Weather! Wedged in for the weekend

A classic winter pattern – the cold air wedge – is going to set up this weekend, but it’s not going to bring us much in the way of winter weather. However, there is a mild icing threat Friday night; be careful if you’re out overnight or Saturday morning.

January 19, 2012; 10:35 PM • by Weather Dan

It’s a little bit of weather alliteration for you on this Friday.

Unfortunately, this next period is going to be a bit messy. The “wedge” setup I’m going to describe is a classic winter weather pattern, but unfortunately, it is a pretty miserable setup.

However, we’ve got to get through Friday first.

Friday: To be honest, Friday’s going to be a pretty seasonable winter day. Partly sunny skies will continue through the day on Friday, thanks to a weak cold front swinging through overnight Thursday night. It’s impact on precipitation and temperatures will be barely perceptible. Temperatures will start off in the mid 30s Friday morning (slightly warmer than our normal low of 28) and climb to 46 (our normal is 48) by Friday afternoon. Clouds increase again Friday night as a weak warm front passes through from south to north; it’s parent low pressure system will slide from the Mississippi and into the Ohio Valley. Some precip begins to move in around midnight along with the front, keeping overnight lows around 34. The combination of near-freezing temperatures and light precip may result in some light sleet or freezing rain accumulation by Saturday morning. Be careful if you’re headed out early.

Saturday: Saturday’s a washout, more or less. High pressure setting up across the Canadian Maritimes will funnel lots of cool, damp air into Virginia ahead of of the cold front attached to the low in the Ohio Valley. This air gets trapped along the eastern slopes of the Blue Ridge, and doesn’t have anywhere to go. Ergo, it’s “wedged” in. (The alternate, and probably more scientific, name for this type of event is “cold air damming.”) What does that mean? Overcast skies with highs in the mid 50s (the temperature boost is due to the passage of the warm front), with rain showers on and off all day long. The cold front attached to that low will swing through Saturday afternoon and evening, giving a place for the moisture to concentrate. We’ll see a little clearing behind the front, as temperatures fall back into the low 30s Saturday night.

Sunday: The wedge stays in place on Sunday, giving us another overcast and slightly gloomy day. Showers are still a possibility, but won’t be widespread or significant. Still can’t rule out some sprinkles at various points, though. Expect highs in the low 40s during the afternoon, but temperatures will stay steady and may even warm up some Sunday night as the wedge begins to erode.

Temperatures make it into the 60s (!) by Monday afternoon as another disturbance approaches and brings a few rain showers with it. Beyond that, we’ll stay mild into next week, with highs in the 50s and lows in the low to mid 40s.

No, I still don’t know where winter has gone.

January 19, 2012 10:35 PM 0