Contacts: Ellen Mecray (Ellen.L.Mecray@noaa.gov)

     Northeast Regional Climate Center (nrcc@cornell.edu)

Eastern Region El Niño Impacts and Outlook|January 2016

www.drought.gov/drought/content/resources/reports

El Niño Impacts 

and Outlook

Eastern Region

January 2016

El Niño & December 2015 Weather Patterns

Impacts 

The weather pattern during December 2015 (see figure above) 

featured a persistent trough over the West and a ridge over 

the East. The ridge directed a warm, moist southerly flow of air 

into the Eastern Region. This contributed to the extremely mild 

December temperatures. In addition, ample moisture was available 

as storms moved through, helping to create above-normal 

precipitation during the month. Although similar, this pattern is 

somewhat different than what would be expected due to El Niño, 

indicating other atmospheric drivers (such as the West Pacific 

pattern, the Madden-Julian Oscillation, and the Arctic Oscillation) 

also influenced the month's weather. The season with the greatest 

El Niño impacts in the U.S. is January through March.

The classic El Niño winter weather pattern features a polar jet 

stream that is farther north than usual and a Pacific jet stream 

that runs across the southern United States (see figure above). 

The active Pacific storm track generally brings above-normal 

precipitation and below-normal temperatures to southern parts 

of the Eastern Region. Drier-than-normal conditions are common 

in Ohio, the Midwest, and western New York and Pennsylvania. As 

storms often move up the coast during El Niño winters, the Eastern 

Seaboard generally experiences above-normal precipitation. 

Typically with strong El Niños, such as the one this year, warmer 

temperatures extend further into the Northeast than seen in the 

accompanying diagram. 

December was a soggy month for the Carolinas, with areas 

receiving over 200% of normal precipitation. It was North 

Carolina's wettest December on record. Heavy rains caused 

river flooding, washed out roads, and delayed holiday 

travels. This wet trend is likely to continue. Data examined 

by the National Centers for Environmental Information and 

the Climate Predication Center show that the Carolinas 

have an increased chance of seeing above-normal 

precipitation during springtime El Niño events. Potential 

impacts of a wet spring on agriculture include planting 

delays, increased diseases, and reduced yields. According 

to the Southeast River Forecast Center, the monthly 

frequencies of river flooding from December through June 

are greater than normal in the Southeast during moderate 

and strong El Niños. 

Wet Carolinas

Temperature anomalies were extremely high during December, setting record 

temperatures across the globle, including the Eastern Region. The mild temperatures 

led to below-normal snowfall for the entire region. Several upstate New York sites had 

their least snowy Decembers on record, latest measurable snow, and/or latest first inch 

of snow. Across the region, transportation departments performed roadwork longer 

into the season, as well as saved money on snow removal, fuel, and personnel costs. 

Home heating costs were also down. The Residential Energy Demand Temperature 

Index for December 2015 ranked lowest in the 1895-2015 record for December. While 

some golf courses saw an increase in business, winter recreation sports and winter 

gear retailers experienced decreased business. In New England, the Mount Washington 

Auto Road opened for guided auto tours in late December for the first time in (at least) 

35 years and thinner than usual ice was reported on many lakes and waterways. Warm 

temperatures allowed some crops such as lettuce to be harvested later into December, 

but caused other plants such as viburnum to bloom early. In addition, insects continued 

to thrive, some bird species delayed their annual migration, and the allergy season was 

prolonged in several areas. 

December: Warm & Lacking Snow
El Niño Outlook

Contacts: Ellen Mecray (Ellen.L.Mecray@noaa.gov)

     Northeast Regional Climate Center (nrcc@cornell.edu)

Eastern Region El Niño Impacts and Outlook|January 2016 

www.drought.gov/drought/content/resources/reports

Comparisons and Limitations Eastern Region Partners

National Oceanic and Atmospheric Administration

www.noaa.gov

National Centers for Environmental Information

www.ncei.noaa.gov

National Weather Service, Eastern Region

www.weather.gov

NOAA Fisheries Science Centers and

Regional Offices, Atlantic

www.nmfs.noaa.gov

Office for Coastal Management

www.oceanservice.noaa.gov

NOAA Research, Climate Program Office and

Geophysical Fluid Dynamics Lab

www.research.noaa.gov

NOAA National Sea Grant Office

www.seagrant.noaa.gov

NOAA’s North Atlantic, South Atlantic, and Great

Lakes Regional Collaboration Teams

www.regions.noaa.gov

Climate Prediction Center

www.cpc.noaa.gov

National Operational Hydrologic Remote Sensing Center

www.nohrsc.noaa.gov

Northeast Regional Climate Center

www.nrcc.cornell.edu

Southeast Regional Climate Center

www.sercc.com

National Integrated Drought Information

System

www.drought.gov

Carolinas Integrated Sciences and Assessments

www.cisa.sc.edu

Consortium on Climate Risk in the Urban Northeast

www.ccrun.org

Cooperative Institute for North Atlantic Research

www.cinar.org

Eastern Region State Climatologists

www.stateclimate.org

#regionalclimateoutlooks

Late Winter/Early Spring Conditions During Past El Niños 

The maps above illustrate the late winter to early spring conditions of the record-breaking 

El Niño of 1997–98. Temperatures were within 3 degrees of normal for a majority of the 

southern portion of the region, with larger above-normal departures in the northern states. 

Precipitation was varied in the region with below-normal amounts in Ohio, West Virginia, western 

Pennsylvania, New York, and New England and above-normal amounts from Pennsylvania down 

to the Carolinas. 

As we move toward spring, the trend for El Niño in the Eastern Region is not as clear as the 

winter trend. While 1998 saw mostly above-normal temperatures, other strong El Niño years 

have seen cooler conditions such as March and April of 1992. But similar to winter, there are 

other factors that affect spring conditions such as long-term trends and soil conditions.

 Temperature and Precipitation Outlooks El Niño Strength

A

The current El Niño is one of the strongest 

recorded since 1950, rivaling that of 1997-

98. The Oct-Dec ONI (Oceanic Niño Index) 

value was 2.3, the only other time the index 

reached that high was during the 1997-98 

event. This El Niño is expected to remain 

strong throughout winter, changing to neutral 

conditions late spring or early summer. El 

Niños are often followed in the next winter by 

La Niñas, the cooling of equatorial Pacific sea 

surface temperatures. The CPC is currently 

forecasting a 40% chance of La Niña by AugOct, with chances expected to increase for the 

subsequent winter. 

Temperatures are expected to remain above normal through April for all but the Carolinas. 

This is consistent with a strong El Niño. The region is divided on the precipitation outlook. 

Coastal areas, including a majority of the Carolinas, have increased probability for abovenormal precipitation. Coastal storms such as the snowstorm of January 22nd-23rd are 

consistent with El Niño impacts that include above-average precipitation for the Mid-Atlantic 

coastal region. Areas surrounding the Great Lakes and the Ohio Valley have increased 

probability for below-normal precipitation. As with a typical El Niño pattern, this dry signal is 

expected to slowly weaken through late spring and early summer. The outlooks above combine 

many factors including dynamical models, the effects of long-term trends, and soil moisture, 

in addition to past El Niño patterns. Therefore, they may not match typical El Niño conditions 

exactly. To learn more about these outlooks or see the latest temperature, precipitation, and 

drought outlooks, please visit the Climate Prediction Center (CPC) at: http://www.cpc.ncep.

noaa.gov.

Valid for 

February - April 2016

A: Above-normal

B: Below-normal

EC: Equal chances of 

above-, near, or belownormal 

Number: Probability of 

above- or below-normal A

B EC A

40

33

40

40

33

33

Early-Jan CPC/IRI 

Concensus Probabilistic ENSO Forecast