John C. Widener, a 73-foot-long buoy tender capable of breaking… (Kim Hairston, Baltimore…)
With each passing day, the creeks and rivers of the Chesapeake Bay are filling with windowpanes of ice, beautiful to look at but capable of slicing through the hull of a boat with deadly precision.
Several weeks of teeth-chattering cold that triggered a massive fish kill, stranded duck hunters on an ice-choked island off Baltimore County and contributed to Maryland's first boating fatality also have put the state's ice-breaking fleet on standby to begin the great push back.
After a fast start to the ice-breaking season in December, sheets of frozen water are again starting to knit together in tributary shallows. Around the bay many places are close to the freezing mark, with the Chesapeake's coldest period still ahead.
It's not unusual for ice to bob in the bay like cubes in a cocktail glass, but it's been seven winters since Maryland's maritime activities have been disrupted by thick floes.
And while it won't rival the unrelenting conditions of the "Big Freeze" of 1977, when people walked and drove across the bay in the shadow of the Bay Bridge, this weekend's temperatures and 30-knot gusts were expected to accelerate the creation of massive ice plates.
"This winter is so cold right now, it's unbelievable," said John Gallagher, director of hydrographic operations for the Department of Natural Resources. "After this weekend, we're going to see some pretty good ice buildup. We think the season is about to spring wide open."
On Thursday, the 73-foot buoy tender J.C. Widener, capable of cutting through 8 inches of ice, moved from Cambridge across the bay to Annapolis, as DNR renewed a warning to watermen to move their boats near one of the ice breakers or police patrol boats as freezing conditions approach.
The other three boats that add ice-breaking duties to their navigation and buoy tending operations are assigned to Crisfield, the Choptank River and Kent Narrows. Coast Guard boats are used to keep the shipping channel clear and ensure that fuel delivery boats can make the run from Virginia up the Nanticoke and Wicomico rivers to Eastern Shore depots.
An analysis late last week by the National Ice Center in Suitland found no ice visible on the bay in satellite images, but determined that there was ice in the small tributaries.
On Dec. 27, two duck hunters in a small boat had to be rescued by Natural Resources Police when they got caught on the bay in deteriorating weather conditions and took shelter on Hart-Miller Island. Officers broke through 100 yards of ice and battled 4-foot waves to reach the men and lead them to safety.
The National Weather Service, too, noted freezing in December on the upper reaches of the bay's rivers and creeks, including the tidal Potomac near Washington.
After a very warm Dec. 1, the month grew quite cold, averaging 32.4 degrees, said Steve Zubrick, science and operations officer for the weather service's Baltimore-Washington Forecast Office in Sterling, Va. It was not a record, but it was 4.3 degrees below the long-term average for Baltimore-Washington International Thurgood Marshall Airport and the coldest December since 2000.
More significantly, Zubrick said, the average maximum temperature at BWI-Marshall in December was 36.9 degrees, or 6 degrees colder than the average. The average low was 24.9 degrees, or 2.4 degrees below the norm.
"It was a fairly persistently cool month," he said. "I would blame it on the NAO."
The NAO, or North Atlantic Oscillation, is an atmospheric pattern in the North Atlantic. Periodically, it enters a "negative" phase that sets up what meteorologists call a "blocking pattern" in the upper atmosphere over Greenland and northeastern Canada.
A barrier of high pressure there forces the northern jet stream to loop south, deep into the United States, opening the door for cold air to plunge south from the Arctic. A negative NAO and a strong coastal storm will sometimes combine to threaten the Mid-Atlantic states with heavy snows.
So far, the cold-weather pattern here does not seem ready to change, Zubrick said.
"It loosened a little at the end of the year, but it's gone right back into it," he said. "The 8- to 14-day outlook, through the 19th, has the whole Mid-Atlantic region having better odds of being below normal."
Readings from the NOAA interpretive buoy just off Annapolis show the mean temperature in December was 39.5 degrees compared with 43.8 degrees during December 2009. The minimum temperature at the buoy last month was 33.7 degrees vs. 39.5 degrees in 2009.
The water temperature may have been a contributing factor in the Jan. 4 death of a Dorchester waterman who was knocked from his boat while oyster dredging and spent 10 to 15 minutes in 39-degree water before rescuers were able to pull him, unconscious, aboard. An autopsy is being conducted on the state's first boating fatality of the year.