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<br />some parts of town may get more rain while others get less. If stonns are randomly located,
<br />over the course of many years these variations will average out so that the campus data will
<br />provide representative information for all parts of the city. In the case of Fort Collins, which
<br />is situated such that the foothills and mountains rise abruptly just west of the city, storms may
<br />not be randomly located. However, there is no other consistent long term data to compare to
<br />at this time.
<br />
<br />The following analyses are based on daily rainfall observations taken each day at 7:00 p.m.
<br />(1900 MST, 2000 MDT when daylight time is in effect). Table 7 shows the greatest daily
<br />precipitation totals since 1889. Table 8 shows the greatest 2-day totals. Keep in mind that
<br />daily measurements through history have been taken at the fixed time of 7:00 p.m. MST (8:00
<br />p.m. MDT). If it happens to be raining at the time of observation, rainfall from that storm will
<br />be split between two daily reports. That was the case with the July 28, 1997 storm. Most of
<br />the rain fell after the 8:00 p.m. (2000 MDT) observation, and that rain appears on the
<br />climatological report for July 29.
<br />
<br />There are many ways that heavy rain can fall, and not all of the heaviest stonns (in tenns of
<br />total rainfall) ever caused significant runoff and flooding. Some of the heaviest one and two-
<br />day stonns partially fell as heavy, wet snow. To more thoroughly describe and historically
<br />document the heaviest precipitation events, a brief description of each storm from Table 7 and
<br />Table 8 is recorded in Appendix C.
<br />
<br />Table 7.
<br />Greatest one-day precipitation totals measured at the Fort Collins weather station on the campus
<br />of Colorado Slate University for the period January 1,1889 - December 31, 1997.
<br />(All toIaIs are for the 2~r period ending all900 MST on the dale indicated.)
<br />
<br /> PrecipiIation Dale of
<br />Rank Total rmches\ Observation Remarks .
<br />1 4.63 JulY 29, 1997 Flash flood, 5 killed, most fell in less than 5 hl$
<br />2 4.43 JulY 25, 1977 Rain, most fell in 15 hours
<br />3 4.34 Seotembar 21, 1902 Rain, intense at first, then gentle
<br />4 3.54 3,1938 Cloudburst, flooding west of town
<br />5 3.54 JlI\8 4, 1949 Sl@advrain but not too intense
<br />6 3.48 March 6, 1990 AN SI1OW', heaW and wet, 12.4 inches
<br />7 3.21 Mav 13,1961 Sleedv rstn changing to SI1OW'
<br />8 3.06 Mav 13,1982 Long and steady rain
<br />9 3.02 Auaust 3, 1951 V... intense rstn, fell In less than 4 houl$
<br />10 3.01 May 2, 1904 Lone and steady rain
<br />11 2.96 Auaust 4, 1951 Vf!!fV Intense rstn, fell less than 4 hours
<br />12 2.97 JlI\8 8, 1974 Rail, - but briefly intense
<br />13 2.85 JulY 9, 1918 p..-v intense rain
<br />14 2.71 June 17, 1965 Brief but intense rain
<br />15 2.69 June 16, 1963 Wi rain
<br />16 2.58 Auaust 19,1961 Sleedv rstn changing to SI1OW'
<br />17 2.49 June 24, 1992 HOBWlhunder and hen, fell less than 1.5 hl$
<br />18 2.40 JlI\811,l970 L""" and steady rain
<br />19 2.39 ~,1900 '-- rain and SI1OW', IOna and steadv
<br />20 2.32 22,1901 Heaw rain and hail
<br />
<br />. EllplInded descripition of each event is given In Appendix C,
<br />
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