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.

Re-examining El Nino's effects on our winters

We start getting a taste of cool weather, and lots of folks start asking about winter.

So I'll begin an early look at the winter ahead by examining what El Nino -- the irregularly recurring warming of equatorial Pacific sea surface temperatures, now occurring for the first time in three years -- might mean, based on history.

Here's the party line that I've repeated many times in this column: El Nino winters tend to be wetter than normal, and are a little more likely to be mild than cold. That's because the southern branch of the jet stream tends to be active.

But does history bear that out for Southwest Virginia?

n Roanoke's snowiest month on record was January 1966, with more than 41 inches. That was during an El Nino.

n Roanoke's coldest winter on record was that of 1977-78, which also had more than 37 inches of snow. That was during an El Nino.

n Roanoke got 19 inches of snow on Feb. 10 and 11, 1983. That was during an El Nino.

n Roanoke's snowiest year of the 1950s (1957-58), second snowiest of the 1990s (1992-93) and snowiest of the 2000s (2002-03) each in the 28-to-30-inch range occurred during El Ninos.

Historically, the statistics just aren't that clear-cut when it comes to El Nino winters in Southwest Virginia.

Using Roanoke Regional Airport observations, the 12 El Nino winters since the 1950s are essentially a coin flip on snowfall: half above normal, half below normal, most many inches above or below normal (about 22 inches). It seems El Nino is feast or famine when it comes to snowfall.

As for temperatures, looking at data for December through February in the 12 El Nino winters, 15 months averaged at least a degree above normal, 15 averaged at least a degree below normal, and six were within a degree of normal. Again, a coin flip.

And even the notion that an El Nino winter must be wet is not ironclad. Of those 36 winter months during El Nino, nine had above-normal precipitation, while eight were below normal. The remaining 19 were within an inch of normal, which is close to 3 inches for each of the winter months.

There is, however, a tendency for the wet months to be extremely wet. January and February of 1998 are a prime example, with close to 16 inches of precipitation, primarily rain.

On a national scale, El Nino does indeed, on average, lead to warmer winters than normal over much of the northern U.S., and wetter winters than normal over much of the South. The Southeast often has somewhat cooler than normal temperatures, but that is often related to so many days being cloudy and dreary rather than any massive punches of Arctic air.

Our region lies on the northern edge of the cooler, wetter region of the Southeast, just east of a typical dry hole in the Ohio Valley, and not too far south of the generally warmer-than-normal area in the North. So our weather can easily go to any of those extremes with some shifts here and there.

Locally, our memory of El Nino winters is heavily colored by the 1990s, when the term moved from weather geekdom into popular usage.

All three months of the 1991-92 winter were above normal in temperature and only 5 inches of snow fell in Roanoke. The '94-'95 and '97-'98 winters each had two months of above-normal temperatures and at least one month with more than 6 inches of rain. As I've already noted, 1992-93 was different

Our most recent El Nino winter, in 2006-07, was warm and dry. We got only 3.4 inches of snow that winter, and rainfall was below normal in December and on the low side of normal in January and February.

So let's be careful not to presume that El Nino means that winter will definitely go a certain way. El Nino varies in strength from year to year, and it is only one of many factors that affect the weather pattern.

For now, just flip a coin.

Weather Journal appears on Monday, Wednesday and Friday.