Skip navigation

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).

   
012812_0 012912_0 031512_0 032612_0 042912_0 050412_3 051712_2 051812_1 051912_0 052012_1 052112_2 052312_1 052512_2 052612_1 053112_0 060112_0 060412_1 060812_1 060912_0 061012_0 061112_0 061112_2 061212_1 061312_1 061912_2 061912_3 062012_1 062212_4 062612_0 062712_1 062812_0 062812_2 062912_0 063012_0 063012_1 070112_0 070212_0 070212_1 070212_2 070312_0 070412_1 070612_3 070712_2 070812_1 070812_5 070912_3 071012_0 071012_3 071112_0 071212_1 071312_4 071312_5 071412_4 071512_3 071612_5 072412_0 072512_0 072712_1 080112_1 080212_1 080512_1 080612_0 080812_1 080912_1 081012_0 081112_1 081212_0 081212_1 081212_2 081312_0 081412_0 081512_0 081612_0 081712_0 081812_0 081812_1 081912_2 081912_3 082012_2 082012_3 082112_1 082112_3 082312_3 082912_0 083012_0 083012_2 083112_0 090112_0 090112_2 090212_0 090312_3 091912_0 092012_0 092212_0 092312_0 093012_2 100112_0 100112_3 100212_3 100412_3 100812_0 100912_0 100912_2 102512_0 102512_1 102612_0 103012_0 122512_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.