an act transferring the weather service to the Department of Agriculture was signed into law by President Benjamin Harrison.
According to the new law:
...the enlisted force of the Signal Service, excepting those hereinafter provided for shall be honorably discharged from the Army on June 30, 1891, and such portion of this entire force, including civilian employees of the Weather Bureau shall, if they so elect be transferred to the Department of Agriculture...
The work of the Signal Corps' meteorological division ended 20 years after it began; yet, in that brief period it succeeded in establishing the foundation for the new Weather Bureau. The United States already led the world in providing public weather information, forecasts, and warnings. Charles Patrick Daly, a famous jurist of the day, wrote:
"Nothing in the nature of scientific investigation by the national government has proved so acceptable to the people, or has been productive in so short a time of such important results, as the establishment of the Signal Service (weather) bureau."
At the time of the transfer, General A. W. Greely wrote:
"In parting from the civil employees the Chief Signal Officer feels assured that the new chief in another department will receive from them the same loyal, faithful, and efficient service they have rendered the Government while serving under his orders. The scientific staff have in view important additional duties looking to the extension of the Weather Service in the interests of agriculture and still further development of the science of meteorology. The Chief Signal Officer will follow with deep interest the development of the new scientific field of weather forecasting and the application of meteorology to agriculture, on which grounds this liberal reorganization of the Weather Bureau was planned and carried out."
So on July 1, 1891, the weather stations, telegraph lines, apparatus, and personnel (military people whom were honorably discharged from the War Department and were now civilians) were transferred from the Signal Corps' Division of Telegrams and Reports for the Benefit of Commerce to the Department of Agriculture's new civilian Weather Bureau.
Quarters of the Commanding Officer of Fort Whipple (Fort Myer), Virginia (1876).
History of Fort Myer
From 1971 to 1886 most weather training for Signal Service forecasters and observers was conducted at Fort Myer, Virginia. In fact, Fort Myer was named for General James Myer, the Army's first commander of the Signal Service.
Fort Myer is located in Virginia just across the Patomac River from Washington, D.C. Fort Myer originally was named Fort Whipple and had its beginning in 1863. During the early years of the Civil War, a federal defense committee recommended that a series of military forts be built on the high terrain of Virginia to protect the nation's capitol from the Confederate Army. One of the forts constructed was Fort Whipple, named to honor Brevet Major General Amiel Weeks Whipple, an 1841 graduate of the U.S. Military Academy.
Initially, Fort Whipple was comprised of earthworks, tentage, and temporary frame structures. By the late 1860s, the Signal Corps had taken over the post since its location and elevation made it ideal for visual communications.
General Myer established the Signal Corps' headquarters, the Signal Corps School, and the weather service school at Fort Myer. The weather school for forecasters and observers was continued at Fort Myer until 1887 when the fort was converted into an Army cavalry fort.
The first military test flights were made from the parade field at Fort Myer on September 3, 1908. On that date, Orville Wright succeeded in keeping his plane aloft for 1 minute and 11 seconds. Six days later, he made 57 complete circles over the same field.
On September 17, 1908, Orville was accompanied by an Army Lieutenant on a flight over the parade field when a propeller broke and the aircraft crashed. Wright was severly cut and bruised, but the Lieutenant was killed, becoming the first fatality associated with a powered aircraft.
Today, Fort Myer remains in use by the Army. It is under the jurisdiction of the commanding general, U.S. Army District of Washington, D.C., but has its own post commander. It also is home of the U.S. Army Information Systems Command which staff the Pentagon Telecommunications Center, as well as other signal operations in the National Capital Region.
Signal Service Office in Washington, D.C.
Because of its location, the Washington, D.C. office was the central forecast center for the entire country until 1887. The first Signal Service weather office in Washington was located in the building of the Chief Signal Officer. This building was located on G Street near the War Department. In 1871, this was the observers office. Upon the flat roof of the building was erected a wooden observatory, designed for the purpose of comparing thermometers and other instruments. Also on the roof was one self-registering rain gauge and one wind vane. All changes required at other Signal Service offices, as well as all new instruments, were thoroughly tested before being implemented.
Signal Service Office in Washington, D.C., located on G Street near the War Department. For over 17 years (1870-1887), this building housed the headquarters of meteorological operations for the Signal Service.
The first Signal Service weather office in Washington, D.C. also served as the central office of the country. Weather observations from across the country were compared for errors. In addition, forecasters at the office prepared maps and various weather bulletins, including forecasts, for the eastern part of the United States. In 1871, Signal Service forecasts and other weather information were posted in the Signal Service office, the post office, and at the main office of the Western Union Telegraphy Company. Maps also were posted in the principal hotels in the nation's capitol.
The first Signal Service weather office contained a printing department to print the maps and other weather information. In addition, a separate department was available to evaluate the weather instruments, and another for checking weather observations. To support the various departments and functions of the office was a correspondence and clerical staff.
NWS People During the Signal Service Years
The early weather service had its share of characters. Since many Signal Service weather offices were occupied by one individual, personal discretion was important. Unfortunately, this was not always the case. One observer in the Midwest who was addicted to poker playing, frequently lost large amounts of money. The observer went to a local pawnbroker and pawned the station's instruments; consequently, the instruments were moved to the pawnbroker's place of business. When the Signal Service inspector arrived on station, he found no instruments. He found the instruments in the pawnbroker's store and the observer taking the weather observations in the pawn shop, instead of at the weather office.
Publications in the Signal Service
During the 20 year history of the Division of Telegrams and Reports for the Bureau of Commerce, considerable documents were published for the benefit of the observers and forecasters. As usual, the quality of the publications varied from insightful (considering the level of science of the day) to the ridiculous. Listed below are 12 publications, and brief summaries, to depict the state of weather observing and forecasting during the Signal Service from 1870 to 1890.
Memoir on the Use of Homing Pigeons for Military Purposes
This Signal Service Note describes the use of homing pigeons by the military for carrying messages, including weather information. A brief historical sketch of the homing pigeon is presented, along with its various uses. It was discovered that the practicability of using pigeons to carry messages in time of war was not encouraging. Despite great care in training, the pigeon frequently failed during critical moments.
To Foretell Frost by Determination of the Dew-Point
This note describes the importance of measuring dew point temperature for the purpose of forecasting the formation of dew or frost. Tables are presented which relate wet-bulb and dry bulb temperatures to dew point temperatures. It was recognized that vegetation could be protected by "kindling a small smudge fire." One interesting feature of the note was that a complete hygrometer cost $7.00 and a minimum thermometer $5.00.
The Use of the Spectroscope in Meteorological Observations
During the 1870's, Professor Piazzi Smyth, a Scottish astronomer, suggested that the absorption lines in the solar spectrum, might be used to forecast rain since the absorption spectra varied with amount of atmospheric moisture. This study presented results of a study to test Smyth's hypothesis. The study found some correlation and it was suggested that the spectroscope could represent a significant forecast tool.
Since the science of meteorology was relatively undeveloped during the late 1800s, considerable emphasis was placed on heuristic rules and folklore. This Signal Service Note listed many rules of thumb and folklore which could be used by forecasters. The list was compiled from Signal Service forecasters and observers across the United States. Listed below are a selection of the weather proverbs.
- A red sun has water in his eye.
- When the walls are more than unusually damp, rain is expected.
- Hark! I hear the asses bray, We shall have some rain today.
- The further the sight, the nearer the rain.
- Clear moon, Frost soon.
- When deer are in gray coat in October, expect a severe winter.
- Much noise made by rats and mice indicates rain.
- Anvil-shaped clouds are very likely to be followed by a gale of wind.
- If rain falls during an east wind, it will continue a full day.
- A light yellow sky at sunset presages wind. A pale yellow sky at sunset presages rain.
Also included in the document were rules of thumb for individual Signal Service stations. Listed below are a few examples:
Albany, NY - Storms set in with southerly winds, and are always preceded by falling barometer, and usually by falling temperatures, with nimbus or cumulo-stratus clouds.
Corsicana, TX - Approach of norther indicated by bank of clouds in north or northwest when the balance of sky is clear. Gentle or brisk east wind precedes rain. Southwest or west wind indicates the approach of clear, dry weather.
Indianola, TX - "Northers" are preceded by protracted southeast winds, rapid rise of barometer from four to six hours in advance of storm, high humidity, with cirrus clouds moving from the west.
North Platte, NB - All storms approach from the northwest without reference to direction in which wind may blow previously. Rain storms are preceded by north or northeast wind.
San Francisco, CA - Rain storms are preceded by falling barometer, low but rising temperature, and west wind. During the rainy season if wind veers to southeast rain follows.
Characteristics of Tornadoes - The author of this Signal Service Note, John P. Finley, described the results of his studies of tornadoes in the United States. Considerable climatological information was presented on tornado movement and times of occurrence. In addition, general weather conditions prior to tornado formation are described.
Finley described tornado appearances, and provides preparedness information on how to avoid tornadoes or to protect oneself from related injuries. The note was detailed and provided Signal Service forecasters with basic information on tornadoes.
The Aurora in its Relation to Meteorology - During the Signal Service years, meteorologists speculated on the importance of the Aurora to weather. The reasoning was that the Aurora was the result of atmospheric electricity, and like lightning, must occur with certain types of weather. This Signal Service Note attempted to evaluate the potential of Aurora occurrence to weather forecasting. Essentially no correlation was found.