II40 



Home Nature-Study Course. 



U. S. DEPARTMENT OF AGRICULTURE, WEATHER BUREAU 



EXPLANATION OF WEATHER FLAGS 



No. I No. 2 No. 3 No. 4 No. 5 



Fair Weather Rain or Snow Local Rain or Snow Temperature Cold Wave 



INTERPRETATION OF DISPLAYS 



No. I, alone, indicates fair weather, stationary temperature. 



No. 2, alone, indicates rain or snow, stationary temperature. 



No. 3, alone, indicates local rain or snow, stationary temperature. 



No. I, with No. 4 above it, indicates fair weather, warmer. 



No. I, with No. 4 below it, indicates fair weather, colder. 



No. 2, with No. 4 above it, indicates rain or snow, warmer. 



No. 2, with No. 4 above it, indicates rain or snow, colder. 



No. 3, with No. 4 above it, indicates local rain or snow, warmer. 



No. 3, with No. 4 above it, indicates local rain or snow colder. 



WILLIS L. TVIOORE, 



Chief U. S. Weather Bureau 



EXPLANATION OK WHISXLE SIQNALS 



A warning blast of fifteen to twenty seconds duration is sounded to attract 

 attention. After this warning the longer blasts (of four to six seconds duration) 

 refer to weather, and shorter blasts (of one to three seconds duration) refer to 

 temperature; those for weather are sounded first. 



Blasts. Indicate. Blasts. Indicate. 



One long Fair weather. One short Lower temperature. 



Two long Rain or snow. Two short Higher temperature. 



Three long Local rain or snow. Three short Cold wave. 



By repeating each combination a few times, with intervals of ten seconds, 

 liability to error in reading the signals may be avoided. 



STOR?vl AND HURRICANE AVARNINGS 



Hurricane 

 warning. 



i:£ winds. 



SE. winds. 



NW. winds. 



SW. winds. 



Explanation of Storm and Hurricane Warnings 



Storm warning — A red flag with a black center indicates that a storm of marked violence is ex- 

 pected. 



The pennants displayed with the flags indicate the direction of the wind; red, easterly (from north- 

 east to south); white (westerly, from southwest to north). The pennant above the flag indicates that 

 the wind is expected to blow from the northerly quadrants; below, from the southerly quadrants. 



By night a red light indicates easterly winds, and a white light below a red light , westerly winds. 



Hurricane warning — Two red flags with black centers, displayed one above the other, indicates the 

 expected approach of a tropical hurricane, or one of those extremely severe and dangerous storms 

 which occasionally move across the Lakes and northern Atlantic coast. 



No night hurricane warnings are displayed. 



