Kevin Myatt is The Roanoke Times' weather columnist.

kevin.myatt
@roanoke.com
981-3341

Weather with Kevin Myatt

Recent columns

• We got graupel, but not on official record
• Moisture could get caught up in cold blast
• Forecast for Weather Journal: Partly print, with frequent Internet
• Column archive

Read the Weather Journal blog

• Sprinkles or flurries possible Tuesday, but maybe something bigger for the weekend?
• For now, it looks like a quiet, mostly mild week ahead for SW Virginia
• Coldest morning of winter so far likely across much of Southwest Virginia; Tuesday precipitation looking doubtful
• Weather Journal blog

#swvawx on Twitter

@KevinMyattWx

• Follow Kevin on Twitter at @KevinMyattWx

We celebrated the generous rain we got for three days in late October, but November has failed to provide any kind of encore.

As a result, we are on the verge of the driest November on record, and one of the top few overall driest months since records began being kept at the Roanoke airport in 1948.

The storm system that moved through Sunday and Monday really underperformed. Roanoke got just less than one-tenth of an inch.

That leaves us at .18 inch of rain for the month, with only spotty showers expected Thursday, the next-to-last day of November.

Roanoke's previous driest November was .44 inch in 1960. There have been only three months at any time of year with less rain than .18 inch: October 2002 (.02), October 1991 (.04) and September 1991 (.15). December 1965 equaled the current monthly total at .18.

Remember that October's 5.33 inches of rain, which was 2.18 inches above normal, broke a streak of 10 below-normal rainfall months for Roanoke. And with our rainfall still about a foot below normal for the year, we're likely to have our third consecutive below-normal rainfall year.

The October rains lifted us out of the more extreme drought categories we were slipping into, but it hasn't ended the long-term dry spell. If we don't get some significant precipitation in a regular pattern soon, we could be really hurting by spring.

While we have had more frequent cold fronts passing through since the summerlike heat finally broke in mid-October, most of them have moved through quickly and have not had a strong low-pressure system attached to them far enough to the south to draw up ample moisture.

Storm systems like the one early this week, with a broad area of low pressure and cold front approaching from the west, sometimes do a split.

The best moisture stays to the south, fueling thunderstorms. The best atmospheric energy goes to our north, across the Ohio Valley into the Northeast. Those areas get more rain than we do in the middle.

So is there any hope of reliable moisture soon?

The persistent La Nina -- colder than normal waters in the central Pacific -- makes a regular pattern of repeated precipitation unlikely.

But the weather pattern for early December does look interesting in other ways.

It appears increasingly likely that a mass of Arctic air is going to become dislodged southward into much of the United States. This will probably mean a substantial period of colder than normal weather.

We may be near the southern boundary of the cold air. Storm systems tend to ride along the boundary between the colder air and the milder air to the south.

If we can get a few storm systems to ride that boundary, then we may get some needed moisture in December.

Some of that moisture may be in a form that requires slow melting into the ground rather than the kind that simply runs off.

There are a lot of ifs, ands and buts to consider for a weather pattern more than a week ahead. But meteorological winter, which begins Saturday with the start of December, may look and feel the part just a few days into it.