Kevin Myatt is The Roanoke Times' weather columnist.

kevin.myatt
@roanoke.com
981-3341

Weather with Kevin Myatt

Recent columns

• Winter trying again to show up with snow
• We got graupel, but not on official record
• Moisture could get caught up in cold blast
• Column archive

Read the Weather Journal blog

• Many looking past mild, quiet week toward possibly wild weekend
• 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
• Weather Journal blog

#swvawx on Twitter

@KevinMyattWx

• Follow Kevin on Twitter at @KevinMyattWx

While it was 55 degrees and raining hard in Roanoke on Thursday morning, it was 33 with heavy snow in New Orleans.

That just doesn't seem right. But a powerful low pressure system marking an atmospheric pattern change turned our usual weather perceptions on their head for a day.

Take a look outside this morning to see if the low spit out some snow on your yard as it passed by. It's possible that some parts of Southwest Virginia could have received some snow overnight as cold air moved in on the back side of the storm.

Though today will be windy and cold behind the low pressure system, this storm actually signals a shift to an overall milder pattern.

Since mid-November, we have been in a pattern in which the jet stream generally flowed far to the north over high pressure in the western U.S. and then dipped southeastward over the East.

The result has been frequent reinforcements of cold air from Canada, sometimes even originating from the Arctic. But the air has been mostly dry, and the cold air masses have moved through quickly rather than locking in. So we haven't had significant winter storms.

The potent storm system that moved northeastward from the Gulf of Mexico on Thursday and this morning marks the beginning of a weather pattern shift.

Over the next several days, the pattern will reverse itself, with the jet stream dipping far to the south over the West and then lifting northeastward over the East.

This will bring cold weather to the West, but milder weather to the East. And this pattern could well last until Christmas.

If you're tired of the cold, it will be a welcome change. And if you're a snow lover wanting a big snowstorm, the previous cold, dry pattern wasn't going to deliver the goods for you anyway. Time for a reset.

Though the overall pattern will be mild, there is always the chance for a burp or two in the atmospheric regime that could bring a temporary winter weather threat.

In the middle to latter part of next week, for instance, there is some chance that cold high pressure will build down the Appalachians as warmer southwest winds aloft bring moisture on top of it.

From this distance, it looks like another rain, but if the cold from the northeast is thicker and stronger, even for a day, an ice or snow threat could materialize. It's a minor player to watch in a larger drama, as we shift from an unseasonably cold late fall and early winter (meteorological winter began Dec. 1) to what could become a mild few weeks.

If nothing else, this pattern switch has at least yielded a drought-denting rain for Southwest Virginia.