FLOOD00626 - Laserfiche WebLink

Home Browse Search

flowing in this hilly area, and rain intensity fluctuated from light showers to occasional downpours. Between 0600 and 0730 MDT, the rain tapered off along the foothills and stopped completely elsewhere. Around 0800 rain began again. A brief but soaking shower caught many morning commuters in Fort Collins, while to the northwest the heaviest rain of the morning began to cause major flooding around Laporte. From southwest Fort Collins near Hughes Stadium northward to Ted's Place (northwest of Laporte), one to two inches of rain fell between 0800 and 0900 MDT. The area of heavy rain shrank after 0930, but remarkably heavy and highly localized torrents continued northwest of Laporte until after 1100 MDT. People driving northwestward out of Fort Collins were shocked to go from dry roads in town to pouring rains and flood waters covering highways near Laporte - all of this without the accompaniment of lightning or thunder. The rains ended across all of Larimer County by noon, but not before six to eight inches of early morning rain had fallen northwest of Laporte. North and south of this storm center, three to six inch rain totals were common in the narrow band along and east of U.S. Highway 287 northward to Owl Canyon (15 miles northwest of Fort Collins) and south to Lory State Park and HOrselooth Reservoir immediately west of Fort Collins. Rainfa1l totals dropped off quickly to the east (Figure 8), but two to four inches fell over portions of west Fort Collins west of Taft Hill Road. All of the Fort Collins area received some rain early Monday morning but most totals were only 0.50 to 0,75 inches over the eastern ha\fofthe city. South of Fort Collins in the vicinity of Loveland and Berthoud, only a few scant showers had fallen. Many irrigation canals exit the Poudre River near Laporte. While the localized rains had little effect on the morning flow rates on the main river, irrigation canals were a different story. Headgates were shut early that morning, and still the ditches filled with runoff from the Laporte and Bellvue floodwaters. Many downstream residents were surprised by the high water, many of whom were not aware' of the heavy rains near Laporte. Skies remained cloudy over the Fort Collins area Monday afternoon. Clouds hung low along the foothills, as steady southeasterly surface winds continued to push very moist surface air into Larimer County. Dewpoint temperatures, a measure of the water content of the air, stayed in the low 60s all day. With weather conditions not unlike those that preceded the infamous Big Thompson flood in Larimer County 21 years previous, weather forecasts called for "locally torrential rains." Hallway, phone and e-mail conversations among climatologists, meteorologists and hydrologists along the Front Range from Denver to Cheyenne speculated on where the flash flood might occur this time. Weather forecasters familiar with Front Range flash flond conditions knew that this situation was potentially dangerous. But with all the rain that had already fallen, no one knew where or even if another flash flood producing storm would erupt. During the afternoon of July 28th, heavy thunderstorms began to develop west of Denver and in other areas of the state. In eastern Larimer County, the first showers appeared around 5:00 p.m. (1700 MDT). They began innocently enough - brief showers moving from south to north with little or no lightning and thunder. Just before 6:00 p.m. (1800 MDT) the first wave 30