Remember: This product is a combination of county-level Flash Flood Guidance and point-level Mesonet data.
A highlighted county indicates that one or more Mesonet stations within that county have observed significant rainfall in a 1-, 3-, or 6-hour period. The color represents the most severe encroachment to the Flash Flood Guidance for that time period. Important: This product is only a tool. Please use this product in combination with watch and warning information from your National Weather Service Forecast Office.

What is "Flash Flood Guidance"?
Flash Flood Guidance ("FFG") is issued three times daily by the National Weather Service's Arkansas-Red Basin River Forecast Center in Tulsa, Oklahoma. The FFG provides an estimate of the amount of rainfall needed in a specific amount of time for flash flooding to occur in the county. These values vary as a result of changes in soil moisture, recent rainfall (and lack of rainfall) and other factors. Note: these estimates represent areal averages across flat, natural terrain. Hilly areas, urban areas, and specific points within the county may experience flash flooding at smaller rainfall values. For more information, please visit http://www.srh.noaa.gov/rfcshare/ffg.php?location=ABRFC.

What do the colors mean?
A colored county indicates significant rainfall was observed by a Mesonet station during the time period appropriate for the map. The specific color indicates the severity of that rainfall, when compared to the most recent FFG. Green indicates at least one station in the county has observed one-tenth inch rainfall, but less than 50% of FFG for the time period. Yellow indicates at least one station observed between 50% and 75% of FFG during the time period. Orange indicates at least one station observed between 75% and 100% of FFG during the time period. Red indicates at least one station exceeded FFG during the time period. For counties with more than one Mesonet station, the color represents the greatest rainfall total for all stations within the county. A list of all Mesonet stations exceeding 50% of FFG during the time period is provided below the map.

What does the "worst case" map show?
This map presents the "worst-case observed" of the 1-hour, 3-hour and 6-hour maps. For example, if the one-hour and three-hour Mayes County rainfall warrant a yellow color, but the six-hour total warrants a red color, then red will be displayed for Mayes County. A complete listing of all "situations" with >50% FFG rainfall is given in tables near the map.

What about missing data?
Occasionally, storms or equipment failure may interrupt the Mesonet data stream, making it impossible to determine Mesonet rainfall for one or more time periods. A list of Mesonet stations with missing or delayed data is given in tables near the map.

How long will significant rainfall be noted?
This product presents the most significant event that came to fruition in the last hour. For example, if the three-hour map shows a colored county, then a three-hour rainfall total ending some time in the last hour was deemed to be significant. Because of the one-hour "lee way" in this product, one-, three- and six-hour rainfall totals on these web pages may not exactly match the most recent one-, three- and six-hour totals provided elsewhere on the Mesonet web pages.

What is The Oklahoma Mesonet?
The Oklahoma Mesonet is a statewide envrionmental monitoring network. This product uses Mesonet rainfall observations, reported at five-minute intervals. For more information, please visit http://www.mesonet.org.