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<br />902
<br />
<br />JOURNAL OF APPLIED METEOROLOGY
<br />
<br />VOLUME 30
<br />
<br />hail suppression experiments in Switzerland should be
<br />based on some hypothesis that does not depend upon
<br />the existence of supercooled rain-water accumulation
<br />zones.
<br />The omission of concern is that of the "no-hail"
<br />cells in Mezeix' analysis. A change in the frequency of
<br />events with no hail is a possible outcome of seeding,
<br />so it is difficult to see how this omission can be justified.
<br />A first glance shows a smaller proportion of no-hail
<br />cells on seed days, which is contrary to any inference
<br />of a hail suppression effect. However, the chi-square
<br />test shows that the difference is not significant. We
<br />nevertheless believe that including the zero events is
<br />essential in this case, though we recognize that it can
<br />complicate the analysis.
<br />
<br />REFERENCES
<br />
<br />Dennis, A. S., B. G. Brown and J. R. Miller, Jr., 1980: Implications
<br />of rainfall and hail damage patterns associated with cloud seeding
<br />in South Dakota. Third WMO Scientific Con! on Weather
<br />Modification. Clermont-Ferrand, France, WMO, 583-589.
<br />Dessens, J., 1986: Hail in southwestern France. Part II: Results ofa
<br />
<br />30-year hail prevention project with silver iodide seeding from
<br />the ground. J. Climate Appl. Meteor., 25,48-58.
<br />Federer, B., A. Waldvogel, W. Schmid, H. H. Schiesser, F. Hampel,
<br />M. Schweingruber, W. Stahel, J. Bader, J. F. Mezeix, N. Doras,
<br />G. d'Aubigny, G. DerMegreditchian and D. Vento, 1986: Main
<br />results of Grossversuch IV. J. Climate Appl. Meteor" 25,917-
<br />957,
<br />Flueck, J. A., M. E. Solak and T. S. Karacostas, 1986: Results of an
<br />exploratory experiment within the Greek National Hail
<br />Suppression Program. J. Wea. Mod.. 18, 57-63.
<br />Holler, H., 1990: Multiparameter radar measurements of hail for-
<br />mation. Preprints, 1990 Con! on Cloud Physics, San Francisco,
<br />Amer. Meteor. Soc., 449-452.
<br />Mezeix, J.-F., 1990: Furth(:r exploratory evaluations ofGrossversuch
<br />IV using hailpad data: Analysis of hail patterns and stratification
<br />by storm type for seeding effect. J. Appl, Meteor" 29,401-417.
<br />Miller, J. R., Jr., and M. J. Fuhs, 1987: Results of hail suppression
<br />efforts in North Dakota as shown by crop hail insurance data.
<br />J. Wea, Mod., 19,45-49.
<br />Smith, P. L., J. R. Miller, Jr., R. L. Rose and P. W. Mielke, Jr., 1987:
<br />An exploratory study of North Dakota crop-hail insurance data
<br />for evidence of seeding effects. Preprints, 11 th Con! on Weather
<br />Modification. Edmonton, Canada, Amer. Meteor. Soc., 86-89.
<br />Waldvogel, A., L. Klein, D. J. Musil and P. L. Smith, 1987: Char-
<br />acteristics of radar-identified big drop zones in Swiss hailstorms.
<br />J. Appl. Meteor., 26,861-877.
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