STORMS AND WEATHER FORI-JCASTS 77 



Now turn to Charts VIII ami IX of tlie followiiij^ niorning 

 and it will be seen from the latter that the cold wave has cov- 

 ered the entire Mississippi valley. The low shown on the preced- 

 ing chart as heinj; central in southern Texas has moved northeast- 

 ward to Alabama, and on Chart VIII appears as a fully developed 

 storm. The difference in pressure between the central isoliar of 

 the low and the central isobar of the higli is now 1.4 incbes. 

 Precipitation has occurred, as shown by the dark shading. 



Special attention is called to the large figures placed in the 

 four quarters of the low-pressure area, about 300 miles from 

 the center. They indicate the average temperatures of their re- 

 spective quadrants, and strikingly illustrate how great may be 

 the difference in temperature under cyclonic influence between 

 regions separated by but short distances. It is certain that as 

 the low or cyclonic whirl moves toward the northeast, along the 

 track usually followed by storms in this locality, the cold of the 

 northwest quadrant, by the action of the horizontally whirling 

 disk of air, will be thrown southeastward toward Florida, lowering 

 the temperature in the orange groves to below tbe freezing point. 

 Chart X shows that the center of the cyclone or low-pressure 

 system has moved during the preceding 24 hours northeast to 

 the coa.st of New Jersey, with greatly increased energy, the 

 barometer at tlie center showing the abnormally low reading of 

 28.7 inches. Cold, northwest winds, as shown by the arrows, are 

 now blowing systematically from tlie high-pressure area of the 

 northwestern states southeast to Florida and the South Atlantic 

 coast. The dotted isotherm of 30 degrees passes through the 

 northern part of Florida, where, on the day before, the temper- 

 ature was over 50 degrees. The cyclonic gyration of this storm 

 extends 1,000 miles inland and probably to an eipial distance 

 out to sea. Heavy snow or rain has fallen througliout the area 

 under its influence, seriously impeding railroad travel, and a 

 gale of hurricane force has prevailed on the coast. But when, 

 on the day preceding, the storm was central in Alabama all 

 these conditions were foreseen and the necessary warnings issued. 

 Chart XI shows the temperature changes caused liy the rapid 

 movement of the storm center. 



Charts XII and XIII show the conditions 24 hours later. The 

 storm center has been three days in i)assing from southern Texas 

 to the mouth of the St Lawrence. The temperature bas fallen 

 still lower on the Atlantic coast and in Florida as the result of 

 uninterrupted northwest winds, and no material rise in tempera- 



