Most kids will be watching today's big storm to see whether it will deliver enough snow to close schools Monday.
But for a handful of students in the city and Baltimore County, the outcome will test the weather forecasting skills learned in the classroom.
Calculations on Friday by the elementary, middle and high school students who contribute to an online weather blog called FootsForecast.org predicted 24 inches of snow at BWI Thurgood Marshall Airport, according to the blog's creator, Rich Foot, a physical-sciences teacher at the county's Crossroads Center in White Marsh.
The students' forecast was no "wish-cast," Foot insisted. The kids do real science. They factor in such weather esoterica as Canadian snow cover, the North Atlantic Oscillation, and the moisture content of the approaching storm. Then they do the math.
And blog readers pay attention.
"We never started this thinking this was for the whole Mid-Atlantic," said Foot, 39, known as Mr. Foot to blog readers. "It was for Dundalk kids, and anyone else who wanted to join in the fun."
But since it was launched in January 2004, the blog's popularity has snowballed. Receiving 1,000 to 2,000 hits a day in the winter, he said, it has zoomed to more than 37,000 so far this month.
And readers are not just Baltimore County students and teachers looking for school-closings predictions. They log in from as far off as Canada's HudsonBay and Southern California. The discussions are lively and sophisticated.
For today's storm, the snow predictions on the blog were not far from the one issued by the National Weather Service for as much as 2 feet of snow by Sunday morning.
And there's more to come. Weather service forecasters were already predicting that another storm will produce more snow Christmas Eve and (perhaps with a little rain) Christmas Day.
Snow was expected to begin falling early this morning, with an inch or two on the ground by daybreak, said National Weather Service meteorologist Nikole Listemaa.
Winds will be picking up, and "the heaviest snow is probably going to come mid- to late morning, through the afternoon and into the evening," she said.
'Light and fluffy'
On top of the first inch or two, we should expect 6 to 10 more inches to fall during the day Saturday, followed by 4 to 6 more tonight into Sunday.
"Let's say it's 14 to 17 by the time it all wraps up," Listemaa said.
The goods news is the snow should not be terribly difficult to shovel. "If anything, it might be slightly on the drier side of average - light and fluffy as opposed to wet and heavy," said weather service meteorologist Rich Hitchens.
If that forecast is even close to correct, today's storm stands to become the deepest snowfall Baltimore has ever recorded on a single date in December, and it's coming two days before the official start of winter, on Monday.
The most snow on record (since 1883) for a single December date in Baltimore was an 11.5-inch storm on Dec. 17, 1932. A two-day snowstorm in 1960, on Dec. 11-12, left 14 inches at the airport.
The long-term average for December snow in Baltimore is just 1.7 inches.
With the inch that fell at BWI on Dec. 5, if this storm gets even close to the upper limits of the weather service forecast, it would set a record for the snowiest December, beating the 20.4 inches that fell in 1966.
'A life lesson'
Rich Foot's passion for weather - winter storms and hurricanes, especially - began at his family's cottage on the Elk River in Cecil County. "We were always waiting for the big one," he said, after Hurricane Hazel in 1954 "did a number on the house."
He squeezed in as much meteorology as he could at Pennsylvania State University, while earning a bachelor's degree in earth science. He wrote and read forecasts for central and western Pennsylvania radio stations through the Penn State campus weather service.
Foot and his wife moved to Dundalk in 2001. He taught earth sciences at Dundalk High, and began to try to interest students in science and math by introducing them to the data meteorologists use to predict the outcome of storms. Soon they began their own forecasts.
In October 2002, using long-term climate data, his class predicted the first snow of the season would fall during the first week of December. And on Dec. 4 and Dec. 5, the airport measuring station recorded nearly 8 inches of snow. "Our first success," Foot said. "After that people were, like, 'How did you figure that out?' "
Then, days before the record-breaking snowstorm of February 2003, Foot's students calculated the water content of the storm, ran the math and forecast 18 to 24 inches of snow in Dundalk.
"Sure enough, in my backyard I had 24 inches, and I have the photo to prove it," he said. "Nobody would believe that a bunch of 10th-grade kids in Dundalk could predict a storm four days in advance down to the inch."
When Hurricane Isabel's trek across the Atlantic in 2003 began to look ominous, one of his students asked him, "Mr. Foot, is this going to hit us?"
"It turned into a life lesson," Foot said. The storm's tidal surge flooded many of his students' homes.
"At that point, I realized ... we need a better platform for conveying this information the students are researching," he said. "I was also tired of people stopping in my class and asking, 'Mr. Foot, what's going to happen?' "
And so FootsForecast.org was born.
Foot's ninth-grade science class at the Crossroads Center is now part of a "Student Climate Collaborative" that includes students in Pat Abrahm's ninth-grade biology class at Mount St. Joseph's High School in Southwest Baltimore and Melissa Gerst's fifth-grade class at Perry Hall Elementary School.
When bad weather threatens, they pull the climate data from the Internet, run their analyses and offer up forecasts.
Foot then hosts an online conference to run the student predictions past a Forecast Roundtable that includes four high school students from Baltimore, Carroll and Anne Arundel counties, and a student at Penn State. They authorize the final forecast that goes on the blog.
Friday night, the roundtable endorsed the students' 24-inch forecast, which Foot fears might wind up on the low side.
But even if the estimate is a bust, Foot believes his students win, especially those at Crossroads, an alternative school for at-risk students removed from other county classrooms.
"What we're aiming to do is show them that your learning and research and understanding of the scientific process is not just for the grade," he said.
"You are doing something meaningful, a life skill that can have an impact on a lot of people, and a technique that you can use, and that can result in a job. ... And that will take you far. I guarantee it."
Worst snowstorms in Baltimore history
1 Feb. 15-18, 2003 28.2 inches
2 Jan. 27-29, 1922 26.5 inches
3 Feb. 11, 1983 22.8 inches
4 Jan. 7-8, 1996 22.5 inches
5 March 29-30, 1942 22 inches
6 Feb. 11-14, 1899 21.4 inches
7 Feb. 18-19, 1979 20 inches
8 March 15-18, 1892 16 inches
9 Feb. 15, 1958 15.5 inches
10 Jan. 25, 2000 14.9 inches
Today's weather
Winter storm warning:
31
High
25
Low
Heavy snow with accumulations of 1 to 2 feet through tonight. PG 3