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<br />40 <br /> <br />A tendency to support the inverse relation can be seen in the data plotted <br />in figure 2.19. These ratios are selected within-storm (paired 6/24- and <br />72/24-hr ratios from the same storm) values from the stations in table 2.4. <br />All storms were used where the 24-hr amount equalled or exceeded 1.0 inch <br />(25 mm). To aid in und~rstanding seasonal variations the data were stratified <br />according to winter (Jan. and Feb.) and summer (Jul. and Aug.) months. An <br />attempt was made to reduce the influence of thunderstorms by purging the data <br />to eliminate 6/24-hr ratios greater than or equal to 0.90 and 72/24-hr ratios <br />less than or equal to 1.10. An envelopment of the data in figure 2.19 sup- <br />ports an inverse relation. Similarly, a rough average through all the points, <br />aside from the wide scatter, supports an inverse relation. <br /> <br /> 20 . <br /> . JAN. FEB (WINTER) <br /> . \ <br /> x.lLl, AUG (SUMMER) <br /> \ OWINTER AVERAGE <br /> \ D SUMMER AVERAGE <br /> 18 \ <br /> \ "'8 - SEE DISCUSSION. <br /> . \ SECTION 2.4.3 <br />;:: <br />Z \ <br />w <br />u . X\ <br />... <br />w 16 \ <br />.... <br />0 \ <br /> 0 \ ENVELOPING <br />;:: . LINE <br />00( \" <br />... <br /> X X <br />... X <br />:I: 14 . >). <br />I \ <br />~ X \ <br />N a X x\ <br />"- <br />N <br />"- <br /> . <br /> 12 x <br /> x <br /> . <br /> Xxx x <br /> 08 <br /> 10 0 40 60 80 100 <br /> 6/24 - HR RATIO (PERCENT) <br /> <br />Figure 2. 19.--Relation between 6/24-hr and 72/24-hr ratios for within- <br />storm cases of 3 consecutive day rainfall for all stations listed in <br />table 2.4 (see text for criteria for selection). Points identified as <br />winter or summer. <br />