Judging by current activity, we are in store for a busy hurricane season in both the Atlantic and Pacific Oceans.
Arthur blew out roads in North Carolina, Neoguri is taking aim on Japan, and Fausto is heading towards Hawaii.
Elsewhere, heat builds in the Pacific northwest, while the midwest continues soggy.
Then there’s the World Cup and Bastille Day. Let’s go around the world.
Bastille Day, July 14
The United States had its Independence Day last weekend, now it’s France’s turn. Commonly called Bastille Day in English-speaking countries, Le Fête Nationale (The National Celebration) commemorates the beginning of the French Revolution with the storming of the Bastille on July 14, 1789.
The long-range weather forecast calls for showers over all of France, associated with a low pressure wave in the jet stream.
World Cup Semi-Final and Championship Games
The semifinal matches today in Belo Horizonte and tomorrow in Sao Paulo, Brazil could be influenced by showers, but conditions will be better than the heat and humidity of the Amazon. The final on Sunday in Rio should be played under good conditions, with just a chance of a shower.
Hurricane Arthur was an unusually intense early-season Atlantic hurricane. It struck the Outer Banks of North Carolina a direct blow, washing out the coastal road — but that happens regularly — and causing some damage to property.
Arthur skirted the coast, sparing New York, but the interaction between Arthur and an old cold front — actually the remnants of Severe Weather Outbreak Elephant — doused parts of southeastern Massachusetts with up to eight inches of rain. Outer Cape Cod, closer to the center of Arthur, received much less rain than Plymouth and New Bedford.
The front associated with Elephant draped itself along the southern New England coast and just north of the Cape Cod Canal. When the moisture at middle levels of the atmosphere pumped northward by Arthur hit the front, the lifting was sufficient to cause the deluge.
Arthur continued on to the Maritime Provinces of Canada, transitioned to an extra-tropical cyclone, and was finally absorbed by the polar vortex over Greenland.
Typhoon Neoguri lost some strength south of Japan yesterday, as dry air was entrained (meteorologists’ euphemistic way of saying sucked) into the system. Neoguri is still a dangerous storm and could regenerate a little strength before passing over colder water, interacting with land, and weakening. Japan’s southern islands are sure to be hit hard with wind and heavy surf; tropical downpours could cause flooding and mudslides even on the northern islands.
Tropical Storm Fausto
Tropical Storm Fausto formed yesterday in the eastern Pacific Ocean. It is far enough south to escape the fate of several previous eastern Pacific systems, including two hurricanes, which quickly fizzled over cold water to their northwest.
Fausto is headed west-northwest and is making a beeline for Hawaii, but a storm on this trajectory will eventually encounter too much cold water to make an impact on the islands.
Strong tropical systems are not unheard of in Hawaii, but in order to get there a storm must stay well to the south over the warmer waters, then turn sharply north and accelerate towards the islands.
Northwest Heat Wave: Return Of The Omega Block
High temperature records have been set the past few days in all the west coast and intermountain states. Though the atmosphere is a continuous medium, so that a departure from normal in one place cannot be proven to be the cause of abnormal weather somewhere else, there is a constant factor in the recurring pattern that goes back to last fall.
The water temperature anomaly in the Gulf of Alaska (the water is several degrees above normal) has repeatedly forced a ridge (high pressure) to develop in the jet stream on and offshore of the west coast. Warm water heats the air above it, and the column of air expands. At any given height, the pressure rises because more air is now above than previously. If the high pressure cuts off from the normal jet stream flow, the movement of weather systems stops. The pattern is called an omega block because of its shape: Ω. The persistent drought and above normal temperatures in the western US are the immediate results.
Downstream, where the dominant wave pattern creates a trough (low pressure), the midwestern states have experienced a cold and stormy winter, and now a very wet and stormy summer. Cold air has driven deep into Dixie, where many cold temperature records have been set recently.
A slight cooling trend will be in evidence in the extreme northern states of the west this week, but next week the temperatures will rise to record highs in an area centered on Idaho and Nevada as the high pressure strengthens.
Mississippi River cresting
The persistent rain in the midwest has filled the Mississippi River to overflowing. The crest is now near St. Louis and headed downstream. More rain is in the forecast, so conditions could get worse.
The American Monsoon
Arizona actually has a monsoon, and this year’s has started. Moisture from the Gulf of Mexico and the Gulf of California works its way into the desert southwest during July and August. Tucson, Arizona gets about 40% of its yearly rainfall in those two months. Thunderstorms will be likely this week in Arizona and New Mexico.
Though the desert rain is paltry compared to what the rest of the country normally receives, flooding can occur because of poor drainage.
Is It Global Warming?
It is tempting to blame the heat wave in the west and the active tropics on global warming. As Decoded Science has repeatedly said: these events are consistent with, but not proof of, human-caused climate change. However, after enough ‘consistent withs,’ there is only one logical conclusion.
How’s the weather changing where you are?