A powerful storm is bearing down on the West Coast and bringing with it a scary-sounding weather term - bomb cyclone.
Bomb cyclone is a term used by weather enthusiasts to describe a process that meteorologists usually call bombogenesis. It's the rapid intensification of a cyclone in a short period of time, and it can happen during powerful storms such as the one northern California and the Pacific Northwest are preparing for this week.
But what is a bomb cyclone, why does it happen and why are these big storms so feared?
A bomb cyclone occurs during the rapid intensification of a cyclone located between the tropics and the polar regions, according to the National Oceanic and Atmospheric Administration. It can happen when a cold air mass collides with a warm air mass, which is something that can occur over ocean waters, the agency says.
The measurement needed to determine whether a cyclone can be classified a bomb cyclone can be tricky, but it largely concerns a swift drop in pressure. Atmospheric pressure is measured in millibars by the National Weather Service. If a storm decreases 24 millibars or more in 24 hours or less, it can be considered a bomb cyclone, said Stephen Baron, a forecaster with the weather service in Gray, Maine.
“I would say rapid intensification of hurricanes is one of the more common times we see it,” Baron said. “We do see it with Nor'easters occasionally.”
The National Weather Service Weather Prediction Center has issued excessive rainfall risks starting Tuesday and running through Friday because of the powerful storm expected in northern California and the Pacific Northwest. The storm is arriving as the region experiences an atmospheric river, which is a long plume of moisture, over the Pacific Ocean.
The Weather Prediction Center said the storm intensified swiftly enough that it's considered a bomb cyclone.
Bomb cyclones can happen in many places, and aren't unique to the West Coast. They can occur in several parts of the world's oceans, including the Northwest Pacific and North Atlantic.
This storm is expected to bring severe rainfall. That could lead to flash flooding as well as winter storms in different parts of the West Coast depending on elevation.
High wind watches are also expected in some parts of the West Coast.
Travel is expected to be hazardous, and power outages are expected. There could also be significant damages to trees and infrastructure.
Bomb cyclones have been associated with major weather events all over the country in recent years. Hurricane Milton, which made landfall in Florida last month as a Category 3 hurricane, was a recent example of a bomb cyclone, Baron said.
A bomb cyclone in 2018, which helped popularize the term on social media, brought snow to the Southeast and winds that were close to hurricane force. Another in 2022 brought extreme weather and bitter cold to much of the country.
This satellite image taken, Nov. 19, 2024, and provided by NOAA, shows weather gathering in northern California and the Pacific Northwest. (NOAA via AP)
NEW YORK (AP) — Nvidia and other tech companies are pulling U.S. stock indexes higher on Tuesday after they stumbled in the morning on worries about escalations in the Russia-Ukraine war.
The S&P 500 was 0.2% higher, as of 2:45 p.m. Eastern time, after erasing an early drop of 0.7%. The Nasdaq composite also shook off an early loss to turn 0.8% higher, while the Dow Jones Industrial Average slipped 154 points, or 0.4%.
Nvidia’s 4.4% climb was the strongest force pushing the S&P 500 upward, and without it, the index would have been down. The chip company’s stock is rallying ahead of its profit report for the latest quarter, which is coming on Wednesday, and vaulting its gain for the year so far above 195% thanks to the craze around artificial-intelligence technology.
Activity in the options market suggests Nvidia’s profit report may be the most anticipated event on Wall Street for the rest of the year, beating out the upcoming jobs report and even the next meeting of the Federal Reserve on interest rates, according to strategists at Barclays Capital.
It’s “a testament to the outsized impact of AI, and the apparent resurgence of upside chasing by” smaller-pocketed, everyday investors known as “retail traders,” according to Barclays’ Stefano Pascale and Anshul Gupta.
Nvidia’s rise helped calm the stock market, even as indexes sank across Europe after Russia said Ukraine fired six U.S.-made ATACMS missiles at it. Earlier in the day, Russian President Vladimir Putin formally lowered the threshold for Russia’s use of its nuclear weapons. Both France’s CAC 40 and Germany’s DAX fell 0.7%.
The worries also sent investors into U.S. Treasury bonds, which are seen as some of the world’s safest investments. The rise in their prices in turn lowered their yields, and the 10-year Treasury yield fell to 4.37% from 4.41% late Monday.
Gold also rose 0.6% and recovered some of the losses it sustained following Donald Trump’s victory in the U.S. presidential election, as investors herded into places traditionally considered safer during times of trouble.
Early in the day, such cautiousness overshadowed optimism coming from reports by big U.S. retailers showing fatter profits for the summer than analysts expected.
Walmart climbed 3.7% after topping forecasts for both profit and revenue. The nation’s biggest retailer said it saw broad-based strength across its categories, including sales made both online and in stores. It also said it served more upper-income households, while raising its forecasts for sales and profit for the full year.
Lowe’s likewise delivered bigger profit and revenue for the latest quarter than analysts expected, but its stock nevertheless dropped 4.2%. A report in the morning said construction crews broke ground on fewer new homes last month than economists expected, and rival Home Depot slipped 0.8%.
Other big companies set to report their latest quarterly results this week include Target on Wednesday and Deere on Thursday.
Elsewhere on Wall Street, Super Micro Computer jumped 31.9% after it filed a plan to keep its stock listed on Nasdaq’s exchange. It hired an independent auditor, BDO USA, which can help it file financial statements needed in order to comply with Nasdaq’s listing requirements.
The company’s stock has been on a wild ride. It more than quadrupled in the first two and a half months of this year because the company makes servers used in AI. But it gave up all that and more, with losses accelerating after Ernst & Young resigned as its public accounting firm. A special committee of the company’s board later said that a three-month investigation found “no evidence of fraud or misconduct on the part of management or the Board of Directors.”
Berry Global Group rose 0.7% after Amcor said it would buy the maker of prescription vials, bags and other products in an all-stock deal. Amcor fell 2.6%.
Incyte dropped 8.6% after the biopharmaceutical company said it’s pausing enrollment in its ongoing study of a potential treatment for hives in chronic spontaneous urticaria. It also said data from another study evaluating a potential treatment for cholestatic pruritus does not support further development.
In stock markets abroad, indexes in Asia were more stable than in Europe. They rose 0.7% in Shanghai and 0.4% in Hong Kong, rebounding from early losses.
AP Business Writers Matt Ott and Elaine Kurtenbach contributed.
FILE - The morning sun shines on Wall Street in New York's Financial District on Tuesday, Nov. 19, 2024. (AP Photo/Peter Morgan)
FILE - People pass the New York Stock Exchange on Nov. 5, 2024, in New York. (AP Photo/Peter Morgan, File)
Currency traders pass by a screen showing the Korea Composite Stock Price Index (KOSPI), left, and the foreign exchange rate between U.S. dollar and South Korean won, center, at the foreign exchange dealing room of the KEB Hana Bank headquarters in Seoul, South Korea, Tuesday, Nov. 19, 2024. (AP Photo/Ahn Young-joon)
Currency traders work near a screen showing the Korea Composite Stock Price Index (KOSPI), left, and the foreign exchange rate between U.S. dollar and South Korean won, center, at the foreign exchange dealing room of the KEB Hana Bank headquarters in Seoul, South Korea, Tuesday, Nov. 19, 2024. (AP Photo/Ahn Young-joon)
A currency trader reacts near a screen showing the Korea Composite Stock Price Index (KOSPI), left, and the foreign exchange rate between U.S. dollar and South Korean won at the foreign exchange dealing room of the KEB Hana Bank headquarters in Seoul, South Korea, Tuesday, Nov. 19, 2024. (AP Photo/Ahn Young-joon)
