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).

   
021012_0 040412_0 043012_1 050112_1 050812_0 051612_1 052712_0 052912_3 053012_0 060112_1 060212_1 060212_3 060312_2 060712_0 060912_2 061012_4 061212_1 061312_0 061612_1 061712_1 061712_2 061812_4 061912_2 061912_3 061912_4 062012_1 062012_2 062112_0 062212_0 062512_2 062612_3 062912_0 062912_3 063012_4 070312_0 070412_0 071012_0 071012_1 071112_2 071312_2 071412_2 071512_0 071612_2 071712_2 071812_0 072612_0 072812_1 072912_0 073012_0 073112_0 080112_0 080212_0 080312_0 080312_1 080412_0 080412_1 080512_1 080512_2 080612_1 080612_3 080712_0 080712_1 080812_1 081012_2 081112_1 081212_0 081312_3 081412_0 081512_0 081812_0 081812_1 082012_0 082012_1 082112_1 082212_4 082312_3 082412_3 082512_4 082512_5 082712_0 082912_0 083012_1 083112_2 090312_1 090512_1 090512_2 090612_0 090712_0 090812_0 090812_1 090912_1 090912_2 091012_0 091012_4 091412_1 091712_1 091812_1 091912_0 092012_0 092112_0 092212_0 092312_0 092312_2 092412_0 092512_0 092712_1 092812_1 092912_1 093012_2 100412_0 101112_0 101112_3 112612_3 121212_0 122212_0 122312_1

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.