What the December 2002 Ice Storm Taught the Triad

If you have lived in the Triad long enough, December 2002 needs no introduction. If you have not, it is the event every conversation about winter tree damage in this region eventually refers back to.

What happened

On December 4 and 5, 2002, a major ice storm blanketed forty North Carolina counties with up to an inch of ice, according to the North Carolina Utilities Commission, affecting approximately two million electric utility customers. Peak outages reached roughly 1.8 million customers by December 6. Power was not completely restored until December 14. Twenty-four deaths were reported, and the North Carolina Insurance News Service estimated property damage at $113 million.

Ten days is a long time to restore a grid, and the reason it took that long is that the failures were not concentrated. They were everywhere at once, tree by tree, across a region the size of a small state.

Why ice and not snow

Snow slides off a leafless hardwood crown. Freezing rain does not. It arrives as liquid, spreads across every surface it touches, and freezes there, building a shell of clear ice around each twig. The Piedmont sits in exactly the part of the country where winter storms most often arrive in that form, in the narrow band of air where precipitation falls as rain through a warm layer and freezes on contact with a cold surface.

The weight is the whole story. A twenty-foot limb two inches thick weighs around twenty-seven pounds green. A quarter inch of radial ice adds about fourteen pounds. Half an inch adds thirty-one, which roughly doubles the load. A full inch adds around seventy-five pounds, and that calculation ignores the twigs entirely, which hold far more ice per pound of wood than the limb behind them does. The ice storm guide sets out the arithmetic.

What came apart

The same names, over and over. Water oaks with long horizontal limbs and old decay at the unions. Bradford pears, which are structurally poor by design, with branches emerging in a crowd from nearly the same point on the trunk. Silver maples. Pines, which hold needles through the winter and therefore collect ice on an enormous surface, bending until the top snaps out.

And trees with codominant forks, regardless of species. Where two stems of the same size meet at a narrow angle, bark gets folded into the join instead of wood, and there is nothing structural crossing the seam. Load it and it opens.

The lesson worth keeping

There is nothing to be done in the forty-eight hours before a storm. No crew prunes a mature oak on a forecast, and any that offers to is not thinking about it seriously.

What works is quiet-season work: taking end weight off long limbs so there is less leverage at the union, clearing deadwood before gravity does it, and correcting tight forks on young trees while the correction is a five-minute cut rather than a removal. It is unglamorous, it is cheap compared with what it prevents, and it is the only preparation that has ever done anything.