What is the LRC?

To put it simply, weather has patterns that repeat.  This is not new, since the 1940’s scientists and meteorologists have discovered many repeating patterns in our weather.

El Niño, La Niña and the Artic Oscillation you’ve probably heard of.  There are others that we will discuss below.

Gary Lezak at Diamond Peak, Lake Tahoe

The LRC stands for Lezak’s Recurring Cycle, named after Gary Lezak, who discovered this forecasting method in the late 1980’s.

While working as a meteorologist for an Oklahoma City television station the winter of 1987-88, it clicked. Oklahoma City had two 12-inch snowstorms that winter that looked eerily similar to how they set up and developed.

This led to a theory that 15 years later, participants from KSHB 41 Weather Blog, in Kansas City, coined the term “LRC” (Lezak’s Recurring Cycle).

How it works:  Patterns begin to emerge each fall as the jet stream begins to move south, from its minimum in late summer.  When this happens, a pattern begins to develop from the unique temperature differences in the Artic. Anchor troughs and anchor ridges develop and shape how the jet stream flows.


This pattern becomes established and repeats until early fall when the process starts over again.   No pattern is the same and cycle lengths vary each year and generally run between 40 to 65 days.  Last year’s pattern was 45 days.

Weather Influences

1. The LRC   The LRC is the biggest influence on our weather.  What follows below are the other influences on our weather pattern and how they affect it.

The other pieces of the atmospheric puzzle are called teleconnections.   We talked about the Artic Oscillation (AO) and El Nino Southern Oscillation (ENSO) above, but there are other influences on our weather.  The Madden Julian Oscillation (MJO), Pacific North American Pattern (PNA), North Atlantic Oscillation (NAO) and the Indian Ocean Dipole (IOD) are the major influences.   All of these teleconnections affect the outcome of weather each cycle.

2.  El Nino Southern Oscillation (ENSO)

ENSO (El Niño-Southern Oscillation) is one of the most powerful climate drivers on the planet, and it has a major influence on global weather and climate patterns. It’s a recurring climate phenomenon in the tropical Pacific Ocean, and it cycles between three phases:

  • El Niño:

    • What happens: Warmer-than-average sea surface temperatures in the central and eastern Pacific near the equator.

  • La Niña:

    • What happens: Cooler-than-average sea surface temperatures in the central and eastern Pacific.
        • More active Atlantic hurricane season: Weaker upper-level winds make it easier for storms to form.
          • Colder, wetter winters: Pacific Northwest and northern U.S.
          • Warmer, drier winters: Southern U.S. and Gulf Coast.

  • Neutral ENSO:

    • What happens: Sea surface temperatures in the Pacific are close to average.
      • Weather patterns are more typical and influenced by other factors like the Indian Ocean Dipole (IOD) or the Madden-Julian Oscillation (MJO).

ENSO’s effects aren’t just limited to the Pacific — they influence atmospheric circulation globally. Changes in wind patterns, jet streams, and pressure systems ripple out, altering weather on multiple continents.

3-4. The Artic Oscillation (AO) and North Atlantic Oscillation (NAO)

These two influences deal with temperature.

5. The Madden Julian Oscillation

The MJO, or Madden-Julian Oscillation, is a large-scale tropical weather phenomenon that moves eastward around the globe. It’s a wave of thunderstorms, convection (rising warm air), and atmospheric circulation, and it travels primarily along the equator, influencing global weather patterns, including monsoons, hurricanes, and even winter weather in mid-latitudes.

The MJO cycles through phases (typically 8), which reflect where its most active convection is located — for example, over the Indian Ocean, Maritime Continent, or Pacific Ocean. Each phase has different impacts on weather across the globe.

The MJO affects the fuel for storms. 

  • Positive MJO: A strong and well-defined signal. It’s more likely to influence global weather patterns, often bringing enhanced convection and rainfall in the active phase and drier weather in the suppressed phase.
  • Negative MJO: A weak or undefined signal, meaning its impact on global weather is less pronounced or harder to detect.

In terms of specific weather impacts:

  • When the positive MJO moves over the Pacific, it often increases the chances of storms in the U.S. West Coast.
  • The negative MJO tends to mean less organized and impactful convection, so global weather patterns are often driven more by other factors.

6. The Indian Ocean Dipole

The Indian Ocean Dipole (IOD) is a climate phenomenon that impacts weather patterns across the Indian Ocean and beyond. It’s kind of like the Indian Ocean’s version of the El Niño-Southern Oscillation (ENSO) in the Pacific, and it describes the difference in sea surface temperatures between the western and eastern parts of the Indian Ocean.

The IOD has three phases:

  • Positive IOD:

    • Warmer-than-average sea surface temperatures in the western Indian Ocean (near Africa).
    • Cooler-than-average sea surface temperatures in the eastern Indian Ocean (near Indonesia and Australia).
    • Weather impacts:
      • East Africa: More rainfall, leading to flooding.
      • Australia: Drier and hotter conditions, increasing risk of drought and wildfires.
      • India: Sometimes enhanced monsoons, but also potential for dry spells depending on timing.

  • Negative IOD:

    • Cooler-than-average sea surface temperatures in the western Indian Ocean.
    • Warmer-than-average sea surface temperatures in the eastern Indian Ocean.
    • Weather impacts:
      • Australia: Wetter-than-average conditions, with more storms and flooding risk.
      • East Africa: Drier-than-normal conditions, sometimes leading to drought.
      • India: Potentially weaker monsoons.

  • Neutral IOD:

    • Balanced sea surface temperatures, with no strong temperature gradient across the ocean.
    • Weather patterns are more typical and driven by other factors like the MJO or ENSO.

The IOD often works in tandem with other climate drivers like the Madden-Julian Oscillation (MJO) and ENSO (El Niño or La Niña) — together, they shape global and regional weather patterns. For example, a positive IOD combined with El Niño can lead to severe droughts in Australia, while a negative IOD paired with La Niña could amplify wet conditions.

The (IOD) affects the temperature of the Indian Ocean, which in turn affects the strength of the MJO.  

What does this year’s pattern look like? 

Early Pioneers 

Before LRC theory evolved, Jerome Namias published many articles on what he termed “The Index Cycle” in the 1940’s, that was just on the cusp of discovering the cycling weather pattern.  

Namias has a very interesting backstory.  Born in 1910, he had a full ride scholarship to Wesleyan University in Connecticut but stayed home to take care of his ailing father.  After a bout of tuberculosis that lasted nearly 5 years, he attended MIT (Massachusetts Institute of Technology) and received a master’s degree in 1941.

While at MIT, he came across another giant in the field of meteorology, Carl-Gustaf Rossby.

Rossby was the first to describe large scale movements in the atmosphere that he compared to fluid mechanics. He demonstrated that long waves in the jet stream and westerlies followed the same rules that govern fluid mechanics.   Those waves were later named Rossby Waves and are a fundamental building block of the LRC. 

The influence of Rossby and the work Namias collaborated with on Carl’s breakthrough paper in 1939 titled “Relation between variations in the intensity of the zonal circulation of the atmosphere and the displacements of the semi-permanent centers of action” led to the development of the Index Cycle.

The LRC is Published

This phenomenon has led Gary to publish a peer reviewed journal titled Cycling Weather Patterns in the Northern Hemisphere