Risk of Seasonal Climate Extremes in the U.S. Related to ENSO

Extremes of temperature and precipitation can occur at any time. However, it can be shown that the El Niño/Southern Oscillation has a relationship to the relative frequency of these climate extremes in the United States. To see which regions of the U.S. have an increased risk of extreme warm/cold (or dry/wet) during an ENSO event, select from the options below. Note that this increased risk varies not only by region but also by season and ENSO lag.

U.S. Maps  |  By Region (0-3 season lead relationships)

How to Interpret Plots and Method Details

Important: These plots show regions where the risk of having a seasonal extreme is high. If you would like average values of temperature and precipitation during El Niņo/La Niņa, you should look at composite plots.

Select type of event, temperature or precipitation and season to show the relative risk of climate extremes based on concurrent value of the ENSO index for the continental United States:

Type of Event:   El Niño   La Niña
Variable: Temperature    Precipitation
Season:

 

The plots show the odds of a wet/dry or warm/cold season with ENSO conditions preceding the season. ENSO conditions are defined from the SOI index. The lead time is 3 seasons to concurrent. Results are based on the US climate division dasaset for 1896-1995. Extreme is defined as being in the highest or lowest 20% of the 100 year record. ENSO is defined as the top 20 SOI years (La Niña) and the lowest 20 SOI years (El Niño). Four extreme events would be expected by chance. A decrease number of years to zero or one year would be significant at the 99.3% and 95.7% level, respectively. An increase to seven, eight or nine years would be significant at the 95.4%, 98.6% and 99.9% levels. Actual significance is probably less due to the number of tests run and time/space correlations in the dataset.
Reference
Wolter, K., R. M. Dole, and C. A. Smith, 1999: Short-Term Climate Extremes over the Continental United States and ENSO. Part I: Seasonal Temperatures. J. Climate, 12, 3255-3272.

Odds of Extreme Seasonal Temperature Anomalies w/ENSO preceding season

Definition of Regions

Risk of an Extreme seasonal anomaly w/ENSO
RegionEl NiñoLa Niña
Pacific NWget plot get Plot
Western Washingtonget Plot get Plot
Southeastget Plot get Plot
Rocky Mountain Frontrangeget Plot get Plot
Gulfcoastget Plot get Plot
Texas/Oklahomaget Plot get Plot
Highplainsget Plot get Plot

Odds of Extreme Seasonal Precipitation Anomalies with ENSO conditions preceding

Definition of Regions

Risk of Extreme seasonal anomaly w/ENSO
RegionEl NiñoLa Niña
Pacific NWget plot get Plot
Western Washingtonget Plot get Plot
Southeast USget Plot get Plot
Rocky Mountain Frontrangeget Plot get Plot
Gulfcoastget Plot get Plot
Texas/Oklahomaget Plot get Plot
Highplainsget Plot get Plot
SE New Mexicoget Plot get Plot
Temperature extremes for El Niño, South Platte Climate division
Precipitation extremes for El Niño, South Platte Climate division
Precipitation extremes for La Niña, South Platte Climate division

Current ENSO State


Method Details

Years that are El Niņo/La Niņa extremes
Details of calculations

This page is based on work-in-progress by Randy Dole, Klaus Wolter and Cathy Smith of the NOAA/ESRL Physical Sciences Division. You can use these plots in publications though we ask that you acknowledge the Physical Sciences Division in the publication. For example, "Image provided by the NOAA/ESRL Physical Sciences Division, Boulder Colorado from their Web site at http://www.esrl.noaa.gov/psd/".


Related Web Pages:

US Precipitation/Temperature plotting page
ENSO Climate Risks Poster from PSD
El Niņo Theme Page from PMEL(NOAA)

References:

Physical Sciences Division ENSO References
Assortment of references from the El Niņo Theme Page (PMEL)
Relationship of ENSO to PRECIPITATION in the US from COAPS
Relationship of ENSO to DROUGHT in the US from COAPS
Relationship of ENSO to CLIMATE in the US from COAPS
Relationship of ENSO to STREAMFLOW in the US from COAPS
1997 ENSO papers from COAPS

Any comments, suggestions or questions on this page are welcome and should be sent to Cathy.Smith@noaa.gov
This is a Research and Development Application