The National Weather Service in Phoenix has issued a Fire Weather Watch for strong winds, low relative humidity and very high fire danger, which is in effect from Friday morning through Saturday evening. * AFFECTED AREA...Yuma/Martinez Lake and Vicinity/Lower Colorado River Valley AZ and Lower Colorado River Valley CA. * TIMING... * WINDS...Southwest 15 to 25 mph with gusts up to 45 mph. * RELATIVE HUMIDITY...As low as 4 percent. * IMPACTS...Rapid spread and growth of any new or existing fires. Fires will have the potential to exhibit extreme fire behavior. Elevated potential for new fire starts.