GENERAL BAROMETER INDICATIONS
A gradual but steady rise indicates settled fair weather.
A gradual but steady fall indicates unsettled or wet weather.
A very slow rise from a low point is usually associated with high winds and dry weather.
A rapid rise indicates clear weather with high winds.
A very slow fall from a high point is usually connected with wet and unpleasant weather without much wind.
The following table of the United States Weather Bureau gives a summary of the wind and barometer indications:
| Barometer Reduced to Sea Level | Wind Direction | Character of Weather Indicated |
|---|---|---|
| 30.10 to 30.20 and steady | SW to NW | Fair with slight temperature changes for 1 to 2 days |
| 30.10 to 30.20 and rising rapidly | SW to NW | Fair, followed within 2 days by warmer and rain |
| 30.10 to 30.20 and falling slowly | SW to NW | Warmer, with rain in 24 to 36 hours |
| 30.10 to 30.20 and falling rapidly | SW to NW | Warmer, with rain in 18 to 24 hours |
| 30.20 and above and stationary | SW to NW | Continued fair, with no decided temperature change |
| 30.20 and above and falling slowly | SW to NW | Slowly rising temperature and fair for two days |
| 30.10 to 30.20 and falling slowly | S to SE | Rain within 24 hours |
| 30.10 to 30.20 and falling rapidly | S to SE | Wind increasing in force, with rain within 12 to 24 hours |
| 30.10 to 30.20 and falling slowly | SE to NE | Rain in 12 to 18 hours |
| 30.10 to 30.20 and falling rapidly | SE to NE | Increasing wind, with rain within 12 hours |
| 30.10 and above and falling slowly | E to NE | In summer, with light winds, rain may not fall for several days. In winter, rain within 24 hours |
| 30.10 and above and falling rapidly | E to NE | In summer, rain probably within 12 to 24 hours. In winter, rain or snow, with increasing wind will often set in, when the barometer begins to fall and the wind sets in from the NE |
| 30 or below and falling slowly | SE to NE | Rain will continue 1 or 2 days |
| 30 or below and falling rapidly | SE to NE | Rain, with high wind, followed within 24 hours by clearing and cooler |
| 30 or below and rising slowly | S to SW | Clearing within a few hours and continued fair for several days |
| 29.80 or below and falling rapidly | S to E | Severe storm of wind and rain or snow imminent, followed within 24 hours by clearing and colder |
| 29.80 or below and falling rapidly | E to N | Severe northeast gales and heavy rain or snow, followed in winter by a cold wave |
| 29.80 or below and rising rapidly | Going to W | Clearing and colder |
A sudden fall indicates a sudden shower or high winds, or both.
Courtesy Julien Friez & Son Baltimore, Md.
Fig. 49
U. S. STANDARD RAIN GAUGE
A stationary barometer indicates a continuance of existing weather conditions. (Note: Tap the barometer slightly on the face. If the hands move a trifle, it indicates that there is the tendency to rise or fall, depending upon the direction of movement of the hands.)
Northeasterly winds precede storms that approach from the southwest; that is, in New England and the Middle States and the Ohio Valley. Southeasterly winds precede storms that approach from the Lake region.