How bomb cyclones form and create dangerous conditions

When turbulent weather with whipping winds and heavy snow is in the forecast, meteorologists sometimes warn that a storm could “bomb out” or become a bomb cyclone. But what exactly does this mean?

According to the U.S. National Oceanic and Atmospheric Administration, certain storms undergo bombogenesis, which happens when a storm’s central pressure drops at least 24 millibars in 24 hours. These storms are sometimes called bomb cyclones. Storm intensity is measured by central pressure, so the lower the pressure, the stronger the storm.

Such rapidly strengthening storms are capable of producing heavy rain, blizzard conditions and intense winds that can create dangerous conditions such as downed trees and power outages.

“If you’re watching TV at night and the weather report comes on and you’re hearing ‘bomb cyclone’ being used, that usually means there’s quite a bit of active weather going on,” said Andrew Orrison, a meteorologist with the National Weather Service in College Park, Maryland.

Bomb cyclones can happen in any season, but mainly occur during fall and winter when frigid air from the Arctic can creep south and clash with warmer air masses.

“It’s really the clash of those air masses that really kind of helps to generate the areas of low pressure in the first place,” said Orrison.

Regions in North America that are prone to seeing bomb cyclones include Alaska, the Pacific Northwest and the Great Lakes region.

“It’s not common to get bomb cyclones at lower latitudes. So generally speaking, you wouldn’t see a bomb cyclone across, let’s say, the southern United States,” said Orrison.

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A man crosses 7th street in the heavy snow Sunday Dec. 28, 2025 in downtown Minneapolis. (Jerry Holt /Star Tribune via AP)

NEW YORK (AP) — Silver and gold futures fell sharply Monday after the Chicago Mercantile Exchange, one of the world’s largest trading floors for commodities, asked traders to put up more cash to make bets on precious metals with prices surging this year.

This year, gold futures are up 65% and silver has more than doubled.

The CME raised margin requirements for gold, silver and other metals in a notice posted to the exchange's website Friday. These notices require traders to put up more cash on their bets in order to insure against the possibility that the trader will default when they take delivery of the contract.

Exchanges sometimes boost margin requirements when a commodity or other security goes on a significant run. In its notice, the CME said it was raising margin requirements “per the normal review of market volatility.”

Silver futures tumbled 8% early Monday while gold slid 5%

Silver prices have skyrocketed this year, topping records dating back to the early 1980s when traders tried and failed to corner the silver market. Supplies have dwindled, with production at major mines slowing. At the same time there's been an increased industrial need for silver for solar panels as well as data centers.

Silver futures were roughly $30 an ounce at the beginning of 2025, and briefly touched $80 an ounce before the CME's announcement.

Gold futures have risen due in part to geopolitical uncertainty and fears that a bubble is forming in some stock markets.

The new requirements for traders dragged down almost all major goldminers as well on Monday. Newmont, the world's largest goldminer, was the biggest decliner on the S&P 500, falling 6%. Smaller goldminers like Vista and Anglogold and Gold Fields, fell even more sharply. .

FILE - An employee of Pro Aurum gold house lifts 1 Kg silver bars of 999.9 purity besides 1 Kg gold bars in the safe deposit boxes room in Munich, Germany, Friday, April 25, 2025. (AP Photo/Matthias Schrader, File)