We’ve got the hurricane outlook, Subtropical Storm Alberto, Extremely Severe Cyclone Mekunu, and much ado about the weather in early June. Let’s go Around The World.
Flooding In Maryland
Anyone experiencing a once-in-a-thousand-year flood could claim they had bad luck. In late May, citizens of Ellicott City, MD experienced their SECOND once-in-a-thousand-year flood in TWO YEARS. Really bad luck. The deluge of a foot in a few hours naturally leads to the question ‘What’s the cause?’
The proximate cause was a cold front with very humid air on one side. The cold front wedging under the warm air and the warm air riding over the cold causes the moisture-laden air to condense as it rises. Lots of moisture condensed and fell as rain in a very short time. But why should there be so much moisture?
The atmosphere’s capacity to hold moisture is not infinite; it is determined by the laws of physics. Those laws allow for the moisture content of the atmosphere to rise as the temperature rises. Anything ring a bell, here? The temperature of the atmosphere has been rising steadily for many decades — nearly a degree Celsius in the last hundred years. The maximum capacity of air to hold water vapor increases about ten per cent with every one degree Celsius rise in temperature. It is easy to see that global warming could be the cause of an increasing occurrence of catastrophic floods. Though it’s not yet time to say that global warming causes flood events, it surely enables them.
Indian Monsoon On Schedule, Reaches Coast May 26, 2018
Monsoon rains reached the coast of India on schedule this year. Though it varied from place to place, the onset of the rainy season reached Kerala on the southwest coast on May 29, 2018, three days ahead of schedule.
The monsoon brings welcome relief to the sweltering interior of India as it progresses northward, reaching extreme northern India in July. The Indian Meteorological Department has forecast a normal monsoon season — not too wet, not too dry, A Goldilocks monsoon is good news for agriculture.
The monsoon is a giant seabreeze, taking place on a seasonal rather than daily schedule. In the winter, the continent cools and the pressure rises, pushing surface air out to sea. In the summer, the heat over land causes pressures to fall and the humid ocean air floods the continent. When the monsoon strikes the southern Himalayas, it produces the heaviest rain anywhere in the world — over a thousand inches a year in some places (average rainfall in the US is 30 inches per year).
Hurricane Season Begins
Though the official hurricane season didn’t begin until June 1, 2018 in the Atlantic Basin, the season got an early start with Subropical Storm Alberto, named on May 25. Alberto became the third-most-powerful May storm as it reached maximum intensity over the Gulf of Mexico at 65 miles per hour on May 28, but it was much weaker at landfall in the Florida Panhandle. Alberto caused some flooding on its trek northward, and became one of only a handful of storms to maintain tropical identity into the Great Lakes.
The fact that Alberto was called subtropical simply means it had characteristics of both tropical and extra-tropical cyclones. Many storms have some of each and the distinctions by NOAA’s definitions among tropical, subtropical, and extra-tropical cyclones are not clear.
Colorado State University and NOAA have released their forecasts for the coming hurricane season.
I will not mince words here: Hurricane forecasts are worthless. First of all, they are often no better at predicting the upcoming hurricane season than the climatological averages — they are sometimes even worse. Second, the chance of any individual location getting hit by a hurricane is low, just as the chance of being hit by a tornado is low. That doesn’t mean citizens in vulnerable locations shouldn’t take precautions. The proclamations of the forecasting entities that this will be a near-normal season invite complacency and do a disservice to those whom they are supposed to serve.
And now I will make MY forecast. A major hurricane will hit somewhere in the continental US this summer. Be prepared to batten down the hatches. Sometime around November first, I will compare my forecast with those of the other ‘experts.’
Cyclone Hits Oman
Mekunu. Remember the name. Omanians will. Extremely Severe Cyclonic Storm (that’s a formal definition) Mekunu made landfall in Oman on May 27 with category three (on the hurricane scale) winds up to 125 miles per hour. It was the most powerful tropical cyclone ever to hit the Arabian Peninsula, dumping three years’ worth of average rainfall in a single day in some places. Thirty-one people are known to have died.
Solstice Around The Corner
By the time the next Weather Around The World is published on July 3, 2018, the solstice will have come and gone. No doubt heat waves will be in the news.
Climate Change Checkup will be published around June 18, 2018.