The schizophrenic nature of the weather has been on display this winter in the United States.
The eastern half of the country has been very cold, with many records set, while the west has been comparably warm.
The pattern is now changing, and thunderstorm and tornado activity could increase from the plains to the deep south. Extremes of temperature and precipitation occur on seasonal, latitudinal, and synoptic scales.
This week is a good time to examine some of the bipolar tendencies of Mother Nature. There’s also a super-typhoon in the western Pacific, rain where it never (yes, never) rains, and a new CO2 record reading.
Let’s go Around The World.
Persistent Temperatures Far Above Normal in Many Locales
As the earth warms, the weather, at least judging by recent years, has become more stagnant. Snowy places stay snowy longer (ask a Bostonian), and hot places stay hot longer. The following are just a few examples of recent persistent warmer-than-normal weather:
- Nairobi, Kenya has been above normal every day since January 1 and is forecast to stay above normal until at least early May.
- North Pole: Temperatures above 80 degrees north latitude, as measured by the Danish Meteorological Institute, have been above normal all winter.
- Mumbai, India, where the average March temperature is 85 degrees, has been above normal every day since March third, twice topping 100.
- Los Angeles, California has been above normal every day since March 4, setting or tying high temperature records on four days.
Atmospheric Carbon Dioxide Goes Up — and Up — and Up
The average weekly CO2 reading for March 22-28, 2015 on Mount Mauna Loa in Hawaii was over 400 parts per million (ppm) for that week for the first time.
At 401.75 for the week, atmospheric carbon dioxide is now five percent higher than it was on the comparable week ten years ago. Carbon dioxide concentrations peak annually in May; Saturday’s reading of 402.94 is at the level of last May and going up at an increasing rate.
Western Pacific Typhoon Season Off to a Roaring Start
Super-Typhoon Maysak is the third typhoon and fourth named tropical system of the western Pacific Ocean season, which begins on January 1.
Water in this part of the ocean is warm enough to support tropical cyclone formation all year. Maysak is now the equivalent of a category five hurricane, with winds of 160 miles per hour, and experts expect it to peak tonight at 175 miles per hour as it heads for — can you guess? — the Philippines.
Maysak should wind down as it encounters wind shear and colder water, but still be a category two storm when it makes landfall in a country that has suffered three devastating Super-Typhoons in the past two years.
2015 got off to an early start in January with Tropical Storm Mekkhala, which briefly reached minimal typhoon status as it grazed the Philippines. Damage from Mekkhala was light, though it did force the Pope to change his itinerary. Then came Typhoon Higos, a category four storm which was the strongest typhoon in February since 1970. It spun harmlessly over open water and did not affect any land masses.
Rain in The Atacama Desert of Chile
The high desert of Chile is a unique place. The high Andes buffers it on the east and an impenetrable marine layer over the Pacific Ocean buffers it on the west, the Atacama has spots where, until last week, no one had ever observed rainfall. Arica, in the northern part of the desert, holds the official record for driest place on earth with a continuous record of observations of more than 40 years, going over 14 years without a drop of rain.
Antofagasta, a little south of Arica, is relatively wet, receiving, on average, seven hundredths of an inch of rain per year. Last week, Antofagasta got a thunderstorm which dropped nearly an inch of rain — about fourteen years’ worth — in half a day. This modest amount of rain caused the Copiapo River, which is almost always dry, to flood and kill nine people.
Some meteorologists are blaming El Niño Eggplant for the rain, but Decoded Science will hold off on that judgment. While the El Niño features higher water temperatures and more available moisture, an unusual undulation in the jet stream is probably the main culprit.
El Niño Update
As of the latest observations on March 30, water temperatures in the eastern Pacific have increased, and the El Niño is looking slightly more robust. NOAA has assigned a 50-60% probability that the El Niño will continue through the summer. Decoded Science feels the odds are a little higher.
Long-Range Forecasts Show a Change in The Jet Stream Pattern Over The US
The wavy jet stream has inhibited thunderstorm formation over the US this year until the recent outbreak of violent weather in Oklahoma. This appears to be a change to a more zonal (west-to-east) jet stream which is an important ingredient in violent weather in the plains, south, and midwest. Longer term, as El Niño takes hold, a southern branch of the jet stream could bring rain to the American southwest and warmer temperatures to the eastern part of the country.
Spring Is In Full Swing
As April dawns, weather patterns have a distinctly different look. What’s up with the weather where you live? Leave a comment if you see something unusual.
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