Overnight freeze along Lake Gaston
November 12, 2010

Many areas around Lake Gaston got their first freeze early Friday morning. Unofficial readings were in the upper 20's at a number of locations and it was still 30 degrees at 6:30 a.m. toward the western end of the lake.

A colder wedge of air apparently dropped into the area on light wind from the north. (See the temperature map from 6:20 a.m. below)

Official readings in the closest weather stations in South Hill and at the Oxford-Henderson airport never dropped below 34 (at 4:00 a.m. in Henderson and 5:00 a.m. in South Hill). But the Emporia weather station hit 32 degrees at 6:36 a.m. and Roxboro (which always seems to be among the coldest reporting stations) was below freezing from 1:00 a.m. until 7:00 a.m. It hit 28 degrees at 4:44 a.m.

A check with several Lake Gaston residents who watch the temperature suggests the frost was widespread around the lake. Several had to scrape windows and there was the tell-tale frost on grassy areas.

The National Weather Service forecasts cold temperatures again Friday and Saturday nights, with some areas near the lake expected to again drop into the low 30's or upper 20's. But because the growing season has passed, the Weather Service no longer issues "freeze warnings." 

Most lake area residents have already brought in plants that cannot tolerate the freezing weather. But have you prepared your irrigation system?  Today's first freeze was probably short enough and the temperature not low enough to cause problems. But it was a warning.

Landscape architect Jess Stryker says pipes buried below the freeze line may be ok, but above ground hoses and sprinkler heads need to be protected. "Every year, before the first freeze," he says, "the ritual of irrigation 'blow out' becomes the priority for all irrigation systems that are in regions of the country where the frost level extends below the depth of the installed piping."

He warns that even if you have drained some water out of the system, the remaining water can freeze, expand and crack the PVC piping, usually from fitting to fitting. Polyethylene pipe (flexible, black pipe) is used in many freezing climates. Although polyethylene pipe is more flexible and can expand under pressure, water left inside could freeze and rupture the pipe walls.