Winter weather possibilities...

Upper level low... weatherman's woe. That old saying in the meteorology profession is on display with our incoming system.

I cover tons of ground with this system in today's video, and I strongly encourage you to watch. A picture is worth a thousand words.

A strong upper level low will strengthen and then move through the region tonight into tomorrow. The result will be a healthy precipitation event for most of the region... the trick is nailing down precip types.

Northwest SC and western and central NC are right on a razor's edge of precipitation types with this one. 1 or 2 degrees of temperature difference 5000' aloft can mean the difference in heavy wet snow vs. rain or freezing rain.

For areas roughly near and north and west of I-85, my best estimate at this point is that an initial mixture of sleet, rain, and snow will arrive this evening. Then, as the atmosphere saturates, freezing rain and sleet will be the main precip types overnight into Friday morning. Then, as a heavy band of precip moves through with the upper level low, some bursts of heavy snow or heavy rain (depending on those temps aloft) will be possible tomorrow morning and early afternoon.

Now, a big fly in the ointment.... the European model is colder aloft than most other modeling, and therefore, it prints out more snow as opposed to freezing rain in the areas cold enough for wintry precip. This bears watching.

Again, please watch the video for more.

This is a fluid situation, and some forecast alterations are almost certain as we approach the event.

Read more...

A little milder today... watching the system late tomorrow into Friday...

Today's video primarily focuses on our incoming storm system. Give it a look:

Read more...

Bitterly cold this morning.... watching our next event Thursday-Friday AM...

In the wake of yesterday's storm system, temps are frigid this morning. Many areas have dipped into the teens in NC, and a couple of spots have even seen single digits.

It will be a chilly day today, and then it will be a bit warmer tomorrow as our next big system takes shape to our southwest.

The results of our Thursday and Friday system will largely hinge on how intense the upper level energy moving through can get. Most modeling (GFS excluded) indicates the upper level energy closing off and becoming an upper level low (ULL) as it moves through the Carolinas. If that idea is correct, and I lean toward that being the case, then I would expect some snow to fall on the northwest side of the ULL.

The 6z NAM, 0z Canadian, and 0z European all show this scenario. Temperatures aloft are borderline for snow, but if the ULL scenario is correct, I would anticipate the areas with heavier rates of precipitation to be largely snow, at least for a period of time. At this point, I would favor the northern Upstate but then especially northwest NC from roughly I-85 and points north and west.

Now, if the upper level energy never closes off (as the GFS shows), then the snow scenario will not occur. Obviously, details still to iron out.

See the video for more.... much easier to understand when I can show you the graphics that go along with this discussion.

Read more...

Wild Monday...

Today's weather is something that is quite unusual. Amazing temperature drops will occur today, and a lot of central NC should be sub-freezing by lunchtime-ish (sooner for some, later further south). As these temp drops occur, rain will change over to a wintry mix of sleet, freezing rain, snow, and a little lingering rain. For a lot of areas though, sleet should take over as the primary precipitation type for a period of time.

This is not an event to really focus on accumulation amounts, but if all goes as it appears, many areas should get the ground covered with at least a little precip.

The biggest takeaway is driving conditions. Driving conditions should really do downhill, especially on untreated roads, by later this afternoon and evening. So, the potential is there for a messy afternoon commute, especially I-40 and points north. Whatever the form the precip is in, any liquid on the roads will quickly freeze this evening as overnight lows will plunge into the teens for most. So, travel problems will be quite likely in many areas tomorrow morning.

Read more...