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Monitoring of heavy precipitation events

These images show locations where average recurrence intervals for precipitation have been exceeded. These are referred to, for example, as "100-year rainstorms", though this terminology can cause confusion, so a more accurate description is "less than a 1% probability of occurring at a given location in any given year." 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, as well as updated to use NOAA's Atlas 14 to define the average recurrence intervals. (In the states of Washington and Oregon, Atlas 14 has not yet been updated, so no points are shown.) Archived images from past events when the thresholds have been exceeded are shown below.

Each dataset has been regridded to a 4-km latitude-longitude grid (the same grid used by the PRISM Climate Group) prior to calculating the exceedance points. This allows for a closer "apples-to-apples" comparison between precipitation datasets. The archive of past events is actively under development; if you don't yet see images for a particular dataset/duration, check back soon! Recent data (e.g., within the current year) has not undergone quality control, so use recent maps with caution.


Select dataset: Stage IVMRMSPRISMCONUS404      Current maps  Interactive maps of past events
Select average recurrence interval: 10-year100-year1000-year
Select duration: 72-hour48-hour24-hour6-hour
Select year: 1981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008200920102011201220132014201520162017201820192020202120222023202420252026

Left arrow for previous frame, right arrow for next, space to pause/play; click to open image in new tab. Each event is listed as "mmddhh_e" (2-digit month, 2-digit day, 2-digit hour for end of accumulation period, one digit for the event number on this date).

   
010812_1 010812_2 010912_0 021712_0 032412_0 032712_0 042612_0 043012_0 043012_1 043012_2 050312_0 050412_0 050912_0 052012_0 052312_3 052512_2 052712_1 052812_1 052912_1 060212_1 060312_1 060312_2 060312_3 060612_0 061112_0 061212_5 061612_5 061612_6 061712_0 061712_2 061712_4 061812_0 061812_1 062012_0 062012_1 062812_2 070412_3 070512_3 071412_2 071512_1 072412_0 072512_0 073012_1 073112_1 073112_3 080812_1 081512_2 081612_0 081812_2 082112_3 082212_2 082412_1 082512_2 082912_1 082912_2 082912_5 083012_0 083012_2 090212_0 090612_1 090912_5 091012_3 091012_4 091212_2 091212_4 091312_1 091512_0 091612_0 091612_1 091712_0 091812_0 091912_0 092012_0 092212_0 092212_2 092612_1 092712_0 092812_1 100512_0 100912_0 101412_2 101512_1 111312_0

This material is based upon work supported by the National Science Foundation under Grant No. AGS-2337380. 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.



DISCLAIMER: The images and data on this site are intended for meteorological education and research purposes and, although they should generally be up to date, are not monitored at all times. Do not use for making decisions where money or lives are at stake. For official forecasts and warnings, visit the National Weather Service.