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<br />season. Fifty-eight to sixty-eight eels were identified <br />mesonet analysis from eight days of radar data in 1981. <br />the days and numbers of convective complexes found. <br /> <br />as candidates for <br />Table II.11 sUII\IlIarizes <br /> <br />Table 11.12 lists the convective complexes which either started, died <br />and/or merged within the mesonet, along with their respective radar derived <br />rainfall characteristics. Figures 11.12 through 11.15 show the movement of the <br />candidate eels as described by radar data analysis. <br /> <br />5. Remarks on the Examination of eovariates <br /> <br />The requirement that a candidate ee exist entirely within the mesonet <br />sometime in its lifespan presents a bias towards investigating smaller s,tolrms. <br />Analysis to date show little, if any, meteorological signal by the mesonet for <br />the small eels. A larger than expected number of candidates have been found; <br />however, a significant portion may be eliminated from fruitful analysis bel:ause <br />of the apparent lack of any detectable signal in the PROBE network. <br /> <br />The lack of signal may be due to elevated inversions and high bases, the <br />spacing of PROBE stations which would preclude the detection of short <br />wavelengths on the scale of the smaller eels, or may indicate a poor <br />meteorological signal to noise level. The smaller eels should not be <br />disregarded without more detailed analysis than attempted thus far because <br />these might be the subject of the next phase of a randomized summer convective <br />weather modification experiment (formerly planned as HIPLEX II). <br /> <br />Preliminary analyses do show some encouraging covariates for convective <br />complex formation. Some impressions are noted below. <br /> <br />Pressure change: There was not a clear negative trend ahead for eels; <br />however, pressure rises were observed behind activity. The longer the period <br />over which trend was derived, the less chaotic the picture. In some cases <br />one-hour pressure trends did show a small drop ahead and a clear rise behind <br />several eels. Larger eels had this trend accentuated. <br /> <br />Streamlines: There was a broad, well-organized confluence evident at <br />appropriate locations. Several complexes showed confluence to the north and <br />the diffluence to the south. There was a zone of confluence 30 to 40 km east <br />of Miles eity over the pine Hills. Figure 11.13 shows this to be a preferred <br />location of ee formation. Areas of diffluence associated with several eels <br />were evident. It should be noted that the streamlines had the mean wind <br />subtracted. <br /> <br />nivergence: Organized kinematic divergence was more evident than <br />convergence about ee IS. Around larger ee IS, there was divergence behind a~nd <br />convergence ahead of the ee IS. With several systems there was an organizE~d, <br />checker-board pattern of convergence/divergence 'with a wavele~gth of <br />approximately 40 km. This may be a relic of the objective analysis SChemE!, <br />since this would be the Nyquist wavelength for the large PROBE spacing. }.s <br />with the streamlines, the convergence tendencies were to the eastern half of <br />the compass, and the divergence was to the western half in the vicinity of <br />eels. There was good coherence from period to period in the analysis. <br /> <br />Relative humidity: <br />enough ahead not to be <br />the eels were preceded <br /> <br />Higher humidities existed ahead of eels. <br />associated with precipitation from the ee. <br />by a tongue of high relative humidity from <br /> <br />This was far <br />Several of <br />the south. <br /> <br />38 <br />