The Discovery Channel HD (Pacific)

Six teams of chasers pursue a violent tornado outbreak in North Dakota; but as day turns to night, the storm unleashes the first EF5 tornado in over a decade; as the mile-wide monster levels homes and farms, chasers race to rescue people and pets.

While chasing a monster in Alabama, Sarah parts ways with Reed moments before he takes the Dominator for a spin inside a tornado; Gorilla hail bombards Freddy and Connor's chase vehicles; Brandon, Jordan and Aaron intercept a tornado at a gas station.

Six teams of chasers brave Oklahoma back roads as a late spring warm front unleashes long-track tornadoes; as the biggest twister grows to EF-3 strength, it destroys a weed farm and forces Reed onto dirt roads to make a drone intercept in the Dominator.

Teams of expert storm chasers and certified weather spotters risk it all to venture into America's Tornado Alley; they self-shoot their encounters with nature at its most extreme, warn people in harm's way and help save lives when disaster strikes.

As winter closes in on the mine, paydirt dwindles and the Black Pearl is down; Todd's 1,000-ounce goal looks out of reach; the Hoffmans gamble by running the Holy Roller day and night; Hunter races to find a new clutch for the Black Pearl.

A heartbreaking revelation sends shockwaves through the crew as they tackle their toughest dive site yet in search of millions in gold.

Jeremy Wade explores a shipwreck that may contain stolen Nazi treasure, the priceless lost furnishings of the 18th century Amber Room; astonishing footage captures the exact moment when freight ship MV Arvin split in two and sank in the Black Sea.

Jeremy Wade explores the hidden and dark secrets behind a 150-year-old shipwreck off the coast of Sisal, Mexico, revealing an unknown and troubling maritime past. Also, a mysterious boiling river hidden deep in the heart of the Amazon is uncovered.

Jeremy Wade explores an accident involving a Russian nuclear submarine on a top-secret mission, and shocking details emerge surrounding the vessel's design; scientists investigate ancient human remains emerging from a lake in Finland.

Exploring the puzzling disappearance of an Indonesian submarine; the latest research into an underwater phenomenon may help piece together how it vanished.

With emergency flares shooting off overhead, 12 Naked and Afraid all-stars are suddenly forced to grab what they can and plunge into the pitch-black Philippine Sea; a venomous jellyfish sting leaves a survivalist in agony and threatens their challenge.

For the first time ever, 12 Naked and Afraid All-Stars are going overboard; they've been told it's a Lost Coast challenge, but they're about to be shipwrecked in the dark of night; they must survive the next 35 days, and then rescue themselves to go home.

Darrin leads a water pipeline build. Patrick calls out his partners; Adam squares off with a deadly viper; Dani scores a potential food win; in the dead of night, Jarrell's fire blazes out of control; a survivalist must be medically evacuated.

When Wizard deckhand Lynn Guitard falls overboard in 15 foot seas, Keith and Monte scramble to rescue him before hypothermia sets in. On the Northwestern, Sig lets Sophia prove herself at the Russian line. A greenhorn joins the crew of the Aleutian Lady.

On the Aleutian Lady, greenhorn Todd's abscessed tooth forces Rick to consider a costly return to Dutch Harbor; Sig hands new protégé, Bob, the helm for her first-ever opilio season; Johnathan performs surgery-at-sea on his favorite Time Bandit shipmate.

As Arctic ice wreaks havoc on the fishing grounds, Rick risks losing a fortune in crab pots. Johnathan tests the Time Bandit's reinforced bow in a desperate attempt to save the gear. A health crisis on the Wizard forces Keith to make a life-or-death call.

Captains Sig and Sophia shift their fishing strategy as back-to-back injuries plague the Northwestern deck crew. When a Time Bandit crewman suffers a concussion, John must make a perilous harbor entry. Jake loses power in heavy seas on the Cornelia Marie.

Captains Sig & Sophia locate hybrid crab, hitting the jackpot — but filling their tanks creates an imbalance, putting the Northwestern on the brink of capsize. After OJ receives tragic news at sea, the Time Bandit crew races incoming ice to get him home.

HSI agents coordinate a massive raid to take down a transnational drug trafficking gang; agents interdict an erratically moving vessel, often a sign of evasive smugglers, but it turns out that its passengers have less sinister motives.