Kevin Myatt

Latest entries from the Weather Journal blog

• Weather Journal remains on break
• Coastal low prompts Southwest Virginia flooding
• Hurricane Ida: Something extraordinary may be happening

About Kevin

Kevin Myatt grew up in Arkansas to the tune of tornado sirens and the rhythm of hailstones, aspiring to be a meteorologist before his studies and career were turned to journalism instead. Though he often chases storms, he prefers living in the cooler, more tranquil weather of the Blue Ridge. He moved to Roanoke in 1999 to take a job on the copy desk of The Roanoke Times; writing headlines and editing copy is his principal work for the newspaper today.

Each May, Kevin assists Pulaski County High School / Virginia Tech meteorology instructor Dave Carroll in leading college and high school students to the Plains to observe severe weather firsthand. The accounts of many of his storm chases can be found here on the storm chasing page of his weather blog on roanoke.com.

Kevin was an editor for "Hurricanes and the Middle Atlantic States," a book written by D.C.-area weather enthusiast Rick Schwartz and published by Blue Diamond Books that documents hurricanes striking the mid-Atlantic states since colonial times.

The Weather Journal column began in 2003 and appears on Friday's Virginia section front in The Roanoke Times. The Weather Journal blog began in 2006 and follows weather day-by-day between the larger columns.

Arctic's influence uncertain

The extent of Arctic Ocean ice at the end of the summer melt season was a little larger than in 2007 or 2008, but still the third-least ice in the Arctic since satellite records began in the late 1970s.

Arctic ice concentration is a focus of global warming discussions. But the effects of Arctic ice extent on any particular North American winter are not clear-cut.

The advance of cold air in the Northern Hemisphere during fall is caused by lengthening nights and lessening sun angle. The rapid re-freezing of Arctic Ocean ice in the autumn is more a result of seasonal cooling rather than a primary cause.

That said, a frozen Arctic does enhance the cooling of air above it. Unfrozen water absorbs warming sun rays and emits heat into the air. Ice reflects solar rays away from Earth, allowing more cooling.

Also, the physical act of freezing itself releases a small amount of heat into the air. The more open water there is to freeze, the more of this heat is released.

But unfrozen water is also easier to evaporate into precipitation, which this time of year is almost exclusively snow in the Arctic Circle and surrounding areas.

Abundant snowfall on land areas surrounding the Arctic Ocean can allow masses of cold air to build above the surface, as snowpack reflects sunlight and chills the lower atmosphere. If these cold air masses become dense enough, they can start pushing southward early in the season.

So, while tracking Arctic ice is important in the big picture of long-term climate, the effects on year-to-year winter weather at our latitude are not easy to determine or predict.