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).

   
010612_0 010812_0 012912_0 050212_0 050312_1 052412_0 052412_1 052412_3 052512_2 052712_0 052712_1 052812_0 060512_1 060612_3 060812_2 060912_0 061012_1 061212_2 061512_1 062912_2 070112_0 070612_1 071012_0 071012_2 071112_0 071212_0 071312_0 071412_0 071512_0 071612_1 072012_1 072112_3 072212_1 072312_1 072512_0 072512_5 072812_0 072912_0 072912_2 073012_2 073112_0 080112_0 080412_2 080512_2 081012_1 081112_0 081212_0 081212_1 081312_0 081412_0 081712_0 081812_0 081912_1 082012_0 082012_1 082112_0 082112_1 082212_1 082312_1 082412_1 082512_0 082612_1 082712_0 082712_1 082812_0 082812_1 082912_0 082912_1 083012_1 090112_0 090412_0 090512_0 090612_1 091012_0 091112_0 091212_0 091212_1 091312_0 091412_1 091512_0 091512_1 092812_0 092912_0 101212_4 101412_0 101512_0 102512_1 110612_0 111412_0 121212_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.