Severe thunderstorms will be possible from the central Plains to the Mid-Atlantic and Northeast on Monday. Hazardous heat will linger across the southern U.S. and build across the West through mid-week. Hot and dry conditions will fuel fire weather concerns for Interior Alaska and the Four Corners region through Monday. Read More >
Gridded Flash Flood Guidance (GFFG) provides a general indication of the amount of rainfall necessary to cause small streams to overflow their natural banks. During heavy rainfall, usage of this guidance must involve combination of rainfall that has already occurred plus any additional rainfall that is expected to fall over the same location, not to exceed the guidance duration (example: 1-hr or 3-hr). It should be noted that these GFFG values are based upon estimates of average soil moisture and stream flow conditions over 4km x 4km grids. GFFG values also assume that the rainfall event will be evenly distributed over the guidance duration. Flooding may occur with less rainfall than indicated in areas of very high rainfall intensities, impervious surfaces (urban areas), or steep slopes.
The 1, 3, and 6 Hourly Gridded Flash Flood Guidance is also viewable on NOAAs GIS Integrated Dissemination Program (IDP) web services. Metadata and additional information on the gridded flash flood guidance and other GIS Web Services can be found at the National Weather Service Data as OGC Web Services site . Flash flood guidance on a national scale, can be found here.
National Precipitation Totals and Flash Flood Guidance
Water Story