Spring in the Red River Valley is often a mixed blessing. Residents welcome the warmer temperatures, but shudder at the inevitability of at least some flooding along the Red River of the North. Now after years of discussion, planning and testing, the national Weather Service has developed a new system for issuing flood forecasts. As Minnesota Public Radio's Bob Reha reports the Advanced Hydrologic Prediction Services or A-H-P-S is getting mixed reviews. (22) {