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Object Overview
Before us is an American Weather Guide, manufactured approximately around 1950 and developed by meteorologist Dr. Irving P. Krick. This unusual instrument is a mechanical cloud-reading forecaster — a visual weather forecasting device intended to provide a short-term forecast based on two directly observable factors: cloud formation and wind direction. This particular example was designed primarily for the North Central States climatic sector, whose name appears in the upper FORECAST window. The instrument does not measure atmospheric parameters: it contains neither a barometer, thermometer, nor hygrometer. Instead, the observer compares the appearance of the sky with a set of reference images of clouds, determines the wind direction, and mechanically enters these two observations into the Weather Guide, after which the corresponding forecast appears in the window.
n/a
aluminium, paper, plastic
The Weather Guide has a characteristic narrow, elongated aluminium case with a rounded upper section. The front and rear panels are almost entirely occupied by a system of vertically arranged windows containing colour illustrations of clouds and brief explanatory captions. At the bottom of the case are two projecting knurled cylindrical knobs, one on each side, which move the printed bands enclosed inside the case and set the necessary input data for the forecast. In this way, numerous combinations of cloud type, wind direction, season, and regional setting are accommodated within a comparatively small pocket-sized instrument.
A small magnetic compass is located at the top. The compass has an entirely practical purpose and forms part of the forecasting procedure: it helps the user determine geographic north and then establish the direction from which the wind is blowing. Along the left side of the main Weather Guide scale are the eight points of the compass, repeatedly arranged opposite the different cloud types. Thus, each selected image of the cloudy sky has its own corresponding sector of wind directions, and the forecast is derived from the combination of these two factors.
The range of cloud formations includes the principal types that a user could identify visually with reasonable confidence: Clear, Cirrus, Altocumulus, Altostratus, Nimbus, Cumulus, and Stratocumulus. Each illustration is accompanied by a brief description of its characteristic features. For example, Cirrus is shown as very high, thin cloud in the form of “mare’s tails” or milky-white streaks, often forming rings around the Sun or Moon; Altocumulus as medium-high cloud sheets composed of regularly spaced rounded masses or bands; as a relatively uniform grey layer through which the Sun may appear blurred; as low, heavy, dark cloud associated with continuous precipitation; as cauliflower-shaped cloud with a dark, flat base, capable of developing into thunderstorms; and as low white or grey cloud ranging from broken patches to complete overcast.
The Weather Guide is based on the idea that short-term weather development can be determined from the relationship between cloud formation, wind direction, and the subsequent sequence of weather conditions. The instruction booklet supplied with the instrument states that long-term archives of daily observations across the Northern Hemisphere were used in developing the system. Researchers looked for recurring sequences in which particular combinations of cloud formation and wind direction corresponded to particular developments in the weather. These identified relationships were then incorporated into the mechanical system of the Weather Guide.
The authors specifically contrast this method with observing atmospheric pressure alone. The instructions make the rather questionable suggestion that a barometer by itself cannot reveal the full complexity of ongoing atmospheric changes, whereas clouds provide a visible manifestation of moisture, temperature, and atmospheric dynamics. Wind direction, in turn, links the current local situation with the larger weather system approaching the observer. For this reason, the Weather Guide uses not pressure, but the combination of “cloud formation and wind direction.”
The practical procedure was extremely simple. On the back of the instrument itself it is reduced to six steps:
The instrument therefore functions as a kind of mechanical correlation table in which the user enters the observed state of the atmosphere, while the printed scales concealed inside the case are brought into the position corresponding to a predetermined combination.
The instructions recommend judging the sky not from one small section but by observing the entire sky. If no more than one quarter of the sky is covered by cloud, the condition should be considered Clear. Only when cloud cover exceeds 1/4 of the sky should the user select one of the cloud types.
For each principal type, the Weather Guide contains two illustrations showing different variations of the same cloud formation. This was done because real clouds rarely correspond exactly to a single idealised picture. The manual advises the user to rely not only on the colour illustrations, but also on the short written descriptions beneath them. The user was therefore expected not to find a literal visual match, but to identify correctly the general morphological type of cloud.
A particularly important feature of the system was the ability to change the input data immediately if the condition of the sky changed. If the wind direction shifted or a different cloud type appeared, the Weather Guide was to be reset according to the new observations. The instructions emphasise this as one of the advantages of the instrument: the forecast was not an unchanging result obtained once per day, but could be continually adjusted as the atmospheric situation developed.
When setting the wind direction, the user had to select specifically the direction from which the wind was coming, rather than the direction in which it was moving. With low clouds, the movement of the clouds themselves provided a useful indication. The instructions also suggested observing smoke, flags, dust, and other visible signs of air movement.
If no such indications were available, the built-in compass was used. The Weather Guide was to be held horizontally in front of the observer so that the compass needle pointed to N. The direction marked on the opposite side of the compass scale then indicated the direction from which the wind was blowing. The small compass was therefore not a decorative addition, but an integral part of the entire observation system.
Although the instructions state that a forecast can be obtained at any time of day, the most favourable period was considered to be approximately between 10:00 a.m. and 12:00 noon local time. In developing the Weather Guide, noon was used as the standard observation time. According to the author’s explanation, minor local discrepancies, particularly variations in the wind, are generally less pronounced around this time, while cloud formations are especially indicative of the general trend in the weather.
The Weather Guide forecast scale is divided into seasonal versions. Red printing indicates summer forecasts, while blue indicates winter forecasts. The duration of the corresponding season for the particular climatic region is marked beside the moving indicator. When one season changed to another, the user had to move the band until the appropriate seasonal arrow and its associated set of forecasts appeared.
This is an important aspect of the design: the instrument did not assume that the same combination of clouds and wind should always result in exactly the same forecast. Season was treated as an additional climatic factor and was incorporated in advance into the system of scales.
The Weather Guide was designed for use in the Northern Hemisphere approximately between 23° and 66° north latitude, essentially within the temperate zone. According to the instructions, the basic system could operate throughout this entire area, but its accuracy was improved by producing versions adapted to individual climatic regions.
The region of a particular instrument could be determined by a special setting of the indicator: when aligned with the mark in the upper left-hand corner of the face, the name of the corresponding area appeared in the forecast window. In the present example this is “4. N. CENTRAL STATES”, indicating a Weather Guide version optimised for the north-central part of the United States.
At the same time, the manual specifically notes that regional specialisation does not mean that the instrument cannot be used outside the designated area. It was merely intended to provide somewhat greater accuracy in the region for which the particular version had been designed.
The Weather Guide was intended primarily to determine the general character of forthcoming weather, rather than to make quantitative meteorological measurements. It was meant to help recognise the approach of improving or deteriorating weather, precipitation, stormy conditions, and changes in the general weather pattern.
The system did not distinguish between rain and snow as separate forms of precipitation. The instructions advise interpreting the forecast in conjunction with temperature: under stormy conditions and at temperatures below freezing, snow should be expected, while at temperatures above freezing, rain should be expected.
The Weather Guide occupies an unusual place among domestic meteorological instruments of the mid-20th century. It is neither a measuring instrument in the conventional sense nor simply an illustrated cloud chart, but an attempt to transform a professional method of synoptic recognition of weather situations into a small, personal mechanical forecaster. The user effectively became a kind of meteorological observer: identifying the cloud formation, establishing the wind direction, taking season and region into account, and then allowing the Weather Guide to translate that combination into a predetermined forecast.
The surviving set, complete with its original box, instructions, and N. CENTRAL STATES regional setting, particularly clearly demonstrates Irving P. Krick’s original concept: to make professional weather forecasting methods accessible to the ordinary user in the form of a simple portable device.
In 2026, director Anthony Maras released Pressure, a historical drama centred on the crucial weather forecasting dispute before the D-Day landings in Normandy. Irving P. Krick, played by Chris Messina, is one of the key figures in the story. For anyone interested in Krick, the history of meteorology, or the role of weather forecasting in D-Day, I highly recommend the film.