urban storm drains within six to 24 hours. It is intended to inform the public and cooperating agencies (including ambulance services and fire departments that may assist in water rescues) in advance of expected flood potential, even though the occurrence of flooding is neither certain nor imminent. Areal flood advisory (FLS) – Minor general or areal flooding of streets, low-lying areas, urban storm drains, creeks, and small streams is occurring, imminent, or highly likely within the next one to three hours, but is not expected to substantially threaten life and property. These advisories are issued on a polygonal basis by the local Weather Forecast Office and are generally in effect for three to six hours. River flood warning (FLS; formerly flood warning for river forecast point) – Flooding of streams or rivers is occurring, imminent, or highly likely. These warnings are issued either by the River Forecast Centers for the area surrounding affected streams or rivers or on a county by county basis by the local Weather Forecast Office and are generally in effect for an indeterminate period until river gauges in the affected areas record water levels receding below the water body's predetermined flood stage. River flood advisory (FLS) – Minor flooding of streams or rivers reaching action stage is occurring, imminent, or highly likely. These advisories are issued on a county by county basis by the local Weather Forecast Office and are generally in effect for a couple of days or longer. Urban and small stream flood advisory – Ponding of water on streets, low-lying areas, highways, underpasses, urban storm drains, and elevation of creek and small stream levels is occurring or imminent. Urban and small stream flood advisories are issued for flooding that occurs within three hours after the excessive rainfall. These advisories are issued on a polygonal basis by the local Weather Forecast Office and are generally in effect for three to four hours. (The watch/warning/advisory display map on the NWS's national and local Forecast Office websites does not display the advisory as an area-specific polygon, instead indicating the affected counties and/or county-equivalent subdivisions.) Flood statement (FLS) – A hydrological weather statement issued to provide updated information on ongoing flooding along major streams in which there is not a serious threat to life and/or property active or flood warnings to the public and emergency managers; information will be provided on observed (or if a dam is