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Real-time monitoring of heavy precipitation

These images show locations where the 100-year recurrence interval for 24-h precipitation has been exceeded. This is an automated search for the types of events discussed in Schumacher and Johnson (2005, 2006) and Stevenson and Schumacher (2014), using gridded precipitation analyses. The current image is below, with a link to past days when the threshold has been exceeded. Images are created at around 1545 UTC each day, and then updated multiple times to incorporate updated data.

UPDATE, 21 December 2018: The threshold maps have now been updated to include NOAA's updates to Atlas 14 that include Texas. Maps after this date will include the updated Texas thresholds. We are in the process of re-running past cases to include these as well; an update will be posted here when this is completed.

Switch to a different threshold:

Current image

Click here to see the threshold

Data sources and notes:
Gridded recurrence intervals come from the NOAA Hydrometeorological Design Studies Center and The Automated Geospatial Watershed Assessment Tool. Where available, the NOAA Atlas 14 values are used, otherwise older recurrence interval information is used, and these are merged together onto a single map.
Precipitation data is the Stage IV analysis over the US, obtained in real-time from NOAA/NCEP.
Archived precipitation data come from NCAR/EOL.
The model forecasts and recurrence interval grids are all re-gridded to the NOAA "HRAP" grid which has approximately 4.75-km horizontal grid spacing. This differs from our original analysis where the stage IV analysis was coarsened slightly. This higher-resolution grid may identify legitimate very-small-scale events but also tends to pick out more spurious events.
Maps of events exceeding the 1-hour precipitation thresholds are not yet available, but we hope to post them soon.

Acknowledgments:
This work is an extension of research conducted by Stephanie Stevenson and Russ Schumacher, published in Stevenson and Schumacher (2014, Monthly Weather Review). Please cite this paper if you make use of the data or analyses from this website in your own research.
This material is based upon work supported by the National Science Foundation under Grant Nos. AGS-0954908 and AGS-1157425. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. This work was also supported by NOAA Award NA14OAR4320125, Amendment 26.