For Twin Citians of a certain age, the massive snowstorm that began on Oct. 31, 1991, and kept going for four days later is one they'll never forget.
It was 20 years ago Monday morning when a light, wet snow began falling on the Twin Cities, hours before prime trick-or-treat time. Before it was over four days later, Twin Cities meteorologist Bruce Watson had issued a remarkably bold, and accurate, forecast:
"It will be the most memorable snowstorm in the life of most people alive today, and may well be for the rest of their lives," said Watson, who died in 2004.
Indeed, the great Halloween Blizzard stands as one of those rare events that achieve I-remember-what-I-was-doing status, a milepost in a few million Minnesotans' personal histories and an occurrence that can still define life in Minnesota as, well, different.
"Climbing over and through the drifts was exhausting," recalled Amber Langley of Lakeville, who was in second grade at the time and made the Halloween rounds dressed as a witch. "In my neighborhood hardly anyone was out, and the neighbors were dumping whatever candy they had into my sack so they could shut their light off. I don't think that Halloween is ever going to fade from my memory. It was beyond insane. "
The storm was freakishly early in the season and freakish in its excess, duration, impact and aftermath.
It forced thousands of trick-or-treaters to wear snowpants under (or over) their costumes, and forced parents or older siblings to carry the young ones through the drifted neighborhoods, often scooping snow out of their parka hoods. It turned Halloween parties into impromptu sleepovers.
It also was lethal.
The storm killed at least 20 people and knocked out power for nearly a week across much of southern Minnesota, where the National Guard was mobilized to get emergency generators to farms. It collapsed roofs. It closed the University of Minnesota Twin Cities campus, which didn't happen again for 19 more years -- until another blizzard last March. It also closed 900 businesses, including Dayton's, Honeywell and 3M.
City was paralyzed
Coming as early as it did, the snowstorm caught city and state road crews without plow blades on their trucks. The first few inches, which fell on warm pavement, froze and turned streets and freeways into crevassed ice fields, multiplying commute times for the next week and turning intersections into slide-through zones. It inspired a local artist to paint a scene of a snowplow passing by a home with a pumpkin on its porch -- a work that now hangs in an office at the Minnesota Department of Transportation.
In short, it was the greatest single snowfall in history in the Twin Cities, Duluth and probably many other places in eastern Minnesota, and it came seven weeks before the official start of winter. And although it had mostly melted away three weeks later, it left tangible symbols behind.
"We went out two days later and purchased a snowblower that we still have," said Karen Wentworth of Lakeville.
Mike Kennedy, now street maintenance superintendent for Minneapolis and who had started working in the street department only the year before, remembers being skeptical of a local forecaster's prediction of 22 inches of snow.
"I'm going, 'That'll be interesting,'" Kennedy recalled. "It turned out to be true.
"It was just huge. The city was just paralyzed, but an event like that is going to paralyze anybody," Kennedy added. "It took weeks and weeks to get through that bonded ice."
Kevin Plummer, an official with Metro Traffic Control at the time, described conditions on Interstate 35W in Bloomington as "like driving on a plowed field."
Massive moisture met frigid air
The storm came straight up from the Gulf of Mexico, carrying copious moisture when it ran into a frigid air mass on its way north. The National Weather Service began issuing warnings before dawn on Halloween Day. The greatest snow depth it predicted was 12 inches, though even that would have been unprecedented for the date.
"It's pretty rare for us to ever think there's going to be more than a foot of snow," NWS meteorologist Todd Krause said. Krause also recalls telling his parents on Halloween Day, his day off, that the moisture in the storm could produce 2 feet of snow, but added that even that was an embellishment.
With temperatures in the low 30s and dew points in the mid-20s, Krause added, falling snow went through a process known as "evaporative cooling," essentially cooling surrounding air as it fell, creating a kind of snowmaking machine.
Since then, Krause said, new weather technology, modeling and knowledge of atmospheric dynamics have made winter storm prediction more reliable, giving commuters, businesses and public works departments a chance to be better prepared.
"I don't think any storm like that could really sneak up or give us as little lead time," he said.