Vincent Vizachero just moved to Baltimore from Houston, where he relied on a Harris County Web site for interactive rainfall maps. "It is handy in storms, of course, but also for gardening," he says. "Do you know of anything like this for Baltimore?" Nothing as detailed as Harris County's, but the NWS has rain data maps at www.erh.noaa.gov/lwx/hydro/precip/There is similar data, from the River Forecast Center, at www.erh.noaa.gov/marfc/Maps/precip.html# daily Better still, spring for a rain gauge. They're cheap.