Confused by the El Niño weather effect on lake levels for Huron Michigan?

Post updated January 19, 2016 and noted inside

El Niño is a weather pattern created from the interaction of the atmosphere and the ocean producing warmer than normal water temperatures in the Pacific Ocean. Even though it occurs at the equator, it produces weather conditions globally – including in the Great Lakes Region.

Water levels are impacted by many variables including short term weather like El Niño and longer term climate conditions. It is important to understand both.

Weather Vs. Climate

image that shows conflicting road signs

NOAA describes it these ways:

  • Weather is what you might see outside on any given day, while climate is the average of that weather over a longer time period.
  • “Climate is what you expect, weather is what you get.”

Long term outlook – According to most scientists water levels for Lake Huron-Michigan are likely to continue to decline over the longer term due largely to climate change – however,  short-term variations of extreme highs due to flashier storms are possible.

In the short term..what is El Niño again and how will it impact water levels?

El Niño is a weather pattern created by the coupling of  the atmosphere and ocean producing warmer than normal water temperatures in the Pacific Ocean. El Niño occurs at the equator, but impacts weather conditions globally. El Niño typically peaks sometime before February driving energy into the atmosphere in the cooler months of the Northern Hemisphere.

Strong El Niño’s have been followed by high water (1982-’83 ) and low water (1997-’98) in Lake Huron-Michigan. The National Oceanic and Atmospheric Administration (NOAA) are predicting this year’s event to be possibly the second highest ever recorded lasting well into 2016, leading to these likely conditions:

  • NOAA expects the increase to track at about 2.1oC above normal with subsurface ocean water temperature increases of up to 6oC in some areas. Couple this with human induced climate change effects and the combined impacts are expected to be significant.
  • The warm air mass pressing up from the equator will likely keep the jet stream’s average path well north this winter resulting in weather conditions in the Great Lakes region that will be warmer and drier than normal.
  • The near record ice coverage due to the Polar Vortex in 2014 is extremely unlikely this winter and that coupled with warmer water and drier air means more evaporation from the lakes.*
  • [* Jan. 19 update -This only occurs if the dry air is cold. Evaporation is highest when there are big contrasts between the water and air temperatures, combined with dry winds. So far water temperatures were higher than the previous year into the fall and winter, as well as the air temperature being warmer.]
  • It also means that the winter may produce more ice storms as temperatures hover around the freezing mark leaving little snowpack for the spring melt.

P1050375Morgue file copy even lower res

 

Less snow pack and more evaporation means less water in Lake Huron-Michigan compared to last year.

      [* Jan. 19 update – Evaporation is highest when there are big contrasts between the water and air temperatures, combined with dry winds. So far water temperatures were higher than previous year into the fall and winter, as well as the air temperature being warmer. Therefore, evaporation may not be as great and

NOAA’s latest 12 month outlook forecasts

    indicate that water levels may be above last year.]

 

Water levels will hover around average. Note the Brown Dash line (most Probable) in the graph below.

      [Jan 19 update – the graph below was from October. for the latest graph goto

NOAA’s latest 12 month outlook forecasts

    ]

 

 

12 month outlook for lake levels in Lake Huron- Michigan

(courtesy of USACE)

USACE Graph illustrates Monthly Mean Water Level Projections for Lake Huron-Michigan

 

  • Brown dash= Bulletin Forecast Most Probable
  • Black dash – Long Term Max/Min
  • Black dot – Long Term Average
  • Black Solid line – Observed Monthly Mean
  • Blue line – 1982-83 Strong El Nino
  • Red solid Line – 1997-98 Strong El Nino
  • Grey – Range of Possible Outcomes
  • Peach – Nov Bulletin Forecast Range

 

***

Sources used in this post:

“What are El Niño and La Niña?” National Ocean Service. NOAA. https://oceanservice.noaa.gov/facts/ninonina.html. Retrieved December 1st at https://oceanservice.noaa.gov/facts/ninonina.html.

January 15, edited post by changing the order of the NOAA quotes on climate and weather.

January 19, edited post with changes indicated in brackets, around evaporation and water levels