Spring Meltdown Triggers River Ice Jams In Maine

April 18, 2005 – Spring in New England features extended minutes and hours of sunlight and milder temperatures. And as these cause frozen rivers to thaw, ice jams can form and create flooding, as is currently the case in northern Maine.

As of Monday morning, NOAA’s National Weather Service in Caribou, Maine was monitoring several ice jams locked in place on the St. John and Allagash rivers. Warm daytime temperatures have sent runoff from melting snow into area rivers. Diurnal river level fluctuations of as much as two feet have been noted, with a rise from 17.3 feet Sunday morning to 19.3 feet Sunday evening, creating a new ice jam on the Allagash River.

Access past the town of Allagash to the village of Dickey has been restricted to residents only. Local and county officials report continued lowland flooding in the backwaters of these ice jams, but flood waters on roads and around houses have receded. Several bridges in the North Maine Woods have been damaged by the ice flow.

Last week, ice along a 12 mile ice jam on the St. John River in northern Maine was as high as 30 feet. “It’s the largest ice jam in the history of the forecast office,” said Tony Sturey, warning coordination meteorologist at Caribou forecast office.

According to Mark Turner, service hydrologist at Caribou forecast office, a nine-mile ice jam developed along the St. John River after a period of thaw in December and was followed by a cold spell that again froze the river. A second thaw and rain on April 2 and 3, started the rivermoving once again. Cool weather from April 11 to 14 tempered the river’s flow until a significant warm up from April 15 through 17. A flood watch for ice jam flooding along the St. John River in Aroostook County, Maine continues until 4 p.m., Friday, April 22.

In a briefing last Thursday with the office of Senator Susan Collins of Maine, Tony Sturey, warning coordination meteorologist at the Caribou forecast office, said the warmer temperatures from April 15 to 17 will cause the rivers to rise again. The senator’s satellite offices in Bangor and Caribou were quickly updated, keeping staff current on the status of the potential flooding. Due to the amount of ice still present in the river system, there is a chance ice jams will re-form and cause renewed flooding this week.

Current river forecast collaboration with Canada’s Environmental and Local Government Water Sciences Section, New Brunswick's River Forecast Center, point to river levels rising another four feet by mid week, sending river levels to near flood stage (25 feet) once again. Such a rise may reinvigorate grounded ice and lead to further ice jam flooding.

“With ice chucks measuring four feet thick that weigh several tons each, this is a WOW event,” said George McKillop, deputy director, hydrologic services division. “Residents in the area should carefully follow the flood watches and warnings issued by NOAA’s National Weather Service as to know when dangerous conditions are developing.”

Media contact:

Marcie Katcher, NOAA’s National Weather Service: (631) 244-0149

Related Web sites:

NOAA: http://www.noaa.gov/
NOAA’s National Weather Service: http://www.nws.noaa.gov/
NOAA’s National Weather Service in Caribou, Maine: http://www.erh.noaa.gov/er/car/