National Weather Service United States Department of Commerce

The National Weather Service in Birmingham also serves the river community in 39 central Alabama counties.  We issue summaries, statements, watches, and warnings.  We also serve our forecast area with Flood watches, warnings, and statements when heavy rain threatens.

· Hydrologic Outlook (ESF)  


The "Hydrologic Outlook" is used for three purposes.  First, we issue the Flood Potential Outlook twice each spring to discuss the possibility for river flooding during the spring due to snowmelt upstream and runoff due to high soil moisture.  The product is also issued when heavy rain may cause rivers to rise above flood stage. It is usually issued a day or two in advance of the event.   We also issue a Hydrologic Outlook if drought conditions are occurring in the area.

· Hydrologic Statement (RVS) 


The "Hydrologic Statement" is used to issue daily river forecasts and river statements for significant rises staying below flood stage. This product is issued daily between 10am and 10:30am.

· Hydrologic Summary (RVA) 


The "Hydrologic Summary" is a daily report of observed river and lake stages and 24 hour changes for a number of river gauges across the area.  The flood stages, for locations where flood stage has been defined, are also shown.  This product is issued daily between 8am and 9am.

· Daily River and Lake Summary (RVD)


The "Daily River and Lake Summary" is a daily report of river stages, 24 hour changes, and a three day forecast.  It also includes a few lake and reservoir stages.  All river points designated as "forecast points" are included in this summary. 

· Flood or Flash Flood Warning (FLW)

Flood vs Flash Flood vs Urban and Small Stream Flood Advisory

A "Flood Warning" or "Flash Flood Warning" is issued when river flooding is expected.  It is issued once a river is forecast to go above its designated flood stage at the forecast point.  The warning will be updated by Flood Statements, unless additional flooding is forecast; then another Flood Warning may be issued. 

· Flood Statement (FLS)


A "Flood Statement" is used to update information on a river in flood, or to terminate a flood warning. This product is also used as an "Urban and Small Stream Flood Advisory". 

· Flood or Flash Flood Watch (FFA)


A "Flood Watch" or "Flash Flood Watch" is issued to inform the public and cooperating agencies that current and developing weather is such that there is a threat of rapid flooding (also known as flash flooding), or widespread river flooding.  The occurrence of flooding is neither certain nor imminent.  Persons in the watch area are advised to check flood action plans, keep informed, and be ready to take necessary actions if a warning is issued or flooding is observed.  A flood watch may also be issued for a dam break.

· Flood or Flash Flood Warning (FFW)


A "Flash Flood Warning" is issued to inform the public that flooding is imminent or in progress.  It focuses on specific counties, communities, streams, or areas. Flash Flood Warnings are issued for flooding usually occurring within 6 hours of heavy rain.

· Dam Break Warning (FFW)


If a dam break has occurred or is imminent, a "Flash Flood Warning" is issued for the dam break.  The warning includes affected counties, the agency verifying the dam break, the name of the dam, the name of the river, the nearest downstream town and its distance from the dam, travel time of the crest, and a forecast of the crest height if known.