Some weeks the weather is more active than others.
This week we have new CO2 records, a Super-Typhoon, a forecast of extreme-heat misery, the onset of a monsoon, and continuing violent weather in the American heartland.
Let’s go Around The World.
New Records For Atmospheric CO2
CO2 averaged 404.11 parts per million the week beginning May 3, a new weekly record.
Since we are now passing the annual spring peak, this record will probably stand until next spring. The week beginning May 10 averaged just under 404. The reading of 404.54 on May 16 set a new single-day record.
The atmospheric concentration of CO2 has been going up at a rate of about one-half of one percent per year. It has risen steadily since the start of the industrial age, and in recent years, despite political lip-service to reducing fossil-fuel burning, the rate of increase has actually accelerated.
Typhoon Dolphin Whacks Guam, Curves Away From Japan
After passing Guam with 100 mile per hour winds, Typhoon Dolphin became a Super-Typhoon on Saturday. Winds peaked at 160 miles per hour as the storm aimed directly at Japan, but southwesterly winds aloft knocked down the intensity and pushed the storm to the north, then northeast. Dolphin is now a minimal typhoon as it heads out over the open Pacific.
Dolphin was the third Super-Typhoon in the northwest Pacific Ocean so far this year, a number that puts 2015 on track to surpass 1997’s record of 10 Super-Typhoons. In 1997, the third Super-Typhoon didn’t form until July.
Indian Monsoon Is On Time
The Indian Monsoon has begun on the Andaman Islands off the coast. It is right on time and expected to reach mainland India by the end of May, proceeding northward and reaching Delhi in the northern part of the country by the end of June.
The monsoon is important to agriculture in India, and some authorities have been worried that El Niño Eggplant will have an effect. El Niños are correlated with weak monsoon seasons.
At Port Blair in the Andaman Islands, the temperature had been over 100 for fifteen consecutive days through last Friday. Then cloudiness and showers reduced the highs to the 90s the last three days. Beginning today, with heavier rain and more clouds, temperatures will probably not reach 90 again this year.
New Study Predicts Many More Will Be Subject To Extreme Heat
A new study published in Nature Climate Change yesterday predicts that, by one measure, the number of Americans subject to extreme heat will quintuple before mid-century.
Though climate change is one factor in this increase in discomfort, human migration from the north to warmer climes is also involved. And after this snowy winter in the northeast, the trend might accelerate.
The authors define a person-day of extreme heat as one person experiencing a temperature over 95 degrees for one day. In the US from 1970 to 2000, the average number of person-days of extreme heat per year was 2.3 billion. That number is expected to rise to over 10 billion by the year 2040, as states like Texas, Florida, and Arizona experience rapid population growth.
Adding to the climate change and demographic effects on the number of person-days of extreme heat is the heat island effect. As cities grow, they produce and retain more heat, and maximum and minimum temperatures increase above the average of the surrounding countryside.
There should be a caveat here: Global warming has feedback effects. One is that cloudiness is expected to increase along with warmer temperatures because warmer air holds more moisture than cooler. The cloudiness could have the effect of increasing nighttime temperatures but decreasing daytime temperatures. Overall, the climate can warm without an increase in the person-days of extreme heat. But I wouldn’t bet on that.
Weather Pattern Government Shows No Sign Of Changing
Weather Pattern Government, so named for its slow movement, will be with us for another week at least. Violent weather connected with Government continues on a daily basis from the plains to the midwest. Snow continues to fall in the high Rockies. And the heat wave in the southeast continues unabated.
The pattern is characterized by a trough (dip) in the jet stream over the west, and a ridge (bulge) in the east. This allows warm and humid air from the Gulf of Mexico to invade the plains and as far north as the midwest. Meanwhile drier air at higher levels crosses the mountains and streams above the warmer air.
The result is conditional instability, a situation in which any lifting of the air column produces an overturning that results in thunderstorms and tornadoes. The sun’s heating of the ground every afternoon provides the lifting.
A push of cooler air could temporarily interrupt the severe weather for the next couple of days, but all forecasts call for a return of Government’s basic pattern by the weekend.
Coming Up In Weather News
NOAA issued its report on April global air and sea temperatures this morning. Though the long-term trend is clear (warmer), month-to-month reports always contain something unusual and interesting. This month, extreme warmth in Argentina and Siberia stand out. Decoded Science will review the report later this week.
Meanwhile, what’s the weather like where you are? See anything interesting? Leave us a comment.