This week’s earth science news has been dominated by the earthquake in Nepal. Nevertheless, violent weather, though by most measures not as violent as the shaking earth in Eurasia, has taken its toll.
Looking ahead, there are signs that this summer could be an active one in terms of tropical cyclone activity — or not. Let’s go Around The World.
Hydra Rears Another Head
Last Friday, Decoded Science warned of impending severe weather in many locations: Extreme Weather Event Hydra. Thunder, lightning, hail and tornadoes roared across the south and were complicit in the deaths of sailors on Mobile Bay Saturday. And Hydra is not finished.
Another round of severe weather began in Texas Sunday and is moving slowly eastward; the major threat of thunderstorms, hail, flooding, and tornadoes today is in the northern Gulf states. This will be the last of the monster, as dry air overspreads the eastern half of the country by Thursday.
However, the basic pattern of warm, humid air from the Gulf of Mexico moving into the southern states and as far north as the midwest and central plains, coupled with dry air aloft moving eastward from the Rockies, will be reestablished by the weekend. Waves in the jet stream could set off another round of severe weather — but it will need a new name.
Tropical Activity: None To Speak Of
For the second week in a row, there is not even a suspicious area of disturbed weather in the tropics anywhere on the planet. So now might be a good time to look at the water temperatures in anticipation of the northern hemisphere’s tropical cyclone season.
Hotspots are evident in the sea surface temperature (SST) anomaly analysis in the eastern Pacific, the Gulf of Mexico, the western Atlantic, and much of the Indian Ocean.
A cold pocket exists in the Cape Verde Island breeding ground for major Atlantic hurricanes, and temperatures in the western Pacific are somewhat below normal. All in all, a mixed picture.
Complicating the forecast is the El Niño, clearly evident along the equator, where SSTs are above normal and have risen in the last few weeks. El Niño typically subdues Atlantic hurricane activity.
Regardless of specific conditions at any given time, the northern hemisphere’s tropical cyclone season is long, and the last time a season went by without a major hurricane (winds over 115 miles per hour) or its equivalent (typhoon in the western Pacific; tropical cyclone in the Indian Ocean) was: never.
What Happens When Severe Weather Warnings Are Ignored
The distance from Kathmandu, Nepal to Mobile, Alabama is 8,400 miles. The earthquake in Nepal and the thunderstorms on Mobile Bay, both of which occurred last Saturday with resulting loss of life, have no physical connection. But there is a similarity in the response of officials who reacted irresponsibly to scientists’ warnings.
In the last 65 million years, India, formerly an island in the Indian Ocean, has made a headlong dash (the rate of about 2 inches per year qualifies a dash in terms of the scale of tectonic plate movement) towards the Eurasian continent. The resulting collision has folded the earth’s crust, producing its highest mountain range, the Himalayas.
As India continues to subduct under Eurasia, large earthquakes have been common (again, common by standards of the geological time scale) along the boundary between the two. Large quakes have occurred with a frequency of less than a century, and it has been a relatively long time since the last one. Seismologists have been predicting a major quake for some time. The exact location and date cannot be determined for these things, but the probability was high that a ‘big one’ would happen within a decade.
Given that the collision of India and Eurasia has produced a 29,000 foot high mountain, it is not surprising that resulting movements of the earth could knock down buildings. Some of the structures that came down were ancient. But many were also modern, shoddily constructed with lax official oversight. For this, government officials bear responsibility. With proper building codes, much of the misery could have been averted.
Over four thousand are confirmed dead and 8,000 injured in the Nepal earthquake.
Organizers of the regatta on Mobile Bay that ended in tragedy had sufficient warning that severe storms were on the way, but they proceeded with the race anyway. One of Hydra’s heads was rumbling through the northern Gulf coast, so in general, organizers should have been on alert (any time people venture onto the water, regardless of local conditions and forecasts, they should continue to monitor the weather).
Specifically, the National Weather Service issued a severe thunderstorm watch at 1:30; it issued a severe thunderstorm warning at 2:30 and a special marine advisory at 3. The race continued. At 4 the storm hit.
Two people are confirmed dead and there is little hope of finding the four who remain missing alive.
The coast guard is investigating who was responsible for the terrible decision to go on with the regatta.
Forecasting movement of the atmosphere, like forecasting movement of the earth, is an inexact science. However, a great deal of effort goes into making forecasts of both. For local officials to ignore warnings is irresponsible at best, criminal at worst.
Seasons Changing Rapidly
As spring transitions into summer, attention will be focused on severe thunderstorms and tornadoes, typhoons and hurricanes, and heat waves. Do you see any evidence of summer weather yet?