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<br />99 <br /> <br />searched, leading to more objective techniques in determining the thresholds <br />for issuing flash flood watches. Flash flood warning decision systems can <br />take into account the individual characteristics of a river basin, the lead time <br />for successful evacuation, and the risk factors to people in the floodplain. It <br />could also factor in the time of year, which may influence the number of <br />people vulnerable to dangerous flooding. <br />One area that needs to be focused on is the delivery of products that <br />convey in more site-specific terms the magnitude and urgency of the flash <br />flood event. The NWS/Office of Hydrology (OH) is currently developing <br />WFO Hydrometeorology applications that will provide forecasters with tools <br />to run site-specific models for small streams and headwater areas. The Office <br />of Hydrology is also developing an "area-wide" hydrologic software model <br />to better define the flash flood potential and delineate areas where flash flood <br />guidance has been exceeded and flooding is possible. This model depends on <br />the use of the modernized flash flood guidance that is being implemented <br />nationwide. The modernized guidance is being developed for small water- <br />sheds and will provide data on a gridded basis (4 x 4 km.). This will enable <br />forecasters to compare high-resolution WSR-88D data with flash flood <br />guidance on small scales, comparable to those that produce local flash floods. <br />To maximize the effectiveness in using these models operationally will <br />require RFCs to deliver accurate and timely state variables as guidance to the <br />WFOs, and a well-trained WFO staff in effectively running the WFO <br />Hydromet System. <br />Product formats for flash flood warnings have not changed appreciably <br />over the last 20 years. However, efforts are now underway to employ <br />graphical representations, depicting flood inundation on small scales through <br />the use of geographic information system (GIS) technology. Increased use of <br />GIS display capabilities by local emergency management officials, and <br />eventually the general public, will usher in a new way of pinpointing areas <br />where flooding is expected. <br />While improvements in warning dissemination continue with improved <br />communications technology, its use in an overall flash flood program varies <br />from location to location. In the events cited, there were times when direct <br />telephone communication was vital, others where NOAA Weather Radio or <br />amateur radio communications were important, and occasions where only <br />directed local communications of a serious flood threat could have prevented <br />loss of life. Redundancy of communications is an important consideration, as <br />is a greater awareness and education of the affected user and communications <br />media in dealing with life-threatening flash flood situations, down to the local <br />level. One recent example of a new dissemination path that is being <br /> <br />Summer <br />