Weather Around The World, 12/15: Climate Pact Praised As CO2 Rises; El Niño Peaks; Weather Event Omni

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Home / Weather Around The World, 12/15: Climate Pact Praised As CO2 Rises; El Niño Peaks; Weather Event Omni
French Foreign Minister Laurent Fabius was instrumental in resolving disputes during negotiations for the Climate Agreement at COP21. Photo courtesy of diplomatie.gouv.fr

French Foreign Minister Laurent Fabius was instrumental in resolving disputes during negotiations for the Climate Agreement at COP21. Photo courtesy of diplomatie.gouv.fr

Last week was historic in terms of international amity. 195 nations signed a Climate Agreement in Paris, even as record-breaking temperatures covered eastern North America, and 2015 was on track to be the warmest year since anyone started measuring temperature.

El Niño, blamed for much of the current worldwide spike in temperatures, appears to be reaching its climax.

And Decoded Science has named a weather event — Omni. The name is significant.

Let’s go Around The World.

COP21 Succeeds Where All Other COPs Failed

The Climate Agreement signed by 195 countries on Saturday delineates steps that nations should/must take to avoid catastrophic global warming. Such a big difference in two small words! Most of the agreement is couched in ‘shoulds;’ the fact is the steps outlined MUST be taken or the weather is likely to spin out of control.

After the accolades, the hard work starts. First, 55 nations must ratify the accord for it to go into effect. Then countries will set about trying to fulfill the promises made in their Intended Nationally Determined Contributions (INDC) to stemming carbon emissions. Ten countries have not yet submitted their INDCs, though they were due on October 1.

Since the Agreement has no compliance mechanism, the world will hold its collective breath waiting to see if the signatories to the Agreement are serious about limiting global warming to as close to a two degree increase over pre-industrial times as possible.

COP21 is a grand first step — though a baby one — and should/must be followed by greater strides.

Atmospheric CO2 Concentrations May Have Permanently Passed A Milestone

We may have seen the last reading of CO2 under 400 ppm. Graphic courtesy of NOAA.

We may have seen the last reading of CO2 under 400 ppm. Graphic courtesy of NOAA.

The most reliable measurements of atmospheric CO2 are taken at the top of Mount Mauna Loa in Hawaii. The concentration fluctuates seasonally, with a maximum in May and a minimum in September.

Before the burning of fossil fuels began in earnest in the late 19th century, the atmospheric CO2 level stood at around 280 parts per million (ppm).

Last year, concentrations passed 400 ppm for the first time, and the weekly average crested at 404 ppm in May, 2015.

Following a minimum around 397 ppm in September, the readings have now risen to consistently over 400. Last Saturday’s reading was over 402 for the first time since July, and Sunday’s reading was 402.70. The most recent weekly average was 401.31. It is possible that we have seen the last of measurements below the psychologically important 400 level.

El Niño Eggplant Cresting — Literally — On The US West Coast

The current El Niño, which Decoded Science long ago named Eggplant, now appears to be nearing a crescendo. A series of Kelvin waves has warmed the equatorial waters of the Pacific Ocean to as much as three degrees Celsius (3C) above normal. The results are felt from America to Asia.

On the coast of Northern California, Oregon, and Washington, powerful winds associated with Pacific storms have whipped up giant waves. The storms ploughed inland with flooding rains and heavy snow, and their effects have been felt through the Rockies and Plains.

Eggplant is now one of the three strongest El Niños since 1950, when records of ocean temperatures became reliable. Typically, a strong El Niño is followed by a significant La Niña (unusual cooling of the tropical Pacific). This has ramifications for the eastern US and Gulf coasts; La Niña events are associated with active Atlantic hurricane seasons.

Virtually all forecasts call for El Niño Eggplant to be subsiding by mid-winter, as El Niños normally do, but Decoded Science is holding back on making that call. The period of record is short, and another Kelvin wave could extend this event into spring or even summer.

Decoded Science Names Weather Event Omni

The jet stream pattern of Weather Event Omni has a trough in the wet and a ridge in the east. Graphic courtesy of NOAA.

The jet stream pattern of Weather Event Omni has a trough in the wet and a ridge in the east. Graphic courtesy of NOAA.

Conflicting names: The Weather Channel has called this Winter Storm Echo. It is actually a jet stream pattern event that has virtually all forms of weather connected with it. Hence Decoded Science’s name Omni.

This winter’s jet stream  over the United States has featured a trough (dip) in the west and a ridge (bulge) in the east. The ridge has kept the east coast and midwest unseasonably warm, while the El Niño has stoked the fires of storms that roar into the Pacific northwest and enter the western trough as they cross the Intermountain area and the Rockies. The temperature is just cold enough to support snow in the central and northern Plains and the Upper Midwest.

On the east side of this pattern is a southerly flow of warm air from the Gulf of Mexico that has reached southern Canada.

Daily record high temperatures have been set in virtually every state in the eastern half of the US.

Here’s a rundown of the weather associated with Weather Event Omni:

  • Heavy rain on the northern Pacific coast.
  • Snow, often heavy, in the Cascades, the Sierras, the Intermountain region, and the Rockies.
  • Snow in the northern plains and midwest.
  • Thunderstorms and a few tornadoes in the southern plains and Mississippi Valley.
  • Rain, sometimes accompanied by flooding, in the southeast.
  • Record warm temperatures in much of the east.
  • Freezing rain in northern Maine and a large swath of southern Canada.

By the end of the week, the jet stream will have flattened out and calmer, more seasonable weather will prevail over the lower 48. But the weather seems to have a memory, and wants to return to a familiar pattern. With El Niño still strong, the weather pattern that produced Omni could return, perhaps more than once, before the winter is over.

The Heavenly Bodies Are Aligned For The Start Of Winter

Meteorologists count December First as the initial winter day each year. But astronomers use the solstices and equinoxes to mark the seasons. Astronomical winter begins on December 22 when the sun reaches the Tropic of Capricorn and heads back north.

In some parts of the northern hemisphere, this week’s weather was hardly representative of winter. What kind of weather do you have?

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