Contacts: Doug Kluck (doug.kluck@noaa.gov)

	 Natalie Umphlett (numphlett2@unl.edu)

Dennis Todey (dennis.todey@sdstate.edu)

Missouri Basin Region El Niño Impacts and Outlook| August 2015 

www.drought.gov/drought/regional-programs/mrb/missouri-river-basin-home

El Niño Impacts 

and Outlook

Missouri Basin Region 

August 2015 

Typical El Niño Winter Pattern

Winter Temperature and Precipitation Outlooks El Niño Strength

El Niño Outlook

Valid for December 2015 - February 2016 Winter 2015-16

El Niño in Winter

An El Niño develops when sea surface 

temperatures are warmer than average in the 

equatorial Pacific for an extended period of time. 

This is important to North America because El 

Niño has an impact on our weather patterns, most 

predominantly in the winter. 

Although each El Niño is different, there are some 

general patterns that are predictable. For instance, 

the polar jet stream is typically farther north than 

usual, while the Pacific jet stream remains across 

the southern United States (see figure to left). 

This pattern brings above-normal temperatures 

to much of the Missouri River Basin region, 

particularly across the northern tier of the basin. 

Keep in mind that this does not mean that cold 

weather will not happen this winter. Extreme 

cold weather may be milder and less frequent, 

however. 

Snowpack can also be impacted by the typical 

El Niño winter pattern as well. Snowpack in the 

northern Rockies and Plains can be reduced and 

heavy snow events may be less frequent.

El Niño conditions have continued this 

summer and forecasts indicate that this El 

Niño will strengthen, peaking as a strong event 

in late fall or early winter. According to the 

Climate Prediction Center, there is a greater 

than 90% chance that these conditions will last 

through the winter and about an 85% chance 

that El Niño will continue into the early spring. 

Research has shown that strong El Niños are 

often followed by La Niñas, so conditions 

should continue to be monitored closely, 

especially if the El Niño weakens next spring, 

as predicted.

As of August, the winter outlooks for the region show that below-normal precipitation is favored 

for the headwaters of the Missouri River, while above-normal precipitation is favored for areas 

of the southern Rockies. This could have implications for many sectors, in both positive ways 

(increased snowpack to the south could be welcomed by ski resorts) and negative ways (reduced 

snowpack to the north could impact spring runoff). Meanwhile, the temperature outlook 

indicates that central and northern areas of the region could have above-normal temperatures, 

while some southern areas could have below-normal temperatures.

The seasonal outlooks above combine many factors including dynamical models, the effects of 

long-term trends, soil moisture, and the El Niño Southern Oscillation cycle (ENSO). Because these 

outlooks combine many inputs, they do not match the typical El Niño conditions exactly. To learn 

more about these outlooks, or to retrieve the latest temperature, precipitation, and drought 

outlooks, please visit the Climate Prediction Center at: http://www.cpc.ncep.noaa.gov

The image above shows the typical pattern in the winter during El Niño events. The polar jet stream 

tends to stay to the north of the Missouri Basin region, while the Pacific jet stream remains across the 

southern U.S. With the Missouri Basin isolated between the storm tracks, warmer and possibly drier 

conditions can develop during El Niño events.

Image courtesy of the National Oceanic and Atmospheric Administration.

For more information please visit: https://www.climate.gov/news-features/department/enso-blog

Precipitation Temperature

EC: Equal chances of above, near or below normal, A: Above normal, B: Below normal

Potential Intensity, Winter 2015-16

Model data courtesy of the Climate Prediction Center and the 

International Research Institute for Climate and Society.
Potential Winter and Spring Impacts

Contacts: Doug Kluck (doug.kluck@noaa.gov)

	 Natalie Umphlett (numphlett2@unl.edu)

Dennis Todey (dennis.todey@sdstate.edu)

Missouri Basin Region El Niño Impacts and Outlook| August 2015 

www.drought.gov/drought/regional-programs/mrb/missouri-river-basin-home

Comparisons and Limitations Missouri Basin Partners

High Plains Regional Climate Center

www.hprcc.unl.edu

International Research Institute for Climate and 

Society

http://iri.columbia.edu

National Drought Mitigation Center

www.drought.unl.edu

National Integrated Drought Information System

www.drought.gov

National Oceanic and Atmospheric Administration

National Weather Service - Central Region

www.crh.noaa.gov/crh

National Centers for Environmental Information

www.ncdc.noaa.gov

Missouri River Basin Forecast Center

www.crh.noaa.gov/mbrfc

Climate Prediction Center

www.cpc.ncep.noaa.gov

Plains & Prairie Potholes Landscape Conservation 

Cooperative

www.plainsandprairiepotholeslcc.org

State Climatologists

www.stateclimate.org

U.S. Army Corps of Engineers - Missouri River Basin 

Water Management Division

www.usace.army.mil

U.S. Department of Agriculture

Natural Resources Conservation Service

www.nrcs.usda.gov

NRCS National Water & Climate Center

www.wcc.nrcs.usda.gov

Regional Climate Hubs

www.usda.gov/oce/climate_change/regional_hubs.htm

U.S. Department of Interior

Bureau of Reclamation

www.usbr.gov

North Central Climate Science Center

www.doi.gov/csc/northcentral/index.cfm

U.S. Geological Survey, Water Mission Area

www.usgs.gov/water

Winter Conditions During Past El Niños

The maps above illustrate the winter conditions of the record breaking El Niño of 1997-98. Much 

of the basin was warmer than average. Precipitation signals varied across the basin, but the 

mountain snowpack peaked near normal. While the current El Niño is on track to be one of the 

strongest on record, please note that each El Niño is different. Other factors can be considered 

such as antecedent conditions or the Arctic Oscillation, which trumped the El Niño during the 

winter of 2009-10. Right now, there is a warm pool of water off the Pacific Northwest coast that 

should be monitored, although it does not seem likely to affect the current El Niño at this time.

While past El Niño events can help inform forecasters about certain conditions, there are some 

limitations. For instance, in the Missouri Basin region, El Niño is not known to impact:

• Potential for ice storms or blizzards.

• Track or intensity of any single weather system.

The Missouri River at Gavins Point, South Dakota.

Image courtesy of Natalie Umphlett.

Missouri River Agriculture Ecosystems

The wet spring resulted in higher than 

normal river levels in the lower Basin, but 

with weather conditions in the upper Basin 

switching from wet to dry to wet again, 2015 

runoff above Sioux City, Iowa is expected to 

be near average at about 25 million acre feet. 

The Missouri River Mainstem Reservoir System 

will begin the 2016 runoff season at the base 

of the Annual Flood Control and Multiple 

Use Zone, which means that all flood control 

storage will be available. Some indicators 

suggest a tilt toward lower than normal 

mountain snowpack in the upper Basin during 

a moderate to strong El Niño. Mountain and 

Plains snowpack will be closely monitored.

Wheat damaged by cold weather in Kansas - 2014.

Image courtesy of Mary Knapp.

An iconic animal of the Great Plains - the bison.

Image courtesy of Natalie Umphlett.

El Niño has worldwide impacts to the 

agricultural sector, and in the Missouri Basin 

region, there could be mixed impacts. Because 

El Niño winters typically result in a reduced 

snowpack in the northern Plains, this could 

expose winter wheat to harsh temperatures 

and wind, and also lead to soil moisture 

concerns. In southern areas, however, good 

soil moisture conditions could be expected 

where above-normal precipitation may 

occur. Additionally, warmer conditions in the 

northern tier of the basin could be beneficial 

for livestock producers both in terms of 

greater gains due to less severe cold weather 

and for calving in the later winter and spring.

For northern areas of the Missouri Basin 

region, higher temperatures combined with 

a lower snowpack could be a recipe for 

increased fire danger this winter and spring. 

These conditions could also result in earlier 

peak stream flows; reduced runoff into 

wetlands, streams, and rivers in the spring; 

reduced spring vegetation growth (depending 

on spring precipitation); and generally warmer 

stream temperatures. Any reduction to spring 

runoff or vegetation growth could have 

negative impacts to wildlife, however these 

impacts may not be apparent until later in the 

spring or summer and will be dependent on 

springtime precipitation.

Departure from mean temperature (left) and percent of mean precipitation (right) during the El Niño winter 

of 1997-98. Maps courtesy of the Midwestern Regional Climate Center.

• First freeze in the fall (early or late).

• Last freeze in the spring (early or late).