A River Flood Watch is issued by the National Weather Service of the United States when flooding at formal forecast points with river gaging sites and established flood stages is possible. Flooding may be caused by various reasons, such as heavy rain in the vicinity of the river, melting snow, and/or ice jams.
Example
The following is an example of a River Flood Watch issued by the National Weather Service office in Seattle, Washington.
ZCZC SEAFFASEWWGUS66 KSEW 151139URGENT - IMMEDIATE BROADCAST REQUESTEDFLOOD WATCHNATIONAL WEATHER SERVICE SEATTLE WA339 AM PST THU NOV 15 2007...THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A FLOOD WATCHFOR THE FOLLOWING RIVERS IN WESTERN WASHINGTON... SKOKOMISH RIVER NEAR POTLATCH AFFECTING MASON COUNTY..FLOOD BULLETIN NO. 1HEAVY RAIN OVER THE OLYMPIC MOUNTAINS COULD DRIVE THE SKOKOMISH RIVERABOVE FLOOD STAGE LATE TONIGHT OR FRIDAY MORNING.A VIGOROUS FRONTAL SYSTEM WILL PRODUCE PERIODS OF HEAVY RAIN OVER THEOLYMPIC PENINSULA TONIGHT...AND SOME SPOTS ON THE SOUTH SLOPES OFTHE OLYMPIC MOUNTAINS COULD RECEIVE MORE THAN THREE INCHES OF RAIN.THE RAINFALL COULD BE HEAVY ENOUGH TO PRODUCE FLOODING ON THESKOKOMISH RIVER.A FLOOD WATCH MEANS THAT FLOODING IS POSSIBLE BUT NOT IMMINENT ORCERTAIN. BE READY TO ACT QUICKLY IF THE NATIONAL WEATHER SERVICEISSUES A FLOOD WARNING.WAC045-151839-/O.NEW.KSEW.FL.A.0004.071115T1139Z-000000T0000Z//SRPW1.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/339 AM PST THU NOV 15 2007THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A* FLOOD WATCH FOR THE SKOKOMISH RIVER NEAR POTLATCH* UNTIL FURTHER NOTICE.* AT 2:45 AM THURSDAY THE STAGE WAS 13.0 FEET.* MINOR FLOODING IS POSSIBLE.* FLOOD STAGE IS 16.0 FEET.* FORECAST...FLOOD STAGE MAY BE REACHED BY LATE TONIGHT OR FRIDAYMORNING.$$MCDONNALWEATHER.GOV/SEATTLEReferences
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