As temperatures plummeted to the single digits in the Northeast on Monday, one Connecticut woman captured a photo of something that seemed a little out of place for winter: a waterspout.
Alvida Veit took the picture from Stonington Point, Conn., looking toward Napatree Point, in Rhode Island. Veit’s sister reported a steamy sunrise over Long Island Sound, spurring her to head to the water for a closer look. Both sisters have been enthralled with weather as long as they can remember, having grown up in a family of fishermen.
“I guess I was in the right place at the right time,” Veit said. “It was very dramatic to see the rotating sea smoke.”
Her photo depicts three funnels all in different stages of development.
The leftmost one shows connection to the cloud base above, evidenced by the rugged tendrils dipping from the cloud. The condensation funnel extends all the way down to the water. A similar spout, perhaps a bit larger and feistier, is seen on the right. In the middle, a more meager “steam devil” whirls off in the distance.
Waterspouts are typically regarded as a warm-weather phenomenon, but they can spin up in frigid air masses, too. Forming a spout doesn’t come down to only temperature: It’s all about temperature differences. Waterspouts in any season feed off rising air. The greater the change in temperature between the surface and the air above, the faster air pockets near ground level rise.
Morning lows bottomed out at 5 degrees in Boston, where the daytime high didn’t make it above 10. Providence dropped down to 1 degree, and Hartford to minus-4. Juxtaposed with this were lukewarm water temperatures: 39 degrees in Long Island Sound, 45 at Block Island and 42 offshore of Boston. The resulting clash led to a spectacular display of “Arctic sea smoke” up and down the Northeast coast.
The relatively warm ocean has a “marine layer” above it a couple of meters thick in the wintertime. There, humidity and temperatures are both higher than in the surrounding air mass. But when icy Arctic air comes marching down from the north, the cold wind mixes with the marine layer. It chills this slightly moist air below its dew point, leading to condensation and “sea smoke.” That’s why the ocean looked like it was smoking Monday morning, with little steam-whirls and devils dancing mischievously against the sunrise. A similar premise explains why a cold beer seems to smoke on a hot summer day.
The nearly 40-degree contrast led to extreme instability, but only in a shallow layer near the sea surface. So instead of massive thunderstorms, clouds in New England had a bit lower top. Puffy cumulus clouds billowed only to about 2,000 or 3,000 feet high. But rapidly rising air near the base of these clouds fostered powerful suction, enough to entrain several near-surface steam eddies and carry their circulations upward. This so-called “vortex stretching” boosted wind speeds within the funnels, while the linkage to clouds above qualify them as legitimate waterspouts.
Winter waterspouts are much weaker than their fair-weather, warm-season cousins but still could pose a hazard to mariners, with erratic 40 mph winds coiled about their narrow centers. The National Weather Service in Upton, N.Y., took the unusual step of issuing a marine warning, advising boaters to “seek safe harbor.”