13 



Figure 3- 1000 nib contours (solid lines) and 1000-500 mb thickness 

 contours (dashed lines) drawn for interval of 200 geopotential feet, 

 1500 GMT, 10 February 1957- (a) "No Flux," and (b) "Complete" 12-hour 

 forecasts. (C) Verification (observed) map. See text page 10. 



