Quarterly Climate Impacts 

and Outlook

Great Lakes Region

March 2014

#regionalclimateoutlooks

Great Lakes Region 

Quarterly Climate Impacts and Outlook

 - March 2014 - 

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

www.ec.gc.ca/eau-water/default.asp?lang=En&n=F5329B03-1

 Great Lakes Significant Events - for December 2013 - February 2014

Great Lakes Ice Cover

Snowfall

Regional Climate Overview - for December 2013 - February 2014

Winter 2013-2014 was unusually cold for the Great 

Lakes basin, especially when compared to recent years. 

An arctic blast in early January blanketed the Great Lakes 

region and sent sub-freezing temperatures as far south 

as Florida. These freezing temperatures were the result 

of a southward dip of the polar vortex. The polar vortex 

is a permanent fixture of the atmospheric circulation 

at the poles, but in early January 2014 the polar vortex 

weakened, allowing fragments of cold air to surge into 

the middle latitudes (see bottom right graphic). This 

surge of cold air via the polar vortex occurred on a 

number of other occasions this winter as well. Since the 

polar vortex is permanent in the atmosphere, there will 

always be a chance for this cold variability.

A season of unusually cold weather in the Great Lakes 

basin is not a sign that the century long trend of rising 

temperatures has reversed. In fact, while Canada and 

the eastern U.S. froze at times this winter, many locations including Alaska and Europe, were experiencing 

unseasonably warm temperatures. 

On December 20th-23rd, a damaging ice storm affected southern Ontario, with ice buildup ranging from 15-30 mm (0.6-1.2 in) throughout 

the region. Total insured losses are estimated at $200 million (CAD) for 

this region, according to the Insurance Bureau of Canada.

As of February 28th, the maximum 

extent of ice cover on the Great Lakes 

this winter was 88.4%, making it the 

4th highest since 1973. The record ice 

cover of 94.7% occurred in 1979. Ice 

cover usually begins in mid-December, 

but this winter season it was reported 

by the end of November. Three of 

the Great Lakes (Superior, Huron, and 

Erie) became 90% or more ice covered 

by the end of winter, which usually 

does not occur. 

The winter season was the 

coldest in 20 years for the Great 

Lakes region. The coldest areas 

surrounded the western half of 

Lake Superior, where departures 

were greater than -5°C (-9°F). 

Areas surrounding the eastern 

half of Lake Ontario had the 

lowest departures, from -0.5°C 

to -2°C (-0.9°F to -3.6°F). 

Water level statistics based on 1918-2013. 

Temperature: Dep. from Normal (°) 

Temperature

Great Lakes Water Levels

Levels of all the Great Lakes remain above last year’s levels at 

the beginning of March. Snowy, cold weather and significant ice 

cover contributed to Lake Superior finishing the quarter near the 

long-term average, 32 cm (12.6 in) above last year’s level and the 

highest at this time of year since 2005. The other lakes received 

near-normal water supplies. At the end of February, Lake MichiganHuron was 32 cm (12.6 in) below average, but 33 cm (13 in) higher 

than at this time last year. Lake Erie and Lake Ontario remained near 

average throughout the quarter and were within 5 cm (~ 2 in) of 

their average levels to start March.

Most of the region saw 

above normal snowfall 

during winter, with 

departures from 100% to 

200% of normal. However, 

generally areas northeast 

and on the southern side of 

Lake Superior only received 

50% to 75% of normal 

winter snowfall. 

Ice cover: Difference from Avg. (%)

Left: wavy polar vortex configuration (January 5, 2014)

Right: more typical, compact 

polar vortex configuration (November 14-16, 2013)

NOAA 

Climate.gov

Snowfall normals based on 

1981-2010. 

Long-term average based on 1973-2013.

Temperature normals based on 1981-2010.

Snowfall: Percent of Normal (%)

Dec. 1, 2013-

Feb. 28, 2014

Dec. 1, 2013-

Feb. 28, 2014

Dec. 1, 2013-

Feb. 28, 2014
Regional Impacts - for December 2013 - February 2014

Regional Outlook - for April - June 2014 Great Lakes Region Partners

Environment Canada

www.ec.gc.ca

Agriculture and Agri-Food Canada

www.agr.gc.ca 

Midwestern Regional Climate Center

www.mrcc.isws.illinois.edu

Northeast Regional Climate Center

www.nrcc.cornell.edu

Great Lakes Region State Climatologists

www.stateclimate.org

National Oceanic and Atmospheric Administration

www.noaa.gov

National Operational Hydrologic Remote Sensing Center

www.nohrsc.nws.gov

Great Lakes Environmental Research Laboratory

www.glerl.noaa.gov

NOAA Great Lakes Sea Grant Network 

www.seagrant.noaa.gov

North Central River Forecast Center

www.crh.noaa.gov/ncrfc

Climate Prediction Center

www.cpc.noaa.gov

Great Lakes Integrated Sciences & Assessments

www.glisa.umich.edu

US Army Corps of Engineers, Detroit District

www.lre.usace.army.mil

National Integrated Drought Information System 

www.drought.gov

Great Lakes Water Level Dashboard

www.glerl.noaa.gov/data/now/wlevels/dbd/

National Park Service

www.nps.gov

#regionalclimateoutlooks

Contact for NOAA: 

Molly Woloszyn: mollyw@illinois.edu

Samantha Borisoff: samantha.borisoff@cornell.edu

Contact for Environment Canada: 

1-800-668-6767 (in Canada only)

416-739-4826 enviroinfo@ec.gc.ca

Great Lakes Region 

Quarterly Climate Impacts and Outlook

 - March 2014 - 

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

www.ec.gc.ca/eau-water/default.asp?lang=En&n=F5329B03-1

Contact Information

Ice cover on 

the Great 

Lakes is 

naturally 

variable from 

year to year. 

Typically, 

maximum 

ice occurs on 

lakes Michigan, Huron, Ontario, and Erie in 

mid-February and in early March on Lake 

Superior. However, the cold temperatures 

and extensive ice cover this winter may 

delay start of ice breakup by two or three 

weeks. In addition, fog may be an issue 

in the coming months in the Great Lakes 

region as it is going to take longer than 

normal for the ice to melt. The significant 

ice cover this winter increases the risk 

for break-up ice jamming in adjacent 

embayments and tributaries, increasing the 

risk for flooding in these areas. However, the 

risk is reduced if the ice thaws gradually. 

Ice shoves from lakes Ontario and Erie 

caused localized flooding in some areas 

in January and February. Ice shoves 

result from strong winds pushing lake 

ice sheets into adjacent embayments 

and downstream. Flood-impacted areas 

included along the Niagara River, Rocky 

and Maumee rivers in Ohio, and North 

Sandy Pond in New York.

Early onset and extensive ice cover has 

made this winter the most challenging for the shipping industry in 

about 24 years, according to the president of the Canadian Shipowners’ Association. This not only impacts the freight community, but also 

the industries that use the cargo they are carrying. 

During the December ice storm, 

Toronto suffered extensive and 

long-term losses to their urban 

tree canopy as a result of ice 

buildup ranging between 15-30 

mm (0.6-1.2 in). Estimates say that 

20% tree canopy has been lost city 

wide, with up to 50-80% on some 

streets. Other impacts during this 

storm include prolonged power 

outages that affected 600,000 households for 3-10 days. There were 

also two fatalities due to carbon monoxide poisoning.

Due to the blockage of water intakes on some of the Great Lakes 

from ice, officials in water utility departments along the lakes could 

not pump water into their plants for several hours in early January.

The cold temperatures produced sufficient 

ice on Lake Superior to allow over 85,000 

visitors to trudge over the lake to explore 

the amazing ice cave formations on the 

Apostle Islands, giving this region an 

estimated economic boost of $10 million 

(USD) according to the Bayfield Chamber of 

Commerce and Visitor Bureau. This is the 

first time in 5 years the ice has been firm 

enough to allow passage. Agriculture may 

also benefit since cold temperatures make pests like the emerald ash 

borer easier to manage and slow the migration of invasive species.

The ice cover on the Great Lakes this winter may help raise persistent 

low water levels on the upper Great Lakes. In addition, lake whitefish 

abundance is positively related to ice cover over near shore spawning 

grounds, as ice helps to reduce the potential for dislodging of eggs 

from turbulent waves. An ice bridge formed between Isle Royale (MI) 

and the mainlands, allowing for the passage of species, particularly 

wolves and the potential diversification of the gene pool on the island.

Lake Level Outlook 

Temperature & Precipitation Outlook

Current projections for April-June indicate that 

levels on lakes Superior, Erie and Ontario will 

remain near average unless exceedingly wet or 

dry water supply conditions are experienced. 

On the other hand, even the wettest scenarios 

suggest levels on Lake Michigan-Huron will 

remain below average, but levels are expected 

to remain higher than they were last spring. 

The range of probable levels on each lake are 

shown on the Outlook map below.

The NOAA Climate Prediction Center is forecasting for April through June 2014 that there 

are greater chances for below normal temperatures in the U.S. Great Lakes basin and equal 

chances for either below, near, or above normal precipitation.

Environment Canada is forecasting equal chances for either below, near, or above normal 

temperature and precipitation in the Canadian Great Lakes basin for April through June 2014.

Outlook from the US Army Corps of Engineers and 

Environment Canada (Apr-June 2014) 

Lake Superior ice cave;

Photo: Bayfield Chamber of 

Commerce

Ice Outlook

Post-ice storm damage in Toronto;

Photo: Alexander Adams (via Flickr)

The Maumee River in Maumee, OH 

in mid-January;

Photo: Lucas County EMA

Lake Michigan from Sheboygan, 

WI in Feb. 2014; WI Sea Grant

Impacts of Unseasonably Cold Temperatures and Significant Ice Cover